Patent ID: 12213012

DESCRIPTION OF EMBODIMENTS

Embodiments of this application provide a cell handover measurement indication method, a network device, and a terminal, to improve reliability and real-time performance of cell handover.

The following describes the cell handover measurement indication method, the network device, and the terminal provided in the embodiments of this application with reference to the accompanying drawings.

For ease of understanding technical solutions in the embodiments of this application, before the cell handover measurement indication method, the network device, and the terminal provided in the embodiments of this application are described, related terms, applicable communication systems, the network device, and the terminal in this application are first described.

In the specification, claims, and accompanying drawings of this application, the terms “first”, “second”, and so on are intended to distinguish between similar objects but do not necessarily indicate a specific order or sequence. It should be understood that the terms used in such a way are interchangeable in proper circumstances, which is merely a discrimination manner that is used when objects having a same attribute are described in the embodiments of this application. Sometimes “first” and “second” may be the same or different. In addition, the terms “include”, “comprise” and any other variants mean to cover the non-exclusive inclusion, so that a process, method, system, product, or device that includes a series of units is not necessarily limited to those units, but may include other units not expressly listed or inherent to such a process, method, system, product, or device.

The technical solutions in the embodiments of this application may be applied to various communication systems for data processing, for example, code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and other systems. The terms “system” and “network” are interchangeable. Wireless technologies such as universal terrestrial radio access (UTRA) and CDMA2000 may be implemented in the CDMA system. UTRA may include a wideband CDMA (WCDMA) technology and another variation technology of CDMA. CDMA2000 may cover an interim standard (IS) 2000 (IS-2000), an IS-95 standard, and an IS-856 standard. Wireless technologies such as global system for mobile communications (GSM) may be implemented in the TDMA system. Wireless technologies such as evolved universal terrestrial radio access (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash OFDMA may be implemented in the OFDMA system. UTRA and E-UTRA correspond to UMTS and an evolved UMTS release respectively. 3GPP long term evolution (LTE) and evolved releases based on LTE are new UMTS releases based on E-UTRA. A 5th Generation (“5G” for short) communication system and New Radio (“NR” for short) are next generation communication systems under study. In addition, the communication systems are further applicable to a future-oriented communication technology, and the technical solutions provided in the embodiments of the present disclosure are applicable to the communication systems. The system architecture and the service scenario described in the embodiments of this application are intended to describe the technical solutions in the embodiments of this application more clearly, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. A person of ordinary skill in the art may know that with the evolution of the network architecture and the emergence of new service scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

FIG.1shows a schematic structural diagram of a communication system to which a cell handover measurement indication method is applicable according to an embodiment of this application. As shown inFIG.1, areas delineated by black bold lines are respectively a signal coverage area of a first network device and a signal coverage area of a second network device. The signal coverage area of the first network device includes a cell1, a cell2, and a cell3, and the signal coverage area of the second network device includes a cell4, a cell5, and a cell6. It is assumed that a terminal moves along a path shown by a dashed line arrow inFIG.1. In a moving process of the terminal, to ensure signal quality of the terminal, the terminal needs to be continuously handed over between various cells. Specifically, when the terminal moves to an overlapping signal coverage area of the cell2and the cell3, namely, a point A inFIG.1, the terminal needs to be handed over from the cell2to the cell3. Because the cell2and the cell3both belong to the signal coverage area of the first network device, handover from the cell2to the cell3is cell handover in a same network device. When the terminal moves to an overlapping signal coverage area of the cell3and the cell5, namely, a point B inFIG.1, the terminal needs to be handed over from the cell3covered by the first network device to the cell5in the signal coverage area of the second network device. This is cell handover between different network devices. Similarly, when the terminal moves to an overlapping signal coverage area of the cell5and the cell6, namely, a point C inFIG.1, the terminal needs to be handed over from the cell5to the cell6. This is cell handover in the second network device. The cell handover measurement indication method in the embodiments of this application is applicable to indicating the two cell handover manners shown inFIG.1, so as to improve reliability and real-time performance of cell handover.

