User equipment identification of target cell for cell handover

Abstract

A user equipment (UE) employs a historical profile of previous handovers to respond to a measurement report associated with a cell handover. The historical profile indicates a preferred cell, among a plurality of available cells, wherein the preferred cell is associated with a threshold number of previously successful handovers. Accordingly, by employing the historical profile to respond to the measurement report request, the UE is able to influence the network to select the preferred cell.

Description

USER EQUIPMENT IDENTIFICATION OF TARGET CELL FOR CELL HANDOVERBACKGROUND

[0001] A user equipment (UE) is configured to attach to a cellular network within range. To establish a data connection between the UE and an attached cellular network, the UE includes a modem to transmit data to and receive data from the cellular network and a subscriber identity module (SIM) device that stores identification and subscriber information associated with the user equipment. The UE connects to a designated cell of the cellular network via a base station assigned to the cell.

[0002] Each cell provides network connectivity for a corresponding location (geographic area). To provide robust communication as the UE moves between locations, a cellular network typically provides a protocol, referred to as cell handover, wherein the UE is disconnected from one cell (associated with the previous location) and connected to a different cell. However, existing cell handover processes can have an undesirable rate of handover failure, wherein the UE fails to connect to the new cell, thus resulting in a poor user experience.BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference symbols in different drawings indicates similar or identical items.

[0004] FIG. 1 is a block diagram of a cellular communications system in which a UE responds to a cell handover measurement report request based on a stored historical profile of previous handovers in accordance with some embodiments.

[0005] FIG. 2 is a block diagram of aspects of the UE of FIG. 1 that support responding to a request for measurement report based on the historical profile in accordance with some embodiments.

[0006] FIG. 3 is a diagram of the historical profile of FIGs 1 and 2 in accordance with some embodiments.

[0007] FIG. 4 is a flow diagram of a method of employing a historical profile of previous handovers to respond to a measurement report request for cell handover in accordance with some embodiments.DETAILED DESCRIPTION

[0008] FIGs. 1-4 illustrate example techniques for employing, at a UE, a historical profile of previous handovers to respond to a measurement report associated with a cell handover. In at least some cases, the historical profile indicates a preferred cell, among a plurality of available cells, wherein the preferred cell is associated with a threshold number of previously successful handovers. Accordingly, by employing the historical profile to respond to the measurement report request, the UE is able to influence the network to select the preferred cell, thus increasing the likelihood of a successful cell handover and improving the user experience.

[0009] To illustrate, at least some cellular networks, including the 5thgeneration (5G) mobile network, perform a cell handover via a measurement report (MR). In particular, when the network determines that a UE is nearing the border of the location associated with the UE’s currently connected cell, the network can send an MR request to the UE. The MR request instructs the UE to provide a MR for a plurality of cells that are available for handover. Conventionally, in response to the MR request, the UE performs signal measurements for each cell, such as Reference Signal Received Power (RSRP) measurements, Reference Signal Received Quality (RSRQ) measurements, Signal to Interference & Noise Ratio (SINR) measurements, and the like, or any combination thereof, for each cell. The UE generates the MR, including the measurements for each of the plurality of cells, and communicates the MR to the network. Based on the MR, the network selects one of the plurality of cells and commands the UE to connect to the selected cell, thus completing the handover. However, in at least some cases the network may select a cell with a historically high handover failure rate, at least relative to the other cells. The network thus increasesthe likelihood of a handover failure, thereby causing the UE to perform a relatively lengthy cell rescan process.

[0010] Using the techniques disclosed herein, the UE records, for each cell handover, the success rate of handover from a source cell to a target cell. The UE thus generates a historical profile of cell handovers, indicating the success rate for a plurality of source cell-target cell pairs. In some embodiments, in response to receiving an MR request indicating a plurality of target cells for measurement, the UE employs the historical profile to identify the source-target cell pair with the highest handover success rate and designated the identified target cell as the preferred target cell. The UE then generates an MR that increases the likelihood that the network will select the preferred target cell for handover. For example, in some embodiments the UE stores a previous MR that triggered a successful handover to the preferred cell. In response to the MR request, the UE provides the stored MR as the requested management report, rather than generating a new management report. In other embodiments, the UE generates the MR report with adjusted measurement values so that the preferred cell is indicated as having the highest signal strengths. The UE thus increases the likelihood that the network will select the preferred cell for handover, thus increasing the overall handover success rate for the UE and improving the user experience.

