WO2013088398A1

WO2013088398A1 - Device to Device Communication

Info

Publication number: WO2013088398A1
Application number: PCT/IB2012/057322
Authority: WO
Inventors: Sami-Jukka Hakola; Jussi K Ojala; Jari Isokangas; Samuli Turtinen; Timo Koskela
Original assignee: Renesas Mobile Corporation
Priority date: 2011-12-16
Filing date: 2012-12-14
Publication date: 2013-06-20
Also published as: GB2497604B; GB201205320D0; GB2497604A; GB2497579A; GB201121661D0

Abstract

The present disclosure provides methods, apparatus, computer software and computer program products for use in relation to changing radio capability of user equipment. Embodiments include in response to a change of radio capability of a user equipment during active mode connection of the user equipment, transmitting, at the user equipment, a radio resource control, RRC, related signalling message including information regarding a change of radio capability of the user equipment to a base station during active mode connection. Embodiments include receiving, at a base station, a radio resource control, RRC, related signalling message including information regarding a change of radio capability of user equipment during active mode connection, the RRC related signalling message having been received in response to a change of radio capability of the user equipment during active mode connection of the user equipment.

Description

Device to Device Communication

Technical field

The present disclosure relates generally to changing radio capability of user equipment, for example in relation to Device to Device (D2D) communication in LTE (long term evolution) systems. In particular, but not exclusively, the present disclosure relates to changing radio capability temporarily or periodically in LTE systems. Background

Recently, a study item has been proposed for Device to Device communication in 3^rd Generation Partnership Project Technical Specification Group Radio Access Network, 3 GPP TSG-RAN #52 plenary, 31 May - 3 June 2011 (cf. documents [1] to [3] referenced below). According to this study item, one of the main targets is to evolve the LTE platform in order to intercept the demand of proximity-based applications by studying enhancements to the LTE radio layers that allow devices to discover each other directly over the air, and potentially communicate directly with appropriate network supervision, when this makes sense from a system management point of view. Furthermore, to provide a scalable solution, the D2D discovery procedure should work between different operators.

According to the study item described above, "this radio-based discovery process needs also to be coupled with a system architecture and a security architecture that allow the 3GPP operators to retain control of the device behaviour, for example who can emit discovery signals, when and where, what information they should carry, and what devices should do once they discover each other" (cf. document [1] referenced below).

In future LTE systems, a high capability device may have, amongst others, inter-band carrier aggregation (CA) as well as D2D capability. The inter-band CA capability together with different possible multiple-input-multiple-output (MIMO) modes per band evidently requires multiple transmitter and receiver chains at the device. D2D discovery and communication should work between different operators which introduces several challenges. It cannot be assumed that operators will exchange information as to how they manage their resources in a co-operative manner. Thus, radio resources for D2D discovery and communication will likely be decided by one operator without any agreement with other operators.

Furthermore, an operator may want to modify the resources according to its own objectives and conditions. Thus, in inter-operator D2D discovery and communication, it may only be assumed that an operator informs other operators covering the same geographical area whether they support D2D communication and in addition may give some hint as to which band they are supporting such communication on.

To support inter-operator D2D discovery function when either in RRC IDLE or RRC CONNECTED state, the device may need to roam to other operators' frequencies to listen to D2D discovery message transmissions. In RRC CONNECTED mode this would effectively reduce the capability to support early indicated capability for inter-band CA together with possible MIMO capabilities per band.

Currently, it can be assumed that a D2D capable device would indicate its radio capabilities including the D2D capability in an attach procedure.

At the radio interface level, UE's capability transfer is described in document

[4] referenced below, see for example section 5.6.3. The purpose of that procedure is to transfer radio access capability information from the UE to the E-UTRAN. If the UE has changed its E-UTRAN radio access capabilities, the UE shall request higher layers to initiate the necessary Non- Access Stratum (NAS) procedures (cf. document [5] referenced below) that would result in the update of UE radio access capabilities using a new radio resource control (RRC) connection.

Furthermore, document [6] referenced below describes methods to change radio access capabilities by an access terminal by conveying the information in a RRC connection setup message which is to be forwarded to the mobility management entity (MME).

