CN119586214A - Method, communication device and infrastructure device - Google Patents

Abstract

A method of operating a communication device configured to transmit signals to and/or receive signals from a wireless communication network via a radio interface provided by the wireless communication network is provided. The method comprises transmitting signals to and/or receiving signals from a first wireless communication network via a first radio interface provided by the first wireless communication network when the communication device is located within a coverage area of the first wireless communication network, determining that one or more conditions to perform a mobility procedure have been met, determining that the mobility procedure comprises switching from the first wireless communication network to a second wireless communication network, performing a mobility procedure from the first wireless communication network to the second wireless communication network, and transmitting signals to and/or receiving signals from the second wireless communication network via a second radio interface provided by the second wireless communication network when the communication device is located both within the coverage area of the second wireless communication network and within the coverage area of the first wireless communication network.

Description

Method, communication device and infrastructure device

Technical Field

The present disclosure relates to a communication device, an infrastructure device, and a method for more efficient and sustainable operation of a communication device in a wireless communication network.

The present application claims priority to the paris convention of european patent application number EP22184806.2 filed on 7/13 of 2022, the contents of which are incorporated herein by reference.

Background

The "background" description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

Previous generations of mobile telecommunication systems, such as mobile telecommunication systems based on 3GPP defined UMTS and Long Term Evolution (LTE) architecture, are capable of supporting a wider range of services than the simple voice and message services provided by previous generations of mobile telecommunication systems. For example, with the improved radio interface and enhanced data rates provided by LTE systems, users can enjoy high data rate applications, such as mobile video streaming and mobile video conferencing, that were previously available only via fixed line data connections. Thus, the need to deploy such networks is great, and the coverage areas of these networks (i.e., the geographic locations where the networks can be accessed) are expected to continue to increase rapidly.

It is expected that current and future wireless communication networks will routinely and efficiently support communications with a wider range of devices associated with a wider range of data traffic profiles and types than are currently supported by system optimization. For example, future wireless communication networks are expected to be effective in supporting communication with devices, including reduced complexity devices, machine Type Communication (MTC) devices, high resolution video displays, virtual reality headphones, augmented reality (XR), and the like. Some of these different types of devices may be deployed in large numbers, e.g., low complexity devices for supporting "internet of things", and may generally be associated with the transmission of smaller amounts of data with higher delay tolerance. Other types of devices, such as supporting high definition video streams, may be associated with the transmission of relatively large amounts of data with relatively low delay margins. Other types of devices, such as for autonomous vehicle communications and for other critical applications, may feature data that should be transmitted over a network with low latency and high reliability. Depending on the application being run, a single device type may also be associated with different traffic profiles/features. For example, when the smartphone is running a video streaming application (high downlink data), different considerations may be applied to efficiently support data exchange with the smartphone than when the smartphone is running an internet browsing application (sporadic uplink and downlink data) or used by an emergency responder for voice communications in an emergency situation (data subject to stringent reliability and latency requirements).

In view of this, current wireless communication networks, such as those that may be referred to as 5G or New Radio (NR) systems/new Radio Access Technology (RAT) systems, or indeed future 6G wireless communications and future iterations/versions of existing systems, are desired to support connectivity for a wide range of devices effectively associated with different applications and different feature data flow profiles and requirements.

One example of a new service is known as an ultra-reliable low latency communication (URLLC) service, which, as the name suggests, requires data units or packets to be communicated with high reliability and low communication latency. Another example of a new service is augmented reality (XR), which may be provided by various user devices (e.g., wearable devices). XR combines real world and virtual environments, fusing aspects of Augmented Reality (AR), mixed Reality (MR), and Virtual Reality (VR), and so forth, thus requiring high quality and minimized interaction delays. Thus, services such as URLLC and XR are challenging examples for both LTE type communication systems and 5G/NR communication systems as well as next generation communication systems.

New and future services and wireless communication systems are also increasingly concerned with meeting or facilitating sustainability considerations. In particular in view of such sustainability factors, the increasing use of different types of network infrastructure devices and terminal devices associated with different traffic profiles presents new challenges to be addressed for efficiently and sustainably processing communications in a wireless communication system.

Disclosure of Invention

The present disclosure may help solve or mitigate at least some of the problems discussed above.

Embodiments of the present technology may provide a method of operating a communication device configured to transmit signals to and/or receive signals from a wireless communication network via a radio interface provided by the wireless communication network. The method comprises transmitting signals to and/or receiving signals from a first wireless communication network via a first radio interface provided by the first wireless communication network when the communication device is located within a coverage area of the first wireless communication network, determining that one or more conditions to perform a mobility procedure have been met, determining that the mobility procedure comprises switching from the first wireless communication network to a second wireless communication network, performing a mobility procedure from the first wireless communication network to the second wireless communication network, and transmitting signals to and/or receiving signals from the second wireless communication network via a second radio interface provided by the second wireless communication network when the communication device is located both within the coverage area of the second wireless communication network and within the coverage area of the first wireless communication network.

In addition to methods of operating communication devices, embodiments of the present technology relate to methods of operating infrastructure devices, communication devices and infrastructure devices, circuits for communication devices and infrastructure devices, computer programs, and computer readable storage media that may allow communication devices operating in a wireless communication network to more consistently and efficiently use radio resources.

Various aspects and features of the present disclosure are defined in the appended claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the technology. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

Drawings

A more complete appreciation of the present disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein like reference numerals designate like or corresponding parts throughout the several views, and wherein:

fig. 1 schematically illustrates some aspects of an LTE-type wireless telecommunications system that may be configured to operate in accordance with certain embodiments of the present disclosure;

fig. 2 schematically represents some aspects of a new Radio Access Technology (RAT) wireless telecommunications system that may be configured to operate in accordance with certain embodiments of the present disclosure;

FIG. 3 is a schematic block diagram of an exemplary infrastructure device and communication device that may be configured to operate in accordance with certain embodiments of the present disclosure;

FIG. 4 schematically illustrates aspects of a conventional handoff process;

fig. 5 shows an example scenario in which a UE is located at the cell edge of its home operator and at the cell center of another operator;

figure 6 shows a partially schematic, partially message flow diagram representation of a wireless communication system including a communication device and an infrastructure device in accordance with an embodiment of the present technique, and

Fig. 7 shows a flowchart illustrating a communication procedure in a communication system according to an embodiment of the present technology.

Detailed Description

Advanced wireless access technology for long term evolution (4G)

Fig. 1 provides a schematic diagram illustrating some basic functions of a mobile telecommunications network/system 6, the mobile telecommunications network/system 100 generally operating according to LTE principles, but may support other radio access technologies as well, and may be adapted to implement embodiments of the present disclosure described herein. Certain aspects of the various elements of fig. 1 and their respective modes of operation are well known and defined in the relevant standards of 3GPP (RTM) agency administration and are also described in numerous books on this subject, for example Holma h. And Toskala a [1]. It should be appreciated that operational aspects of the telecommunications network discussed herein that are not specifically described (e.g., with respect to particular communication protocols and physical channels for communicating between the different elements) may be implemented in accordance with any known technique, such as, for example, modifications and additions to the related standards and known proposals for the related standards.

The network 6 comprises a plurality of base stations 1 connected to a core network 2. Each base station provides a coverage area 3 (i.e., a cell) within which data may be communicated with a communication device 4. Although each base station 1 is shown as a single entity in fig. 1, it will be understood by those skilled in the art that some of the functions of the base stations may be performed by different, interconnected elements, such as antennas (or antennas), remote radio heads, amplifiers, etc. In general, one or more base stations may form a radio access network.

Data is transmitted from the base station 1 via the radio downlink to the communication devices 4 within their respective coverage areas 3. Data is transmitted from the communication device 4 to the base station 1 via the radio uplink. The core network 2 routes data to and from the communication devices 4 and 104 via the respective base stations 1 and provides functions such as authentication, mobility management, charging, etc. The terminal device may also be referred to as a mobile station, user Equipment (UE), user terminal, mobile radio, communication device, etc. The services provided by the core network 2 may include connections to the internet or to external telephony services. The core network 2 may further track the location of the communication device 4 so that it can effectively contact (i.e., page) the communication device 4 for transmitting downlink data to the communication device 4.

A base station is an example of a network infrastructure device and may also be referred to as a transceiver station, nodeB, e-nodeB, eNB, g-nodeB, gNB, etc. In this regard, different terms are generally associated with different generations of wireless telecommunication systems for providing elements of widely comparable functionality. However, certain embodiments of the present disclosure may be equally implemented in different generations of wireless telecommunication systems, and certain terminology may be used for simplicity, regardless of the underlying network architecture. That is, the use of particular terminology in connection with particular example embodiments is not intended to be limiting of such implementations to the particular generation of networks with which the particular terminology is most relevant.

New radio access technology (5G)

Systems employing NR technology are expected to support different services (or service types) that may be characterized by different requirements for latency, data rate, and/or reliability. For example, enhanced mobile broadband (eMBB) services are characterized by high capacity, requiring up to 20Gb/s support. Requirements of ultra-reliable low delay communication (URLLC) services transmission of 32 byte packets once from the radio protocol layer 2/3SDU ingress point to the radio protocol layer 2/3SDU egress point of the radio interface within 1ms, reliability is 1-10 ^-5 (99.999%) or higher 99.9999% [2].

Large-scale machine type communication (mMTC) is another example of a service that may be supported by NR-based communication networks. Furthermore, it is expected that the system will support further enhancements in connection with industrial internet of things (IIoT) to support new requirements for high availability, high reliability, low latency, and in some cases high accuracy positioning.

An exemplary configuration of a wireless communication network using some of the terms proposed and used for NR and 5G is shown in fig. 2. In fig. 2, a plurality of Transmission and Reception Points (TRP) 10 are connected to distribution control units (DU) 41, 42 through a connection interface denoted by line 16. Each of the TRPs 10 is arranged to transmit and receive signals via the wireless access interface within the radio frequency bandwidth available to the wireless communication network. Thus, each of the TRPs 10 forms a cell of the wireless communication network represented by circle 12 within a range for performing radio communication via the wireless access interface. In this way, the wireless communication device 14 within the radio communication range provided by the unit 12 can transmit signals to the TRP 10 and receive signals from the TRP 10 via the wireless access interface. Each of the distribution units 41, 42 is connected to a Central Unit (CU) 40 (which may be referred to as a control node) via an interface 46. The central unit 40 is then connected to the core network 20, the core network 20 may contain all other functions necessary for transmitting data for communication with the wireless communication device, and the core network 20 may be connected to other networks 30.