[0011] In some cases, even when the UE indicates a preferred cell for handover (e.g., by communicating a stored MR report as described herein), the network instructs the UE to connect to a different cell resulting in a handover failure. In some embodiments, in response to such a handover failure, the UE prioritizes the preferred cell for scanning, over other available cells, resulting in the preferred cell being scanned relatively early (e.g., first) in the scanning process, and increasing the likelihood that the preferred cell is subsequently selected by the network for handover.

[0012] FIG. 1 is a block diagram of a cellular communications system 100 a stored historical profile of previous handovers is employed to respond to measurement report requests in accordance with some embodiments. As shown, the system 100 includes a user equipment (UE) 102 and a UE-facing network 110. In at least someembodiments, the network 110, in turn, is connected to at least one public data network (PDN) (not shown) or another larger-scale network, such as the Internet The UE 102 can be any of a variety of electronic wireless communication devices, such as a cellular phone, a cellular-enabled tablet computer or cellular-enabled notebook computer, a cellular-enabled watch or another wearable device, an automobile or other vehicle employing cellular services (e.g., for navigation, provision of entertainment services, in-vehicle mobile hotspots, etc.), a cellular access point (or “hot spot), and the like.

[0013] In some embodiments, the cellular infrastructure network 110 includes a core network and a plurality of edge networks, or radio access networks (RANs), connected via a backhaul infrastructure. Each edge network includes a plurality of cells (e.g., cells 112-115), wherein each cell includes a corresponding base station operable to wirelessly communicate with UEs within signal range based on one or more radio access technologies (RATs). Examples of the base station include, for example, a NodeB (or base transceiver station (BTS)) for a Universal Mobile Telecommunications System (UMTS) RAN implementation (also known as “3G”), an enhanced NodeB (eNodeB) for a 4G LTE RAN implementation, a 5G Node B (gNB) for a 5G NR RAN implementation, and the like. As is well known in the art, the base station of a cell operates as an “air interface” to establish radio frequency (RF) wireless connections with UEs, and these wireless connections (or “links”) then serve as data and voice paths between the UEs and the core networks for providing various services to the UEs, including voice services via circuit-switched networks or packet-switched networks, messaging services such as simple messaging service (SMS) or multimedia messaging service (MMS), multimedia content delivery, presence services, and the like. For ease of illustration, network 110 is described in various scenarios below as a 5G NR radio access network (RAN), and thus each of the cells 112-115 includes a gNB in such scenarios. However, it will be appreciated that the cells 112-115 are not limited to this example configuration and instead, could be, for example, cells including a 4G LTE RAN (e.g., an eNB).

[0014] Each of the cells 112-115 provides connectivity to the network 110 for UEs over a corresponding location (geographic area). Furthermore, to ensure robustnessof connectivity, the cells of the network 110 are configured to provide connectivity to each location in overlapping fashion, such that multiple cells provide connectivity for an individual location. Thus, for example, the cells 112-114 each provide connectivity to the UE 102 for a given location. However, because of the differing locations of the base stations corresponding to the cells 112-114, each of the cells 112-114 may provide different signal strength, and thus different reliability and robustness of connectivity, at a particular point within the location.

[0015] When the UE 102 is connected to the network 110 via a given cell, the UE 102 is referred to herein as being camped on that cell. As the UE 102 moves while being camped on a cell, the network 110 may determine that the UE 102 is likely to move out of the location corresponding to the camped cell, and thus transfer the connection of the UE 102 to a different cell. This process is referred to as a handover of the UE 102 from a source cell (the cell on which the UE 102 is camped) to a target cell (the new cell to which the UE 102 is to connect). In some cases, the network 110 may determine that the UE 102 is moving to a location for which multiple cells provide connectivity. These multiple cells are referred to herein as “candidate cells” with respect to the handover process. During the handover process, the network 110 identifies the candidate cells, identifies which of the candidate cells is to be the target cell, and sends a command to the UE 102 to connect to the target cell. In response, the UE 102 uses an internal modem to connect to the target cell, thus camping on the target cell and completing the handover.