Related documents: [1] Tdoc-RP- 110706, "On the need for a 3 GPP study on LTE device-to-device discovery and communication", Qualcomm Incorporated, 3GPP TSG-RA #52 plenary, 31 May - 3 June 2011.

[2] Tdoc-RP- 110707, "Study on LTE Device to Device Discovery and Communication - Radio Aspects", Qualcomm Incorporated, 3GPP TSG-RAN #52 plenary, 31 May - 3 June 2011.

[3] Tdoc-RP-110708, "Study on LTE Device to Device Discovery and Communication - Service and System Aspects", Qualcomm Incorporated, 3GPP TSG-RAN #52 plenary, 31 May - 3 June 2011.

[4] 3GPP TS 36.331, "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E- UTRA); Radio Resource Control (RRC); Protocol specification (Release 10), " vlO.1.0 (2011-03).

[5] 3GPP TS 23.401, ""3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access (Release 10), " vlO. 5.0 (2011-09).

[6] US 2010034094 (Al), "Access Terminal Capability Update", Qualcomm Inc. Summary

The present disclosure provides apparatus, methods, computer software and computer program products for use in relation to changing radio capability of user equipment. The present disclosure can for example be applied in relation to D2D communication.

According to first embodiments, there is a method for use in relation to changing radio capability of user equipment, the method comprising, at a user equipment:

in response to a change of radio capability of the user equipment during active mode connection of the user equipment, transmitting a radio resource control, RRC, related signalling message comprising information regarding the change of radio capability of the user equipment to a base station, wherein the RRC related signalling message further includes information as to whether the change of radio capability is temporary or periodical;

setting a time domain threshold; and

comparing the time domain threshold with either a duration of the temporary capability change or a duration of one occasion of the periodical capability change, wherein said transmittal of said RRC related signalling message is carried out in response to said comparison indicating a duration within said time domain threshold.

According to second embodiments, there is a method for use in relation to changing radio capability of user equipment, the method comprising, at a base station: receiving a radio resource control, RRC, related signalling message including information regarding a change of radio capability of a user equipment, the RRC related signalling message having been received in response to a change of radio capability of the user equipment during active mode connection of the user equipment;

in response to receipt of said RRC related signalling message, triggering a radio resource capability change procedure in relation to said user equipment, wherein the RRC related signalling message further includes information as to whether the change of radio capability is temporary or periodical;

setting a time domain threshold; and

transmitting an indication of said time domain threshold to said user equipment,

whereby said user equipment is able to compare the time domain threshold with either a duration of the temporary capability change or a duration of one occasion of the periodical capability change and transmit said RRC related signalling message received at said base station in response to said comparison indicating a duration within said time domain threshold.

According to third embodiments, there is apparatus for use in relation to changing radio capability of user equipment, the apparatus comprising a processing system adapted to, at a user equipment:

in response to a change of radio capability of the user equipment during active mode connection of the user equipment, transmit a radio resource control, RRC, related signalling message comprising information regarding the change of radio capability of the user equipment to a base station, wherein the RRC related signalling message further includes information as to whether the change of radio capability is temporary or periodical;

set a time domain threshold; and

compare the time domain threshold with either a duration of the temporary capability change or a duration of one occasion of the periodical capability change, wherein said transmittal of said RRC related signalling message is carried out in response to said comparison indicating a duration within said time domain threshold. The apparatus of the third embodiments may comprise one or more of a chipset, a radio receiver and a user equipment.

According to fourth embodiments, there is apparatus for use in relation to changing radio capability of user equipment, the apparatus comprising a processing system adapted to, at a base station:

receive a radio resource control, RRC, related signalling message including information regarding a change of radio capability of a user equipment, the RRC related signalling message having been received in response to a change of radio capability of the user equipment during active mode connection of the user equipment;

in response to receipt of said RRC related signalling message, trigger a radio resource capability change procedure in relation to said user equipment, wherein the RRC related signalling message further includes information as to whether the change of radio capability is temporary or periodical,

set a time domain threshold; and

transmit an indication of said time domain threshold to said user equipment, whereby said user equipment is able to compare the time domain threshold with either a duration of the temporary capability change or a duration of one occasion of the periodical capability change and transmit said RRC related signalling message received at said base station in response to said comparison indicating a duration within said time domain threshold.