The elements of the radio access network shown in fig. 2 may operate in a similar manner to the corresponding elements of the LTE network described with respect to the example of fig. 1. It will be appreciated that the operational aspects of the telecommunications network represented in fig. 2, as well as the operational aspects of other networks discussed herein in accordance with embodiments of the present disclosure, which are not specifically described (e.g., with respect to specific communication protocols and physical channels for communicating between the different elements), may be implemented in accordance with any known technique, e.g., in accordance with currently used methods for implementing such operational aspects of a wireless telecommunications system, e.g., in accordance with related standards.

The TRP 10 of fig. 2 may have, in part, functions corresponding to a base station or eNodeB of an LTE network. Similarly, the communication apparatus 14 may have functionality corresponding to UE devices 4 known for LTE network operation. Thus, it will be appreciated that operational aspects of the new RAT network (e.g., with respect to specific communication protocols and physical channels for communicating between different elements) may differ from those known from LTE or other known mobile telecommunications standards. However, it will also be appreciated that each of the core network components, base stations and communication devices of the new RAT network will be similar in function to the core network components, base stations and communication devices, respectively, of the LTE wireless communication network.

In terms of broad top-level functionality, the core network 20 shown in fig. 2 connected to the new RAT telecommunication system may be broadly considered to correspond to the core network 2 shown in fig. 1, and the central unit and its associated distributed units/TRP 10 may be broadly considered to provide functionality corresponding to the base station 1 of fig. 1. The term network infrastructure equipment/access node may be used to encompass these elements of the wireless telecommunications system as well as more conventional base station type elements. Depending on the application at hand, the responsibility of scheduling transmissions scheduled on the radio interface between the respective distributed unit and the communication device may consist in the control node/central unit and/or the distributed units/TRP. In fig. 2, the communication device 14 is shown within the coverage area of the first communication cell 12. The communication device 14 may thus exchange signaling with the first central unit 40 in the first communication cell 12 via one of the distributed units/TRP 10 associated with the first communication cell 12.

It should also be appreciated that fig. 2 represents only one example of a proposed architecture of a new RAT-based telecommunication system, wherein methods according to the principles described herein may be employed and that the functionality disclosed herein may also be applied to wireless telecommunication systems having different architectures.

Thus, certain embodiments of the present disclosure discussed herein may be implemented in a wireless telecommunications system/network according to a variety of different architectures (e.g., the example architectures shown in fig. 1 and 2). Thus, it should be understood that the particular wireless telecommunications architecture in any given implementation is not of major significance to the principles described herein. In this regard, certain embodiments of the present disclosure may be generally described in the context of communication between a network infrastructure device/access node and a communication device, where the particular nature of the network infrastructure device/access node and communication device will depend on the network infrastructure for the intended implementation. For example, in some cases, the network infrastructure device/access node may comprise a base station, e.g., an LTE type base station 1 shown in fig. 1 adapted to provide functionality in accordance with the principles described herein, and in other examples, the network infrastructure device may comprise a control unit/control node 40 and/or TRP 10 of the type shown in fig. 2 adapted to provide functionality in accordance with the principles described herein.

Fig. 3 provides a more detailed diagram of some of the network components shown in fig. 2. In fig. 3, the TRP 10 as shown in fig. 2 includes, as a simplified representation, a wireless transmitter 30, a wireless receiver 32, and a controller or control processor 34, the controller or control processor 34 being operable to control the transmitter 30 and the wireless receiver 32 to transmit and receive radio signals to one or more UEs 14 within the cell 12 formed by the TRP 10. As shown in fig. 3, the example UE 14 is shown to include a respective transmitter 49, receiver 48, and controller 44, the controller 44 being configured to control the transmitter 49 and receiver 48 to transmit signals representing uplink data to the wireless communication network via the wireless access interface formed by the TRP 10, and to receive downlink data as signals transmitted by the transmitter 30 and received by the receiver 48 in accordance with conventional operation.

The transmitters 30, 49 and receivers 32, 48 (and other transmitters, receivers and transceivers described with respect to examples and embodiments of the present disclosure) may include radio frequency filters and amplifiers and signal processing components and devices to transmit and receive radio signals according to, for example, the 5G/NR standard. The controllers 34, 44 (and other controllers described with respect to examples and embodiments of the present disclosure) may be, for example, microprocessors, CPUs, or special purpose chipsets, etc., configured to execute instructions stored on computer readable media (e.g., non-volatile memory). The process steps described herein may be performed by, for example, a microprocessor in combination with random access memory operating in accordance with instructions stored on a computer readable medium. For ease of illustration, the transmitter, receiver and controller are schematically shown as separate elements in fig. 3. However, it should be understood that the functionality of these elements may be provided in a variety of different ways, for example using one or more suitably programmed programmable computers or one or more suitably configured application specific integrated circuits/circuitry/chips/chipsets. It should be appreciated that the infrastructure equipment/TRP/base station as well as the UE/communication device will typically include various other elements associated with its operational functions.

As shown in fig. 3, TRP 10 also includes a network interface 50 connected to DU 42 via physical interface 16. Thus, the network interface 50 provides a communication link for data and signaling traffic from the TRP 10 to the core network 20 via the DU 42 and CU 40.

The interface 46 between the DU 42 and the CU 40 is referred to as the F1 interface, and the F1 interface may be a physical interface or a logical interface. The F1 interface 46 between the CU and the DU may operate according to specifications 3gpp TS 38.470 and 3gpp TS 38.473 and may be formed from an optical fiber or other wired or wireless high bandwidth connection. In one example, connection 16 from TRP10 to DU 42 is connected via an optical fiber. The connection between TRP10 and core network 20 may be generally referred to as a backhaul, which includes interface 16 from network interface 50 of TRP10 to DU 42 and F1 interface 46 from DU 42 to CU 40.

Fig. 4 shows a detailed illustration of a wireless communication network in which a Handover (HO) may be performed. As can be appreciated from fig. 4, the communication device 72 switches from the source infrastructure device 74 to the target infrastructure device 76, the target infrastructure device 76 forming part of the radio access network to the core network 60. It should be appreciated that communication device 72 is an example of a communication device (e.g., communication device 14 of fig. 1,2, and 3). In one example, the communication device 72 may be a UE.

Prior to the handover, the communication device 72 transmits signals on the uplink UL and receives signals from the source infrastructure device 74 on the downlink DL. Both the source infrastructure device 74 and the target infrastructure device 76 may be considered as a gNB 1 (as shown in FIG. 1) or a combination of the control node 40 and the TRP 10 (as shown in FIGS. 2 and 3). Prior to the handoff, the communication device 72 is shown transmitting uplink data to the source infrastructure device 74 via an uplink resource UL of a wireless access interface (as indicated generally by dashed arrow 64 b) to the source infrastructure device 74. The communication device 72 may similarly be configured to receive downlink data transmitted by the source infrastructure device 74 from the source infrastructure device 74 to the communication device 72 via the downlink resource DL, as indicated by the dashed arrow 288 b. After the handoff, the communication device 72 is shown transmitting uplink data to the target infrastructure device 76 via the uplink resource UL of the wireless access interface (as indicated by solid line arrow 66 a) to the target infrastructure device 76. The communication device 72 may similarly be configured to receive downlink data transmitted by the target infrastructure device 76 from the target infrastructure device 76 to the communication device 72 via the downlink resource DL, as indicated by solid line arrow 64 a.

In fig. 4, both source and target infrastructure devices 74, 76 are connected to the core network 60 via interfaces 61, 62 to controllers 74c, 76c of the respective infrastructure devices 74. The source and target infrastructure devices 74, 76 each include a receiver 74b, 76b connected to an antenna 74d, 76d and a transmitter 74a, 76a connected to the antenna 74d, 76 d. Accordingly, the communication device 72 includes a controller 72c that is connected to a receiver 72b that receives signals from an antenna 72d, and the transmitter 72a is also connected to the antenna 72d.

The controllers 74c, 76c are configured to control the source and target infrastructure devices 74, 76, respectively, and may include processor circuitry, which in turn may include various sub-units/sub-circuits for providing the functionality further explained herein. These sub-units may be implemented as discrete hardware elements or as suitably configured functions of a processor circuit. Accordingly, the controllers 74c, 76c may include circuitry suitably configured/programmed to provide the desired functionality for devices in the wireless telecommunications system using conventional programming/configuration techniques. The transmitters 74a, 76a and receivers 74b, 76b may include signal processors and radio frequency filters, amplifiers and circuitry according to conventional arrangements. For ease of illustration, the transmitters 74a, 76a, receivers 74b, 76b, and controllers 74c, 76c are schematically illustrated as separate elements in fig. 4. However, it should be understood that the functionality of these elements may be provided in a variety of different ways, for example using one or more suitably programmed programmable computers or one or more suitably configured application specific integrated circuits/circuitry/chips/chipsets. It should be understood that the infrastructure device 74 will typically include various other elements associated with its operational functions.

Accordingly, the controller 72c of the communication device 72 is configured to control the transmitter 72a and the receiver 72b and may include processor circuitry, which in turn may include various sub-units/sub-circuits for providing the functionality further explained herein. These sub-units may be implemented as discrete hardware elements or as suitably configured functions of a processor circuit. Accordingly, the controller 72c may include circuitry suitably configured/programmed to provide the desired functionality for devices in the wireless telecommunication system using conventional programming/configuration techniques. Also, the transmitter 72a and receiver 72b may include signal processors and radio frequency filters, amplifiers and circuitry according to conventional arrangements. For ease of illustration, the transmitter 72a, receiver 72b, and controller 72c are schematically illustrated as separate elements in fig. 3. However, it should be understood that the functionality of these elements may be provided in a variety of different ways, for example using one or more suitably programmed programmable computers or one or more suitably configured application specific integrated circuits/circuitry/chips/chipsets. It should be appreciated that the communication device 72 will typically include various other elements associated with its operational functionality, e.g., a power source, a user interface, etc., but these are not shown in fig. 4 for simplicity.

The controllers 74c, 72c may be configured to execute instructions stored on a computer readable medium such as non-volatile memory. The process steps described herein may be performed by, for example, a microprocessor in combination with random access memory operating in accordance with instructions stored on a computer readable medium.

Random access procedure

In wireless telecommunication networks (e.g., LTE and NR type networks), terminal devices have different Radio Resource Control (RRC) modes. For example, an RRC IDLE mode (rrc_idle) and an RRC CONNECTED mode (rrc_connected) are generally supported. A terminal device in idle mode may switch to connected mode, for example, because it is required to transmit uplink data by taking a random access procedure or respond to a paging request. The random access procedure involves the terminal device transmitting a preamble on a physical random access channel, and is therefore commonly referred to as RACH or PRACH procedure/process. As will be appreciated by those skilled in the art, a typical RACH procedure may include four steps (referred to as msg1, msg2, msg3, and msg 4) or two steps (referred to as msgA and msgB).