The communication system shown inFIG.1may be a base station access system of a 2G network (to be specific, the RAN includes a base station and a base station controller), or may be a base station access system of a 3G network (to be specific, the RAN includes a base station and an RNC), or may be a base station access system of a 4G network (to be specific, the RAN includes an eNB and an RNC), or may be a base station access system of a 5G network. The RAN includes one or more network devices. The network device may be any device with a wireless transmitting and receiving function, or a chip disposed in a specific device with a wireless transmitting and receiving function. The network device includes but is not limited to a base station (for example, a base station (BS), a NodeB (NB), an evolved NodeB (eNB), a gNodeB (gNB) in a fifth generation 5G communication system, a base station in a future communication system, or an access node, a wireless relay node, or a wireless backhaul node in a Wi-Fi system). The base station may be a macro base station, a micro base station, a picocell base station, a small cell, a relay station, or the like. A plurality of base stations may support networks of one or more technologies mentioned above, or a future evolved network. A core network may support networks of one or more technologies mentioned above, or a future evolved network. The base station may include one or more co-sited or non-co-sited transmission reception points (TRP). Alternatively, the network device may be a radio controller, a centralized unit (CU), or a distributed unit (DU) in a cloud radio access network (CRAN) scenario. Alternatively, the network device may be a server, a wearable device, a vehicle-mounted device, or the like. The following provides description by using an example in which the network device is a base station. The plurality of network devices may be base stations of a same type, or may be base stations of different types. The base station may communicate with terminal devices1to6, or may communicate with terminal devices1to6by using a relay station. The terminal devices1to6may support communication with a plurality of base stations of different technologies. For example, the terminal device may support communication with a base station supporting an LTE network, or may support communication with a base station supporting a 5G network, or may further support dual connections to a base station in the LTE network and a base station in the 5G network. For example, the terminal is connected to a RAN node in a wireless network. Currently, some RAN nodes are, for example, a gNB, a transmission reception point (TRP), an evolved NodeB (eNB), a radio network controller (RNC), a NodeB (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (for example, a home evolved NodeB or a home Node B, HNB), a baseband unit (BBU), or a wireless fidelity (Wi-fi) access point (AP). In a network structure, the network device may include a centralized unit (CU) node, or a distributed unit (DU) node, or a RAN device including a CU node and a DU node.

FIG.1is described by using satellite communication as an example, and certainly may be used in another communication system. Alternatively, the communication system shown inFIG.1may be a mobile satellite communication system in satellite communication, and in the mobile satellite communication system, the network device includes but is not limited to a non-geostationary earth orbit (NGEO) communication satellite, a device having a wireless transmitting and receiving function in the NGEO communication satellite, or a chip disposed in a specific device having a wireless transmitting and receiving function in the NGEO communication satellite.

The terminal in this embodiment of this application is also referred to as user equipment (UE), a mobile station (MS), a mobile terminal (MT), a terminal device, or the like, and is a device that provides voice and/or data connectivity for a user, or a chip disposed in the device, for example, a handheld device allowed by wireless connection power, or a vehicle-mounted device. The terminal may include but is not limited to a handheld device having a wireless communication function, a vehicle-mounted device, a wearable device, a computing device, another processing device connected to a wireless modem, a mobile phone (mobile phone), a tablet computer, a notebook computer, a palmtop computer, a mobile Internet device (MID), a machine type communication terminal, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical surgery, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, and the like.

The following describes in detail a cell handover measurement indication method in an embodiment of this application with reference to the accompanying drawings.FIG.2is a schematic diagram of an embodiment of a cell handover measurement indication method according to an embodiment of this application.

As shown inFIG.2, an embodiment of cell handover measurement indication in this embodiment of this application includes:

201: A network device calculates a measurement moment of cell handover based on a measurement event.