According to fifth embodiments, there is computer software adapted to perform the method of the first embodiments. According to sixth embodiments, there is computer software adapted to perform the method of the second embodiments.

According to seventh embodiments, there is a computer program product comprising a non-transitory computer-readable storage medium having computer readable instructions stored thereon, the computer readable instructions being executable by a computerized device to cause the computerized device to perform a method for use in relation to changing radio capability of user equipment according to the first embodiments.

According to eighth embodiments, there is a computer program product comprising a non-transitory computer-readable storage medium having computer readable instructions stored thereon, the computer readable instructions being executable by a computerized device to cause the computerized device to perform a method for use in relation to changing radio capability of user equipment according to the second embodiments.

Further features and advantages will become apparent from the following description of preferred embodiments, given by way of example only, which is made with reference to the accompanying drawings

Brief Description of the Drawings

The above and other objects, features, details and advantages will become more fully apparent from the following detailed description of embodiments which is to be taken in conjunction with the appended drawings, in which:

Fig. 1 shows apparatus according to embodiments of the present disclosure; and

Fig. 2 shows apparatus according to embodiments of the present disclosure.

Detailed Description

In the following, embodiments of the present disclosure are described by referring to general and specific examples of the embodiments. It is to be understood, however, that the description is given by way of example only, and that the described embodiments are by no means to be understood as limiting the present disclosure thereto. According to aspects of the present disclosure, it is proposed to define a new RRC signaling procedure between a device and an evolved node B (eNB) by means of which the device can dynamically indicate the change of its capability during active mode connection (RRC CONNECTED) .

Furthermore, the change can be temporary or periodical which shall be indicated by the D2D device. Such an indication, whether the capability change is temporary or periodical, includes information about how long the capability change would be effective. In the periodical case, the device shall inform the period and duration of capability change per each capability change occasion. The periodicity shall reflect the periodicity of the D2D discovery function to take place for instance on radio resources of the other operator. In contrast to current specified behavior, where a device requests higher layers to initiate the necessary NAS procedures for changing its capabilities (cf. document [4] referenced above for example), an RRC level capability change procedure could be applied between the eNB and the device. The eNB would then use the temporary or periodical capability change(s) in the scheduling decisions for that specific device.

While it can be assumed that a D2D device has indicated its radio capabilities including the D2D capability in an attach procedure and that D2D discovery may be performed in the RRC IDLE state too, the D2D device shall include aforementioned information about temporary or periodical radio capability change (lowered inter-band CA capability as an example) in the RRC connection setup message exchange with the eNB.

Furthermore, the temporary and periodical change in radio capability information does not need to be conveyed to the MME but could be considered as temporary or periodical scheduling restrictions, lower allowed MIMO modes on certain bands in case of inter-band CA, etc.

Furthermore, there could be a time domain threshold, or other limits within which the signaled temporary capability change indicated by the device remains just as a scheduling or resource allocation restriction at the eNB for the device in question. Based on the time domain threshold, a decision can be made whether to use the conventional method or the method according to the present disclosure. In this regard, the device compares either the duration of the temporary capability change or the duration of one occasion of the periodical capability change accordingly with the threshold, and if the duration is less than the threshold, the device selects the method according to the present disclosure. Otherwise, the device selects the conventional method.

Otherwise, the conventional procedure could be triggered to change the capability also in the MME. To provide such functionality points to different needs in D2D communication:

Periodical and temporary capability change could be useful in D2D discovery phase

- Conventional capability change procedures could make sense when the device starts a D2D communication taking place on another operator's band that continuously requires a certain amount of transmitter chains and receiver chains

According to embodiments of the present disclosure, there are provided means for temporary and periodical capability change due to inter-operator D2D communication. In addition, the proposal could be seen as a new trigger for the capability change procedure.

Furthermore, according to embodiments of the present disclosure it could be decided whether to use a conventional capability change procedure or the above proposed new procedure that takes place just between the eNB and device, for example, based on the time domain threshold.

