Power Control for Random Access Protocols

Abstract

Methods, systems and apparatus for power control of a random access protocol in mobile communication technologies are described. An exemplary method for wireless communication includes broadcasting, by a network node serving a cell, an indication of a transmit power level specific to the cell, wherein the indication is used by wireless devices operating in the cell for a two-step random access procedure. Another exemplary method for wireless communication includes receiving, by a wireless device operating in a cell served by the network node, an indication of a transmit power level specific to the cell for use in a two-step random access procedure, and transmitting a first message for the two-step random access procedure at the transmit power level.

Description

Technical Field

[0001] The present application relates generally to wireless communications. Background Art

[0002] Wireless communication technology is pushing the world towards an increasingly connected and networked society. The rapid development of wireless communications and technological advances have led to greater demands for capacity and connectivity. Other aspects such as energy consumption, equipment cost, spectrum efficiency, and latency are also important to meet the needs of various communication scenarios. Compared with existing wireless networks, next-generation systems and wireless communication technologies need to support more users and devices, as well as higher data rates, requiring user equipment to implement power control of random access protocols. Summary of the invention

[0003] The present application relates to methods, systems and devices for generating sequences for reference signals in mobile communication technologies, including fifth generation (5G) and new radio (NR) communication systems.

[0004] In one exemplary aspect, a method of wireless communication is disclosed. The method includes broadcasting, by a network node serving a cell, an indication of a transmit power level specific to the cell, wherein the indication is used by wireless devices operating in the cell for a two-step random access procedure.

[0005] In another exemplary aspect, a method of wireless communication is disclosed. The method includes receiving, by a wireless device operating in a cell served by a network node, an indication of a transmit power level for a two-step random access procedure specific to the cell, and transmitting a first message of the two-step random access procedure at the transmit power level.

[0006] In yet another exemplary aspect, the above method is embodied in the form of processor executable code and stored in a computer readable program medium.

[0007] In yet another exemplary embodiment, a device configured or operable to perform the above method is disclosed.

[0008] The above-described aspects and other aspects and embodiments thereof are described in more detail in the drawings, the description and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Examples of a base station (BS) and a user equipment (UE) in wireless communications according to some embodiments of the disclosed technology are shown.

[0010] Figure 2 An example of the message flow in a 4-step random access protocol is shown.

[0011] Figure 3An example of message flow in a 2-step random access protocol is shown.

[0012] Figure 4 An example of pre-configured coordination between cells is shown.

[0013] Figure 5 An example of using a high interference indication (HII) is shown.

[0014] Figure 6 An example of using an overload indication (OI) is shown.

[0015] Figure 7 An example of broadcasting based on geographic areas is shown.

[0016] Fig. 8A and 8B An example of a wireless communication method is shown.

[0017] Fig. 9 is a block diagram representation of a portion of an apparatus according to some embodiments of the disclosed technology. DETAILED DESCRIPTION

[0018] There is an increasing demand for the fourth generation of mobile communication technology (4G), long term evolution (LTE), advanced long term evolution (LTE-Advanced / LTE-A) and fifth generation of mobile communication technology (5G). From the current development trend, 4G and 5G systems are studying features that support enhanced mobile broadband, ultra-high reliability, ultra-low latency transmission and massive connections.

[0019] Embodiments of the disclosed technology provide methods and systems for power control of random access procedures (eg, 2-step RACH) in current cellular systems. Figure 1 An example of a wireless communication system (e.g., an LTE, 5G, or New Radio (NR) cellular network) including a BS 120 and one or more user equipment (UE) 111, 112, and 113 is shown. In some embodiments, a downlink transmission (141, 142, 143) includes an indication of a cell-specific transmit power level provided to the UE served by the BS. An uplink transmission (131, 132, 133) includes a first message of a 2-step RACH procedure. The UE may be, for example, a smartphone, a tablet, a mobile computer, a machine-to-machine (M2M) device, a terminal, a mobile device, an Internet of Things (IoT) device, etc.

[0020] This application uses section headings and subheadings to facilitate understanding, rather than to limit the scope of the disclosed techniques and embodiments to certain sections. Therefore, the embodiments disclosed in different sections can be used interchangeably. In addition, this application only uses examples from the 3GPP New Radio (NR) network architecture and 5G protocols to facilitate understanding, and the disclosed techniques and embodiments can be practiced in other wireless systems using communication protocols different from the 3GPP protocols.