Sustainability of 6G wireless communications and telecommunications

As described above, several generations of mobile communication have been standardized worldwide, wherein each generation of mobile communication takes about ten years before another generation of mobile communication is developed and introduced. For example, several generations of mobile communications have evolved from the global system for mobile communications (GSM) (2G) to Wideband Code Division Multiple Access (WCDMA) (3G), from WCDMA (3G) to LTE (4G), and recently from LTE (4G) to NR (5G).

As discussed above with reference to the example configurations of fig. 2 and 3, the latest generation of mobile communications is 5G, in which a number of additional features have been incorporated into different versions to provide new services and capabilities. These services include eMBB, IIoT, and URLLC as described above, but also include services such as 2-step Random Access (RACH), unlicensed NR (NR-U), cross-link interference (CLI) processing for Time Division Duplexing (TDD), positioning, small Data Transmission (SDT), multicast and Broadcast Services (MBS), reduced capacity UEs, vehicle communications (V2X), integrated Access and Backhaul (IAB), UE power saving, non-terrestrial network (NTN), NR operation up to 71GHz, ioT over NTN, non-public network (NPN), and Radio Access Network (RAN) slicing.

However, as with every decade, a new generation (e.g., 6G) is expected to be developed and deployed in the near future (about 2030), and would be expected to provide new services and capabilities that current 5G cannot provide.

One area of research in future mobile communication networks is Uplink (UL) scheduling enhancements, which are expected to be needed due to the increased number of services requiring low latency communication and high reliability, and high throughput UL data transmissions from terminals, e.g., haptic internet, audio-video field production and augmented reality (XR). In essence, it is proposed that a mobile terminal should be able to schedule unrestricted UL resources immediately after the data arrives in its buffer for transmission, while taking into account link adaptation parameters, in order to ensure maximum transmission success. Doing so will allow such a mobile terminal to operate not only more efficiently, but also in a more sustainable manner, wasting less power.

Sustainability is an increasingly important topic for 6G, with mobile network operators, network providers, and mobile phone/other user equipment manufacturers increasingly focusing on their carbon footprints. The united nations have determined 17 sustainability targets [3], which are:

● No poverty;

● Zero starvation;

● Health and wellbeing;

● High-quality education;

equal in both sexes;

● Clean drinking water and sanitation;

affordable clean energy sources;

body surface work and economic growth;

industry, innovation, and infrastructure;

● Reducing unevenness;

● Sustainable cities and communities;

responsible consumption and production;

● Climate action;

● Living underwater;

● Land life;

● Peace, sense and powerful mechanism, and

● Partnership of the target.

There are several known mobile network use cases that are helping to achieve these sustainability goals. For example, sustainability goals being addressed by mobile networks might include no poverty (by improving awareness), zero hunger (by smart agriculture), health (mobile health), premium education (tele-and immersive learning), clean drinking and hygiene (smart city), and industry innovation (URLLC, etc. services). However, the role of mobile networks in helping to achieve some of the other sustainability goals described above-e.g., affordable clean energy, sustainable cities and communities, climate action, and life on earth-is more questionable.

In terms of global deployment, mobile networks consume considerable energy. In current (i.e., predominantly 4G) mobile network deployments, RAN networks are especially leading in terms of energy consumption. This is because all RAN equipment (e.g., base stations) are deployed in the field, rather than a more centralized deployment of core network devices. Meanwhile, mobile networks are processing more and more data generated by more and more users desiring data, and thus the overall data usage is increasing every month. With the advent of new wireless access technologies such as 5G and 6G, new services and use cases are being proposed that require continuous data applications, such as digital twinning, XR, gaming, and virtual reality. Another development of 5G and beyond is that the spectrum used for data communication is a higher spectrum (e.g., higher than that used by previous generations of wireless communication networks), resulting in smaller cell sizes. All these factors contribute to the necessary deployment of larger numbers of RAN devices in order to meet the ever-increasing data and coverage/capacity requirements. These requirements are counter to the above-described sustainability objectives described in [3], thus presenting challenges to the overall efforts of wireless network operators, network providers, and mobile phone manufacturers to achieve these sustainability objectives.

Fig. 5 shows an example scenario in which UE 85 is a customer of operator a and is located at the cell edge of one cell 81 of operator a controlled by the gNB 82. Meanwhile, UE 85 is located in the center of cell 83 of operator B controlled by the gNB 84, which overlaps with cell 81 of operator a. From a purely energy saving point of view, it can be said that the UE 85 should simply connect to the network of operator B instead of its own home operator (i.e. operator a) in order to reduce the required transmission power and to increase throughput and energy efficiency. Thus, fig. 5 shows an example of a scenario in which national roaming techniques would be beneficial from a power saving and sustainability perspective.

However, although national roaming is of course technically possible, it is not allowed in current networks, since different operators have different regulations and therefore mobility from one operator to another in the same country is not supported. In contrast, intra-operator handover (e.g., in the example of fig. 4) is a handover that allows the UE to make. Furthermore, while known and supported international roaming techniques are typically performed because the UE cannot find its home Public Land Mobile Network (PLMN), the UE 85 in the example scenario of fig. 5 is instead in a more efficient location for the cell 83 connected to operator B than for the cell 81 connected to its home PLMN (i.e., operator a). That is, such a national roaming scenario cannot be said to correspond to international roaming, since this would not be performed under the same conditions, i.e. as a result of the UE being unable to find its home PLMN.

In the example of fig. 5, since UE 85 cannot switch to cell 83 of operator B, the uplink transmission power that needs to be used by a UE (e.g., UE 85) located at the cell edge of cell 81 of operator a will increase, even though technically there is a better cell 83 (i.e., in terms of required transmission power) that can be selected from operator B. This is disadvantageous, especially when the sustainability of the wireless network needs to be considered.

Accordingly, embodiments of the present technology seek to provide solutions to the efficiency and sustainability problems in wireless communication networks.

Sustainable roaming in wireless communication networks

Fig. 6 illustrates a partial schematic, partial message flow diagram representation of a wireless communication system including a communication device 101, a first infrastructure device 102, and a second infrastructure device 103 in accordance with at least some embodiments of the present technology. The communication device 101 is configured to (initially) transmit signals to and/or receive signals from a first wireless communication network (of which the first infrastructure device 102 may form part), e.g. to the first infrastructure device 102 and to the first infrastructure device 102. Further, at a later time, the communication device 101 may be configured to transmit signals to and/or receive signals from a second wireless communication network (of which the second infrastructure device 103 may form part), e.g. to the second infrastructure device 103 and to receive signals from the second infrastructure device 103. In particular, the communication device 101 may be configured to transmit data to and/or receive data from the first and/or second wireless communication networks (e.g., to/from the first and second infrastructure devices 102, 103) via radio interfaces provided by the first and second wireless communication networks (e.g., uu interfaces between the communication device 101 and a Radio Access Network (RAN) of the first and second wireless communication networks including the first and second infrastructure devices 102, 103, respectively). The communication device 101 and the first and second infrastructure devices 102, 103 each comprise a transceiver (or transceiver circuit) 101.1, 102.1, 103.1 and a controller (or controller circuit) 101.2, 102.2, 103.2. Each of the controllers 101.2, 102.2, 103.2 may be, for example, a microprocessor, a CPU, or a dedicated chipset, etc.

As shown in the example of fig. 6, the transceiver circuit 101.1 and the controller circuit 101.2 of the communication device 101 are together configured to transmit 103 signals to and/or receive signals from the first wireless communication network (e.g. to/from the first infrastructure device 102) via a first radio interface provided by the first wireless communication network when the communication device 101 is located within the coverage area of the first wireless communication network, to determine 104 that one or more conditions to perform a mobility procedure have been met, to determine 105 that the mobility procedure comprises switching from the first wireless communication network to the second wireless communication network, to perform 106 a mobility procedure from the first wireless communication network to the second wireless communication network, and to transmit 107 signals to and/or receive signals from the second wireless communication network (e.g. to/from the second infrastructure device 103) via a second radio interface provided by the second wireless communication network when the communication device 101 is located within both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network.

Here, the first wireless communication network and the second wireless communication network may be controlled by different network operators, and/or signals transmitted to and/or received from the first wireless communication network may be transmitted and/or received within a first frequency band, and signals transmitted to and/or received from the second wireless communication network are transmitted and/or received within a second frequency band, wherein the first frequency band is different from the second frequency band. Here, the coverage area of the first wireless communication network and the coverage area of the second wireless communication network may both be within a predetermined geographic area, which may be defined by one or more of a country boundary, a region boundary, or a political boundary, or may be defined as any other type of geographic area, wherein the entire area is an area of a single country, region, or political land. Furthermore, the coverage areas of the first and second wireless communication networks may be defined by the respective first and second PLMNs, i.e. cellular networks of the respective operators of the first and second wireless communication networks in a particular country/region defined by a predetermined geographical area in which the communication device is located.

Essentially, embodiments of the present technology propose novel network configurations and UE behavior to support UE mobility between different operators within a country or other predetermined geographic region, thereby optimizing the energy efficiency performance of the UE.

Mobility between different operators within a country should be supported to improve the energy efficiency performance of the network. We have different alternatives to support this mobility.

In some arrangements of embodiments of the present technology, the conditions that allow mobility between different mobile network operators are configured by a non-access stratum (NAS) layer. In other words, the communication device may be configured to receive non-access stratum NAS signaling from the core network (e.g., from an Access and Mobility Function (AMF) or Mobility Management Entity (MME) within the core network), the signaling including an indication of one or more conditions to perform a mobility procedure. The conditions triggering such a handover may be:

● Link quality, e.g., when a link quality metric such as Reference Signal Received Power (RSRP) or Reference Signal Received Quality (RSRQ) is below a threshold and no other cells of the same home mobile network operator are available for selection, the UE may be allowed to search for and connect to a cell of another mobile network operator having better link quality. In other words, the one or more conditions to perform the mobility procedure may include that the signal quality received from the first wireless communication network is below a first threshold and/or that the signal quality received from the second wireless communication network exceeds a second threshold (wherein the first and second thresholds may be the same or there may be a gap between them, which gap may be fixed or may be configured by the network);

● Distance between UE and serving cell (and/or neighboring cells of the same network operator).

The path loss increases in proportion to the distance between the UE and the cell, and thus, if the UE knows its own location and the location of the serving/neighbor cell, the UE can roughly determine the path loss. The UE may receive assistance information from the network in advance about the serving/neighbor cell location, allowing such distance (and path loss) to be more easily determined based on its own location and this received assistance information. In other words, the one or more conditions to perform the mobility procedure may include that a distance between the communication device and an infrastructure equipment of the first wireless communication network exceeds a first threshold and/or that a distance between the communication device and an infrastructure equipment of the second wireless communication network is below a second threshold (wherein the first and second thresholds may be the same or there may be a gap between them that may be fixed or may be configured by the network), and

● When the UE's energy efficiency performance (e.g., joules/bit) is worse than its configured energy efficiency profile, the UE may be allowed to handover to a cell operated by a network operator different from its home PLMN, which is capable of supporting energy efficient operation according to the UE's energy efficiency profile. In other words, the one or more conditions to perform the mobility procedure may include that the energy efficiency performance of the communication device is below a defined threshold. Here, such energy efficiency capabilities of the communication device may define the amount of energy required to transmit a particular portion of data.