[0016] In at least some cases, the network 110 identifies the target cell by issuing a management report (MR) request 108 to the UE 102 for one or more of the candidate cells. The MR request 108 represents a request by the network 110 for the UE 102 to perform one or more signal strength tests for one or more of the candidate cells, and to provide the results of the tests via an MR response 106. In some embodiments, the MR request 108 is a Radio Resource Control (RRC) message that configures a management object (not shown) stored at the UE 102. Based on the configuration of the management object, the UE 102 takes responsive action, such as executing one or more of the signal strength tests, and generates an MR. The UE102 provides the MR to the network 110 via the MR response 106. Based on the MR, the network 110 selects the target cell.

[0017] In some cases, the network 110 may select a target cell to which the UE 102 is unable to connect because of signaling issues or other connection issues. When a UE is unable to connect to the target cell, this is referred to herein as handover failure. In response to a handover failure, the UE 102 can take corrective action, such as scanning for cells, communicating the results of the scanning to the network 110, waiting for the network 110 to select a new target cell, and connecting to the new target cell. However, these corrective actions can consume system resources, including power, and can also interfere with user communication with the network 110. Accordingly, to reduce the likelihood of handover failure and thus conserve system resources, the UE 102 is configured to generate and maintain a handover (HO) historical profile 104, indicating the rate of successful handovers from a set of source cells to corresponding target cells. The UE 102 employs the HO historical profile 104 to generate the MR response 106 such that a cell having a high rate of handover success is more likely to be selected by the network 110 as the target cell, thus increasing the likelihood of a successful handover and conserving system resources.

[0018] To illustrate, in response to the network 110 indicating initiation of a handover (e.g., via the MR request 108 or other message), the UE 102 uses the HO historical profile 104 to identify the handover success rates for each of the candidate cells from the source cell. The UE 102 then designates the candidate cell having the highest handover success rate as the preferred cell. The UE 102 generates the MR response 106 so that the network 110 is more likely to select the preferred cell as the target cell for handover. For example, in some embodiments the UE 102, in some embodiments the UE 102 stores a previous MR, for a previous handover instance, that resulted in the network 110 selecting from among the candidate cells, the preferred cell as the target cell. Instead of generating a new MR, the UE 102 provides the stored MR as the MR response 106, thus increasing the likelihood that the network 110 will select the preferred cell as the target cell.

[0019] In some embodiments, rather than employ a previous MR, the UE 102 generates a new MR, but generates or adjusts the new MR so that the preferred cell is indicated as having better connectivity characteristics, such as signal power, than the other candidate cells. For example, in some embodiments the UE 102 performs signal measurements for each candidate cell in response to the MR request 108. If the signal measurements indicate that the preferred cell has similar or less connectivity than at least one of the other target cells, the UE 102 adjusts the signal measurements for the preferred cell, so that the preferred cell is indicated as having better connectivity than the other target cells. The UE 102 provides the adjusted signal measurements to the network 110 via the MR response 106, thus increasing the likelihood that the network 110 will select the preferred cell as the target cell.

[0020] In some cases, even when the UE 102 generates the MR request to indicate the preferred cell, the network 110 commands the UE 102 to connect to a different (non-preferred) target cell. Furthermore, in some cases this command results in a handover failure. In some embodiments, in such cases the UE 102 is configured to prioritize the preferred cell for scanning, thereby increasing the likelihood that the network 110 selects the preferred cell after the handover failure.

[0021] FIG. 2 illustrates an example hardware configuration for the UE 102 in support of employing the HO historic profile 104 to respond to MR requests in accordance with some embodiments. For purposes of description, it is assumed that the UE 102 is any device that is capable of connecting to one or more cellular networks using a subscriber identity module (SIM). Thus, in different embodiments, the UE 102 is a smartphone, a computer (e.g., a desktop or laptop computer), a wearable device (e.g., a smartwatch), a game console, a vehicular entertainment or navigation unit, and the like.