[0021] Overview of Random Access Process

[0022] Figure 2 An example of a contention-based LTE random access procedure involving four steps is shown. Figure 2 As shown, four messages (designated as MSG1 to MSG4) are sent between the UE and the BS (eg, Figure 2 The random access message is transmitted between gNBs in the network and includes (1) a random access preamble, (2) a random access response, (3) scheduled transmissions, and (4) contention resolution.

[0023] In 4-step RACH, MSG3( Figure 2 The transmit power of the scheduled transmission in is determined by the BS via MSG2 ( Figure 2 The random access response in the MSG2 indicates the transmission power. In some embodiments, the format of MSG2 is as shown in Table 1.

[0024] Table 1: Random Access Response (MSG2) Grant Content Field Size

[0025] RAR Authorization Field Number of bits Frequency Hopping Flag 1 Msg3 PUSCH frequency resource allocation 14 Msg3 PUSCH time resource allocation 4 MCS 4 Msg3 PUSCH TPC command 3 CSI Request 1

[0026] In some embodiments, the UE applies the TPC command for Msg3 PUSCH (the transmit power control command received in MSG2) to the subsequent MSG3 ( Figure 2 The scheduled transmission in ).

[0027] Figure 3 An example of a 2-step RACH is shown, which is incorporated into an embodiment of the disclosed technology. Figure 3 As shown, the contention-based random access procedure involves the transmission of two messages (designated as MSG_A and MSG_B) between the UE and the BS. MSG_A includes a preamble and a payload, while MSG_B includes a response and other messages.

[0028] Overview of Inter-cell Interference Coordination

[0029] The performance of cellular wireless communication networks is usually limited by interference. In a given geographical area covered by multiple cells, different cells may use a given frequency band. Co-channel interference may occur between those cells sharing the same frequency band. To suppress uplink co-channel interference, the transmit power of a given UE may be adjusted by the BS. The TPC command for the Msg3 PUSCH is an example.

[0030] In some embodiments, coordinating transmit power between cells is based on preconfigured resources. Figure 4 An example of preconfigured resources is shown in . As shown therein, cells 1, 2 and 3 are neighboring cells and share the same frequency resources A, B and C. It is possible to preconfigure resource A as the "cell edge band" of cell 1, on which cell 1 can have a higher uplink transmit power. With this preconfiguration, cells 2 and 3 cannot allocate resource A to their cell edge UEs to keep the uplink transmit power low. The same principle applies to resource B and resource C for cell 2 and cell 3, respectively. Typically, such preconfiguration is semi-static, which usually leads to a lack of flexibility in resource allocation.

[0031] In some embodiments (eg, LTE), the BSs may exchange interference indications over an X2 or Xn interface. In an exemplary embodiment, there are two different indications: a high interference indication (HII) and an overload indication (OI).

[0032] Examples of HII are Figure 5 As shown therein, cell 1 allocates resource A to its cell edge UE, which typically results in a high transmit power expected on A. Therefore, cell 1 sends HII to cell 2 and cell 3 via the X2 (or Xn) interface. Cell 2 checks its own resource allocation and can avoid allocating A to any cell edge UE. Cell 3 may have very little traffic at that time, and it may not allocate A to any UE.

[0033] Examples of OIs include Figure 6 As shown therein, cell 1 detects high interference on resource A and sends OI to cell 2 and cell 3 via the X2 (or Xn) interface. Cell 2 checks its own resource allocation and may allocate A only to the cell center UE to reduce the uplink transmit power on A. Cell 3 checks its own resource allocation and may find that A is not used at all due to very small traffic.

[0034] In these examples, inter-cell interference coordination is directly controlled by the BS via UE-specific resource allocation or closed-loop adjustment.In contrast, embodiments of the disclosed techniques that deploy 2-step RACH include UEs transmitting their payloads without UE-specific resource allocation or closed-loop adjustment.

[0035] Exemplary Embodiment of Power Control for Random Access Procedure

[0036] In some embodiments (e.g., LTE), power control is performed on each physical channel using the following formula:

[0037] P=P 0 +α·path_loss+dynamic_offset+bandwidth_factor.

