GB2493724A

GB2493724A - Releasing or suspending EDCH resource to cause cell reselection when a mobile terminal is causing adjacent cell interference.

Info

Publication number: GB2493724A
Application number: GB1114029.0A
Authority: GB
Inventors: Brian Alexander Martin; Keiichi Kubota; Tao Chen
Original assignee: Renesas Mobile Corp
Current assignee: Renesas Electronics Corp
Priority date: 2011-08-15
Filing date: 2011-08-15
Publication date: 2013-02-20
Anticipated expiration: 2031-08-15
Also published as: GB201114029D0; CN103891350A; GB2493724B; WO2013024443A1

Abstract

A method, apparatus and computer program product are provided in order to trigger a reselection of a serving cell 12 in an instance in which a mobile terminal 10 may be creating adjacent or neighbour cell 16 interference. Based upon received reselection data, the mobile terminal may modify, release and/or suspend a network resource, such as an enhanced dedicated channel EDCH, in order to trigger a reselection of a new serving cell. The method also includes causing a reselection of a serving cell.

Description

Wireless Communications Cell Reselection

Technical Field

Embodiments of the present invention relate generally to wireless communications and, more particularly, although not exclusively, to suspension and/or release of a resource for triggering reselection of a serving cell.

Background

The communications between a mobile terminal and a serving cell, such as the uplink communications from the mobile terminal to the serving cell, may sometimes create interference with neighbor cells. This interference may inhibit the operation of the neighbor cells or may at least cause the mobile terminal and/or the neighbor cells to operate less efficiently. In some operational states, such as a CELL DCH state, the mobile terminal and the serving cell may monitor the neighbor cells in such a manner that instances of neighbor cell interference may be identified and the operation of thc mobile terminal and/or the serving cell may be modified in such a manner as to reduce the potential for the neighbor cdl interference. Indeed, in the CELL_DCH state, the neighbor cells may be added to the active set so as to be involved in uplink power control. In this regard, the mobile terminal may receive signals from the sen'ing cell as well as from the neighbor cells. As such, neighbor cells may identil instances in which the mobilc terminal is creating interference such that the mobile terminal may reduce its uplink power in an effort to correspondingly reduce the neighbor cell interference. More particularly, for a mobile terminal operating in a CELL DCH state, the uplink powcr from the mobile terminal may be controlled via relative grants from neighbor cells within the active set of the mobile terminal.

In other operational states, however, the mobile terminal may not communicate with the neighbor cells in the same manner and, as such, may not be able to identiTy instances of potential neighbor cell interference. For example, a mobile terminal in a CELL FACH state may only receive signals from the serving cell. As such, in instances in which the mobile terminal is creating interference for the neighbor cells, the neighbor cells are unable to communicate with the mobile terminal in order to request that the power, such as the uplink power, be reduced in an effort to correspondingly reduce the neighbor cell interference. For example, in contrast to the relative grants from neighbor cells to a mobile terminal in a CELL DCH state that serve to control the uplink power, a mobile terminal operating in the CELL FACH state may not have similar control of its uplink power since the uplink power of the mobile terminal may only be controlled by the serving cell using absolute grants without consideration of possible neighbor cell interference. As such, a mobile terminal that is creating neighbor cell interference may impair the operation of the neighbor cells and, in some instances, may suffer from radio link failure.

In Release 8 of the Third Generation Partnership Project (3GPP) specification, an enhanced uplink for a mobile terminal in the CELL FACE state in the idle mode was introduced. This enhanced uplink is termed a common enhanced dedicated channel (Common E-DCH). As such, mobile terminals may utilize the E-DCH in other radio resource control (RRC) states in addition to or other than the CELL_DCH state. Notwithstanding the potential for the neighbor cell interference to be created by the uplink transmissions of a mobile terminal in the CELL_FACE state, it is anticipated that mobile terminals will frequently operate in the 1 5 CELL FACH state, such as to perform infrequent or bursty data transmissions, and that operation of mobile terminals in the CELL_FACE state may increase as a result of the introduction of the E-DCH. As such, the issues relating to potential neighbor cell interference while a mobile terminal is operating in the CELL_FACH state may also become more frequent and problematic.

A number of signaling based methods have been proposed in an effort to provide some measure of interference control for the neighbor cells in instances in which a mobile terminal is operating in the CELL_FACH state. However the proposals have generally suffered from various drawbacks including, for example, increased complexity for the mobile terminal and/or the serving cell or the failure to address all use cases or scenarios.

Summary

A method, apparatus and computer program product are therefore generally provided (according to an example embodiment to be described) in order to trigger a reselection of a serving cell in an instance in which a mobile terminal may be creating interference with a neighbor cell. Based upon received reselection data, the mobile terminal may release and/or suspend a network resource, such as an enhanced dedicated channel (E-DCH), in order to trigger a reselection of a new serving cell. In one embodiment, the method, apparatus and computer program product may trigger reselection of a new cell in an instance in which neighbor cell interference has been potentially created while the mobile terminal is in the CELL FACH state.

As such, the method, apparatus and computer program product of example embodiments of the present invention may reduce neighbor cell interference, thereby improving overall system performance.

