Maintaining a neighbor relations table in a cellular communication network

Abstract

A node in a cellular communication network receives reports of PCIs that are not globally unique from user equipment. The node determines whether to add the PCIs to a neighbor relation table (NRT) based on threshold conditions such as critical reports (only one PCI listed) including the PCI being greater than a critical threshold, non-critical reports including the PCI being greater than a non-critical threshold. Thresholds may be required to be met within a time limit. The node may add PCIs to the NRT without regard to the threshold conditions until a number of PCIs in the NRT reaches a threshold number. The threshold conditions may be evaluated with respect to globally unique identifiers associated with the PCIs.

Description

Title: MAINTAINING A NEIGHBOR RELATIONS TABLE IN A CELLULARCOMMUNICATION NETWORKBACKGROUNDFIELD OF THE INVENTION

[0001] This invention relates to maintaining a neighbor relations table (NRT) in a cellular communication network.BACKGROUND OF THE INVENTION

[0002] The 3 GPP (third generation partnership project) specification defines an “automatic neighbor relation” (ANR) functionality by which a node in a cellular communication network can automatically discover adjacent nodes. As used herein a “node” may be understood as an eNodeB or gNodeB computing device that manages radio connections to mobile devices in the cellular telecommunication network. The node may assembly a neighbor relations table (NRT) list that includes information used to handoff cellular calls and data connections to a neighboring node. The information in an NRT may include the absolute radio frequency control number (ARFCN), physical cell identifier (PCI), and a global identifier (e.g., EUTRAN Cell Global ID (ECGI)) of the neighboring node. The use of ANR and an NRT list relieves operators of the burden of manually configuring a cellular communication network.SUMMARY OF THE INVENTION

[0003] In one aspect of the invention, a first node of a cellular communication network is configured to receive a plurality of reports from user equipment. Each report of the plurality of reports includes one or more physical cell identifiers (PCI) identifying a second node of a plurality of second nodes in the cellular communication network. Thefirst node is configured to add each PCI included in the plurality of reports to a neighbor relation table (NRT) in response to a number of reports of the plurality of reports including the each PCI meeting one or more threshold conditions.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through use of the accompanying drawings, in which:

[0005] Fig. 1 is a diagram illustrating user equipment in a cellular communication network including multiple overlapping cells;

[0006] Fig. 2A is a process flow diagram of a method for adding PCIs to an NRT in accordance with an embodiment;

[0007] Fig. 2B is a process flow diagram of a method for adding PCIs to an NRT in accordance with an embodiment;

[0008] Fig. 3A is a process flow diagram of a method for adding PCIs to an NRT in accordance with an embodiment;

[0009] Fig. 3B is a process flow diagram of a method for handling adding of conflicting PCIs to an NRT in accordance with an embodiment;

[0010] Fig. 4A is a process flow diagram of a method for adding PCIs to an NRT in accordance with an embodiment;

[0011] Fig. 4B is a process flow diagram of a method for handling adding of conflicting PCIs to an NRT in accordance with an embodiment;

[0012] Fig. 5A is a process flow diagram of a method for adding PCIs to an NRT in accordance with an embodiment;

[0013] Fig. 5B is a process flow diagram of a method for handling adding of conflicting PCIs to an NRT in accordance with an embodiment;

[0014] Fig. 6 is a schematic block diagram of an example computing device suitable for implementing methods in accordance with embodiments according to the disclosure.DETAILED DESCRIPTION

[0015] Fig. 1 illustrates an example cellular communication network 100 in which a plurality of nodes 102a-102d are capable of communicating with user equipment 104 located within a cell 106a-106d defined by each node. The user equipment 104 may be a mobile phone or other device capable of cellular radio communication. The illustrated cells 106a-106d are shown as symmetrical about the nodes 102a-102d but directional antennas may be used to achieve asymmetrical cells. As shown, each cell 106a-106d may overlap one or more other cells 106a-106d. For example, an umbrella cell 106d may be much large and provide coverage for gaps between smaller cells 106a- 106c.

[0016] As shown in Fig. 1, the user equipment 104 may be located in multiple overlapping cells 106a-106d and may be in motion such that the user equipment 104 will eventually leave one of the overlapping cells 106a-106d. Therefore, one of the nodes 102a- 102d to which the user equipment 104 is currently connected will need to hand off the connection to another node 102a-102d and will use the NRT to do so. As used herein“connected” may include a node 102a-102d receiving packets of voice or other data in the context of a voice telephone call or data communication connection.

[0017] In the following example, node 102a refers to the node to which the user equipment 104 is currently connected and node 102b refers to one or more nodes to which the user equipment 104 is not currently connected but within whose cell 106b the user equipment 104 is located.