[0038] Here, P 0 is the target received power at the BS, α·path_loss is the compensation for the propagation path attenuation, dynamic_offset is a UE-specific closed-loop control parameter, and bandwidth_factor is an adjustment associated with the used transmission bandwidth.

[0039] In contrast, embodiments of the disclosed technology use the following formula for each physical channel:

[0040] P=P 0 +α·path_loss+dynamic_offset new +bandwidth_factor.

[0041] Here, dynamic_offset new It is a cell-specific parameter.

[0042] In some embodiments, the network node may broadcast power control information that may be used by the UE to set its transmit power level for MSG_A transmitted as part of the 2-step RACH procedure.The following exemplary scenario is provided to explain certain features of the disclosed embodiments.

[0043] Situation 1. exist Figure 4 In the context of, if resource pre-configuration is used in inter-cell interference coordination, the broadcast information may include different transmit power offsets on different resources; an example is shown in Table 2.

[0044] Table 2: Resource index and transmit power offset of preconfigured resources

[0045] Resource Index Transmit power offset A <![CDATA[Offset 1 ]]> B <![CDATA[Offset 2 ]]> C <![CDATA[Offset 2 ]]>

[0046] In some embodiments, the exemplary resource is a physical resource block (PRB) and the resource index may be one of the following:

[0047] (1) PRB start index and PRB number, used to indicate continuous PRB resources

[0048] (2) PRB start index and end index, used to indicate continuous PRB resources

[0049] (3) PRB index list, used to indicate continuous or distributed PRB resources

[0050] In some embodiments, the transmit power offset may be one of the following:

[0051] (1)Offset 1 and Offset 2 For example, on resource A, you can define Offset 1 =0dB and Offset 2 =-3dB;

[0052] (2)Offset 1 and differential offset delta offset (may be positive or negative). Then Offset 2 =Offset 1 +delta offset For example, on resource A, define Offset 1 =0dB, delta offset =-3dB, making Offset 2 =-3dB.

[0053] Situation 2. exist Figure 5 and 6 In the context of, if dynamic indications (e.g., HII or OI) are used in inter-cell interference coordination, the broadcast information of the cells is dynamically changed. In the example, cell 1 allocates resource A to its cell edge UEs, which means that high transmit power is expected on A. Therefore, cell 1 sends HII to cells 2 and 3 via X2 (or Xn). Cells 2 and 3 may need to broadcast the following information to avoid high uplink transmit power on A. In another example, cell 1 detects high interference on resource A and sends OI to cells 2 and 3 via X2. Cells 2 and 3 may need to broadcast the following information to reduce the high uplink transmit power on A. An example is shown in Table 3.

[0054] Table 3: Resource index and transmit power offset of dynamically configured resources

[0055] Resource Index Transmit power offset A <![CDATA[Offset 1 ]]> B <![CDATA[Offset 2 ]]> C <![CDATA[Offset 2 ]]>

[0056] In some embodiments, the exemplary resource is a physical resource block (PRB) and the resource index may be one of the following:

[0057] (1) PRB start index and PRB number, used to indicate continuous PRB resources

[0058] (2) PRB start index and end index, used to indicate continuous PRB resources

[0059] (3) PRB index list, used to indicate continuous or distributed PRB resources

[0060] In some embodiments, the transmit power offset may be one of the following:

[0061] (1)Offset 1 and Offset 2 For example, on resource A, you can define Offset 1 =0dB and Offset 2 =-3dB;

[0062] (2)Offset 1 and differential offset delta offset (may be positive or negative). Then Offset 2 =Offset 1 +delta offset For example, on resource A, define Offset 1 =0dB, delta offset =-3dB, making Offset 2 =-3dB.

[0063] (3) Only broadcast modified (or updated) values. For example, due to HII, only the Offset corresponding to resource A 1 Therefore, only the updated Offset can be broadcasted. 1 =-3dB.

[0064] (4) Only broadcast the difference (or power difference / offset). For example, when receiving HII, the Offset on resource A 1 The change is from -3dB to -6dB. Therefore, the difference (or gap) between the new value and the old value is -6-(-3) = -3dB, so -3dB can be broadcast. The UE will accumulate the received difference to obtain the latest Offset 1 .