The measurement event is a location relationship between a terminal and the network device. Specifically, the measurement event may include one of a first measurement event or a second measurement event. The first measurement event may be that a distance between the terminal and a center point of a serving cell is greater than a first threshold. The second measurement event may be that a distance between the terminal and the network device is greater than a second threshold.

Specifically, in a mobile satellite communication system, the first measurement event may be specifically that a distance between the terminal and a beam center point is greater than the first threshold, and the second measurement event may be specifically that a distance between the terminal and a ground mapping point of a communication satellite is greater than the second threshold. Optionally, the communication satellite performs calculation based on the first threshold, location information of the center point of the serving cell, and a signal coverage area of the serving cell, to obtain a handover point location corresponding to the cell; and the communication satellite obtains the measurement moment of the cell handover through calculation based on the handover point location and a moving speed of the communication satellite. Optionally, the first threshold may be determined based on at least one of a delay of handover between cells covered by a same communication satellite, a cell diameter corresponding to the serving cell, an orbit height of the communication satellite, a motion speed of the communication satellite, or a service type of the terminal. The second threshold may be determined based on at least one of a delay of handover between cells covered by different communication satellites, a cell diameter corresponding to the serving cell, an orbit height of the communication satellite, a motion speed of the communication satellite, or a service type of the terminal. It should be understood that the first measurement event is applicable to cell handover between cells in a coverage area of a same communication satellite, where the cell handover may also be referred to as intra-satellite handover. The second measurement event is applicable to cell handover between cells in coverage areas of different communication satellites, where the cell handover may also be referred to as inter-satellite handover.

In a base station access system, the first measurement event may be specifically that the distance between the terminal and the center point of the serving cell is greater than the first threshold, and the second measurement event may be specifically that a distance between the terminal and a base station is greater than the second threshold. Optionally, the base station may perform calculation based on the first threshold, location information of the center point of the serving cell, and a signal coverage area of the serving cell, to obtain a handover point location corresponding to the cell. Finally, the base station obtains the measurement moment of the cell handover through calculation based on the handover point location corresponding to the cell. Optionally, the first threshold may be determined based on at least one of a delay of handover between cells covered by a same base station, a cell diameter corresponding to the serving cell, or a service type of the terminal. Similarly, the second threshold may be determined based on at least one of a delay of handover between cells covered by different base stations, a cell diameter corresponding to the serving cell, or a service type of the terminal. It should be understood that the first measurement event is applicable to cell handover between cells in a coverage area of a same base station, and the second measurement event is applicable to cell handover between cells in coverage areas of different communication satellites.

Optionally, the location information may include but is not limited to latitude and longitude information.

It should be noted that, because a coverage area of a cell is usually an ellipse other than a circle, the cell diameter may be determined based on a semi-major axis and a semi-minor axis of the elliptical coverage area of the cell, or may be obtained after the coverage area of the cell is approximate to a circle.

In an implementation, the first threshold and/or the second threshold may be dynamically changed, to adapt to cell handover requirements of terminals of different service types or in different scenarios.

Specifically, in a low earth orbit (LEO) scenario in the mobile satellite communication system, a threshold may be appropriately increased when the motion speed of the satellite becomes slower as the orbit height becomes higher, and the threshold increases when the cell diameter becomes larger at a same orbit height. Optionally, for the LEO scenario, both the first threshold and the second threshold may be configured by using, but not limited to, thresholds in Table 1.

TABLE 1LEO scenarioFirst threshold and second thresholdLEO (an orbit height: 600 km; a cell170 (km)diameter: 200 km)LEO (an orbit height: 1200 km; a cell185 (km)diameter: 200 km)LEO (an orbit height: 600 km; a cell450 (km)diameter: 500 km)LEO (an orbit height: 1200 km; a cell475 (km)diameter: 500 km)......