Information about temporary or periodical capability change or periodical required scheduling restriction due to D2D discovery taking place on another operator's spectrum could be included in the RRCConnectionSetupComplete message in the state transition from RRC IDLE to RRC CONNECTED state. This could be implemented as a new non-critical extension field to be used by D2D devices.

The proposed time domain threshold could be indicated in the system information block (SIB) used to convey D2D specific common information in a cell, thus decided by the eNB/RAN. Using the broadcast threshold, the device will decide whether to include proposed information into the RRC message without triggering NAS for capability change, or just use the conventional capability change procedure to reach the MME too. In RRC CONNECTED state, the proposed information about temporary or periodical capability change could be sent via R C message or MAC Control Element (CE); the latter may limit how much information can be transmitted.

Temporary or periodical capability change could be indicated per supported band given in the initial capability. One example could be lowering the MIMO capability on a certain band.

Hence, according to embodiments of the present disclosure, there is proposed signaling to provide a scheduler with information about temporary or periodical capability restriction due to inter-operator D2D communication.

Fig. 1 shows a principle configuration of an example of an apparatus according to certain embodiments of the present disclosure. One option for implementing this example of an apparatus according to certain embodiments of the present disclosure would be a component in a handset such as user equipment UE according to LTE.

Specifically, as shown in Fig. 1 , the example of an apparatus 10 comprises at least one processor 11 (or processing system), and at least one memory 12 including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to, in response to a change of radio capability of a user equipment during active mode connection of the user equipment, transmit a radio resource control, RRC, related signalling message comprising information regarding the change of radio capability of the user equipment to a base station.

In embodiments, the RRC related signalling message further includes information as to whether the change of radio capability is temporary or periodical.

Embodiments may comprise, at the user equipment, setting a time domain threshold, and comparing the time domain threshold with either a duration of the temporary capability change or a duration of one occasion of the periodical capability change. In such embodiments, the transmittal of the RRC related signalling message is carried out in response to the comparison indicating a duration within said time domain threshold.

In alternative embodiments, the transmittal of the RRC related signalling message is not carried out in response to the comparison indicating a duration outside the time domain threshold. In such embodiments, the user equipment cancels transmittal of the R C related signalling message to the base station. In such embodiments, conventional capability change procedures such as NAS procedures can be employed.

In embodiments, the time domain threshold to be set is indicated to the user equipment in a system information block, SIB. The time domain threshold may be stored in memory 12.

In embodiments, the RRC related signalling message comprises a RRC connection setup complete message or a media access control, MAC, control element.

In embodiments, the RRC related signalling message comprises an RRC connection setup complete message and the information regarding the change of radio capability of the user equipment is inserted into a non-critical extension field of the RRC connection setup complete message.

In embodiments, the change of radio capability occurs due to one or more device-to-device discovery functions of the user equipment.

In embodiments, the temporary or periodical change of radio capability is indicated in the RRC related signalling message per supported band.

In embodiments, the change of radio capability comprises a change in one or more of an inter-band carrier aggregation capability, and a Multiple-Input Multiple- Output, MIMO, capability. In such embodiments, the change of radio capability may comprise a decrease or an increase of an inter-band carrier aggregation capability and/or a MIMO capability.

Fig. 2 shows another principle configuration of an example for an apparatus according to certain embodiments of the present disclosure. One option for implementing this example of an apparatus according to certain embodiments of the present disclosure would be a component in a base station such as an eNB according to LTE.

Specifically, as shown in Fig. 2, the example of an apparatus 20 comprises at least one processor 21 (or processing system), and at least one memory 22 including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to receive a radio resource control, RRC, related signalling message including information regarding a change of radio capability of a user equipment, the R C related signalling message having been received in response to a change of radio capability of the user equipment during active mode connection of the user equipment.

In embodiments, in response to receipt of the RRC related signalling message, a radio resource capability change procedure is triggered in relation to the user equipment.

Some embodiments comprise, at a base station, setting a time domain threshold, and transmitting an indication of the time domain threshold to the user equipment. In such embodiments, the user equipment is able to compare the time domain threshold with either a duration of the temporary capability change or a duration of one occasion of the periodical capability change and transmit the RRC related signalling message received at the base station in response to the comparison indicating a duration within the time domain threshold. Such embodiments involve the user equipment deciding, at least on the basis of the time domain threshold, whether to inform the base station about a radio capability change.