According to a first aspect, a wireless communications method comprises determining based on reselection data the presence of a cell reseleetion condition, in an instance in which a cell reselection condition is determined to be present, causing a network resource to be modified, and causing a reselection of a serving cell.

According to a second aspect, an apparatus comprises processing means arranged to: determine based on received reselection data the presence of a cell reselection condition, in an instance in which a cell reselection condition is determined to be present, cause a network resource to be modified, and cause a reselection of a serving cell.

According to a third aspect, a method comprises determining the presence of uplink 1 5 interference while a mobile terminal is in a CELL EACH statc, in an instance where the presence of uplink interference is determined, causing an enhanced dedicated channel "E-DCH" to be modified, and causing a reselection of a serving cell.

According to a fourth aspect, a computer program product is provided that includes at least one computer-readable storage medium having computer-readable program instructions stored therein, the computer-readable program instructions including program instructions configured, when executed, to determine based on reselection data the presence of a reselection condition, in an instance in which the reselection condition is determined to be present, cause a network resource to be modified, and cause a reselection of a serving cell.

According to a fifth aspect, a computer program product is provided that includes at least computer-readable storage medium having computer-readable program instructions stored therein, the computer-readable program instructions including program instructions configured, when executed, to determine the presence of uplink interfercnce while a mobile terminal is in a CELL_EACH state, in an instance in which the presence of uplink interference is determined, to cause an E-DCH to be modified, and to cause a reselcction of a serving cell.

Further aspccts and embodiments will become apparent from the following description and claims.

Brief Description of the Drawing

Having thus described the example embodiments of the invention in general terms, refcrenee will now be made to the accompanying drawings, which are not necessarily drawn to scale, and rhercin Figure I is a schematic representation of a system having a serving cell and one or more neighbor cells that may experience interference created by the mobile terminal and that may benefit from an embodiment ofthe present invention; Figure 2 is a block diagram of an apparatus that may be embodied by a mobile terminal in accordance with one embodiment of the present invention; Figure 3 is a flow chart illustrating operations performed in accorthmce with one embodiment of the present invention; and Figure 4 is a flow diagram illustrating the flow chart of operations performed in accordance with another embodiment of the present invention.

Detailed Description

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the inventions are shown.

Indeed, these inventions may be embodied in many different forms and should not be consmted as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.

As used in this application, the term circuitry' refers to all of the following: (a)hardware-only circuit implementations (such as implementations in only analog andIor digital circuitry) and (b) to combinations of circuits and software (and/or firmware), such as (as applicable): (i) to a combination of processor(s) or (ii) to portions of processor(s)/software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) to circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.

This definition of circuitry' applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term "circuitry" would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term "circuitry" would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit or application specific integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, or other network device.

A method, apparatus and computer program product of an example embodiment of the present invention are configured to determine instances in which a mobile terminal may be creating neighbor cell interference, such as a result of interference created by uplink transmissions from the mobile terminal to a serving cell. In accordance with an example embodiment, a network resource, such as an E-DCFI, may be modified (e.g., suspended and/or released) by the mobile terminal that may be creating neighbor cell interference. Based upon the modified network resource, the mobile terminal may select a new serving cell in an effort to reduce neighbor cell interference. In one embodiment, the mobile terminal identifies the potential for neighbor cell interference while in the CELL_FACH state, thereby permitting neighbor cell interference to be reduced or othenvise addressed even while the mobile terminal is in the CELL_FACE state.

Although the method, apparatus and computer program product may be implemented in a variety of different systems, one example of such a system is shown in Figure 1, which includes a first communication device (e.g., mobile terminal 10) that is capable of communication via a serving cell 12, such as a base station, a Node B, an evolved Node B (eNB) or other access point, with a network 14 (e.g., a core network). While the network may be configured in accordance with Long Term Evolution (LTE) or LTE-Advanced (LTE-A), other networks may support the method, apparatus and computer program product of embodiments of the present invention including those configured in accordance with wideband code division multiple access (W-CDMA), CDMA2000, global system for mobile communications (GSM), general packet radio service (GPRS) and/or the like.

The network 14 may include a collection of various different nodes, devices or functions that may be in communication with each other via corresponding wired and/or wireless interfaces. For example, the network may include one or more cells, including serving cell 12 and one or more neighbor cells 6 (designated neighbor cell I, neighbor cell 2,.. neighbor cell n in the embodiment of Figure I), each of which may serve a respective coverage area. The serving cell and the neighbor cells could be, for example, part of one or more cellular or mobile networks or public land mobile networks (PLMNs). In turn, other devices such as processing devices (e.g., personal computers, server computers or the like) may be coupled to the mobile terminal I 0 and!or other communication devices via the network.

A communication device, such as the mobile terminal 10 (also known as user equipment (UE)), may be in communication with other communication devices or other devices via the serving cell 12 and, in turn, the network 14. In some cases, the communication device may include an antenna for transmitting signals to and for receiving signals from a serving cell.