[0018] In anticipation of potential handoffs, the user equipment 104 transports reports to the node 102a, the reports including at least the PCI of one or more cells 106b within which the user equipment is located. The reports, referred to herein as “PCI reports,” may include information such as signal strength (e.g., reference signal receive power (RSRP) or reference signal receive quality (RSRQ)) for the cell 106b, ARFCN of the cell 106b, tracking area code (TAC), public land mobile network (PLMN) code, or other parameters. The PCI report may include a globally unique identifier of the cell 106b, referred to herein as a cell global identifier (CGI), or the CGI may be obtained later. The CGI may be implemented as ECGI or other type of global identifier. The PCI may be a relatively short value, such as nine bits, that is broadcasted by the node 102b within the cell 106b of the node 102b identified by the PCI. The CGI may be a much larger value, such as at least 28 bits, that is not as readily embedded and may be transmitted less frequently or only when the user equipment 104 is instructed to do so by the node 102a.

[0019] The node 102a stores the PCIs received in PCI reports in the NRT as a way to discover the configuration of the cellular communication and to facilitate performing handoffs for the user equipment 104 and other user equipment that subsequently enter the cell 106a. Storing a PCI may include storing some or all of other items of informationincluded in the PCI report. Inasmuch as the PCI is much shorter than the CGI, it is possible for multiple cells to have the same PCI. The NRT may therefore include an entry including a PCI in association with a first CGI and receive a report including the PCI in association with a second CGI, an event known as PCI confusion. In some embodiments, a PCI confusion results only if both of the PCI and the ARFCN for a CGI are the same as the PCI and ARFCN of another CGI. Adding a PCI to the NRT may therefore include adding creating an entry including all of the PCI, the CGI, and the ARFCN as reported by one or more items of user equipment.

[0020] Dealing with PCI confusion requires that one or more nodes be assigned a new PCI, resulting in a temporary outage. For example, suppose that 10 percent of PCIs in a cluster of 1000 cells are PCI confusions that could be eliminated. This would mean 100 cells would be impacted and about 50 of them would need to be restarted. If about 50 restarts could be avoided, then approximately 250 to 300 minutes of service outage could be saved. Likewise, any manual intervention required to deal with the PCI confusions would be reduced or eliminated. An algorithm used to resolve any remaining PCI confusions would likewise be able to converge on a solution sooner. In prior approaches, a pruning algorithm is used retrospectively to remove unused PCIs from the NRT. However, such algorithms are invoked only in response to occurrence of PCI confusions and therefore can still result in outages. Figures 2A to 5B illustrate methods that may be used to prospectively control adding of PCIs to the NRT of the node 102a in order to reduce the likelihood of PCI confusion.

[0021] Referring specifically to Fig. 2A, the method 200a may be executed by the node 102a. The method 200a includes receiving 202 a PCI report including a PCI of node102b. The method 200a may include obtaining 204 a CGI corresponding the PCI. The CGI may have been included in the PCI report or the node 102a may configure the user equipment 104 to transmit the CGI after receiving the PCI report followed by receiving the CGI from the user equipment 104, e.g., using the reportCGI function according to 3GPP.

[0022] The node 102a may then update 206 one or more counters. Examples of counters may include:• A critical counter indicating a number of units of user equipment that transmitted PCI reports in which the PCI is the only PCI included, referred to herein as “critical reports.”• A non-critical counter indicating a number of units of user equipment that reported the PCI.• A CGI-specific counter indicating a number of units of user equipment that reported the PCI in association with the CGI from step 204.

[0023] The method 200a may include evaluating the counters with respect to a frequency threshold. For example, the method 200a includes evaluating whether the critical counter is found 208 to indicate that a frequency of the critical reports for the PCI meets a first threshold condition, such as whether the number of critical reports for the PCI received within a first time window are greater than a critical threshold. The first time window may be a rolling time window preceding the time of execution of the method 200a or may be started upon receiving a first PCI report referencing the PCI from any user equipment.

[0024] In another example, the method 200a includes evaluating whether the non- critical counter is found 210 to indicate that a frequency of the non-critical reports for thePCI meets a second threshold condition, such as the number of non-critical reports for the PCI received within a second time window being greater than a non-critical threshold. The second time window may be a rolling time window preceding the time of execution of the method 200a or may be started upon receiving a first PCI report referencing the PCI from any user equipment. The second time window may be the same as or different from the first time window. The non-critical threshold may be much larger than the critical threshold, such as at least 5 times, at least 10 times, or at least 100 times greater.