Other embodiments comprise, at a base station, setting a time domain threshold, transmitting an indication of the time domain threshold to the user equipment, and comparing the time domain threshold with either a duration of the temporary capability change or a duration of one occasion of the periodical capability change. In some embodiments, the triggering of the radio resource capability change procedure in relation to the user equipment is carried out in response to the comparison indicating a duration within the time domain threshold. In some embodiments, the triggering of the radio resource capability change procedure in relation to the user equipment is not carried out in response to the comparison indicating a duration outside the time domain threshold. Such embodiments involve the base station deciding, at least on the basis of the time domain threshold, how to react upon receipt of the RRC related signalling message from the user equipment, i.e. whether to trigger a radio resource capability change procedure in relation to the user equipment or not.

In embodiments, the indication of the time domain threshold is comprised in a system information block, SIB, transmitted to the user equipment from the base station. The time domain threshold may be stored in memory 22. In the foregoing exemplary description of the apparatuses, only the units that are relevant for understanding the principles of embodiments have been described using functional blocks. The apparatus may comprise further units that are necessary for its respective operation. However, a description of these units is omitted in this specification. The arrangement of the functional blocks of the devices is not construed to limit embodiments, and the functions may be performed by one block or further split into sub-blocks.

For the purpose of the present disclosure as described herein above, it should be noted that:

- method steps likely to be implemented as software code portions and being run using a processor at a user equipment or base station (as examples of devices, apparatuses and/or modules thereof, or as examples of entities including apparatuses and/or modules therefore), are software code independent and can be specified using any known or future developed programming language as long as the functionality defined by the method steps is preserved;

- generally, any method step is suitable to be implemented as software or by hardware without changing the idea of the embodiments and its modification in terms of the functionality implemented;

- method steps and/or devices, units or means likely to be implemented as hardware components at the above-defined apparatuses, or any module(s) thereof, (e.g., devices carrying out the functions of the apparatuses according to the embodiments as described above) are hardware independent and can be implemented using any known or future developed hardware technology or any hybrids of these, such as MOS (Metal Oxide Semiconductor), CMOS (Complementary MOS), BiMOS (Bipolar MOS), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled Logic), TTL (Transistor- Transistor Logic), etc., using for example ASIC (Application Specific IC (Integrated Circuit)) components, FPGA (Field-programmable Gate Arrays) components, CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components;

- devices, units or means (e.g. the above-defined apparatuses and user equipments, or any one of their respective units/means) can be implemented as individual devices, units or means, but this does not exclude that they are implemented in a distributed fashion throughout the system, as long as the functionality of the device, unit or means is preserved;

- an apparatus may be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of an apparatus or module, instead of being hardware implemented, be implemented as software in a (software) module such as a computer program or a computer program product comprising executable software code portions for execution/being run on a processor;

- a device may be regarded as an apparatus or as an assembly of more than one apparatus, whether functionally in cooperation with each other or functionally independently of each other but in a same device housing, for example.

In general, it is to be noted that respective functional blocks or elements according to above-described aspects can be implemented by any known means, either in hardware and/or software, respectively, if it is only adapted to perform the described functions of the respective parts. The mentioned method steps can be realized in individual functional blocks or by individual devices, or one or more of the method steps can be realized in a single functional block or by a single device.

Generally, any method step is suitable to be implemented as software or by hardware without changing the ideas of embodiments. Devices and means can be implemented as individual devices, but this does not exclude that they are implemented in a distributed fashion throughout the system, as long as the functionality of the device is preserved. Such and similar principles are to be considered as known to a skilled person.

Software in the sense of the present description comprises software code as such comprising code means or portions or a computer program or a computer program product for performing the respective functions, as well as software (or a computer program or a computer program product) embodied on a tangible medium such as a computer-readable (storage) medium having stored thereon a respective data structure or code means/portions or embodied in a signal or in a chip, potentially during processing thereof.