[0065] Situation 3. In some embodiments, Figure 6As shown, and if an area-based inter-cell interference coordination strategy is used, the broadcast information can also be used. As shown therein, a cell is represented by a hexagon, which is divided into a cell center (denoted as "1") part and a cell edge (denoted as "2") part, and the transmit power level of a UE can be determined based on its location within the cell (e.g., whether the UE is in area "1" or area "2").

[0066] In some embodiments, the hexagonal cell may be divided into more regions, eg, a finer granularity, each region having a different transmit power level.

[0067] The UE may determine its location using a variety of methods; examples include:

[0068] (1) The UE continuously monitors and compares the downlink reference signal received power (RSRP) from the serving cell and the neighboring cells. At the cell center, the UE may find that the RSRP from the neighboring cell is smaller, and it can use a higher uplink transmit power without severely interfering with UEs in the neighboring cell. At the cell edge, the UE may find that the RSRP from the neighboring cell is higher, and it needs to use a lower uplink transmit power to avoid severely interfering with UEs in the neighboring cell.

[0069] (2) In a satellite communication network, the UE has its own location information, the location information of the BS on the satellite, and the cell definition on the ground. Therefore, if the geographical information of the cell center and cell edge is broadcast, the UE can adjust its uplink transmission power accordingly.

[0070] In this scenario, the broadcast information from the BS is given in Table 4.

[0071] Table 4: Information available in broadcasts based on geographical area

[0072] Comparison Standards Transmit power offset <![CDATA[Threshold 1 ]]> <![CDATA[Offset 1 ]]> <![CDATA[Threshold 2 ]]> <![CDATA[Offset 2 ]]>

[0073] In some embodiments, the comparison criteria may be one of the following:

[0074] (1) The ratio of the serving cell RSRP to the neighboring cell RSRP, or vice versa.

[0075] (2) The ratio of the serving cell distance to the neighboring cell distance, or vice versa (e.g., applicable to satellite communications with LOS channels and when the UE knows all reachable BS locations as well as its own location).

[0076] (3) The boundary of the area to be compared with the UE's location

[0077] (4) More than one threshold for multiple transmit power offsets

[0078] (5) Use a single threshold; for example, if the criterion is valid, then an offset is applied in the power control. Otherwise, no offset is added in the power control.

[0079] In some embodiments, the transmit power offset may be:

[0080] (1) When the UE meets the comparison criteria Threshold 1 and Threshold 2 Offset 1 and Offset 2 For example, if RSRP serving / RSRP neighboring >Threshold 1 , the UE uses Offset in its power control 1 , and if RSRP serving / RSRP neighboring <Threshold 2 , the UE uses the Offset in its transmit power 2 Offset 2 .

[0081] Exemplary Methods of the Disclosed Technology

[0082] Embodiments of the disclosed technology advantageously result in a UE being able to determine its transmit power in a 2-step RACH procedure based on resource and / or geographic information, and no UE-specific signaling is required. For example, the methods disclosed herein are applicable to semi-static and dynamic inter-cell interference coordination between base stations during a 2-step RACH procedure with a served UE.

[0083] Fig. 8A An example of a wireless communication method 800 for power control of a random access procedure in a mobile communication technology is shown. The method 800 includes: at step 802, broadcasting by a network node serving a cell an indication of a transmit power level specific to the cell, wherein the indication is used for a wireless device operating in the cell for a two-step random access procedure. In some embodiments, the indication of the transmit power level may be the power level itself. In other embodiments, an implicit or explicit field may be the indication of the transmit power level. In other embodiments, the indication may be an index to a lookup table having a stored transmit power value being used for the current configuration.

[0084] In some embodiments, the method 800 further comprises the step of receiving a first message of the two-step random access procedure, wherein the wireless device is capable of transmitting the first message at a transmit power level, and transmitting a second message of the two-step random access procedure.

[0085] In some embodiments, and in Figure 5 In the context of , the method 800 also includes the step of receiving an HII from another network node serving a neighboring cell indicating that there is high interference from the neighboring cell. In an example, the network node can adjust the indication of the transmit power level based on receiving the HII.

[0086] In some embodiments, and in Figure 6 In the context of , the method 800 further comprises the step of receiving an OI from another network node serving a neighboring cell indicating that there is high interference from the neighboring cell. In an example, the network node is capable of adjusting the indication of the transmit power level based on receiving the OI.