In addition, different first thresholds and/or second thresholds may be set for terminals of different service types, so as to adjust measurement times of the terminals. For example, a threshold of an Internet of Things (IoT) device may be relatively large, to reduce a measurement time of the terminal, thereby saving energy overheads. A threshold of a mobile device needs to be reduced, to reduce uncertainty caused by motion of the UE. For terminals of different service types, both the first threshold and the second threshold may be configured by using, but not limited to, thresholds in Table 2.

TABLE 2First threshold and secondTerminal typethreshold (R is a cell diameter)IoT device0.95 * RFixed access device0.9 * RMobile device0.8 * R......

202: The network device sends a measurement indication, where the measurement indication carries the measurement moment of the cell handover.

The measurement moment of the cell handover includes but is not limited to at least one of a measurement start moment, a measurement end moment, or a time offset, where the time offset is a time difference between the measurement start moment and the measurement end moment. Specifically, the measurement moment may include the measurement start moment and the measurement end moment, or may include the measurement start moment and the time offset.

Optionally, the network device may send the measurement indication by using, but not limited to, a radio resource control message or downlink control information. In other words, the measurement indication that carries the measurement moment is carried in the radio resource control message or the downlink control information for sending. It should be noted that, the measurement indication may be periodically sent according to a specific period, to update the measurement moment in a timely manner. A value of the period may be determined based on a motion status of the terminal, a service type of the terminal, and the like. This is not limited herein.

Specifically, when the measurement moment may include the measurement start moment and the measurement end moment, the network device may add the measurement start moment and the measurement end moment to the radio resource control message or the downlink control information, and send the radio resource control message or the downlink control information to the terminal. Alternatively, when the measurement moment may include the measurement start moment and the time offset, the network device may add the measurement start moment and the time offset to the radio resource control message or the downlink control information, and send the radio resource control message or the downlink control information to the terminal. It should be noted that the measurement indication may be further sent by using another message other than the radio resource control message or the downlink control information. This is not limited in this application.

Optionally, the network device may send the measurement indication in a manner of reusing a field or adding a new field.

Optionally, the measurement indication may further include indication information that indicates the terminal to enable or disable measurement. Alternatively, the indication information that indicates the terminal to enable or disable measurement may be sent separately. This is not limited in this application.

Specifically, the network device may reuse an existing field in the radio resource control message or the downlink control information to send the measurement indication, or the network device may add a new field to the radio resource control message or the downlink control information to send the measurement indication, where the newly added field may use a reserved field in the radio resource control message or the downlink control message.

An example in which anew field is added to the radio resource control message is used, and the measurement indication may be sent by using the following two implementations.

In a first implementation, the base station or the communication satellite may add a corresponding field to a measurement configuration information element MeasConfig information element carried in the radio resource control (RRC) message transmitted in the system, and send the measurement start moment and the measurement end moment to the terminal. Optionally, the RRC message is typically an RRC reconfiguration message. Optionally, a quantity of bits that may be occupied by the measurement start moment in the RRC message includes but is not limited to 32 bits, and a quantity of bits that may be occupied by the measurement end moment in the RRC message also includes but is not limited to 32 bits.

In a second implementation, the base station or the communication satellite may add a corresponding field to a measurement configuration information element MeasConfig information element carried in the radio resource control (RRC) message transmitted in the system, and send the measurement start moment and the time offset to the terminal. Optionally, a quantity of bits that may be occupied by the measurement start moment in the RRC message includes but is not limited to 32 bits, and a quantity of bits that may be occupied by the time offset in the RRC message includes but is not limited to 12 bits. This manner is applicable to a scenario in which the height of the communication satellite ranges from 600 km to 1500 km, a minimum speed is 7 km/s, and a typical value of the corresponding cell diameter is 200 km. In this case, a maximum residence time of the terminal in the cell is about 30 s, and time precision of 10 ms is adopted. Therefore, a maximum time offset is 3000, so that 12 bits are used to represent the time offset. It should be noted that the RRC message is one of radio resource control messages.