[0022] In the depicted example, the UE 102 includes a central processing unit (CPU) or other general processor 220, a modem 224, a memory 225, and a SIM 221 . In some embodiments, the UE 102 includes additional circuitry to support wireless network connections, such as a wireless local area network (WLAN) transceiver and modem, at least one WLAN antenna suitable for radio frequency (RF) signaling and signal processing in one or more frequency bands typically associated with WLANconnections, an RF transceiver, and at least one RF antenna suitable for RF signaling and signal processing in frequency bands associated with cellular radio access technologies (RATs). Further, it will be appreciated that the UE 102 can include a number of additional components omitted from FIG. 1 for ease of illustration, including, for example, one or more displays, one or more touchscreens, keypads, mice, touchpads, microphones, speakers, and other user input / output devices, one or more sensors, batteries or other power sources, graphical processing units (GPUs) or other coprocessors, and the like.

[0023] As a general operational overview, the general processor 220 executes executable instructions from a software stack that includes an operating system (OS) and one or more user software applications, and which further can include the protocol stacks executed by processors of the modem 224. The OS manages the general operation of the various hardware components of the UE 102 as well as supports the execution of the one or more user software applications, with the user software applications typically accessed from system memory 225 for execution by the general processor 220. During execution, one or more processes of the OS or the user software application (referred to generally as “local processes”) may seek to wirelessly communicate data with a network connected to the UE 102.

[0024] In the event that a local process is seeking to communicate data with a network, the general processor 220 can employ a cellular RAT connection, communicating data via the modem 224. For these connections the modem 224 can handle lower-level operations associated with the corresponding network protocol, such as some or all of the physical, data link, and network layers, while the OS and the user software application executing at the general processor 220 support the higher-level layers of the network protocol, such as the transport, session, presentation, and application layers. To support connection to the network, the UE 102 employs the SIM 221. In particular, the SIM 221 provides the data and functionality for connection to a corresponding network.

[0025] As noted above with respect to FIG. 1 , the network 110 can, when determining a target cell for handover, issue an MR request 108 to the UE 102. In response to the MR request 108, the processor 220 accesses the HO historic profile104, at the memory 105, to generate the MR response 106. An example of the HO historic profile 104 is illustrated at FIG. 3 in accordance with some embodiments.

[0026] In the example of FIG. 3, the HO historic profile 104 includes a plurality of entries, such as entries 340, 342, 344, and 346 (collectively referred to as the entries 340-346). Each of the entries 340-346 corresponds to a source cell-target cell pair and includes information regarding previous handovers between the cell pair. In particular, each of the entries 340-346 includes a plurality of fields, including a source cell field 330, a handover cell field 332, a success rate field 334, and a handover number field 336.

[0027] The source cell field 330 indicates the source cell associated with the entry. Thus, in the depicted example, each of the entries 340, 342, and 344 is associated with the source cell X (that is, cell 115 of FIG. 1), while the entry 346 is associated with a different source cell Y (not shown at FIG. 1). The handover cell field 332 indicates the handover cell for the entry. Thus, entry 340 is associated with handover cell A (cell 112), entry 342 is associated with cell B (cell 113), and entry 344 is associated with handover cell C (cell 114). Accordingly, in the example of FIG. 3, entry 340 includes information regarding previous handovers between cell 115 (cell X) and cell 112 (cell A), entry 342 includes information regarding previous handovers between cell 115 and cell 113 (cell B), entry 344 includes information regarding previous handovers between cell 115 and cell 114 (cell C), and entry 344 includes information regarding previous handovers between cell Y and a cell Z.

[0028] The success rate field 334 indicates the rate of successful handovers from the source cell to the handover cell over a specified amount of time, a specified number of previous handovers, and the like. In some embodiments, the processor 220 (FIG. 2) is configured to update the success rate field for a particular entry in response to a handover success or a handover failure from the corresponding source cell to the corresponding handover cell. For example, in response to determining a successful handover from cell 115 to cell 113, the processor 220 increases the success rate field for entry 342.

[0029] The handover number field 336 indicates the total number of handover attempts for the corresponding source and handover cells. For example, the handover number field for entry 342 indicates the total number of handover attempts from cell 115 to cell 113. In some embodiments, the processor 220 calculates the success rate field 334 for an entry by keeping track of the number of successful handover attempts for the corresponding source and handover cells and dividing the number of successful handover attempts by the total number of attempts indicated by the handover number field 336. In some embodiments, the processor 220 does not use an entry of the HO historical profile 104 if the handover number field for the entry is below a specified threshold. The processor 220 thus ensures that a sufficient number (e.g., a statistically significant number) of handover attempts have been made between a source cell and a candidate cell before employing the HO historical profile 104 for a corresponding handover.