The above embodiments are to be understood as illustrative examples of embodiments. Further embodiments are envisaged. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.

Claims

1. A method for use in relation to changing radio capability of user equipment, the method comprising, at a user equipment:

setting a time domain threshold; and

2. A method according to claim 1, wherein said transmittal of said RRC related signalling message is not carried out in response to said comparison indicating a duration outside said time domain threshold.

3. A method according to claim 1 or 2, comprising receiving a system information block, SIB, indicating said time domain threshold to be set.

4. A method according to any preceding claim, wherein the RRC related signalling message comprises a RRC connection setup complete message or a media access control, MAC, control element.

5. A method according to any preceding claim, wherein the RRC related signalling message comprises an RRC connection setup complete message and said information regarding the change of radio capability of the user equipment is inserted into a non-critical extension field of said RRC connection setup complete message.

6. A method according to any preceding claim, wherein the change of radio capability occurs due to one or more device-to-device discovery functions of the user equipment.

7. A method according to any preceding claim, wherein said temporary or periodical change of radio capability is indicated in said RRC related signalling message per supported band.

8. A method according to any preceding claim, wherein said change of radio capability comprises a change in one or more of:

an inter-band carrier aggregation capability, and

a Multiple-Input Multiple-Output, MIMO, capability.

9. A method according to claim 8, wherein said change of radio capability comprises a decrease or an increase of an inter-band carrier aggregation capability and/or a MIMO capability.

10. A method for use in relation to changing radio capability of user equipment, the method comprising, at a base station:

receiving a radio resource control, RRC, related signalling message including information regarding a change of radio capability of a user equipment, the RRC related signalling message having been received in response to a change of radio capability of the user equipment during active mode connection of the user equipment;

setting a time domain threshold; and

transmitting an indication of said time domain threshold to said user equipment, whereby said user equipment is able to compare the time domain threshold with either a duration of the temporary capability change or a duration of one occasion of the periodical capability change and transmit said RRC related signalling message received at said base station in response to said comparison indicating a duration within said time domain threshold.

11. A method according to claim 10, further comprising:

setting a time domain threshold;

transmitting an indication of said time domain threshold to said user equipment; and

comparing the time domain threshold with either a duration of the temporary capability change or a duration of one occasion of the periodical capability change, wherein said triggering of said radio resource capability change procedure in relation to said user equipment is carried out in response to said comparison indicating a duration within said time domain threshold.

12. A method according to claim 11, wherein said triggering of said radio resource capability change procedure in relation to said user equipment is not carried out in response to said comparison indicating a duration outside said time domain threshold.

13. A method according to any of claims 10 to 12, wherein said indication of said time domain threshold is comprised in a system information block, SIB, transmitted to said user equipment.

14. A method according to any of claims 10 to 13, wherein the RRC related signalling message comprises a RRC connection setup complete message or a media access control, MAC, control element.

15. A method according to any of claims 10 to 14, wherein the RRC related signalling message comprises an RRC connection setup complete message and said information regarding the change of radio capability of the user equipment is comprised in a non-critical extension field of said RRC connection setup complete message.

16. A method according to any of claims 10 to 15, wherein the change of radio capability occurs due to device-to-device discovery functions of the user equipment.

17. A method according to any of claims 10 to 16, wherein said temporary or periodical change of radio capability is indicated in said RRC related signalling message per supported band.

18. A method according to any of claims 10 to 17, wherein the change of radio capability comprises a change in one or more of:

an inter-band carrier aggregation capability, and

a MIMO capability.

19. A method according to claim 18, wherein said radio capability change comprises a decrease or an increase of an inter-band carrier aggregation capability and/or a MIMO capability.

20. Apparatus for use in relation to changing radio capability of user equipment, the apparatus comprising a processing system adapted to, at a user equipment:

set a time domain threshold; and

compare the time domain threshold with either a duration of the temporary capability change or a duration of one occasion of the periodical capability change, wherein said transmittal of said RRC related signalling message is carried out in response to said comparison indicating a duration within said time domain threshold.

21. Apparatus according to claim 20, wherein said transmittal of said RRC related signalling message is not carried out in response to said comparison indicating a duration outside said time domain threshold.