In sonic example embodiments, the mobile terminal 10 may be a mobile communication device such as, for example, a mobile telephone, a portable digital assistant (PDA), a pager, a laptop computer, or any of numerous other hand held or portable communication devices, computation devices, content generation devices, content consumption devices, or combinations thereof As such, the mobile terminal I 0 may include one or more processors that may define processing circuitry either alone or in combination with one or more memories. The processing circuitry may utilize instructions stored in the memory to cause the mobile terminal 10 to operate in a particular way or execute specific functionality when the instructions are executed by the one or more processors. The mobile terminal 10 may also include communication circuitry and corresponding hardware/software to enable communication with other devices and/or the network 14.

In one embodiment, for example, the mobile terminal 10 and/or the serving cell 12 may be embodied as or otherwise include an apparatus 20 as generically represented by the block diagram of Figure 2. While the apparatus 20 may be employed, for example, by a mobile terminal 10 or a serving cell 12, it should be noted that the components, devices or elements described below may not be mandatory and thus some may be omitted in certain embodiments.

Additionally, some embodiments may include further or different components, devices or elements beyond those shown and described herein.

As shown in Figure 2, the apparatus 20 may include or otherwise be in communication with processing circuitry 22 that is configurable to perform actions in accordance \vith example embodiments described herein. The processing circuitry may be configured to perform data processing, application execution and/or other proccssing and management services according to an example embodiment of the present invention. In some embodiments, the apparatus or the processing circuitry may be embodied as a chip or chip set. In other words, the apparatus or the processing circuitry may comprise one or more physical packages (e.g., chips) including materials, components and/or wires on a structural assembly (e.g., a baseboard). The structural assembly may provide physical strength, conservation of size, and/or limitation of electrical interaction for component circuitry included thereon. The apparatus or the processing circuitry may therefore, in some cases, be configured to implement an embodiment of the present invention on a single chip or as a single "system on a chip." As such, in some cases, a chip or chipset may constitute means for performing one or more operations for providing the functionalities described herein.

In an example embodiment, the processing circuitry 22 may include a processor 24 and memory 28 that may be in communication with or otherwise control a communication interface 26 and, in some cases, a user interface 30. As such, the processing circuitry may be embodied as a circuit chip (e.g., an integrated circuit chip) configured (e.g., with hardware, software or a combination of hardware and software) to perform operations described herein. However, in some embodiments taken in the context of the mobile terminal 10, the processing circuitry may be embodied as a portion of a mobile computing device or other mobile terminal.

The user interface 30 (if implemented) may be in communication with the processing circuitry 22 to receive an indication of a user input at the user interface andIor to provide an audible, visual, mechanical or other output to the user. As such, the user interface may include, for example, a keyboard, a mouse, a joystick, a display, a touch screen, a microphone, a speaker, and/or other input/output mechanisms. The apparatus 20 need not always include a user interthce. For example, in instances in which the apparatus is embodied as a serving cell 12, the apparatus may not include a user interface. As such, the user interface is shown in dashed lines in Figure 2.

The communication intcrface 26 may include one or more interface mechanisms for enabling communication with other devices and/or networks. In some cases, the communication interface may be any means such as a device or circuitry embodied in either hardware, or a combination of hardware and software that is configured to receive and/or transmit data from/to a network 14 and/or any other device or module in communication with the processing circuitry 22, such as between the mobile terminal 10 and the serving cell 12. In this regard, the communication interface may include, for example, an antenna (or multiple antennas) and supporting hardware and/or software for enabling communications with a wireless communication network and/or a communication modem or other hardware/sofhvare for supporting communication via cable, digital subscriber line (DSL), universal serial bus (USB), Ethernet or other methods.

In an example embodiment, the memory 28 may include one or more non-transitory memory devices such as, for example, volatile and/or non-volatile memory that may be either fixed or removable. The memory may be configured to store information, data, applications, instructions or the like for enabling the apparatus 20 to carry out various ftinctions in accordance with example cmbodiments of the present invention. For example, the memory could be configured to buffer input data for processing by the processor 24. Additionally or alternatively, the memory could be configured to store instructions for execution by the processor. As yet another alternative, the memory may include one of a plurality of databases that may store a variety of files, contents or data sets. Among the contents of the memory, applications may be stored for execution by the processor in order to carry out the functionality associated with each respective application. In some cases, the memory may be in communication with the processor via a bus for passing information among components of the apparatus.

1 5 The processor 24 may bc embodied in a number of different ways. For example, the processor may be embodied as various processing means such as one or more of a microprocessor or other processing element, a coprocessor, a controller or various other computing or processing devices including integrated circuits such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), or the like. In an example embodiment, the processor may be configured to execute instructions stored in the memory 28 or otherwise accessible to the processor. As such, whether configured by hardware or by a combination of hardware and software, the processor may represent an entity (e.g., physically embodied in circuitry -in the form of processing circuitry 22) capable of performing operations according to embodiments of the present invention while configured accordingly.

Thus, for example, when the processor is embodied as an ASIC, FPGA or the like, the processor may be specifically configured hardware for conducting the operations described herein.

Alternatively, as another example, when the processor is embodied as an executor of software instructions, the instructions may specifically configure the processor to perform the operations described herein.