[0025] Other counters as described above may additionally or alternatively be evaluated with respect to corresponding threshold conditions.

[0026] In some embodiments, if either of the first and second threshold conditions and / or one or more additional threshold conditions are all met, the PCI is added 212 to the NRT of the node 102a in association with the CGI from step 204. Otherwise, the PCI is not added to the NRT of the node 102a.

[0027] In other embodiments, the PCI is added 212 to the NRT of the node 102a in association with the CGI from step 204 only if both of the first and second threshold conditions are met. Otherwise, the PCI is not added to the NRT of the node 102a.

[0028] Fig. 2B illustrates an alternative method 200b that may be implemented by the node 102a. In the method 200b, in response to the PCI report received at step 202, a number of PCIs in the NRT is evaluated with respect to a threshold Noptimai. If the number is not greater then Noptimai, the PCI is added 212 to the NRT in association with the CGI from step 204. Otherwise, processing continues at step 206. Using the approach of Fig. 2B, the node 102a is able to populate an empty NRT up to a point where PCI confusion is more likely to occur, following which PCIs are added selectively, such as according to theconditions of one or both of steps 208 and 210. The NRT is therefore able to more quickly begin to perform its intended function.

[0029] The value of Noptimai may be a function of the configuration of the cellular communication network 100, such as geographic density of cells in the cellular communication network (increase Noptimai with increasing density) or cell radius (decrease Noptimai with increasing cell radius). The value of Noptimai may be determined experimentally: increase the value of Noptimai for the node 102a until the number of PCI confusions reaches a threshold, e.g., 1, 5, or 10 percent of PCIs stored in the NRT of a node.

[0030] Fig. 3 A illustrates an alternative method 300a that may be performed by the node 102a. The method 300a includes receiving 302 a PCI report (“the subject PCI report”) including a PCI for node 102b. The method 300a may include obtaining 304 a CGI corresponding the PCI. The CGI may have been included in the subject PCI report or the node 102a may configure the user equipment 104 to transmit the CGI after receiving the subject PCI report followed by receiving the CGI from the user equipment 104.

[0031] The method 300a may include evaluating 306 whether N is greater than Noptimai, where N is the number of PCIs included in the NRT of the node 102a. If not, the PCI is added 308 to the NRT in association with the CGI from step 304. If so, the subject PCI report may be further processed.

[0032] For example, the method 300a may include evaluating 310 whether the subject PCI report is a first report received by the node 102a that includes the PCI. If not, the method 300a may include evaluating 312 whether the CGI from step 304 is the same as the CGI of at least one prior PCI report including the PCI. If so, a counter MCGI for theCGI from step 204 is incremented 314. The counter MCGI, and any counter according to any method disclosed herein, may begin at zero each time the method is performed, including subsequent iterations after a previous iteration has ended.

[0033] The method 300a may include evaluating 316 whether the PCI is the only PCI included in the subject PCI report. If so, a counter Mcriticai is incremented 318, where Mcriticai is the number of PCI reports that only include the PCI and no other PCIs, i.e., indicate that the user equipment 104 is located in a single cell.

[0034] If the counter Mcriticai is found 320 to be greater than a critical threshold Mt2, the PCI is added 308 to the NRT in association with the CGI from step 304.

[0035] If the PCI is not found 316 to be the only PCI, the method 300a may include evaluating 322 whether the counter MCGI is greater than a non-critical threshold Mu. If so, the PCI is added 308 to the NRT in association with the CGI from step 304. Mti may be much greater than Me, such as at least 5 times, at least 10 times, or at least 100 times greater.

[0036] To account for frequency of reports including the PCI, a timer may be defined. The timer may be a time window preceding the time the subject PCI report was received 302 or a timer counting down from a predefined value, the timer starting when a first report including the PCI was received.

[0037] The method 300a may include evaluating 324 whether the timer has expired without the threshold conditions of one or both of steps 320 and 322 being met. If so, the method 300a may include refraining 326 from adding the PCI to the NRT and ending the method 300a. If not, the method 300a may continue with step 302 at which a subsequentPCI report is received from different user equipment and processed as “the subject PCIreport.”

[0038] if the subject PCI report is found 310 to be the first PCI report, the timer is started 310a counting down from a predefined value or up to the predefined value and processing continues at step 302 for a subsequent PCI report as “the subject PCI report.” Step 324 may be performed if the CGI from step 304 is not found 312 to be the same as a prior report including the PCI.

[0039] Fig. 3B illustrates a method 300b that may be performed by the node 102a alone or in conjunction with the method 300a. The method 300b includes receiving 302 a PCI report (“the subject PCI report”) including a PCI for node 102b. The method 300b may include obtaining 304 a CGI corresponding the PCI. The CGI may have been included in the subj ect PCI report or the node 102a may configure the user equipment 104 to transmit the CGI after receiving the subject PCI report followed by receiving the CGI from the user equipment 104.