In accordance with this arrangement of embodiments of the present technology, energy efficiency performance may be monitored in any of a variety of ways, for example, by the network and/or by the UE.

In the case of network monitoring energy efficiency performance, the base station may measure the UE's transmission power and baseband processing power consumption in addition to the total amount of traffic. The base station may then calculate the energy capacity per data based on the measurements. The base station may then indicate the monitored energy efficiency performance to the UE. In other words, the communication device may be configured to receive an indication of energy efficiency performance of the communication device from the first wireless communication network.

In the case where the UE monitors energy efficiency performance, the UE may measure power consumption in addition to throughput. However, those skilled in the art will appreciate that the UE may not be able to distinguish between the power consumption of the application and the power consumption of the radio communication. Instead, as measured power consumption, the UE may use the transmission power (or power headroom) and the total amount of traffic of the UE to estimate the power consumption of the radio communication in a simplified manner. In other words, the communication device may be configured to measure power consumption of the communication device, measure throughput of the communication device, and determine energy efficiency performance of the communication device based on the measured power consumption and the measured throughput. Here, the UE may be configured to report the determined energy efficiency performance to the network.

In some arrangements of embodiments of the present technology, to allow the UE to know the presence of cells belonging to another operator to which the UE may be handed over, the serving cell may broadcast the cell configuration of the other operator (or an operator willing to cooperate with the home operator of the UE). In other words, the communication device may be configured to receive signaling from the first wireless communication network, the signaling including an indication of configuration information associated with the second wireless communication network.

In some implementations, this (cell configuration of another operator) may be implemented as an on-demand SI in the system information. In other words, the communication device may be configured to transmit a request for signaling to the first wireless communication network, wherein the signaling is received from the first wireless communication network in response to the transmitted request.

In various arrangements of embodiments of the present technology, the mobility procedure may be a handover procedure including a handover of the communication device from the first wireless communication network to the second wireless communication network when the communication device is operating in a connected mode. Or the mobility procedure may be a cell reselection procedure comprising switching the communication device from the first wireless communication network to the second wireless communication network when the communication device is operating in idle mode/inactive mode.

In some other arrangements of embodiments of the present technology, as a mobility procedure, the network (i.e., via the serving cell of the UE) may send an RRC connection release message to the UE, wherein the RRC connection release message includes a redirection message and specifies a frequency (which may be a frequency band of a different mobile network operator according to embodiments of the present technology) or specifies a different mobile network operator itself for the UE to access. In other words, the communication device may be configured to perform the mobility procedure by receiving a connection release message from the first wireless communication network indicating that the communication device is to release a connection between the communication device and the first wireless communication network, wherein the connection release message comprises an indicator indicating that the mobility procedure comprises a handover from the first wireless communication network to the second wireless communication network. Here, the indicator may explicitly identify the second wireless communication network, and/or the indicator may identify a second frequency band, which is a frequency band in which the communication device is to transmit signals to and/or receive signals from the second wireless communication network, and which is different from a first frequency band in which signals transmitted to and/or received from the first wireless communication network are transmitted and/or received.

In some arrangements of embodiments of the present technology, the network may detect that the UE is connecting to the network in an energy inefficient manner, which may be determined from, for example, the location of the UE (i.e., via a location report received from the UE), and/or a sustainability profile of the UE in the core network, and/or a measured energy efficiency performance of the UE that may be determined by the network or the UE in the manner described above. In this case, the network may include a preferred frequency band for the UE to access (where the preferred frequency band may belong to another operator) in the RRC connection release message.

In some implementations, the indication may be included in a CellReselectionPriority list in an RRC connection release message to indicate that the UE is connected to another network via the frequency band. For example, the network may configure the priority of the inter-operator frequency band to be high/medium high in CellReselectionPriority list (which defines a value between 0 and 7, where 0 represents the lowest priority and 7 represents the highest priority). In other words, the indicator may be included in a cell reselection priority list and indicate the priority of the second wireless communication network. This may be triggered by the network, for example, when the RSRP at the UE is below a certain threshold and no other cells from the same operator are available for selection, and/or when the UE is located at the cell edge, and/or when the energy efficiency performance of the UE is not met.

In some other implementations, the frequency bands of other operators may be indicated outside of the CellReselectionPriority list, or may be listed such that the UE sees the frequency band as the highest priority and does not waste power measuring other (lower priority) frequencies listed in the priority list. In other words, the indicator may be included in a connection release message separate from the cell reselection priority list.

In some arrangements of embodiments of the present technology, the network (i.e., via the serving cell of the UE) may configure the frequency priority according to certain conditions, for example, in broadcast SI. In other words, the configuration information may comprise an indication of the priority of the second wireless communication network, wherein here the configuration information may further comprise an indication of one or more conditions under which the communication device performs the mobility procedure by switching from the first wireless communication network to the second wireless communication network.

For example, in broadcast SI, the network may configure the priority of inter-operator frequencies to be high/medium high in CellReselectionPriority list, but especially if the link quality of e.g. UEs operating in this band should be above a certain threshold. Otherwise, if the link quality of the UE operating in this band is not above a certain threshold, such high/medium priority for other network operators, i.e. only those inter-operator frequency cells with good quality (e.g. above the threshold), will be available for the UE to select. The same is true for other conditions, e.g., conditions related to UE distance from cell, UE energy efficiency performance or sustainability profile, etc. In other words, the indicator may indicate one or more conditions under which the communication device performs the mobility procedure by switching from the first wireless communication network to the second wireless communication network.

In other arrangements of embodiments of the present technology, the UE may remember its sustainability profile from its previous connection/communication with the core network, and thus may indicate the sustainability profile to the network for a new connection with the network (e.g., in msg1/msg3 when performing RACH procedures). Here, the sustainability profile can indicate an expected energy efficiency performance associated with the UE, which can be a performance that the UE is willing or required (if possible) to achieve. The energy efficiency performance may be defined in terms of joules per bit or power level and may indicate that the UE is willing to accept a particular energy efficiency level (or in some cases within the amounts specified below) indicated by the sustainability profile. Also, the UE's sustainability profile may indicate that the UE is ready to accept a particular service with or without a lower quality of service (QoS) and/or quality of experience (QoE), assuming that doing so (i.e., accepting a particular QoS and/or QoE) would be able to achieve a sustainability goal (which may be associated with or defined by the sustainability profile).

The cells of the first and second wireless communication networks may also be associated with a sustainability profile, e.g., indicating that full service delivery of the UE within the cell or less service delivery of the UE within the cell is supported, and this information may be considered (e.g., in connection with the sustainability profile of the UE) when considering whether the UE should perform mobility procedures such as handover or cell reselection. For example, the resolution (e.g., 4K- > HD) and/or refresh rate (e.g., 120 frames per second to 30 frames per second) of the video may be reduced to conserve radio resources. The sustainability profile (of the UE and/or cell) can be primarily related to sustainability objectives (e.g., power consumption). However, such a sustainability profile is not necessarily related to sustainability objectives. For example, the delay of the backhaul link may depend on the cell/base station. The delay is primarily dependent on the type of backhaul link (e.g., fiber, millimeter wave, satellite, etc.) connected to the cell/base station. If the delay is long, the UE may determine whether to accept less service with high delay or whether to drop the service based on the cell sustainability profile (and/or its own sustainability profile).

If the network determines that the UE is experiencing poor radio conditions and, thus, the UE connected to the network does not meet the UE's sustainability profile when experiencing these poor radio conditions, the network may immediately send an RRC reject message to end the RACH procedure and send redirected carrier information including an indication of the frequency band of neighboring (and different mobile network operators) cells/frequencies. In other words, the communication device may be configured to receive an indication of a sustainability profile associated with the communication device from the core network, and subsequently the communication device may be configured to perform a mobility procedure by transmitting the indication of the sustainability profile to the first wireless communication network, and receiving an indication that the communication device is to perform the mobility procedure from the first wireless communication network to the second wireless communication network based on the transmitted indication of the sustainability profile. Here, if the sustainability profile is indicated by the UE's random access preamble (i.e., msg 1), and in some cases where the preamble is transmitted at high power, the Random Access Response (RAR) message may include a rejection (and an indication that the UE should switch to another cell, which may be a cell of a different mobile network operator). Or if the sustainability profile is transmitted within msg3, the RRC reject message can be transmitted as described above. In another alternative implementation, the UE's sustainability can be transmitted after msg5 or (i.e., where the RACH procedure has been completed and the UE is connected to the network). In this case, the network may send an RRC connection release message, as described in the previous paragraph above.

In some such arrangements, RACH resources may be reserved for Energy Efficient (EE) UEs, which, as described above, may be used to indicate a sustainability profile during a RACH procedure. Here, for example, the EE-UE may be a UE whose energy efficiency performance is at or above a particular predefined or dynamic/semi-static threshold (where energy efficiency performance may be determined by the UE or the network in the same or similar manner as described above), and/or for example, the EE-UE may be a particular type of UE defined in the specification. In other words, the indication of the sustainability profile can be transmitted within the random access control RACH resource of the first radio interface as part of the RACH message, and wherein the RACH resource is reserved for the energy efficient communication device.

In other arrangements of embodiments of the present technology, if the UE knows its sustainability profile (e.g., from its previous connection/communication with the core network), during cell selection/reselection, the UE may not select the cell of its home PLMN if the cell is below a certain threshold, e.g., in terms of quality (RSRP/RSRQ, etc.). If the system information indicates that selection of another operator cell is allowed, the UE may select/reselect a cell belonging to another operator as long as the cell does meet the radio conditions of cell selection/reselection (e.g., the quality of reference signals received from neighboring cells of another operator is above a threshold). In other words, the communication device may be configured to determine that the mobility procedure includes a handover from the first wireless communication network to the second wireless communication network based on satisfying both the one or more conditions to perform the mobility procedure and the sustainability profile.

In other arrangements of embodiments of the present technology, a UE in connected mode may be configured to measure a cell of another operator and may define a new measurement event for this purpose, whereby the UE reports (to its own serving cell) whether the signal quality received from the cell of the other operator is above a threshold. In other words, the communication device may be configured to perform measurements of reference signals received from the second wireless communication network and to transmit an indication of the performed measurements to the first wireless communication network if specified conditions are met. Here, the specified condition may include that the quality of the measured reference signal is higher than a threshold value.