[0087] Figure 8B An example of a wireless communication method 810 for power control of a random access procedure in a mobile communication technology is shown. The method 810 includes receiving, by a wireless device operating in a cell served by a network node, an indication of a transmit power level specific to the cell for a two-step random access procedure at step 812. At step 814, the method 810 includes transmitting a first message of the two-step random access procedure at the transmit power level.

[0088] In some embodiments, the method 810 further comprises the step of receiving a second message of the two-step random access procedure from the network node.

[0089] In some embodiments, and in the context of methods 800 and 810, the indication comprises at least one resource index and at least one cell-specific transmit power offset. In an example, at least one resource index is preconfigured.

[0090] In some embodiments, at least one resource index includes a physical resource block (PRB) start index and the number of PRBs. In other embodiments, at least one resource index includes a PRB start index and a PRB end index. In other embodiments, at least one resource index includes multiple PRB indices.

[0091] In some embodiments, at least one cell-specific transmit power offset includes a first power offset and a second power offset. In other embodiments, at least one cell-specific transmit power offset includes a first power offset and a differential power offset, and the second power offset is the sum of the first power offset and the differential power offset. In other embodiments, at least one cell-specific transmit power offset is based on a location of the wireless device in a cell served by a network node. In an example, the determination of the location of the wireless device is based on a first reference signal received power (RSRP) from the network node and one or more RSRPs from one or more network nodes serving cells adjacent to the cell.

[0092] Embodiments of the disclosed technology

[0093] Fig. 9 905 is a block diagram representation of a portion of an apparatus according to some embodiments of the disclosed technology. An apparatus 905, such as a base station or a wireless device (or UE), may include a processor electronic device 910, such as a microprocessor, which implements one or more techniques presented in this application. The apparatus 905 may include a transceiver electronic device 915 to send and / or receive wireless signals through one or more communication interfaces (such as one or more antennas 920). The apparatus 905 may include other communication interfaces for transmitting and receiving data. The apparatus 905 may include one or more memories (not explicitly shown) configured to store information such as data and / or instructions. In some embodiments, the processor electronic device 910 may include at least a portion of the transceiver electronic device 915. In some embodiments, at least some of the disclosed techniques, modules, or functions are implemented using the apparatus 905.

[0094] The specification and drawings are to be regarded as illustrative only, wherein exemplary means examples and does not imply ideal or preferred embodiments unless otherwise specified. As used herein, the use of "or" is intended to include "and / or" unless the context clearly indicates otherwise.

[0095] Some embodiments described herein are described in the context of the entire method or process, which may be implemented in one embodiment by a computer program product, which is contained in a computer-readable medium, including computer executable instructions such as program code executed by a computer in a network environment. Computer-readable media may include removable and non-removable storage devices, including but not limited to read-only memory (ROM), random access memory (RAM), compact disk (CD), digital versatile disk (DVD), etc. Therefore, the computer-readable medium may include non-temporary storage media. Generally, program modules may include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. Computer or processor executable instructions, related data structures, and program modules represent examples of program codes for executing the method steps disclosed herein. A specific sequence of such executable instructions or related data structures represents an example of corresponding actions for implementing the functions described in such steps or processes.

[0096] Some disclosed embodiments can be implemented as devices or modules using hardware circuits, software or a combination thereof. For example, a hardware circuit implementation may include discrete analog and / or digital components that are, for example, integrated as a part of a printed circuit board. Alternatively, or additionally, the disclosed components or modules may be implemented as application specific integrated circuits (ASICs) and / or field programmable gate arrays (FPGAs) devices. Some embodiments may additionally or alternatively include a digital signal processor (DSP), which is a dedicated microprocessor with an architecture optimized for the operation needs of digital signal processing associated with the disclosed functions of the present application. Similarly, various components or subcomponents within each module may be implemented with software, hardware or firmware. The connection between the modules and / or the components within the modules may be provided using any connection method and medium known in the art, including but not limited to communication over the Internet, wired or wireless networks using appropriate protocols.

[0097] Although the present application contains many details, these should not be interpreted as limitations on the scope of the claimed invention or the content that may be claimed, but as descriptions of features for specific embodiments. Certain features described in the present application in the context of separate embodiments may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination. In addition, although the above-mentioned features may be described as working in certain combinations, and even initially claimed as such, in some cases, one or more features from the combination may be deleted from the combination, and the combination may involve a sub-combination or a variant of a sub-combination. Similarly, although the operations are described in a particular order in the accompanying drawings, this should not be understood as requiring the operations to be performed in the particular order or sequence shown, or requiring the execution of all the operations shown to obtain the desired results.