[0040] The method 300b may include evaluating 330 whether the CGI from step 304 is the same as the CGI of an entry in the NR.T of the node 102a. If so, the method 300b ends. If not, subject PCI report may be processed further.

[0041] For example, the method 300b may include evaluating 316 whether the PCI is the only PCI included in the subject PCI report. If so, a counter Mcriticai is incremented 318, where Mcriticai is the number of PCI reports that only include the PCI and no other PCIs, i.e., indicate that the user equipment 104 is located in a single cell. If the counter Mcriticai is found 320 to be greater than a critical threshold Mt2, the PCI is added 308 to the NRT in association with the CGI from step 304. Adding 308 the PCI may further include ending the method 300b. As is apparent, this will result in PCI confusion. However, sincethe PCI is critical for the user equipment 104, the PCI confusion may be handled according to any approach known in the art.

[0042] If the PCI is not found 316 to be the only PCI in the subject PCI report, the method 300b may include incrementing 332 a counter MCGO, which is the number of times the node 102a has received PCI Reports including the PCI in association with the CGI received at step 304. If the value of MCGI2 is found 334 to exceed a non-critical threshold MB, then the PCI is added 308 to the NRT in association with the CGI from step 304. The value of Mt3 may be much greater than Mu, such as at least 5 times, at least 10 times, or at least 100 times greater.

[0043] The method 300b may include evaluating 324 whether a timer has expired without the threshold of at least one of steps 320 and 334 being met. If so, the method 300b may include refraining 326 from adding the PCI to the NRT and ending the method 300b. If not, the method 300b may continue with step 302 at which a subsequent PCI report is received from different user equipment and processed as “the subject PCI report.” The time for the method 300b may start down from a predefined value or up to the predefined value upon receipt of a first PCI report including a PCI that is already present in the NRT or a first PCI report including the PCI following a previous iteration of the method 300b.

[0044] Fig. 4A illustrates an alternative method 400a that may be performed by the node 102a. The method 400a includes receiving 402 a PCI report (“the subj ect PCI report”) including a PCI for node 102b. The method 400a may include evaluating 404 whether the PCI is the only PCI included in the subject PCI report. If so, a counter Mcriticai is incremented 406, where Mcriticai is the number of PCI reports that only include the PCI andno other PCIs, i.e., indicate that the user equipment 104 is located in a single cell.

[0045] In either case, the method 400a may include obtaining 408 a CGI corresponding the PCI. The CGI may have been included in the subject PCI report or the node 102a may configure the user equipment 104 to transmit the CGI after receiving the subject PCI report followed by receiving the CGI from the user equipment 104.

[0046] The method 400a may include evaluating 410 whether N is greater than Noptimai, where N is the number of PCIs included in the NRT of the node 102a. If not, the PCI is added 412 to the NRT in association with the CGI from step 408. If so, the subject PCI report may be further processed. Adding 412 the PCI may further include ending the method 400a.

[0047] For example, the method 400a may include evaluating 414 whether the subject PCI report is a first report received by the node 102a that includes the PCI. If not, the method 300a may include evaluating 416 whether the CGI from step 304 is the same as the CGI of at least one prior PCI report including the PCI. If so, a counter MCGI for the CGI from step 408 is incremented 418.

[0048] If the counter MCGI is found 420 to be greater than a non-critical threshold Mti and if the counter Mcriticai is found 422 to be greater than a critical threshold Mt2, the PCI is added 412 to the NRT in association with the CGI from step 304.

[0049] To account for frequency of reports including the PCI a timer may be defined. The timer may be a time window preceding the time the subject PCI report was received 402 or a timer counting down from a predefined value or up to the predefined value, the timer starting when a first report including the PCI was received.

[0050] The method 400a may include evaluating 424 whether the timer has expiredwithout the threshold conditions of one or both of steps 420 and 322 being met. If so, the method 400a may include refraining 426 from adding the PCI to the NRT and ending the method 400a. If not, the method 400a may continue with step 402 at which a subsequent PCI report is received from different user equipment and processed as “the subject PCI report.”

[0051] If the subject PCI report is found 414 to be the first report including the PCI, the timer is started 414a and processing continues at step 402 for a subsequent PCI report as “the subject PCI report.” Step 424 may be performed where step 416 finds the CGI from step 408 to be different from the CGI associated with a prior report including the PCI.