In some such arrangements of embodiments of the present technology, another new event may be if the measurement of another operator cell is higher than the measurement of the serving cell. These measurements may be modeled as inter-frequency or inter-RAT measurements within the current measurement configuration, and a model for performing measurements (of the frequency bands of other operators) may be configured as inter-frequency measurement objects. Here, the UE may be configured to perform measurements, e.g., inter-frequency measurements, based on the capabilities of the UE, e.g., as to whether a measurement gap is required. Similarly, the frequency of another operator may instead be included in the inter-RAT measurements. In other words, the specified condition may include that the quality of the measured reference signal is higher than the quality of the measured reference signal received from the first wireless communication network.

In some such arrangements, it may be the case that the home PLMN of the UE is given a degree of priority in order to agree between different network operators on the permission of national roaming and network configuration/UE behaviour. For example, with respect to the arrangement of the new events described above with respect to comparing the measured quality of the cells of the service and the other operator, the UE may be configured to switch to the cell of the other operator (or even simply report the quality of the cell of the other operator) only if the quality of the cell is better than the quality of the serving cell by more than a certain amount (i.e. more than a threshold amount). In other words, the specified condition may include that the quality of the measured reference signal exceeds a specified amount that is higher than the quality of the measured reference signal received from the first wireless communication network.

If the optimal path beyond the RAN node communicating with a given UE is not specified also in terms of those energy saving objectives, the energy saving objectives of the mobile communication network may not be fully achieved for that UE. Similar to international roaming, in the case of domestic roaming, there are mainly two options for data transmission:

● Offloading data in visited PLMN, or

● The data is routed back to the home PLMN and then offloaded to the internet/application.

In other words, in accordance with embodiments of the present technology, in a first of the above options, the second (i.e., other operator's) wireless communication network (e.g., via an infrastructure device controlling a cell of the network) may be configured to receive data from the communication device after the mobility procedure has been performed, and to transmit the data received from the communication device to the core network.

In a second of the above options, in accordance with embodiments of the present technique, a first (i.e., of the home PLMN) wireless communication network (e.g., via an infrastructure equipment controlling a cell of the network) may be configured to receive data transmitted by the communication device to the second wireless communication network from the second wireless communication network after a mobility procedure has been performed, and to transmit the received data to the core network.

With respect to the second option, in terms of international roaming, this typically involves a longer data offload path due to the country boundary and the need to pass through the international gateway. However, this may not always be correct in terms of domestic roaming, as the data does not need to pass through an international gateway, and the cells of different network operators may also be very close in geographical sense. For example, it may be more meaningful that data from a user of a first PLMN connected to a cell of a different PLMN and located near the HQ location of the different PLMN is offloaded to the core network through the different PLMN to which the user's UE is connected, rather than that traffic is routed back to its home (first) PLMN. In this regard, there are three options for the arrangement according to embodiments of the present technology:

● Traffic rules may be handled like roaming, as described above. Here, the core network may be common to the first wireless communication network and the second wireless communication network;

● The RAN nodes may be interconnected to different operator core networks in a similar manner as RAN sharing (where data may be sent to any of these different core networks based on the operator cell to which the UE is connected). Here, sharing may be applicable only to selected UEs based on their sustainability profile and/or the radio conditions they are currently experiencing (i.e., UEs whose sustainability profile is not currently met or experiencing poor radio conditions may be allowed to participate in such RAN sharing, where such permissions/conditions may be configured individually for each UE via dedicated signaling). In other words, both the core network and the second wireless communication network may be controlled by a second network operator, which is different from the first network operator controlling the first wireless communication network. Here, the infrastructure equipment may transmit signals to and/or receive signals from the communication devices on behalf of both the first wireless communication network and the second wireless communication network. Further, herein, an infrastructure device may transmit signals to and/or receive signals from a communication device on behalf of both the first wireless communication network and the second wireless communication network, depending on one or both of a quality of the signals transmitted between the communication device and the infrastructure device and a sustainability profile associated with the communication device, and

● An operator packet gateway (P-GW) or data network may be interconnected to offload traffic for home UEs and to initiate from another operator's network. In other words, the data may be transmitted to a packet gateway of the core network, wherein the packet gateway is common to the first wireless communication network and the second wireless communication network. The data network may be used to provide sustainable services.

Fig. 7 shows a flow chart illustrating an example communication procedure in a communication system in accordance with an embodiment of the present technology. The process shown in fig. 7 is a method of operating a communication device.

The method starts in step S1. The method comprises, in step S2, transmitting signals to and/or receiving signals from the first wireless communication network via a first radio interface provided by the first wireless communication network when the communication device is located within the coverage area of the first wireless communication network. In step S3, the process includes determining that one or more conditions to perform the mobility procedure have been met. In step S4, the method comprises determining that the mobility procedure comprises a handover from the first wireless communication network to the second wireless communication network. Then, in step S5, the process includes performing a mobility process from the first wireless communication network to the second wireless communication network. Thereafter, at step S6, the method includes transmitting signals to and/or receiving signals from the second wireless communication network via a second radio interface provided by the second wireless communication network when the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network. The process ends at step S7.

Those skilled in the art will appreciate that the method illustrated in fig. 7 may be adapted according to embodiments of the present technology. For example, the method may include other intermediate steps, or the steps may be performed in any logical order. Although embodiments of the present technology have been described primarily by way of an example communication system shown in fig. 6, it will be apparent to those skilled in the art that they may be equally applied to other systems than those described herein.

Those skilled in the art will further appreciate that such infrastructure devices and/or communication devices defined herein may be further defined in accordance with the various arrangements and embodiments discussed in the preceding paragraphs. Those skilled in the art will further appreciate that such infrastructure devices and communication devices as defined and described herein may form part of a communication system other than those defined by the present disclosure. As will be appreciated by those skilled in the art, although embodiments of the present technology are described primarily with respect to 5G/6G technology, these embodiments of the present technology may be similarly applied to macro cells of 2G, 3G, 4G and 5G, as well as to 6G, and more broadly to these radio access technologies.

The following numbered paragraphs provide further example aspects and features of the present technology:

paragraph 1. A method of operating a communication device, the method comprising:

Transmitting signals to and/or receiving signals from a first wireless communication network via a first radio interface provided by the first wireless communication network when the communication device is located within a coverage area of the first wireless communication network;

Determining that one or more conditions to perform a mobility procedure have been met;

Determining a mobility procedure includes handing over from a first wireless communication network to a second wireless communication network, performing a mobility procedure from the first wireless communication network to the second wireless communication network, and

When the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network, signals are transmitted to and/or received from the second wireless communication network via a second radio interface provided by the second wireless communication network.

Paragraph 2. The method of paragraph 1 wherein the first wireless communication network and the second wireless communication network are controlled by different network operators.

Paragraph 3. The method of paragraphs 1 or 2 wherein signals transmitted to and/or received from the first wireless communication network are transmitted and/or received within a first frequency band and signals transmitted to and/or received from the second wireless communication network are transmitted and/or received within a second frequency band, the first frequency band being different from the second frequency band.

A method according to any of paragraphs 1 to 3, wherein the coverage area of the first wireless communication network and the coverage area of the second wireless communication network are both within a predetermined geographic area defined by a country boundary, a region boundary or a political boundary.

Paragraph 5. The method of paragraph 4 wherein the coverage area of the first wireless communication network is defined by a first public land mobile network PLMN of a first network operator within the predetermined geographic area and wherein the coverage area of the second wireless communication network is defined by a second PLMN of a second network operator within the predetermined geographic area.

Paragraph 6. The method according to any of paragraphs 1 to 5, comprising:

Non-access stratum NAS signaling is received from the core network, the NAS signaling including an indication of one or more conditions to perform mobility procedures.

Paragraph 7. The method of paragraph 6 wherein the one or more conditions to perform the mobility procedure include the signal quality received from the first wireless communication network being below a first threshold and/or the signal quality received from the second wireless communication network exceeding a second threshold.

Paragraph 8. The method of paragraphs 6 or 7 wherein the one or more conditions to perform the mobility procedure comprise a distance between the communication device and an infrastructure device of the first wireless communication network exceeding a first threshold and/or a distance between the communication device and an infrastructure device of the second wireless communication network being below a second threshold.

A method according to any of paragraphs 6 to 8, wherein the one or more conditions to perform the mobility procedure comprise an energy efficiency performance of the communication device being below a defined threshold.

Paragraph 10. The method of paragraph 9 wherein the energy efficiency performance of the communication device defines an amount of energy required to transmit the specified portion of data.

Paragraph 11. The method according to paragraphs 9 or 10, comprising:

an indication of energy efficiency performance of a communication device is received from a first wireless communication network.

Paragraph 12. The method according to any of paragraphs 9 to 11, comprising:

measuring power consumption of the communication device;

Measuring throughput of a communication device, and

Energy efficiency performance of the communication device is determined based on the measured power consumption and the measured throughput.

Paragraph 13. The method according to any of paragraphs 1 to 12, comprising:

Signaling is received from the first wireless communication network, the signaling including an indication of configuration information associated with the second wireless communication network.

Paragraph 14. The method according to paragraph 13, comprising:

Transmitting a request for signaling to a first wireless communication network,

Wherein signaling is received from the first wireless communication network in response to the transmitted request.

Paragraph 15. The method of paragraphs 13 or 14 wherein the configuration information comprises an indication of a priority of the second wireless communication network.

A method according to any of paragraphs 13 to 15, wherein the configuration information comprises an indication of one or more conditions under which the communication device is to perform the mobility procedure by switching from the first wireless communication network to the second wireless communication network.

A method according to any of paragraphs 17, wherein the mobility procedure is a handover procedure and comprises switching the communication device from the first wireless communication network to the second wireless communication network when the communication device is operating in a connected mode.

A method according to any of paragraphs 1 to 17, wherein the mobility procedure is a cell reselection procedure and comprises switching the communication device from the first wireless communication network to the second wireless communication network when the communication device is operating in an idle mode or an inactive mode.

A method according to any of paragraphs 1 to 18, wherein performing the mobility procedure comprises:

receiving a connection release message from the first wireless communication network, the connection release message indicating that the communication device is to release a connection between the communication device and the first wireless communication network,

Wherein the connection release message comprises an indicator indicating that the mobility procedure comprises a handover from the first wireless communication network to the second wireless communication network.

Paragraph 20. The method of paragraph 19 wherein the indicator explicitly identifies the second wireless communication network.

Paragraph 21. The method of paragraphs 19 or 20, wherein the indicator identifies a second frequency band, the second frequency band being a frequency band in which the communication device is to transmit signals to and/or receive signals from the second wireless communication network, and the second frequency band being different from a first frequency band in which signals transmitted to and/or received from the first wireless communication network are transmitted and/or received.