The measurement indication sent by using the first implementation or the second implementation may further carry the indication information that indicates the terminal to enable or disable measurement.

Specifically, a corresponding field is added to the measurement configuration information element MeasConfig information element carried in the RRC message, to send the measurement start moment and the time offset to the terminal, or send the measurement start moment and the measurement end moment to the terminal. In addition, a corresponding field is further added to the measurement configuration information element MeasConfig information element, to send, to the terminal, the indication information that indicates the terminal to enable or disable measurement. For example, a new bit is added to indicate the terminal to enable or disable measurement, when the bit is 1, the terminal is indicated to enable measurement, and when the bit is 0, the terminal is indicated to disable measurement.

The indication information that indicates the terminal to enable or disable measurement may be further sent in a manner of adding a new field to the downlink control information. Specifically, any one bit may be added to original downlink control information fields of a signal broadcast by the satellite or the base station, and used as the indication information for enabling or disabling measurement. When the bit is 1, the terminal is indicated to enable measurement, and when the bit is 0, the terminal is indicated to disable measurement.

Optionally, the measurement indication may include the measurement moment of one or more cells, where the one or more cells include the serving cell, and a plurality of cells mean two or more cells.

Specifically, in a base station scenario, the plurality of cells may be cells corresponding to a same base station, and/or cells corresponding to different base stations. Similarly, in a communication satellite scenario, the plurality of cells may be cells corresponding to a same communication satellite, or cells corresponding to different communication satellites.

203: The terminal performs cell handover measurement based on the measurement indication or directly triggers cell handover based on the measurement indication.

The terminal determines, based on the measurement indication, the measurement start moment and the measurement end moment corresponding to the cell, and further, the terminal may perform the cell handover measurement based on the measurement start moment and the measurement end moment corresponding to the cell, or the terminal may directly trigger cell handover based on any moment between the measurement start moment and the measurement end moment corresponding to the cell, to execute a corresponding cell handover procedure.

Specifically, when the measurement start moment corresponding to the cell is reached, the terminal enables the cell handover measurement, for example, triggering at least one of existing new radio (new radio, NR) measurement events A1 to A6 and B1 to B2. When the measurement disabling time corresponding to the cell is reached, the terminal may disable the NR measurement event that is enabled at the measurement start moment, or the terminal may delay, based on an actual situation, disabling the NR measurement event that is enabled at the measurement start moment. For related description of the NR measurement events A1 to A6 and B1 to B2, refer to related documents. Details are not described herein again.

In this embodiment of this application, the network device calculates the measurement moment of the cell handover based on the location relationship between the terminal and the network device, and indicates the terminal to perform the cell handover measurement at the measurement moment. It is easily understood that, in the cell handover measurement indication method in this embodiment of this application, the network device calculates the measurement moment based on the location relationship, and the terminal performs the cell handover measurement based on the measurement moment. The network device and the terminal simultaneously participate in cell handover decision making, and this can effectively improve reliability and real-time performance of cell handover.

FIG.3is a schematic diagram of another embodiment of a cell handover measurement indication method according to an embodiment of this application.

As shown inFIG.3, another embodiment of cell handover measurement indication in this embodiment of this application includes:

301: A network device sends a measurement indication, where the measurement indication carries a measurement moment of cell handover.

302: A terminal performs cell handover measurement based on the measurement indication or directly triggers cell handover based on the measurement indication.

Steps301and302are respectively similar to the foregoing steps202and203. For description of step301, refer to the description of the foregoing step202. For description of step302, refer to the description of the foregoing step203. Details are not described herein again.

A corresponding beneficial effect in this embodiment of this application is also similar to that in the embodiment corresponding toFIG.2, and details are not described herein again.