[0052] Fig. 4B illustrates a method 400b that may be performed by the node 102a alone or in conjunction with the method 400b. The method 400b includes receiving 402 a PCI report (“the subject PCI report”) including a PCI for node 102b. The method 400b may include evaluating 404 whether the PCI is the only PCI included in the subject PCI report. If so, a counter Mcnticai is incremented 406, where Mcnticai is the number of PCI reports that only include the PCI and no other PCIs, i.e., indicate that the user equipment 104 is located in a single cell.

[0053] In either case, the method 400b may include obtaining 408 a CGI corresponding the PCI. The CGI may have been included in the subject PCI report or the node 102a may configure the user equipment 104 to transmit the CGI after receiving the subject PCI report followed by receiving the CGI from the user equipment 104.

[0054] The method 400b may include evaluating 430 whether the CGI from step 404 is the same as the CGI of an entry in the NRT of the node 102a. If so, the method 400b ends. If not, subject PCI report may be processed further.

[0055] For example, the method 400b may include incrementing 432 a counter MCGI2, which is the number of times the node 102a has received PCI Reports including the PCI in association with the CGI received at step 408. If the value of MCGI2 is found 434 to exceed a non-critical threshold Mt3 and the value of Mcriticai is found 436 to exceed a critical threshold Mt2, then the PCI is added 412 to the NRT in association with the CGI from step 408. Adding 412 the PCI may further include ending the method 400b. The value of Mt3 may be much greater than Mu, such as at least 5 times, at least 10 times, or at least 100 times greater.

[0056] The method 400b may include evaluating 424 whether a timer has expired without the threshold conditions of both of steps 434 and 436 being met. If so, the method 400b may include refraining 426 from adding the PCI to the NRT and ending the method 400b. If not, the method 400b may continue with step 402 at which a subsequent PCI report is received and processed as “the subject PCI report.” The time for the method 400b may start counting down from a predefined value or up to the predefined value upon receipt of a first PCI report including a PCI that is already present in the NRT or a first PCI report received following a previous iteration of the method 400b.

[0057] Fig. 5A illustrates an alternative method 500a that may be performed by the node 102a. The method 500a may be characterized as lacking an initial phase in which PCIs are added to the NRT until N = Noptimai.

[0058] The method 500a includes receiving 502 a PCI report (“the subject PCI report”) including a PCI for node 102b. The method 500a may include obtaining 504 a CGI corresponding the PCI. The CGI may have been included in the subject PCI report or the node 102a may configure the user equipment 104 to transmit the CGI after receivingthe subject PCI report followed by receiving the CGI from the user equipment 104.

[0059] For example, the method 500a may include evaluating 506 whether the subject PCI report is a first report received by the node 102a that includes the PCI. If so, the method 500a may include starting 508 a timer counting down from a predefined value or counting up to the predefined value and continuing processing from step 502 with a subsequent PCI report being processed as “the subject PCI report.” If not, the method 500a may include evaluating 510 whether the CGI from step 504 is the same as the CGI of at least one prior PCI report including the PCI. If so, a counter Mevai is incremented 512. In some embodiments, Mevai is incremented only once per iteration of the method 500a for each item of user equipment reporting the PCI.

[0060] The method 500a may include evaluating 514 whether all PCIs referenced in the PCI report are unknown. As used herein “unknown” may mean (a) not reported in any previous PCI report received by the node 102a or (b) not in the NRT. If all of the PCIs in the subject PCI report are unknown, then all of the PCIs are added 516 to the NRT along with corresponding CGIs obtained from the user equipment, such as at step 504. In some applications, only one PCI is included per PCI report. Adding 516 the PCI may further include ending the method 500a.

[0061] The method 500b may include evaluating 518 whether Mevai is greater that a threshold Mt. If so, the PCI is added 516 to the NRT along with the CGI obtained for the PCI at step 504.

[0062] If not, method 500a may include evaluating 520 whether the timer has expired without the threshold conditions of step 518 being met. If so, the method 500a may include refraining 522 from adding the PCI to the NRT and ending the method 500a.If not, the method 500a may continue with step 502 at which a subsequent PCI report is received and processed as “the subject PCI report.” Step 520 may also be performed in the case that the CGI from step 504 is found 510 not to be the same as the CGI associated with a previous PCI report for the PCI.

[0063] Fig. 5B illustrates an alternative method 500b that may be performed by the node 102a alone or in conjunction with the method 500a. The method 500a includes receiving 502 a PCI report (“the subject PCI report”) including a PCI for node 102b. The method 500b may include obtaining 504 a CGI corresponding the PCI. The CGI may have been included in the subject PCI report or the node 102a may configure the user equipment 104 to transmit the CGI after receiving the subject PCI report followed by receiving the CGI from the user equipment 104.