[0030] Returning to FIG. 2, the processor 220 is generally configured to respond to MR requests using the HO historical profile 104. To illustrate via an example set of operations, in some embodiments the modem 224 receives the MR request 108 from the network in response to the UE 102 nearing an edge of the location associated with cell 115. In response, the network 110 identifies the cells 112-114 as candidate target cells for handover and sends the MR request 108 to request a measurement report for one or more of the cells 112-114. In some embodiments, the particular cells for which an MR is requested are indicated in a field of the MR request 108. In other embodiments, the MR request 108 modifies a measurement object (not shown) stored at the memory 105 to indicate for which cells the MR is to be generated.

[0031] In response to the MR request 108, the processor 220 determines the current cell on which the UE 102 is camped (the source cell). Thus, for the present example, the UE 102 determines that the source cell is cell 115. The processor 220 then accesses the HO historical profile 104 to determine if there are valid statistical profiles for each candidate target cell, based on the handover number field 336. In particular, the processor 220 determines if, for each of the candidate target cells, the corresponding handover number exceeds a threshold. If not, the processor 220commands the modem 224 to perform the signal strength measurements for the candidate target cells, both as indicated by the MR request 108.

[0032] If the HO historical profile 104 stores valid statistical profiles for the candidate target cells, the processor 220 next identifies the candidate target cell having the highest handover success rate, as indicated by the HO historical profile 104. The processor 220 designates the candidate target cell having the highest handover success rate as the preferred cell. Thus, for the present example, the processor 220 determines, based on the HO historical profile 104 illustrated at FIG. 3, that cell 114 (cell C) has the highest handover success rate, at 90 per cent. The processor 220 therefore designated cell 114 as the preferred cell.

[0033] The processor 220 next determines whether the MR request 108 identifies the preferred cell. For example, in some cases the process that the network 110 employs to identify candidate target cells for handover does not identify the preferred cell as a candidate target cell. In such cases, the processor 220 commands the modem 224 to perform the signal strength measurements for the candidate target cells, both as indicated by the MR request 108.

[0034] If the MR request 108 does identify the preferred cell as one of the cells for which an MR is requested, in response the processor 220 determines whether a previous MR that resulted in a successful handover to the preferred cell is stored at a set of previous measurement reports 226, at the memory 225. For example, in some embodiments, when the processor 220 identifies a successful handover from a source cell (e.g., cell 115) to a preferred cell (e.g., cell 114), the processor 220 stores the MR that resulted in the successful handover at the set of previous measurement reports 226. In response to receiving an MR request 108 requesting an MR for the same source cell and same preferred cell, the processor 220 retrieves the previous MR from the set of previous measurement reports 226. Rather than generating a new MR, the processor 220 sends the previous MR that resulted in the successful handover. This increases the likelihood that the network will respond to the MR by commanding the UE 102 to camp on the preferred cell, thus increasing the likelihood of a successful handover.

[0035] In some cases, the set of previous measurement reports 226 does not store a previous MR for the preferred cell. For example, in some embodiments, and in order to save space at the memory 225, the set previous measurement reports 226 only stores reports for the previous N handovers, where N is an integer, and is smaller than the total number of previous handovers. In response to determining that the set of previous management reports 226 does not store an MR for the preferred cell, the processor 204 generates a new MR by instructing the modem 224 to perform the indicated signal measurements for each of the candidate target cells. The processor 220 then determines if the signal measurements indicate that the preferred cell has the best signal quality (e.g., highest signal power) among all of the candidate target cells. If so, the processor 220 sends the generated MR report. If not, the processor 220 adjusts the MR report by 1) increasing the signal power measurements for the preferred cell; 2) decreasing the signal power measurements for the non-preferred cells; or 3) a combination thereof, until the MR report reflects better signal measurements for the preferred cell than for the non-preferred cells.