22. Apparatus according to claim 20 or 21, the processing system being adapted to receive a system information block, SIB, indicating said time domain threshold to be set.

23. Apparatus according to any of claims 20 to 22, wherein the RRC related signalling message comprises a RRC connection setup complete message or a media access control, MAC, control element.

24. Apparatus according to any of claims 20 to 23, wherein the RRC related signalling message comprises an RRC connection setup complete message and said information regarding the change of radio capability of the user equipment is inserted into a non-critical extension field of said RRC connection setup complete message.

25. Apparatus according to any of claims 20 to 24, wherein the change of radio capability occurs due to one or more device-to-device discovery functions of the user equipment.

26. Apparatus according to any of claims 20 to 25, wherein said temporary or periodical change of radio capability is indicated in said RRC related signalling message per supported band.

27. Apparatus according to any of claims 20 to 26, wherein said change of radio capability comprises a change in one or more of: an inter-band carrier aggregation capability, and

a Multiple-Input Multiple-Output, MIMO, capability.

28. Apparatus according to claim 27, wherein said change of radio capability comprises a decrease or an increase of an inter-band carrier aggregation capability and/or a MIMO capability.

29. Apparatus for use in relation to changing radio capability of user equipment, the apparatus comprising a processing system adapted to, at a base station: receive a radio resource control, RRC, related signalling message including information regarding a change of radio capability of a user equipment, the RRC related signalling message having been received in response to a change of radio capability of the user equipment during active mode connection of the user equipment;

set a time domain threshold; and

30. Apparatus according to claim 29, the processing system being adapted to:

set a time domain threshold;

transmit an indication of said time domain threshold to said user equipment; and compare the time domain threshold with either a duration of the temporary capability change or a duration of one occasion of the periodical capability change, wherein said triggering of said radio resource capability change procedure in relation to said user equipment is carried out in response to said comparison indicating a duration within said time domain threshold.

31. Apparatus according to claim 30, wherein said triggering of said radio resource capability change procedure in relation to said user equipment is not carried out in response to said comparison indicating a duration outside said time domain threshold.

32. Apparatus according to any of claims 29 to 31, wherein said indication of said time domain threshold is comprised in a system information block, SIB, transmitted to said user equipment.

33. Apparatus according to any of claims 29 to 32, wherein the RRC related signalling message comprises a RRC connection setup complete message or a media access control, MAC, control element.

34. Apparatus according to any of claims 29 to 33, wherein the RRC related signalling message comprises an RRC connection setup complete message and said information regarding the change of radio capability of the user equipment is comprised in a non-critical extension field of said RRC connection setup complete message.

35. Apparatus according to any of claims 29 to 34, wherein the change of radio capability occurs due to device-to-device discovery functions of the user equipment.

36. Apparatus according to any of claims 29 to 35, wherein said temporary or periodical change of radio capability is indicated in said RRC related signalling message per supported band.

37. Apparatus according to any of claims 29 to 36, wherein the chang radio capability comprises a change in one or more of:

an inter-band carrier aggregation capability, and

a MIMO capability.

38. Apparatus according to claim 37, wherein said radio capability change comprises a decrease or an increase of an inter-band carrier aggregation capability and/or a MIMO capability.

39. Computer software adapted to perform the method of any of claims 1 to 9.

40. Computer software adapted to perform the method of any of claims 10 to 19.

41. A computer program product comprising a non-transitory computer- readable storage medium having computer readable instructions stored thereon, the computer readable instructions being executable by a computerized device to cause the computerized device to perform a method for use in relation to changing radio capability of user equipment according to any of claims 1 to 9.

42. A computer program product comprising a non-transitory computer- readable storage medium having computer readable instructions stored thereon, the computer readable instructions being executable by a computerized device to cause the computerized device to perform a method for use in relation to changing radio capability of user equipment according to any of claims 10 to 19.

43. Apparatus according to any of claims 20 to 28, wherein the apparatus comprises a chipset.

44. Apparatus according to any of claims 20 to 28, wherein the apparatus comprises a radio receiver.

45. Apparatus according to any of claims 20 to 28, wherein the apparatus comprises a user equipment.