Paragraph 22. The method according to any of paragraphs 19 to 21, wherein the indicator is included in a cell reselection priority list and indicates a priority of the second wireless communication network.

Paragraph 23. The method according to any of paragraphs 19 to 22, wherein the indicator is included in a connection release message separate from the cell reselection priority list.

Paragraph 24. The method of any of paragraphs 19 to 23, wherein the indicator indicates one or more conditions under which the communication device performs the mobility procedure by switching from the first wireless communication network to the second wireless communication network.

Paragraph 25. The method according to any of paragraphs 1 to 24, comprising:

An indication of a sustainability profile associated with a communication device is received from a core network.

Paragraph 26. The method of paragraph 25 wherein the performing the mobility procedure comprises:

Transmitting an indication of the sustainability profile to the first wireless communication network, and

Based on the transmitted indication of the sustainability profile, an indication is received that the communication device is to perform a mobility procedure from the first wireless communication network to the second wireless communication network.

Paragraph 27. The method of paragraph 26 wherein the indication of the sustainability profile is transmitted as part of a RACH message within a random access control RACH resource of the first radio interface, and wherein the RACH resource is reserved for the energy efficient communication device.

A method according to any of paragraphs 25 to 27, wherein determining the mobility procedure comprises switching from the first wireless communication network to the second wireless communication network is based on satisfying both the one or more conditions and the sustainability profile to perform the mobility procedure.

Paragraph 29. The method according to any of paragraphs 1 to 28, comprising:

Performing measurements on reference signals received from a second wireless communication network, and

An indication of the performed measurement is transmitted to the first wireless communication network if the specified condition is met.

Paragraph 30. The method of paragraph 29 wherein the specified condition comprises the measured quality of the reference signal being above a threshold.

Paragraph 31. The method of paragraphs 29 or 30 wherein the specified condition comprises the quality of the measured reference signal being higher than the quality of the measured reference signal received from the first wireless communication network.

A method according to any of paragraphs 29 to 31, wherein the specified condition comprises the quality of the measured reference signal exceeding a specified amount that is higher than the quality of the measured reference signal received from the first wireless communication network.

Paragraph 33. A communication device comprising:

transceiver circuit, and

A controller circuit configured with the transceiver circuit to:

Transmitting signals to and/or receiving signals from a first wireless communication network via a first radio interface provided by the first wireless communication network when the communication device is located within a coverage area of the first wireless communication network;

Determining that one or more conditions to perform a mobility procedure have been met;

Determining a mobility procedure includes handing over from a first wireless communication network to a second wireless communication network, performing a mobility procedure from the first wireless communication network to the second wireless communication network, and

When the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network, signals are transmitted to and/or received from the second wireless communication network via a second radio interface provided by the second wireless communication network.

Paragraph 34. A circuit for a communication device comprising:

transceiver circuit, and

A controller circuit configured with the transceiver circuit to:

Transmitting signals to and/or receiving signals from a first wireless communication network via a first radio interface provided by the first wireless communication network when the communication device is located within a coverage area of the first wireless communication network;

Determining that one or more conditions to perform a mobility procedure have been met;

Determining a mobility procedure includes handing over from a first wireless communication network to a second wireless communication network, performing a mobility procedure from the first wireless communication network to the second wireless communication network, and

When the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network, signals are transmitted to and/or received from the second wireless communication network via a second radio interface provided by the second wireless communication network.

Paragraph 35. A method of operating an infrastructure equipment forming part of a first wireless communications network, the method comprising:

Transmitting signals to and/or receiving signals from a communication device via a radio interface provided by an infrastructure device when the communication device is located within a coverage area of a first wireless communication network;

performing mobility procedures with a communication device, and

The determining mobility procedure includes a handover of the communication device from the first wireless communication network to the second wireless communication network when the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network.

Paragraph 36. The method of paragraph 35 wherein the first wireless communication network and the second wireless communication network are controlled by different network operators.

Paragraph 37. The method of paragraphs 35 or 36, wherein the signals transmitted to and/or received from the communication device are transmitted and/or received within a first frequency band that is different from a second frequency band in which the communication device will transmit signals to and/or receive signals from the second wireless communication network after the mobility procedure has been performed.

A method according to any of paragraphs 35 to 37, wherein the coverage area of the first wireless communication network and the coverage area of the second wireless communication network are both within a predetermined geographic area defined by a country boundary, a region boundary or a political boundary.

Paragraph 39. The method of paragraph 38 wherein the coverage area of the first wireless communication network is defined by a first public land mobile network PLMN of a first network operator within the predetermined geographic area and wherein the coverage area of the second wireless communication network is defined by a second PLMN of a second network operator within the predetermined geographic area.

Paragraph 40. The method according to any of paragraphs 35 to 39, comprising:

An indication of an energy efficiency performance of the communication device is transmitted to the communication device, wherein the energy efficiency performance of the communication device defines an amount of energy required to transmit the specified portion of data.

Paragraph 41. The method according to any of paragraphs 35 to 40, comprising:

signaling is transmitted to the communication device, the signaling including an indication of configuration information associated with the second wireless communication network.

Paragraph 42. The method according to paragraph 41, comprising:

Receiving a request for signaling from a communication device, and

Signaling is transmitted to the communication device in response to the received request.

Paragraph 43. The method of paragraphs 41 or 42 wherein the configuration information comprises an indication of a priority of the second wireless communication network.

Paragraph 44. The method of any of paragraphs 41 to 43, wherein the configuration information comprises an indication of one or more conditions under which the communication device is to perform the mobility procedure by switching from the first wireless communication network to the second wireless communication network.

Paragraph 45. The method according to any of paragraphs 35 to 44, wherein the mobility procedure is a handover procedure and comprises the communication device being handed over from the first wireless communication network to the second wireless communication network when the communication device is operating in a connected mode.

A method according to any of paragraphs 46, wherein the mobility procedure is a cell reselection procedure and comprises switching the communication device from the first wireless communication network to the second wireless communication network when the communication device is operating in an idle mode or an inactive mode.

Paragraph 47. The method according to any of paragraphs 35 to 46, wherein performing the mobility procedure comprises:

Transmitting a connection release message to the communication device, the connection release message indicating that the communication device is to release the connection between the communication device and the infrastructure equipment,

Wherein the connection release message comprises an indicator indicating that the mobility procedure comprises a handover from the first wireless communication network to the second wireless communication network.

Paragraph 48. The method of paragraph 47 wherein the indicator explicitly identifies the second wireless communication network.

Paragraph 49. The method of paragraphs 47 or 48, wherein the indicator identifies a second frequency band, the second frequency band being a frequency band in which the communication device is to transmit signals to and/or receive signals from the second wireless communication network, and the second frequency band being different from the first frequency band in which signals transmitted to and/or received from the infrastructure device are transmitted and/or received.

Paragraph 50. The method according to any of paragraphs 47 to 49, wherein an indicator is included in the cell reselection priority list and indicates a priority of the second wireless communication network.

Paragraph 51. The method according to any of paragraphs 47 to 50, wherein the indicator is included in a connection release message separate from the cell reselection priority list.

Paragraph 52. The method according to any of paragraphs 47 to 51, wherein the indicator indicates one or more conditions under which the communication device performs the mobility procedure by switching from the first wireless communication network to the second wireless communication network.

Paragraph 53. The method according to any of paragraphs 35 to 52, wherein performing the mobility procedure comprises:

receiving an indication of a sustainability profile associated with a communication device from the communication device, and

Based on the received indication of the sustainability profile, an indication is transmitted that the communication device is to perform a mobility procedure from the first wireless communication network to the second wireless communication network.

Paragraph 54. The method of paragraph 53 wherein the indication of the sustainability profile is received as part of a RACH message within a random access control RACH resource of the radio interface and wherein the RACH resource is reserved for the energy efficient communication device.

Paragraph 55. The method according to any of paragraphs 35 to 53, comprising:

an indication of a measured reference signal received by the communication device from the second wireless communication network is received from the communication device if the specified condition is met.

Paragraph 56. The method of paragraph 55 wherein the specified condition comprises the measured quality of the reference signal being above a threshold.

Paragraph 57. The method of paragraphs 55 or 56 wherein the specified condition comprises the quality of the measured reference signal being higher than the quality of the measured reference signal received from the infrastructure equipment.

Paragraph 58. The method according to any of paragraphs 55 to 57 wherein the specified condition comprises the quality of the measured reference signal exceeding a specified amount that is higher than the quality of the measured reference signal received from the infrastructure equipment.

Paragraph 59. The method according to any one of paragraphs 35 to 58, comprising:

receiving data transmitted by the communication device to the second wireless communication network from the second wireless communication network after the mobility procedure has been performed, and

The received data is transmitted to the core network.

Paragraph 60. An infrastructure equipment forming part of a first wireless communications network, the infrastructure equipment comprising:

transceiver circuit, and

A controller circuit configured with the transceiver circuit to:

Transmitting signals to and/or receiving signals from a communication device via a radio interface provided by an infrastructure device when the communication device is located within a coverage area of a first wireless communication network;

performing mobility procedures with a communication device, and

The determining mobility procedure includes a handover of the communication device from the first wireless communication network to the second wireless communication network when the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network.

Paragraph 61. A circuit for an infrastructure device forming part of a first wireless communication network, the infrastructure device comprising:

transceiver circuit, and

A controller circuit configured with the transceiver circuit to:

Transmitting signals to and/or receiving signals from a communication device via a radio interface provided by an infrastructure device when the communication device is located within a coverage area of a first wireless communication network;

performing mobility procedures with a communication device, and

The determining mobility procedure includes a handover of the communication device from the first wireless communication network to the second wireless communication network when the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network.

Paragraph 62. A method of operating an infrastructure device forming part of a second wireless communications network, the method comprising:

Performing a mobility procedure with a communication device currently connected to a first wireless communication network for transmitting and/or receiving signals when the communication device is located within the coverage area of the first wireless communication network, wherein the mobility procedure comprises a handover of the communication device from the first wireless communication network to a second wireless communication network, and

When the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network, signals are transmitted to and/or received from the communication device via a radio interface provided by the infrastructure equipment.

Paragraph 63. The method of paragraph 62 wherein the first wireless communication network and the second wireless communication network are controlled by different network operators.

Paragraph 64. The method of paragraphs 62 or 63, wherein the signals transmitted to and/or received from the communication device are transmitted and/or received within a second frequency band, the second frequency band being different from the first frequency band in which the communication device will transmit signals to and/or receive signals from the first wireless communication network before the mobility procedure has been performed.