[0036] In some embodiments, the processor 220 adjusts the signal measurement of an MR over time, and based on whether the adjusted report results in the network 110 instructing the UE 102 to camp on the preferred cell. For example, in some embodiments, the processor 220 initially generates an MR for the preferred cell and the other target cells using the measured signal values (e.g., RSRP value, RSRQ value, SINR value, or a combination thereof). The processor 220 provides the report to the network 110 and stores the report at the set of previous management reports 226. In response, the network 110 commands the UE to camp on a non-preferred cell. In response, the next time the processor 220 is generating an MR for the same source cell and same preferred cell, the processor 220 retrieves the previously-stored report and adjusts (increases or decreases) the signal values for the preferred cell by a specified step size (e.g., 1 dB, 3 dB). The processor 220 continues to adjust the signal measurements for the preferred cell until either 1) the network 110 commands the UE 102 to handover to the preferred cell (indicating that the adjusted signal measurement is at a sufficient level to cause handover to the preferred cell); or 2) the amount of adjustment to the original signal measurement has reached a specified maximum (e.g., 3 dB). In some embodiments the processor 220 changes the stepsize for each adjustment, such as increasing the step size over time from a relatively small initial value, decreasing the step size over time from a relatively large initial value, and the like.

[0037] In some cases, even when the processor 220 sends an MR that is expected to result in a handover to the preferred cell, the network 110 sends a command to camp on a different, non-preferred cell. In response to the network 110 commanding the UE to camp on a non-preferred cell, the processor 220 instructs the modem 224 to connect to the indicated cell. In response to a failure to connect to the indicated cell (that is, in response to a handover failure), the processor 220 sends the modem 224 a list of cells to scan for connection, and to connect to the first cell wherein the scan indicates a threshold signal quality. In at least some embodiments, the processor 220 sends the list to the modem 224 in a prioritized order, so that the modem 224 first scans the cell having the highest priority in the list, then scans the cell having the next-highest priority, and so on. In some embodiments, the processor 220 provides the list so that the preferred cell is prioritized first for scanning, increasing the likelihood that the UE 102 will camp on the preferred cell.

[0038] FIG. 4 illustrates a flow diagram of a method 400 of employing a historical profile of previous handovers to respond to a measurement report request for cell handover in accordance with some embodiments. For purposes of description, the method 400 is described with respect to an example embodiment at the UE 102 of FIGs. 1 and 2. At block 402, the network 110 identifies a handover condition for the UE 102, and in particular determines that the UE 102 is nearing a border of the location associated with cell 115. In response, the network 110 sends the MR request 108, requesting that the UE 102 generate an MR for one or more of the candidate target cells 112-114.

[0039] In response to receiving the MR request 108, at block 404 the processor 220 of the UE 102 determines whether the historical HO profile 104 stores valid handover success rates for each of the candidate target cells 112-114. If not, the method flow moves to block 406 and the processor 220 commands the modem 224 to perform the measurements indicated by the MR request 108, and based on the measurements generates an MR. Returning to block 404, in response to determining that thehistorical HO profile 104 stores valid handover information for the candidate target cells 112-114, the method flow moves to block 408 and the processor 220 uses the historical HO profile 104 to identify the preferred cell. For example, the processor 220 identifies the candidate target cell having the highest historical rate of successful handovers as being the preferred cell.

[0040] At block 410, the processor 220 determines whether the MR request 108 identifies the preferred cell as a cell for which the MR is to be generated. If not, the method flow moves to block 406 and the processor 220 commands the modem 224 to perform the measurements indicated by the MR request 108, and based on the measurements generates an MR. If, at block 410, the MR request 108 does identify the preferred cell, the method flow proceeds to block 412 and the processor 220 determines whether the set of previous measurement reports 226 stores a previous MR that resulted in a successful handover from the source cell (cell 115) to the preferred cell. If so, the method flow moves to block 414 and the processor 220 retrieves the stored report from the set of previous measurement reports 226.

[0041] If, at block 412, the processor 220 determines that a previous MR that resulted in a successful handover is not stored at the set of previous measurement reports 226, the method flow moves to block 416 and the processor 220 generates an MR with a signal measurement for the preferred cell and at least one other candidate target cell. The processor 220 then adjusts one more of the signal measurements for the preferred cell such that the preferred cell has better signal measurements than the other candidate target cells.