[0064] The method 500b may include evaluating 506 whether the subject PCI report is a first report received by the node 102a that includes the PCI. If so, the method 500b may include starting 508 a timer counting down from a predefined value or counting up to the predefined value and continuing processing from step 502 with a subsequent PCI report being processed as “the subject PCI report.”

[0065] If not, the method 500b may include evaluating 530 whether the CGI from step 504 is the same as the CGI of an entry in the NRT of the node 102a. If not, the subject PCI report may be processed further.

[0066] For example, the method 500b may include evaluating 532 whether the PCI is the only PCI included in the PCI report. If so, the PCI is added 516 to the NRT in association with the CGI from step 504. Adding 516 the PCI may further include ending the method 500b. As is apparent, the method 500b does not count critical reports or use acritical threshold. However, the method 500b may be related to the other methods disclosed herein as having a critical threshold of zero, i.e., a single critical report being sufficient to invoke adding of a PCI to the NRT.

[0067] If not, a counter Mevai is incremented 514. In some embodiments, Mevai is incremented only once per iteration of the method 500b for each item of user equipment reporting the PCI. The method 500b may include evaluating whether Mevai is greater that a threshold Mt. If so, the PCI is added 516 to the NRT along with the CGI obtained for the PCI at step 504.

[0068] If not, method 500a may include evaluating 520 whether the timer has expired without the threshold conditions of step 518 being met. If so, the method 500b may include refraining 522 from adding the PCI to the NRT and ending the method 500b. If not, the method 500b may continue with step 502 at which a subsequent PCI report is received and processed as “the subject PCI report.” Step 520 may also be performed in the case that the CGI from step 504 is found 530 to be included in the NRT.

[0069] The values for threshold used herein such as Mti, Mt2, Mo, and Mt and the predefined value used for timers according to any of the preceding embodiments may be a function of the configuration of the cellular communication network 100. For example, a threshold M representing any of the previously listed thresholds and a predefined value T for a timer according to any of the embodiments disclosed herein may have a correspondence to the configuration of the cellular communication network 100 as shown in Table 1. As is apparent, as the cell radius decreases, the value of T decreases and the value of M increases. The values of M and T may be a function of cell radius such as a linear, quadratic, or other monotonic function.Table 1. Example values for M and T

[0070] Fig. 6 is a block diagram illustrating an example computing device 600. Computing device 600 may be used to perform various procedures, such as those discussed herein. The nodes 102a-102d and user equipment 104 may have some or all of the attributes of the computing device 600.

[0071] Computing device 600 includes one or more processor(s) 602, one or more memory device(s) 604, one or more interface(s) 606, one or more mass storage device(s) 608, one or more Input / output (I / O) device(s) 610, and a display device 630 all of which are coupled to a bus 612. Processor(s) 602 include one or more processors or controllers that execute instructions stored in memory device(s) 604 and / or mass storage device(s) 608. Processor(s) 602 may also include various types of computer-readable media, such as cache memory.

[0072] Memory device(s) 604 include various computer-readable media, such as volatile memory (e.g., random access memory (RAM) 614) and / or nonvolatile memory (e.g., read-only memory (ROM) 616). Memory device(s) 604 may also include rewritable ROM, such as Flash memory.

[0073] Mass storage device(s) 608 include various computer readable media, such as magnetic tapes, magnetic disks, optical disks, solid-state memory (e.g., Flash memory), and so forth. As shown in Fig. 6, a particular mass storage device is a hard disk drive 624.Various drives may also be included in mass storage device(s) 608 to enable reading from and / or writing to the various computer readable media. Mass storage device(s) 608 include removable media 626 and / or non-removable media.

[0074] I / O device(s) 610 include various devices that allow data and / or other information to be input to or retrieved from computing device 600. Example I / O device(s) 610 include cursor control devices, keyboards, keypads, microphones, monitors or other display devices, speakers, printers, network interface cards, modems, lenses, CCDs or other image capture devices, and the like.

[0075] Display device 630 includes any type of device capable of displaying information to one or more users of computing device 600. Examples of display device 630 include a monitor, display terminal, video projection device, and the like.

[0076] Interface(s) 606 include various interfaces that allow computing device 600 to interact with other systems, devices, or computing environments. Example interface(s) 606 include any number of different network interfaces 620, such as interfaces to local area networks (LANs), wide area networks (WANs), wireless networks, and the Internet. Other interface(s) include user interface 618 and peripheral device interface 622. The interface(s) 606 may also include one or more peripheral interfaces such as interfaces for printers, pointing devices (mice, track pad, etc ), keyboards, and the like.