Referring now to Figures 3 and 4, flowcharts illustrating the operations performed by a method, apparatus and computer program product, such as apparatus 20 of Figure 2, from the perspective of a mobile terminal 10 in accordance with one embodiment of the present invention are illustrated. It will be understood that each block of the flowcharts, and combinations of blocks in the flowcharts, may be implemented by various means, such as hardware, firmware, processor, circuitry and/or other device associated with execution of software including one or more computer program instructions. For example, one or more of the procedures described above may be embodied by computer program instructions. In this regard, the computer program instructions which embody the procedures described above may be stored by a memory device 28 of an apparatus employing an embodiment of the present invention and executed by a processor 24 in the apparatus. As will be appreciated, any such computer program instructions may be loaded onto a computer or other programmable apparatus (e.g., hardware) to produce a machine, such that the resulting computer or other programmable apparatus provides for implementation of the frmnctions specified in the flowcharts' block(s). These computer program instructions may also be stored in a non-transitory computer-readable storage memory that may direct a computer or other programmable apparatus to function in a particular manner, such that the instructions stored in the computer-readable storage memory produce an article of manufacture, the execution of which implements the ftmnction specified in the flowcharts' block(s). The computer program instructions may also be loaded onto a computer or other programmable apparatus to cause a series of operations to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide operations for implementing the functions specified in the flowcharts' block(s). As such, the operations of Figures 3 and 4, when executed, convert a computer or processing circuitry into a particular machine configured to perform an example embodiment of the present invention. Accordingly, the operations of each of Figures 3 and 4 define an algorithm for configuring a computer or processing circuitry 22, e.g., processor, to perform an example embodiment. In some cases, a general purpose computer may be provided with an instance of the processor which performs the algorithm of a respective one of Figures 3 and 4 to transform the general purpose computer into a particular machine configured to perform an example embodiment.

Accordingly, blocks of the flowcharts support combinations of means for performing the specified functions and combinations of operations for performing the specified functions. It will also be understood that one or more blocks of the flowchart, and combinations of blocks in the flowcharts, can be implemented by special purpose hardware-based computer systems which perform the specified functions, or combinations of special purpose hardware and computer instructions.

In some embodiments, certain ones of the operations above may be modified or further amplified as described below. Moreover, in some embodiments additional optional operations may also be included (some examples ofwhich are shown in dashed lines in Figures 3 and 4). It should be appreciated that each of the modifications, optional additions or amplifications below may be included with the operations above either alone or in combination with any others among the features described herein.

Figure 3 is a flow chart illustrating serving cell reselection performed in accordance with one embodiment of the present invention. Referring now to Figure 3, as shown in operation 30, the apparatus 20 embodied, for example, by a mobile terminal I 0, may include means, such as the processing circuitry 22, the processor 24, the communications interface 26 or the like, for receiving reselection data. In an embodiment, reselection data may comprise interference data, reselection criteria, and/or a network command. Reselection criteria, in one embodiment, is that criteria that would generally cause an apparatus 20, such as mobile terminal 10, to transition from a current serving cell, such as serving cell 12, to another serving cell, such as neighbor cell 16 when a neighbor cell 16 received power is determined to be higher than the serving cell 12 received power. hi an example embodiment, and as described above, the received reselection data may also include interference data. Interference data may indicate the level of interference between a mobile terminal, such as mobile terminal 10, and one or more neighbor cells, such as neighbor cell 16.

As shown in decision operation 32 of Figure 3, the apparatus 20 may also include means, such as the processing circuitry 22, the processor 24 or the like, for determining the presence of a reselection condition. In an example embodiment, a reselection condition may occur in an instance in which it is determined, such as by the processor, that the reselection criteria have been met, in an instance in which it is determined, again such as by the processor, that interference exists between the mobile terminal and one or more neighboring cells and/or in an instance in which a network command is received, such as by the communications interface, that indicates that the mobile terminal, for example, is to release a network resource, such as the E-DCH. Potential interference between the mobile terminal 10 and neighbor cells 16 may be identified in various manners including, for example, by analyzing the transmission power of the mobile terminal, path loss and/or neighbor cells' uplink interference levels may be analyzed. ii

In one embodiment, the apparatus 20, such as the processor 24, may determine the transmission power of the signals transmitted via the uplink dedicated physical control channel (DPCCH) to the serving cell 12. In an instance in which the transmission power for signals transmitted via an uplink channel, such as the uplink DPCCH, is relatively high, the mobile terminal 10 may be located relatively far from the serving cell and!or the mobile terminal 10 may be suffering from uplink interference from other mobile terminals served by the neighbor cells 16. In either instance, a relatively high transmission power for signals transmitted via an uplink channel of the mobile terminal 10 may create interference with the neighbor cells 16.

Additionally or alternatively, the apparatus 20, such as the processor 24, may determine, in one embodiment, the path loss may be determined to be the difference between the value of the primary common pilot channel (CPICH) transmission power as signaled by the network and the CPICH received signal code power (RSCP) as measured by the mobile terminal. The path loss of a neighbor cell 16 provides an indication as to the distance between the mobile terminal and the neighbor cell 16. In an instance in which the path loss is relatively small, the mobile terminal tO may be relatively near the neighbor cell 16, thereby increasing the likelihood that the signal transmissions by the mobile terminal 10 may create interference for the neighbor cell 16.