Paragraph 65. The method of any of paragraphs 62 to 64, wherein the coverage area of the first wireless communication network and the coverage area of the second wireless communication network are both within a predetermined geographic area defined by a country boundary, a region boundary, or a political boundary.

Paragraph 66. The method of paragraph 65 wherein the coverage area of the first wireless communication network is defined by a first public land mobile network PLMN of a first network operator within the predetermined geographic area and wherein the coverage area of the second wireless communication network is defined by a second PLMN of a second network operator within the predetermined geographic area.

Paragraph 67. The method according to any of paragraphs 62 to 66, comprising:

Receiving data from the communication device after the mobility procedure has been performed, and

Data received from the communication device is transmitted to the core network.

Paragraph 68. The method of paragraph 67 wherein the core network is common to the first wireless communication network and the second wireless communication network.

Paragraph 69. The method of paragraphs 67 or 68 wherein the data is transmitted to a packet gateway of the core network, wherein the packet gateway is common to the first wireless communication network and the second wireless communication network.

A method according to any of paragraphs 67 to 69, wherein the core network and the second wireless communication network are both controlled by a second network operator, the second network operator being different from the first network operator controlling the first wireless communication network.

Paragraph 71. The method of paragraph 70 wherein the infrastructure device transmits signals to and/or receives signals from the communication device on behalf of both the first wireless communication network and the second wireless communication network.

Paragraph 72. The method of paragraph 71 wherein the infrastructure device transmits and/or receives signals to and/or from the communication device on behalf of both the first wireless communication network and the second wireless communication network, depending on one or both of a quality of the signal transmitted between the communication device and the infrastructure device and a sustainability profile associated with the communication device.

Paragraph 73. The method according to any of paragraphs 62 to 72, comprising:

Receiving data from the communication device after the mobility procedure has been performed, and

Data received from the communication device is transmitted to the first wireless communication network for forwarding by the first wireless communication network to the core network.

Paragraph 74. An infrastructure equipment forming part of a second wireless communications network, the infrastructure equipment comprising:

transceiver circuit, and

A controller circuit configured with the transceiver circuit to:

Performing a mobility procedure with a communication device currently connected to a first wireless communication network for transmitting and/or receiving signals when the communication device is located within the coverage area of the first wireless communication network, wherein the mobility procedure comprises a handover of the communication device from the first wireless communication network to a second wireless communication network, and

When the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network, signals are transmitted to and/or received from the communication device via a radio interface provided by the infrastructure equipment.

Paragraph 75. A circuit for an infrastructure device forming part of a wireless communications network, the infrastructure device comprising:

transceiver circuit, and

A controller circuit configured with the transceiver circuit to:

performing a mobility procedure with a communication device currently connected to a first wireless communication network for transmitting and/or receiving signals when the communication device is located within the coverage area of the first wireless communication network, wherein the mobility procedure comprises a handover of the communication device from the first wireless communication network to a second wireless communication network, and

When the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network, signals are transmitted to and/or received from the communication device via a radio interface provided by the infrastructure equipment.

Paragraph 76, a wireless communication system comprising a communication device according to paragraph 33 and at least one of an infrastructure device according to paragraph 60 and an infrastructure device according to paragraph 74.

Paragraph 77. A computer program comprising instructions which, when loaded onto a computer, cause the computer to perform the method according to any of paragraphs 1 to 32, paragraphs 35 to 59 or paragraphs 62 to 73.

Paragraph 78. A non-transitory computer readable storage medium storing the computer program according to paragraph 77.

It is to be understood that the foregoing description, for clarity, has described embodiments with reference to different functional units, circuits, and/or processors. However, it will be apparent that any suitable distribution of functionality between different functional units, circuits and/or processors may be used without detracting from the implementation.

The described embodiments may be implemented in any suitable form including hardware, software, firmware or any combination of these. The described embodiments may optionally be implemented at least partly as computer software running on one or more data processors and/or digital signal processors. The elements and components of any embodiment may be physically, functionally and logically implemented in any suitable way. Indeed the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units. As such, the disclosed embodiments may be implemented in a single unit or may be physically and functionally distributed between different units, circuits and/or processors.

Although the present disclosure has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Furthermore, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognize that the various features of the described embodiments may be combined in any manner suitable for implementing the techniques.

Reference to the literature

[1]Holma H.and Toskala A,"LTE for UMTS OFDMAand SC-FDMA based radio access",John Wiley and Sons,2009.

[2]TR 38.913,"Study on Scenarios and Requirements for Next Generation Access Technologies(Release 14)",3rd Generation Partnership Project,vl4.3.0,August 2017.

[3]United Nations,“Sustainable Development Goals”,[Online],Available at:https://sdgs.un.org/goals.

Claims (78)

1. A method of operating a communication device, the method comprising:

Transmitting signals to and/or receiving signals from a first wireless communication network via a first radio interface provided by the first wireless communication network when the communication device is located within a coverage area of the first wireless communication network;

Determining that one or more conditions to perform a mobility procedure have been met;

Determining the mobility procedure includes switching from the first wireless communication network to a second wireless communication network;

Performing the mobility procedure from the first wireless communication network to the second wireless communication network, and

Transmitting signals to and/or receiving signals from the second wireless communication network via a second radio interface provided by the second wireless communication network when the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network.

2. The method of claim 1, wherein the first wireless communication network and the second wireless communication network are controlled by different network operators.

3. The method of claim 1, wherein signals transmitted to and/or received from the first wireless communication network are transmitted and/or received within a first frequency band, and signals transmitted to and/or received from the second wireless communication network are transmitted and/or received within a second frequency band, the first frequency band being different from the second frequency band.

4. The method of claim 1, wherein the coverage area of the first wireless communication network and the coverage area of the second wireless communication network are both within a predetermined geographic area defined by a country boundary, a region boundary, or a political boundary.

5. The method of claim 4, wherein the coverage area of the first wireless communication network is defined by a first public land mobile network PLMN of a first network operator within the predetermined geographic area, and wherein the coverage area of the second wireless communication network is defined by a second PLMN of a second network operator within the predetermined geographic area.

6. The method according to claim 1, comprising:

Non-access stratum NAS signaling is received from a core network, the NAS signaling including an indication of the one or more conditions to perform the mobility procedure.

7. The method of claim 6, wherein the one or more conditions to perform the mobility procedure comprise a signal quality received from the first wireless communication network being below a first threshold and/or a signal quality received from the second wireless communication network exceeding a second threshold.

8. The method of claim 6, wherein the one or more conditions to perform the mobility procedure include a distance between the communication device and an infrastructure device of the first wireless communication network exceeding a first threshold and/or a distance between the communication device and an infrastructure device of the second wireless communication network being below a second threshold.

9. The method of claim 6, wherein the one or more conditions to perform the mobility procedure include an energy efficiency performance of the communication device below a defined threshold.

10. The method of claim 9, wherein the energy efficiency performance of the communication device defines an amount of energy required to transmit a specified portion of data.

11. The method of claim 9, comprising:

an indication of the energy efficiency performance of the communication device is received from the first wireless communication network.

12. The method of claim 9, comprising:

Measuring power consumption of the communication device;

Measuring throughput of the communication device, and

The energy efficiency performance of the communication device is determined based on the measured power consumption and the measured throughput.

13. The method according to claim 1, comprising:

Signaling is received from the first wireless communication network, the signaling including an indication of configuration information associated with the second wireless communication network.

14. The method of claim 13, comprising:

Transmitting a request for the signaling to the first wireless communication network,

Wherein the signaling is received from the first wireless communication network in response to the transmitted request.

15. The method of claim 13, wherein the configuration information comprises an indication of a priority of the second wireless communication network.

16. The method of claim 13, wherein the configuration information comprises an indication of one or more conditions under which the communication device is to perform the mobility procedure by switching from the first wireless communication network to the second wireless communication network.

17. The method of claim 1, wherein the mobility procedure is a handover procedure and comprises the communication device handing over from the first wireless communication network to a second wireless communication network when the communication device is operating in a connected mode.

18. The method of claim 1, wherein the mobility procedure is a cell reselection procedure and comprises switching the communication device from the first wireless communication network to a second wireless communication network when the communication device is operating in an idle mode or an inactive mode.

19. The method of claim 1, wherein performing the mobility procedure comprises:

Receiving a connection release message from the first wireless communication network, the connection release message indicating that the communication device is to release a connection between the communication device and the first wireless communication network,

Wherein the connection release message comprises an indicator indicating that the mobility procedure comprises a handover from the first wireless communication network to the second wireless communication network.

20. The method of claim 19, wherein the indicator explicitly identifies the second wireless communication network.

21. The method of claim 19, wherein the indicator identifies a second frequency band, the second frequency band being a frequency band in which a communication device is to transmit the signal to and/or receive the signal from the second wireless communication network, and the second frequency band being different from a first frequency band in which the signal is transmitted and/or received to and/or from the first wireless communication network.

22. The method of claim 19, wherein the indicator is included in a cell reselection priority list and indicates a priority of the second wireless communication network.

23. The method of claim 19, wherein the indicator is included in a connection release message separate from a cell reselection priority list.

24. The method of claim 19, wherein the indicator indicates one or more conditions under which the communication device performs the mobility procedure by switching from the first wireless communication network to the second wireless communication network.

25. The method according to claim 1, comprising:

an indication of a sustainability profile associated with the communication device is received from a core network.

26. The method of claim 25, wherein performing the mobility procedure comprises:

Transmitting an indication of the sustainability profile to the first wireless communication network, and

Based on the transmitted indication of the sustainability profile, an indication is received that the communication device is to perform the mobility procedure from the first wireless communication network to the second wireless communication network.

27. The method of claim 26, wherein the indication of the sustainability profile is transmitted as part of a RACH message within a random access control RACH resource of the first radio interface, and wherein the RACH resource is reserved for energy efficient communication devices.

28. The method of claim 25, wherein determining the mobility procedure comprises switching from the first wireless communication network to the second wireless communication network based on satisfying both one or more conditions to perform the mobility procedure and the sustainability profile.

29. The method according to claim 1, comprising:

performing measurements of reference signals received from the second wireless communication network, and

An indication of the performed measurement is transmitted to the first wireless communication network if a specified condition is met.

30. The method of claim 29, wherein the specified condition comprises a measured quality of a reference signal being above a threshold.

31. The method of claim 29, wherein the specified condition comprises a quality of the measured reference signal being higher than a quality of the measured reference signal received from the first wireless communication network.

32. The method of claim 29, wherein the specified condition comprises a quality of the measured reference signal exceeding a specified amount that is higher than a quality of the measured reference signal received from the first wireless communication network.