[0098] Only a few implementations and examples are described, and other implementations, enhancements, and variations can be made based on what is described and illustrated in this disclosure.

Claims

1. A method for wireless communication, the method comprising: broadcasting, by a network node serving a cell, an indication of at least one transmit power offset, the at least one transmit power offset being specific to the cell and comprising a first power offset for a first resource and any of: a second power offset and a differential power offset for a second resource, wherein the indication is for use by a wireless device operating in the cell to determine a transmit power level based on use of designated resources and their corresponding transmit power offsets during a two-step random access procedure; and A first message of the two-step random access procedure is received at the transmit power level.

2. The method according to claim 1, further comprising: A second message of the two-step random access procedure is transmitted.

3. The method according to claim 2, wherein: The at least one transmit power offset is based on at least one resource index.

4. The method according to claim 3, wherein: The at least one resource index is preconfigured.

5. The method according to claim 1, further comprising: A high interference indication HII is received from another network node serving a neighboring cell, the high interference indication indicating the presence of high interference from the neighboring cell.

6. The method according to claim 5, wherein: The network node can adjust the at least one transmit power offset based on the received HII.

7. The method according to claim 1, further comprising: An overload indication OI is received from another network node serving a neighboring cell, the overload indication indicating the presence of high interference from the neighboring cell.

8. The method according to claim 7, wherein: The network node can adjust the at least one transmit power offset based on the received OI.

9. The method according to any one of claims 3 to 8, wherein: The at least one resource index includes a physical resource block start index and the number of physical resource blocks.

10. The method according to any one of claims 3 to 8, wherein: The at least one resource index includes a physical resource block start index and a physical resource block end index.

11. The method according to any one of claims 3 to 8, wherein: The at least one resource index includes a plurality of physical resource block indexes.

12. The method according to any one of claims 3 to 8, wherein: The third power offset is the sum of the first power offset and the differential power offset.

13. The method according to claim 3, wherein: The at least one cell-specific transmit power offset is based on a location of the wireless device in the cell served by the network node.

14. The method according to claim 13, wherein: The determination of the location of the wireless device is based on a first reference signal received power, RSRP, from the network node and one or more RSRPs from one or more network nodes serving cells neighboring the cell.

15. A method for wireless communication, the method comprising: receiving, by a wireless device operating in a cell served by a network node, an indication of at least one transmit power offset, the at least one transmit power offset being specific to the cell and comprising a first power offset for a first resource and any of: a second power offset and a differential power offset for a second resource, wherein the indication is used by the wireless device to determine a transmit power level based on using designated resources and their corresponding transmit power offsets during a two-step random access procedure; and A first message of the two-step random access procedure is transmitted at the transmit power level.

16. The method according to claim 15, further comprising: A second message of the two-step random access procedure is received from the network node.

17. The method according to claim 16, wherein: The at least one transmit power offset is based on at least one resource index.

18. The method according to claim 17, wherein: The at least one resource index is preconfigured.

19. The method according to claim 17 or 18, wherein: The at least one resource index includes a physical resource block start index and the number of physical resource blocks.

20. The method according to claim 17 or 18, wherein: The at least one resource index includes a physical resource block start index and a physical resource block end index.

21. The method according to claim 17 or 18, wherein: The at least one resource index includes a plurality of physical resource block indexes.

22. The method according to claim 17 or 18, wherein: The third power offset is the sum of the first power offset and the differential power offset.

23. The method according to claim 17, wherein: The at least one cell-specific transmit power offset is based on a location of the wireless device in the cell served by the network node.

24. The method according to claim 23, wherein: The determination of the location of the wireless device is based on a first reference signal received power, RSRP, from the network node and one or more RSRPs from one or more network nodes serving cells neighboring the cell.

25. A wireless communication device, comprising a processor and a memory, wherein: The processor is configured to read code from the memory and implement the method according to any one of claims 1 to 24.

26. A computer program product comprising computer readable program medium code stored thereon, which, when executed by a processor, causes the processor to implement the method according to any one of claims 1 to 24.

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