Conversely, in an instance in which the path loss is relatively large, the mobile terminal may be relatively far away from the neighbor cell such that there is a lower likelihood that the signal transmissions from the mobile terminal 10 will create interference for the neighbor cell 16.

The apparatus 20 may additionally or alternatively include means, such as the processing circuitry 22, the processor 24 or the like, for determining other parameters or conditions associated with the operation of the mobile terminal 10 that may be indicative of neighbor cell interference. For example, the apparatus, such as the processor, the communication interface 26 or the like, may receive information provided by the neighbor cell 16, such as via a system information block (SIB), e.g., 51B7, so as to obtain information regarding the uplink interference level of the neighbor cell. Based upon at least some of the foregoing parameters, such as the transmission power, the path loss and/or the uplink interference level, the apparatus 20, such as the processor 24. may determine if the operation of the mobile terminal 10 is creating or is likely to have created interference for the neighbor cells 16.

In one embodiment, the apparatus 20, such as the processor 24, may be configured to compare the transmission power to a first threshold with the transmission power satisiing the first threshold by exceeding the first threshold, to compare the path loss to a second threshold with the path loss satising the second threshold by being less than the second threshold and optionally compare one or more other parameters, such as the uplink interference level, to respective thresholds. The thresholds may be pre-defined and stored by memory 28 of the apparatus 20. Alternatively, a network clement, such as the serving cell 12, a radio network controller or the like, may noti' the mobile terminal of the respective thresholds, such as via an RRC measurement control message or via system information, such as SIB5, SIB 11, SIB 11 bis and/or SIB 12.

In an example embodiment and as described herein, the apparatus 20, such as the processor 24, may determine that a reselection condition may be present based on the above described reselection criteria and interference data, alone or in combination. However, the apparatus 20, such as the processor 24, may alternatively or additionally determine that a reselection condition is present based upon the existence of a predetermined amount of data to be transmitted to/from the mobile terminal. For example, when there is only a small amount of data to be transmitted (e.g., a common control channel (CCCH) transmission) then there is a lower 1 5 probability of a reselection condition and thus a lower chance that a network resource, such as the E-DCH, needs to be suspended. However when there is a larger amount of data, for example an amount of data that exceeds an uplink buffer and/or another predetermined limit, then it is more likely that a reselection condition will occur and a network resource, such as the E-DCH, needs to be suspended. The network resource. such as the E-DCH, may be released and or suspended in order to permit reselection to occur prior to the transfer of the large amount of data.

As shown in operation 34 of Figure 3, the apparatus 20 may also include means, such as the processing circuitry 22, the processor 24, communications interface 26 or the like, for causing a report to be transmitted. In an embodiment, in an instance in which the apparatus determines the presence of a reselection condition, as described with reference to decision operation 32, then the apparatus may advise a serving cell, a network resource, radio network controller and/or the like, that a network resource, such as the E-DCH, has been released.

In one embodiment, the report that is caused to be transmitted by the apparatus 20, such as the mobile terminal 10, may provide a buffer status, such as an empty buffer status regardless of the actual state of the buffer. For example, the apparatus 20, embodied, for example by the mobile terminal 10, may report an empty buffer status (e.g., Total E-DCH Buffer Status (TEBS) 0 bytes) in the scheduling information (SI) even though the buffer is not empty. Upon receipt of the empty buffer status, the network, such as the serving cell 12, may release the network resource, such as the E-DCH. Once the mobile terminal 10 recovers (e.g. there is no longer interference with a neighbor cell) then the resource, such as the E-DCH, may be resumed or allocated again.

In another embodiment, the apparatus 20, such as the mobile terminal I 0, may add a new field to the SI that functions to transmit a report to a network resource, radio network controller andior the like indicating that the network resource, such as the E-DCH, may need to be suspended. Alternatively or additionally, the new field may also take the form of a special value of TEBS. Alternatively or additionally, the new field may also take the form of a special value of Channel Quality Indication (CQI).

As shown in operation 36 of Figure 3, the apparatus 20 may also include means, such as the processing circuitry 22, the processor 24, communications interface 26 or the like, for causing a network resource, such as the E-DCH, to be modified in an instance in which the presence of a reselection condition has been identified and a report has provided to the network.

In one embodiment, the apparatus 20, such the mobile terminal 10, modifies the network 1 5 resource by autonomously releasing or suspending the network resource, such as the E-DCH. By autonomously acting, the mobile terminal 10 may reduce latency. In other embodiments, the network resource, such as the E-DCH, may be released while the apparatus 20, such as the mobile terminal 10, is in the CELL-FACH state using an inactive absolute grant. Alternatively or additionally, the use of an inactive absolute grant and/or an autonomous action by the apparatus 20, such as the mobile terminal 10, may also be accompanied by the establishment of a timeout procedure, such as defined by a timer. The timeout procedure defined by the timer may be configured to prevent the requesting of another resource within the timeout procedure or may prevent the mobile terminal from requesting a new resource until the interference conditions are no longer present.