33. A communication device, comprising:

transceiver circuit, and

A controller circuit configured with the transceiver circuit to:

Transmitting signals to and/or receiving signals from a first wireless communication network via a first radio interface provided by the first wireless communication network when the communication device is located within a coverage area of the first wireless communication network;

Determining that one or more conditions to perform a mobility procedure have been met;

Determining the mobility procedure includes switching from the first wireless communication network to a second wireless communication network;

Performing the mobility procedure from the first wireless communication network to the second wireless communication network, and

Transmitting signals to and/or receiving signals from the second wireless communication network via a second radio interface provided by the second wireless communication network when the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network.

34. A circuit for a communication device, comprising:

transceiver circuit, and

A controller circuit configured with the transceiver circuit to:

Transmitting signals to and/or receiving signals from a first wireless communication network via a first radio interface provided by the first wireless communication network when the communication device is located within a coverage area of the first wireless communication network;

Determining that one or more conditions to perform a mobility procedure have been met;

Determining the mobility procedure includes switching from the first wireless communication network to a second wireless communication network;

Performing the mobility procedure from the first wireless communication network to the second wireless communication network, and

Transmitting signals to and/or receiving signals from the second wireless communication network via a second radio interface provided by the second wireless communication network when the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network.

35. A method of operating an infrastructure device forming part of a first wireless communications network, the method comprising:

Transmitting signals to and/or receiving signals from a communication device via a radio interface provided by the infrastructure equipment when the communication device is located within a coverage area of the first wireless communication network;

performing mobility procedures with the communication device, and

Determining the mobility procedure includes the communication device handing over from the first wireless communication network to the second wireless communication network when the communication device is located in both a coverage area of the second wireless communication network and a coverage area of the first wireless communication network.

36. The method of claim 35, wherein the first wireless communication network and the second wireless communication network are controlled by different network operators.

37. The method of claim 35, wherein signals transmitted to and/or received from the communication device are transmitted and/or received within a first frequency band that is different from a second frequency band in which the communication device will transmit signals to and/or receive signals from the second wireless communication network after the mobility procedure has been performed.

38. The method of claim 35, wherein the coverage area of the first wireless communication network and the coverage area of the second wireless communication network are both within a predetermined geographic area defined by a country boundary, a region boundary, or a political boundary.

39. The method of claim 38, wherein the coverage area of the first wireless communication network is defined by a first public land mobile network PLMN of a first network operator within the predetermined geographic area, and wherein the coverage area of the second wireless communication network is defined by a second PLMN of a second network operator within the predetermined geographic area.

40. The method of claim 35, comprising:

Transmitting an indication of energy efficiency performance of the communication device to the communication device, wherein the energy efficiency performance of the communication device defines an amount of energy required to transmit the specified portion of data.

41. The method of claim 35, comprising:

Signaling is transmitted to the communication device, the signaling including an indication of configuration information associated with the second wireless communication network.

42. The method of claim 41, comprising:

receiving a request for said signaling from said communication device, and

The signaling is transmitted to the communication device in response to the received request.

43. A method as defined in claim 41, wherein the configuration information includes an indication of a priority of the second wireless communication network.

44. The method of claim 41, wherein the configuration information comprises an indication of one or more conditions under which the communication device is to perform the mobility procedure by switching from the first wireless communication network to the second wireless communication network.

45. The method of claim 35, wherein the mobility procedure is a handover procedure and comprises the communication device handing over from the first wireless communication network to a second wireless communication network when the communication device is operating in a connected mode.

46. The method of claim 35, wherein the mobility procedure is a cell reselection procedure and comprises switching the communication device from the first wireless communication network to a second wireless communication network when the communication device is operating in an idle mode or an inactive mode.

47. The method of claim 35, wherein performing the mobility procedure comprises:

transmitting a connection release message to the communication device, the connection release message indicating that the communication device is to release a connection between the communication device and the infrastructure device,

Wherein the connection release message comprises an indicator indicating that the mobility procedure comprises a handover from the first wireless communication network to the second wireless communication network.

48. The method of claim 47, wherein the indicator explicitly identifies the second wireless communication network.

49. The method of claim 47, wherein the indicator identifies a second frequency band, the second frequency band being a frequency band in which a communication device is to transmit the signal to and/or receive the signal from the second wireless communication network, and the second frequency band being different from a first frequency band in which the signal is transmitted to and/or received from the infrastructure device.

50. The method of claim 47, wherein the indicator is included in a cell reselection priority list and indicates a priority of the second wireless communication network.

51. The method of claim 47, wherein the indicator is included in a connection release message separate from a cell reselection priority list.

52. The method of claim 47, wherein the indicator indicates one or more conditions under which the communication device performs the mobility procedure by switching from the first wireless communication network to the second wireless communication network.

53. The method of claim 35, wherein performing the mobility procedure comprises:

Receiving an indication of a sustainability profile associated with the communication device from the communication device, and

Based on the received indication of the sustainability profile, an indication is transmitted that the communication device is to perform the mobility procedure from the first wireless communication network to the second wireless communication network.

54. The method of claim 53, wherein the indication of the sustainability profile is received as part of a RACH message within a random access control RACH resource of the radio interface, and wherein the RACH resource is reserved for energy efficient communication devices.

55. The method of claim 35, comprising:

An indication of a measured reference signal received by the communication device from the second wireless communication network is received from the communication device if a specified condition is met.

56. The method of claim 55, wherein the specified condition comprises a measured quality of a reference signal being above a threshold.

57. The method of claim 55, wherein the specified condition comprises a quality of the measured reference signal being higher than a quality of the measured reference signal received from the infrastructure device.

58. The method of claim 55, wherein the specified condition comprises a quality of the measured reference signal exceeding a specified amount that is higher than a quality of the measured reference signal received from the infrastructure device.

59. The method of claim 35, comprising:

receiving data transmitted by the communication device to the second wireless communication network from the second wireless communication network after the mobility procedure has been performed, and

The received data is transmitted to the core network.

60. An infrastructure equipment forming part of a first wireless communications network, the infrastructure equipment comprising:

transceiver circuit, and

A controller circuit configured with the transceiver circuit to:

Transmitting signals to and/or receiving signals from a communication device via a radio interface provided by the infrastructure equipment when the communication device is located within a coverage area of the first wireless communication network;

performing mobility procedures with the communication device, and

Determining the mobility procedure includes the communication device handing over from the first wireless communication network to the second wireless communication network when the communication device is located in both a coverage area of the second wireless communication network and a coverage area of the first wireless communication network.

61. A circuit for an infrastructure device forming part of a first wireless communication network, the infrastructure device comprising:

transceiver circuit, and

A controller circuit configured with the transceiver circuit to:

Transmitting signals to and/or receiving signals from a communication device via a radio interface provided by the infrastructure equipment when the communication device is located within a coverage area of the first wireless communication network;

performing mobility procedures with the communication device, and

Determining the mobility procedure includes the communication device handing over from the first wireless communication network to the second wireless communication network when the communication device is located in both a coverage area of the second wireless communication network and a coverage area of the first wireless communication network.

62. A method of operating an infrastructure device forming part of a second wireless communications network, the method comprising:

Performing a mobility procedure with a communication device currently connected to a first wireless communication network for transmitting and/or receiving signals when the communication device is located within the coverage area of the first wireless communication network, wherein the mobility procedure comprises the communication device switching from the first wireless communication network to the second wireless communication network, and

Transmitting signals to and/or receiving signals from the communication device via a radio interface provided by the infrastructure equipment when the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network.

63. The method of claim 62, wherein the first wireless communication network and the second wireless communication network are controlled by different network operators.

64. A method as defined in claim 62, wherein signals transmitted to and/or received from the communication device are transmitted and/or received within a second frequency band different from a first frequency band in which the communication device is to transmit signals to and/or receive signals from the first wireless communication network before the mobility procedure has been performed.

65. The method of claim 62, wherein the coverage area of the first wireless communication network and the coverage area of the second wireless communication network are both within a predetermined geographic area defined by a country boundary, a region boundary, or a political boundary.

66. The method of claim 65, wherein the coverage area of the first wireless communication network is defined by a first public land mobile network PLMN of a first network operator within the predetermined geographic area, and wherein the coverage area of the second wireless communication network is defined by a second PLMN of a second network operator within the predetermined geographic area.

67. The method of claim 62, comprising:

Receiving data from the communication device after the mobility procedure has been performed, and

Transmitting said data received from said communication device to a core network.

68. The method of claim 67, wherein the core network is common to the first and second wireless communication networks.

69. The method of claim 67, wherein the data is transmitted to a packet gateway of the core network, wherein the packet gateway is common to the first wireless communication network and the second wireless communication network.

70. The method of claim 67, wherein the core network and the second wireless communication network are both controlled by a second network operator, the second network operator being different from a first network operator controlling the first wireless communication network.

71. A method as defined in claim 70, wherein the infrastructure device transmits signals to and/or receives signals from the communication device on behalf of both the first wireless communication network and the second wireless communication network.

72. A method as claimed in claim 71, wherein the infrastructure device transmits signals to and/or receives signals from the communication device on behalf of both the first and second wireless communication networks, depending on one or both of the quality of the signals transmitted between the communication device and the infrastructure device and a sustainability profile associated with the communication device.

73. The method of claim 62, comprising:

Receiving data from the communication device after the mobility procedure has been performed, and

Transmitting the data received from the communication device to the first wireless communication network for forwarding by the first wireless communication network to a core network.

74. An infrastructure equipment forming part of a second wireless communication network, the infrastructure equipment comprising:

transceiver circuit, and

A controller circuit configured with the transceiver circuit to:

Performing a mobility procedure with a communication device currently connected to a first wireless communication network for transmitting and/or receiving signals when the communication device is located within the coverage area of the first wireless communication network, wherein the mobility procedure comprises the communication device switching from the first wireless communication network to the second wireless communication network, and

Transmitting signals to and/or receiving signals from the communication device via a radio interface provided by the infrastructure equipment when the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network.

75. A circuit for an infrastructure device forming part of a wireless communications network, the infrastructure device comprising:

transceiver circuit, and

A controller circuit configured with the transceiver circuit to:

Performing a mobility procedure with a communication device currently connected to a first wireless communication network for transmitting and/or receiving signals when the communication device is located within the coverage area of the first wireless communication network, wherein the mobility procedure comprises the communication device switching from the first wireless communication network to a second wireless communication network, and

Transmitting signals to and/or receiving signals from the communication device via a radio interface provided by the infrastructure equipment when the communication device is located in both the coverage area of the second wireless communication network and the coverage area of the first wireless communication network.

76. A wireless communication system comprising a communication device according to claim 33 and at least one of an infrastructure device according to claim 60 and an infrastructure device according to claim 74.

77. A computer program comprising instructions which, when loaded onto a computer, cause the computer to perform the method of any one of claims 1, 35 or 62.

78. A non-transitory computer-readable storage medium storing a computer program according to claim 77.