[0077] Bus 612 allows processor(s) 602, memory device(s) 604, interface(s) 606, mass storage device(s) 608, I / O device(s) 610, and display device 630 to communicate with one another, as well as other devices or components coupled to bus 612. Bus 612 represents one or more of several types of bus structures, such as a system bus, PCI bus, IEEE 1394 bus, USB bus, and so forth.

[0078] For purposes of illustration, programs and other executable program components are shown herein as discrete blocks, although it is understood that such programs and components may reside at various times in different storage components of computing device 600, and are executed by processor(s) 602. Alternatively, the systems and procedures described herein can be implemented in hardware, or a combination of hardware, software, and / or firmware. For example, one or more application specific integrated circuits (ASICs) can be programmed to carry out one or more of the systems and procedures described herein.

[0079] In the above disclosure, reference has been made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific implementations in which the disclosure may be practiced. It is understood that other implementations may be utilized and structural changes may be made without departing from the scope of the present disclosure. References in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0080] Implementations of the systems, devices, and methods disclosed herein may comprise or utilize a special purpose or general-purpose computer including computerhardware, such as, for example, one or more processors and system memory, as discussed herein. Implementations within the scope of the present disclosure may also include physical and other computer-readable media for carrying or storing computer-executable instructions and / or data structures. Such computer-readable media can be any available media that can be accessed by a general purpose or special purpose computer system. Computer-readable media that store computer-executable instructions are computer storage media (devices). Computer-readable media that carry computerexecutable instructions are transmission media. Thus, by way of example, and not limitation, implementations of the disclosure can comprise at least two distinctly different kinds of computer-readable media: computer storage media (devices) and transmission media.

[0081] Computer storage media (devices) includes RAM, ROM, EEPROM, CD- ROM, solid state drives (“SSDs”) (e.g., based on RAM), Flash memory, phase-change memory (“PCM”), other types of memory, other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store desired program code means in the form of computer-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer.

[0082] An implementation of the devices, systems, and methods disclosed herein may communicate over a computer network. A “network” is defined as one or more data links that enable the transport of electronic data between computer systems and / or modules and / or other electronic devices. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a computer, the computer properly views theconnection as a transmission medium. Transmissions media can include a network and / or data links, which can be used to carry desired program code means in the form of computerexecutable instructions or data structures and which can be accessed by a general purpose or special purpose computer. Combinations of the above should also be included within the scope of computer-readable media.

[0083] Computer-executable instructions comprise, for example, instructions and data which, when executed at a processor, cause a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. The computer executable instructions may be, for example, binaries, intermediate format instructions such as assembly language, or even source code. Although the subject matter has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the described features or acts described above. Rather, the described features and acts are disclosed as example forms of implementing the claims.

[0084] Those skilled in the art will appreciate that the disclosure may be practiced in network computing environments with many types of computer system configurations, including, an in-dash vehicle computer, personal computers, desktop computers, laptop computers, message processors, hand-held devices, multi-processor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, mobile telephones, PDAs, tablets, pagers, routers, switches, various storage devices, and the like. The disclosure may also be practiced in distributed system environments where local and remote computer systems, which arelinked (either by hardwired data links, wireless data links, or by a combination of hardwired and wireless data links) through a network, both perform tasks. In a distributed system environment, program modules may be located in both local and remote memory storage devices.

[0085] Further, where appropriate, functions described herein can be performed in one or more of: hardware, software, firmware, digital components, or analog components. For example, one or more application specific integrated circuits (ASICs) can be programmed to carry out one or more of the systems and procedures described herein. Certain terms are used throughout the description and claims to refer to particular system components. As one skilled in the art will appreciate, components may be referred to by different names. This document does not intend to distinguish between components that differ in name, but not function.

[0086] It should be noted that the sensor embodiments discussed above may comprise computer hardware, software, firmware, or any combination thereof to perform at least a portion of their functions. For example, a sensor may include computer code configured to be executed in one or more processors, and may include hardware logic / electrical circuitry controlled by the computer code. These example devices are provided herein purposes of illustration, and are not intended to be limiting. Embodiments of the present disclosure may be implemented in further types of devices, as would be known to persons skilled in the relevant art(s).

[0087] At least some embodiments of the disclosure have been directed to computer program products comprising such logic (e.g., in the form of software) stored onany computer useable medium. Such software, when executed in one or more data processing devices, causes a device to operate as described herein.

[0088] While various embodiments of the present disclosure have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the disclosure. Thus, the breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. The foregoing description has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. Further, it should be noted that any or all of the aforementioned alternate implementations may be used in any combination desired to form additional hybrid implementations of the disclosure.