Alternatively or additionally, the apparatus 20, embodied, for example, by the mobile terminal 10, may receive a message using means such as the processor 24 and the communications interface 26, for receiving a message from a serving cell 12, a network resource, radio network controller and/or the like that causes the modification of the network resource, such as the E-DCH as is described with respect to Operation 36 of Figure 3. In an embodiment, a command (e.g., absolute grant value, high speed shared control channel order, and!or MAC header information) may be received that insflucts the mobile terminal to suspend or release the network resource, such as the E-DCH. In another embodiment, the mobile terminal 10 may receive an indication ofa modified serving grant (e.g., mobile terminal transmit power is reduced to avoid interfcrence) which causcs thc mobile terminal 10 to suspend or release the resource.

Alternatively or additionally, a message may indicate that the apparatus 20, embodied by, for example, the processor 24, may apply a specific bias, offset andIor priority to a neighbor cell or frequency when evaluating reselection as shown with respect to Operation 38. For example, applying a specific bias, offset andIor priority to a neighbor cell effectively allows for a fast trigger for cell reselection. In this example, the use of RRC signalling to release the RRC connection and perform redirection may be avoided. The mobile terminal I 0 may reselect and maintain the RRC signalling and any packet data protocol (PDP) context to be re-established on the other frequency.

Alternatively or additionally, an apparatus, embodied, by for example, the serving cell 12 may trigger a reselection condition. In some cases the serving cell 12 may trigger a reselection condition without the mobile terminal 12 reporting an interference condition and/or the presence of reselection criteria. A serving cell 12, in an instance in which the network experiences high 1 5 load on a frequency, may for example, cause a network transmission that indicates a reselection condition as described with reference to Figure 3 to cause the mobile terminal 10 to modify a nePvork resource, such as the E-DCH for purposes of load balancing. In this example case, the release of the network resource, such as the E-DCH would be triggered by the serving cell 12 (e.g. via High Speed Shared Control Channel order, or inactive grant, etc) and the network comnand would likely be accompanied by a reselection offset. The reselection offset is configured to cause the mobile terminal 10 to switch to another frequency.

Alternatively or additionally, the apparatus 20, embodied, for example, by the processor 24, may receive a specific adjustment for a reselection calculation. For example, a reselection calculation may include applying a temporary bias (such as offset and/or priority) for neighboring cells 16.

As shown in operation 38 of Figure 3, the apparatus 20 may also include means, such as the processing circuitry 22, the processor 24, communications interface 26 or the like, for causing the reselection of a serving cell. As described herein, the apparatus 20, such as the mobile terminal I 0 may perform reselection of a new serving cell to avoid interference situations. Alternatively or additionally, the reseleetion may include activating a previous serving cell that was suspended or released, by the mobile terminal 10. Alternatively or additionally, in one embodiment, when the reselection criteria are met, the radio resource control (RRC) layer may indicate to the medium access control (MAC) that a network resource, such as an E-DCH resource, should be suspended or relcased. The suspension or modification of a network resource is further described with reference to opcration 34.

As indicated above, the method, apparatus and computer program product of one embodiment are configured to permit a mobile terminal 10 operating in a CELL FACH to determine the potential for neighbor cell interference and to suspend and/or release a network resource, such as the E-DCH, to trigger rcsclection of a cell even while the mobile terminal is in the CELL FACH state. In order to provide further explanation of this embodiment, reference is made to Figure 4 in which the mobile terminal is initially operating in a CELL_FACH state as shown in operation 40. The apparatus 20 of this embodiment may include means, such as the processing circuitiy 22, the processor 24 or the like, for determining whether neighbor cell interference is being caused by the mobile terminal while the mobile terminal is in the CELL EACH state. See, for example, operation 42 of Figure 4. As described above, the apparatus, such as a processor, may determine whether neighbor cell interference is being caused 1 5 by determining whether one or more parameters satis respective thresholds and/or whether a reselection criterion is present. For example, to determine the presence of an interference the apparatus, such as a processor, may determine whether the transmission power for signals transmitted via an uplink channel satisfies a respective threshold, whether a path loss for signals received from the neighbor cell satisfies a respective threshold and/or whether an uplink interference level at the neighbor cell satisfies a respective threshold.

In an instance in which the apparatus 20, such as the processor 24, does not determine that neighbor cell interference is being created, the apparatus need not issue suspend and/or release the network resource and, instead, the mobile terminal 10 may continue to operate in the CELL_EACH state while the apparatus continues to monitor the various parameters for an indication of neighbor cell interference and/or the reselection criteria. However, the apparatus may also include means, such as the processing circuitry 22, the processor 24, the communication intcrface 26 or the like, for causing a measurement report to bc provided to a network element, such as the serving cell 12, a radio network controller or other network element, in an instance in which it is determined that neighbor cell interference is being caused.

Based on the determined interference with the neighbor cell, in one embodiment, the apparatus may include means, such as the processing circuitry, the processor, the communication interface or the like, for causing a network resource, such as an E-DCH, to be modified. See operation 44 of Figure 4. As described with respect to operation 36 of Figure 3, the apparatus may release and/or suspend the E-DCH resource. As shown in operation 46 of Figure 4, the apparatus 20 may also include means, such as the processing circuitiy 22, the processor 24, communications interface 26 or the like, for causing the reseleetion of a serving cell.