[0042] At block 418, the processor 220 sends the MR (generated at one of blocks 406, 415, and 416). At block 420, the processor 220 receives a command from the network 110 to camp on one of the candidate target cells 412-414. The processor 220 instructs the modem 224 to connect to the identified cell and determines whether the handover was successful. If so, the method flow moves to block 422 and the method ends. If the handover was not successful, the method flow moves to block 424 and the processor 220 generates a list of cells for scanning, with the preferred cell prioritized to be scanned first. The processor 220 sends the list to the modem 224, which scans the cells in priority order, and connects the UE 102 to the first cellwith sufficient signal quality. The method flow proceeds to block 422 and the method ends.

[0043] As disclosed herein in some embodiments a method includes: receiving, at a user equipment (UE), a request from a network for a measurement report; and responding, at the UE, to the measurement report based on a historical profile of handovers of the UE to a first cell of the network. In one aspect, responding based on the historical profile includes: responding based on the historical profile responsive to the request for the measurement report identifying the first cell. In another aspect, responding based on the historical profile includes: responding based on the historical profile responsive to the historical profile indicating the first cell has a higher handover success rate than a plurality of other cells available for handover. In still another aspect, the method includes: responsive to the measurement report omitting identification of the first cell, generating a measurement report at the UE.

[0044] In one aspect, responding includes providing a first measurement report stored at the UE, the first measurement report generated based on a previous measurement report request from the network. In another aspect, responding includes generating a measurement report at the UE and adjusting a signal value of the generated measurement report based on the historical profile indicating the first cell has a higher handover success rate than a plurality of other cells available for handover. In yet another aspect, the method includes: sending a measurement report based on the historical profile to the network; responsive to the measurement report, receiving at the UE a request to handover the UE to a second cell; and in response to a handover failure to the second cell, prioritizing the first cell for scanning at the UE. In still another aspect, prioritizing includes: prioritizing the first cell for scanning based on the historical profile responsive to the historical profile indicating the first cell has a higher handover success rate than a plurality of other cells available for handover.

[0045] In one aspect, the historical profile indicates a rate of success of handovers from a source cell to the first cell. In another aspect, the historical profile indicates arate of success of handovers when the UE moves from a first location to a second location associated with the first cell.

[0046] In some embodiments a method includes: storing, at a user equipment, a historical handover profile for a plurality of cells of a network; and responding to a request from the network for a measurement report based on the historical handover profile at the UE. In one aspect, responding to the request includes: identifying a preferred cell based on the historical handover profile; and responding to the request based on the preferred cell. In another aspect, responding to the request includes: responding to the request with a stored measurement report responsive to the request identifying the preferred cell. In yet another aspect, responding to the request includes: responsive to the request omitting the preferred cell, generating a measurement report for a set of cells indicated by the request. In still another aspect, the method includes: receiving a request from the network to handover the UE to a first cell different from the preferred cell; and in response to a handover failure to the first cell, prioritizing the preferred cell for scanning at the UE.

[0047] In some embodiments a user equipment device includes: one or more modems configured to wirelessly communicate with at least one network; one or more processors coupled to the one or more modems; and at least one memory storing executable instructions, the executable instructions configured to manipulate at least one of the one or more processors or the one or more RF modems to perform any of the methods described.

[0048] In some embodiments, a computer-readable storage medium embodies a set of executable instructions, the set of executable instructions to manipulate a user equipment device to perform the method of any of the methods described herein.

[0049] In some embodiments, certain aspects of the techniques described above may be implemented by one or more processors of a processing system executing software. The software comprises one or more sets of executable instructions stored or otherwise tangibly embodied on a non-transitory computer readable storage medium. The software can include the instructions and certain data that, when executed by the one or more processors, manipulate the one or more processors toperform one or more aspects of the techniques described above. The non-transitory computer readable storage medium can include, for example, a magnetic or optical disk storage device, solid state storage devices such as Flash memory, a cache, random access memory (RAM) or other non-volatile memory device or devices, and the like. The executable instructions stored on the non-transitory computer readable storage medium may be in source code, assembly language code, object code, or other instruction format that is interpreted or otherwise executable by one or more processors.