Claims

Claims:

1. A system comprising: a first node of a cellular communication network, the first node configured to: receive a plurality of reports from a plurality of items of user equipment, each report of the plurality of reports including one or more physical cell identifiers (PCI) each identifying a second node of a plurality of second nodes in the cellular communication network; and adding each PCI included in the plurality of reports to a neighbor relation table (NRT) in response to a number of reports of the plurality of reports including the each PCI meeting one or more threshold conditions.

2. The system of claim 1, wherein the one or more threshold conditions include a number of the plurality of reports including the each PCI being greater than a threshold.

3. The system of claim 1, wherein the one or more threshold conditions include a number of the plurality of reports including only the each PCI being greater than a threshold.

4. The system of claim 1, wherein the one or more threshold conditions include both of: a number of the plurality of reports including the each PCI being greater than a first threshold; anda number of the plurality of reports including only the each PCI being greater than a second threshold.

5. The system of claim 4, wherein the first threshold is at least 5 times the second threshold.

6. The system of claim 5, wherein the first threshold is at least 100 times the second threshold.

7. The system of claim 1, wherein the one or more threshold conditions include a number of the plurality of reports including the each PCI received prior to expiration of a timer being greater than a threshold.

8. The system of claim 1, wherein the one or more threshold conditions include a number of the plurality of reports including only the each PCI received prior to expiration of a timer being greater than a threshold.

9. The system of claim 1, wherein the one or more threshold conditions include both of: a number of the plurality of reports including the each PCI received prior to expiration of a timer being greater than a first threshold; and a number of the plurality of reports including only the each PCI received prior to expiration of a timer being greater than a second threshold.

10. The system of claim 1, wherein the one or more threshold conditions include a number of the plurality of reports including the each PCI and associated with a same globally unique identifier and received prior to expiration of a timer being greater than a threshold.

11. The system of claim 1, wherein the one or more threshold conditions include a number the plurality of reports including only the each PCI and associated with a same globally unique identifier and received prior to expiration of a timer being greater than a threshold.

12. The system of claim 1, wherein the one or more threshold conditions include both of a number of the plurality of reports including the each PCI and associated with a same globally unique identifier and received prior to expiration of a timer being greater than a first threshold; and a number of the plurality of reports including only the each PCI and associated with the same globally unique identifier and received prior to expiration of a timer being greater than a second threshold.

13. The system of claim 1, wherein first node is further configured to: add PCIs included in the plurality of reports to the NRT without evaluating the one or more threshold conditions until a number of PCIs in the NRT reaches a threshold number.

14. The system of claim 1, wherein first node is further configured to, for each report of the plurality of reports: add all of the one or more PCI included in the each report to the NRT without evaluating the one or more threshold conditions if all of the one or more PCI included in the each report are not currently included in the NRT.

15. The system of claim 1, wherein the first node is further configured to manage handoffs of radio connections to the plurality of items of user equipment using the NRT.

16. A method compri sin : receiving, by a first node in a cellular communication network, a plurality of reports from a plurality of items of user equipment, each report of the plurality of reports including one or more physical cell identifiers (PCI) of one or more second nodes of the cellular communication network; and adding each PCI included in the plurality of reports to a neighbor relation table (NRT) in response to a number of the plurality of reports that include the each PCI meeting one or more threshold conditions.

17. The method of claim 16, wherein the one or more threshold conditions includes: a number of the plurality of reports including the each PCI being greater than a first threshold; ora number of the plurality of reports including only the each PCI being greater than a second threshold, the first threshold being at least 5 times the second threshold.

18. The method of claim 16, wherein the one or more threshold conditions includes: a number of the plurality of reports including the each PCI and associated with a same globally unique identifier and received prior to expiration of a timer being greater than a first threshold; or a number of the plurality of reports including only the each PCI and associated with the same globally unique identifier and received prior to expiration of a timer being greater than a second threshold.

19. The method of claim 16, further comprising: adding, by the first node, the one or more PCI included in the each report to the NRT without evaluating the one or more threshold conditions if all of the one or more PCI included in the each report are not currently included in the NRT.

20. A non-transitory computer-readable medium storing computer code that, when executed by one or more processing devices, causes the one or more processing devices to perform a method comprising: receiving, by a first node in a cellular communication network, a plurality of reports from a plurality of items of user equipment, each report of the plurality of reports including one or more physical cell identifiers (PCI) of one or more second nodes of the cellular communication network; and adding each PCI included in the plurality of reports to a neighbor relation table (NRT) in response to a number of the plurality of reports that include the each PCI meeting one or more threshold conditions.

Images