Advantageously, the apparatus 20, method and computer program product as described herein enables a mobile terminal 10 to perform cell reselection when a network resource, such as an E-DCH, is allocated. The apparatus, method and computer program product as described herein ffirther allows flexible conditions as to the suitable conditions to perform reselection (e.g., large amount of data may cause high interference thereby indicating reselection). In some embodiments, the apparatus, method and computer program product as described herein avoids causing interference to neighbor cells 16, radio link failures and dropped calls, while avoiding complex interference control algorithms. The apparatus, method and computer program product as described herein further provides for dynamic load balancing between frequencies with reduced latency and reduced power consumption.

1 5 Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or ifinctions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes ofliniitation.

Claims

<claim-text>Claims A wireless communications method comprising: determining based on reselection data the presence of a cell reselection condition; in an instance in which a cell reselection condition is determined to be present, causing a network resource to be modified; and causing a reselection of a serving cell.</claim-text> <claim-text>2. A method of Claim 1 wherein causing the network resource to be modified comprises at least one of suspending or releasing the network resource, and wherein the network resource comprises an enhanced dedicated channel "E-DCH".</claim-text> <claim-text>3. A method of Claim 1 or Claim 2, wherein a cell reselection condition is caused to be present in the presence of a determination ofat least one of: an instance in which a serving cell reselection criteria is met; an instance in which an interference condition is met; and an instance in which a network command is received.</claim-text> <claim-text>4. A method of any one of the preceding Claims further comprising causing a report to be transmitted, wherein the report indicates the presence ofthe cell reselection condition.</claim-text> <claim-text>5. A method of Claim 4 wherein causing a report to be transmitted further comprises causing an empty buffer message to be transmitted.</claim-text> <claim-text>6. A method of Claim 4 wherein causing a report to be transmitted further comprises generating a new field in a scheduling information report, wherein the new field indicates the modification of the resource.</claim-text> <claim-text>7. A method of Claim 1 wherein causing the network resource to be modified comprises generating an inactive grant, while in a CELL-FACH state; and causing the generated inactive grant to be transmitted.</claim-text> <claim-text>8. A method of Claim I wherein causing the network resource to be modified comprises at least one of receiving a suspension message indicating the suspension of an enhanced dedicated channel "E-DCH" resource, receiving an indication that a serving grant has been modified, or receiving a cell reselection message.</claim-text> <claim-text>9. A method of the preceding Claims wherein the serving cell is at least one of the current serving cell and another serving cell.</claim-text> <claim-text>10. A wireless communications apparatus comprising processing means arranged to: determine based on received reselection data the presence of a cell reselcction condition; in an instance in which a cell reselcction condition is determined to be present, cause a network resource to be modified; and cause a reselection of a serving cell.</claim-text> <claim-text>11. An apparatus according to Claim 10 wherein the processing means is further arranged to cause the apparatus to at least one of suspend or release the network resource, and wherein the network resource comprises an enhanced dedicated channel "E-DCH".</claim-text> <claim-text>12. An apparatus according to Claim 10 or Claim 11 wherein a cell reselection condition is caused to be present in the presence of a determination of at least one of: an instance in which a cell reselection criteria is met; an instance in which an interference condition is met; and an instance in which a network command is received.</claim-text> <claim-text>13. An apparatus according to any one of Claims tO to 12 wherein the processing means is arranged to cause a report to be transmitted, wherein the report indicates the presence of the cell reselection condition.</claim-text> <claim-text>14. An apparatus according to Claim 13 wherein causing the report to be transmitted causes an empty buffer message to be transmitted.</claim-text> <claim-text>15. An apparatus according to Claim 13 wherein causing the rcport to be transmitted comprises gcncrating a new field in a scheduling information report, wherein the new field indicates the modification of the resource.</claim-text> <claim-text>16. An apparatus according to Claim 10 wherein to the processing means is arranged to generate an inactive grant, while in a CELL-FACH state; and cause the generated inactive grant to be transmitted.</claim-text> <claim-text>17. An apparatus according to Claim 10 wherein the processing means is arranged to receive at least one of a suspension message indicating the suspension of an enhanced dedicated channel "E-DCH" resource, an indication that a serving grant has been modified, or a cell reselection message.</claim-text> <claim-text>18. A method comprising: 1 5 determining the presence of uplink interference while a mobile terminal is in a CELL FACH state; in an instance where the presence of uplink interference is determined, causing an enhanced dedicated channel "E-DCH" to be modified; and causing a reselection ofa serving cell.</claim-text> <claim-text>19. A method of Claim 18 comprising causing the presence of the reselection condition if the presence of uplink interference is determined, wherein the presence of uplink interference is determined in the presence ofat least one of: an instance in which a cell reselection criteria is met; an instance in which an interference condition is met; and an instance in which a network command is received.</claim-text> <claim-text>20. A method of Claim 18 or 19 wherein causing the E-DCH to be modified comprises at least one of receiving a suspension message indicating the suspension of a E-DCH resource, receiving an indication that a serving grant has been modified, or receiving a cell reselection message.