[0050] A computer readable storage medium may include any storage medium, or combination of storage media, accessible by a computer system during use to provide instructions and / or data to the computer system. Such storage media can include, but is not limited to, optical media (e.g., compact disc (CD), digital versatile disc (DVD), Blu-Ray disc), magnetic media (e.g., floppy disc , magnetic tape, or magnetic hard drive), volatile memory (e.g., random access memory (RAM) or cache), non-volatile memory (e.g., read-only memory (ROM) or Flash memory), or microelectromechanical systems (MEMS)-based storage media. The computer readable storage medium may be embedded in the computing system (e.g., system RAM or ROM), fixedly attached to the computing system (e.g., a magnetic hard drive), removably attached to the computing system (e.g., an optical disc or Universal Serial Bus (USB)-based Flash memory), or coupled to the computer system via a wired or wireless network (e.g., network accessible storage (NAS)).

[0051] Note that not all of the activities or elements described above in the general description are required, that a portion of a specific activity or device may not be required, and that one or more further activities may be performed, or elements included, in addition to those described. Still further, the order in which activities are listed is not necessarily the order in which they are performed. Also, the concepts have been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present disclosure as set forth in the claims below. Accordingly, the specification and figures are to be regarded in anillustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present disclosure.

[0052] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims. Moreover, the particular embodiments disclosed above are illustrative only, as the disclosed subject matter may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. No limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope of the disclosed subject matter. Accordingly, the protection sought herein is as set forth in the claims below.

Claims

WHAT IS CLAIMED IS:

1. A method comprising: receiving, at a user equipment (UE), a request from a network for a measurement report; and responding, at the UE, to the measurement report based on a historical profile of handovers of the UE to a first cell of the network.

2. The method of claim 1 , wherein responding based on the historical profile comprises: responding based on the historical profile responsive to the request for the measurement report identifying the first cell.

3. The method of claim 2, wherein responding based on the historical profile comprises: responding based on the historical profile responsive to the historical profile indicating the first cell has a higher handover success rate than a plurality of other cells available for handover.

4. The method of claim 3, further comprising: responsive to the measurement report omitting identification of the first cell, generating a measurement report at the UE.

5. The method of claim 1 , wherein responding comprises providing a first measurement report stored at the UE, the first measurement report generated based on a previous measurement report request from the network.

6. The method of claim 1 , wherein responding comprises generating a measurement report at the UE and adjusting a signal value of the generated measurement report based on the historical profile indicating the first cell has a higher handover success rate than a plurality of other cells available for handover.

7. The method of claim 1 , further comprising: sending a measurement report based on the historical profile to the network;responsive to the measurement report, receiving at the UE a request to handover the UE to a second cell; and in response to a handover failure to the second cell, prioritizing the first cell for scanning at the UE.

8. The method of claim 7, wherein prioritizing comprises: prioritizing the first cell for scanning based on the historical profile responsive to the historical profile indicating the first cell has a higher handover success rate than a plurality of other cells available for handover.

9. The method of claim 1 , wherein the historical profile indicates a rate of success of handovers from a source cell to the first cell.

10. The method of claim 1 , wherein the historical profile indicates a rate of success of handovers when the UE moves from a first location to a second location associated with the first cell.11 . A method, comprising: storing, at a user equipment, a historical handover profile for a plurality of cells of a network; and responding to a request from the network for a measurement report based on the historical handover profile at the UE.

12. The method of claim 11 , wherein responding to the request comprises: identifying a preferred cell based on the historical handover profile; and responding to the request based on the preferred cell.

13. The method of claim 12, wherein responding to the request comprises: responding to the request with a stored measurement report responsive to the request identifying the preferred cell.

14. The method of claim 13, wherein responding to the request comprises:responsive to the request omitting the preferred cell, generating a measurement report for a set of cells indicated by the request.

15. The method of claim 13, further comprising: receiving a request from the network to handover the UE to a first cell different from the preferred cell; and in response to a handover failure to the first cell, prioritizing the preferred cell for scanning at the UE.

16. A user equipment device, comprising: one or more modems configured to wirelessly communicate with at least one network; one or more processors coupled to the one or more modems; and at least one memory storing executable instructions, the executable instructions configured to manipulate at least one of the one or more processors or the one or more RF modems to perform the method of any of the preceding claims.

17. A computer-readable storage medium embodying a set of executable instructions, the set of executable instructions to manipulate a user equipment device to perform the method of any of claims 1 to 15.

Images