</claim-text> <claim-text>2 I. A computer program product comprising at least one computer-readable storage medium having computer-readable program instructions stored therein, the computer-readable program instructions including program instructions configured, when executed, to determine based on reselection data the presence of a reselection condition, in an instance in which the reselection condition is determined to bc prcscnt, cause a network resource to be modified, and cause a reselection of a serving cell.</claim-text> <claim-text>22. A computer program product comprising at least computer-readable storage medium having computer-readable program instructions stored therein, the computer-readable program instructions including program instructions configured, when executed, to determine the presence of uplink interference while a mobile terminal is in a CELL FACH state, in an instance in which the presence of uplink interference is determined, to cause an E-DCH to be modified, and to cause a reselection of a serving cell.Amendments to the claims have been made as follows: Claims 1. A method of reducing the potential for neighbour cell interference in a wireless communications network, the method comprising: dctermining bascd on rcsclcction data the prcscncc ofa cell reselection condition; in an instance in which a cell reselection condition is determined to be present, causing a network resource to be modified; and causing a reselection of a serving cell.
2. A method of Claim 1 wherein causing the network resource to be modified comprises at least one of suspending or releasing the network resource, and wherein the network resource comprises an enhanced dedicated channel "E-DCH".r
3. A method of Claim 1 or Claim 2, wherein a cell reselection condition is caused to be present in the presence of a determination of at least one of: C an instance in which a serving cell reselection criteria is met; an instance in which an interference condition is met; and an instance in which a network command is received.
4. A method of any one of the preceding Claims further comprising causing a report to be transmitted, wherein the report indicates the presence ofthe cell reselection condition.
5. A method of Claim 4 wherein causing a report to be transmitted further comprises causing an empty buffer message to be transmitted.
6. A method of Claim 4 wherein causing a report to be transmitted further comprises generating a new field in a scheduling information report, wherein the new field indicates the modification of the resource.
7. A method of Claim 1 wherein causing the network resource to be modified comprises generating an inactive grant, while in a CELL-FACE state; and causing the generated inactive grant to be transmitted.
8. A method of Claim I wherein causing the network resource to be modified comprises at least one of receiving a suspension message indicating the suspension of an enhanced dedicated channel "E-DCH" resource, receiving an indication that a serving grant has been modified, or receiving a cell reselection message.
9. A method of the preceding Claims wherein the serving cell is at least one of the current serving cell and another serving cell.
10. A wireless communications apparatus arranged to reduce the potential for neighbour cell interference in a wireless communications network, the apparatus comprising processing means arranged to: determine based on received reselection data the presence of a cell reselection condition; r in an instance in which a cell reselection condition is determined to be present, cause a Qu)lS network resource to be modified; and o cause a reselection of a serving cell. r11. An apparatus according to Claim 10 wherein the processing means is ffirthcr arranged to cause the apparatus to at least one of suspend or release the network resource, and wherein the network resource comprises an enhanced dedicated channel "E-DCH".12, An apparatus according to Claim 10 or Claim II wherein a cell reseleetion condition is caused to be present in the presence of a determination of at least one of: an instance in which a cell reselcction criteria is met; an instance in which an interference condition is met; and an instance in which a network command is received.13. An apparatus according to any one of Claims 10 to 12 wherein the processing means is arranged to cause a report to be transmitted, wherein the report indicates the presence of the cell reselection condition.14, An apparatus according to Claim 13 wherein causing the report to be transmitted causes an empty buffer message to be transmitted.15. An apparatus according to Claim 13 wherein causing the report to be transmitted compriscs generating a ncw field in a scheduling information report, wherein thc new field indicates the modification of the resource.16. An apparatus according to Claim tO wherein to the processing means is arranged to generate an inactive grant, while in a CELL-FAQ-I state; and cause the generated inactive grant to be transmitted.17. An apparatus according to Claim 10 wherein the processing means is arranged to receive at least one of a suspension message indicating the suspension of an enhanced dedicated r channel "E-DCH" resource, an indication that a serving grant has been modified, or a cell reselection message.18. A wireless communication method comprising: determining the presence of uplink interference while a mobile terminal is in a CELL FACH stale; in an instance where the presence of uplink interference is determined, causing an enhanced dedicated channel "E-DCH" to be modified; and causing a reselection of a serving cell.19. A method of Claim 18 comprising causing the presence of the resclcction condition if the presence of uplink interference is determined, wherein the presence of uplink interference is determined in the presence of at least one of: an instance in which a cell reselection criteria is met; an instance in which an interference condition is met; and an instance in which a network command is received.20. A method of Claim 18 or 19 wherein causing the E-DCH to be modified comprises at least one of receiving a suspension message indicating the suspension of a E-DCH resource, receiving an indication that a serving grant has been modified, or receiving a cell reselection message.21. A computer program product comprising at least one computer-readable storage medium having computer-readable program instructions stored therein, the computer-readable program instructions including program instructions configured, when executed, to perform the method of any one of claims I to 9.22. A computer program product comprising at least computer-readable storage medium having computer-readable program instructions stored therein, the computer-readable program instructions including program instructions configured, when executed, to perform the method of any one of claims 18 to 20. (4 r r (4</claim-text>