A mobile satellite communication system scenario is used as an example to describe in detail a possible calculation manner of a corresponding measurement moment based on a measurement event:

1. Calculating the Measurement Moment Based on a First Measurement Event Denoted as a Measurement Event C1

Step 1: The network device calculates a first threshold based on a service type of the terminal, a delay of handover between cells in a same communication satellite, and a motion speed of the communication satellite. It is assumed that cell handover is performed between cells covered by a same communication satellite, an average delay required from a time at which the terminal sends a handover request to a time at which cell handover processing is completed is t1, a moving speed of the satellite is v, and a cell diameter is R. In this case, the first threshold TH1 may be (R−v*t1). According to different terminal service types in Table 2, if the terminal is an IoT device, the first threshold TH1 may be (0.95*R−v*t1); if the terminal is a fixed access device, the first threshold TH1 may be (0.9*R−v*t1); if the terminal is a mobile device, the first threshold TH1 may be (0.9*R−v*t1).

Step 2: Calculate, based on the first threshold by using a first calculation formula, longitude and latitude locations (longho, latho) of handover points corresponding to one or more cells.

The first calculation formula is

(latho-latbcac)2+(longho-longbcbc)2=TH⁢⁢1,
where longbc, is a longitude location of a beam center point, latbcis a latitude location of the beam center point, acis a semi-major axis length of a coverage area of a cell, and bcis a semi-minor axis length of the coverage area of the cell.

It should be noted that, a signal coverage area corresponding to a case in which a distance between the terminal and the beam center point is greater than the first threshold is a protected area, and cell handover measurement needs to be performed when the terminal is located in the protected area; a signal coverage area corresponding to a case in which a distance between the terminal and the beam center point is not greater than the first threshold is a non-protected area, and there is no need to perform cell handover measurement when the terminal is located in the non-protected area.

Step 3: Calculate, based on initial locations (longu, latu) of the terminal, an initial moment Tu, longitude and latitude locations (longho, latho) of a handover point, and the moving speed v of the satellite by using a second calculation formula, a moment t_meas corresponding to the handover point.

The second calculation formula is

t_meas=Tu+1v*(latho-latu)2+(longho-longu)2.

2. Calculating the Measurement Moment Based on a Second Measurement Event Denoted as a Measurement Event C2.

Step 1: The network device calculates a second threshold based on a service type of the terminal, a delay of handover between cells in different communication satellites, and a motion speed of a communication satellite. It is assumed that cell handover is performed between cells covered by different communication satellites, an average delay required from a time at which the terminal sends a handover request to a time at which cell handover processing is completed is t2, a moving speed of the satellite is v, and a cell diameter is R, the second threshold TH2 may be (R−v*t2). According to different terminal service types in Table 2, if the terminal is an IoT device, the second threshold TH2 may be (0.95R−v*t2); if the terminal is a fixed access device, the second threshold TH2 may be (0.9*R−v*t2); if the terminal is a mobile device, the second threshold TH2 may be (0.9*R−v*t2).

Step 2: Calculate, based on the second threshold by using a third calculation formula, longitude and latitude locations (longho, latho) of handover points corresponding to one or more cells.

The third calculation formula is

(latho-latbcac)2+(longho-longbcbc)2=TH⁢⁢2,
where longscis a longitude location of a ground mapping point of a communications satellite, latscis a latitude location of a ground mapping point of a communication satellite, asis a semi-major axis length of a coverage area of the communication satellite, and bcis a semi-minor axis length of the coverage area of the communication satellite.

Similarly, it should be noted that, a signal coverage area corresponding to a case in which a distance between the terminal and the ground mapping point of the communication satellite is greater than the second threshold is a protected area, and cell handover measurement needs to be performed when the terminal is located in the protected area; a signal coverage area corresponding to a case in which a distance between the terminal and the ground mapping point of the communication satellite is not greater than the second threshold is a non-protected area, and there is no need to perform cell handover measurement when the terminal is located in the non-protected area.

Step 3: Calculate, based on initial locations (longu, latu) of the terminal, an initial moment Tu, longitude and latitude locations (longho, latho) of a handover point, and the moving speed v of the satellite by using a second calculation formula, a moment t_meas corresponding to the handover point.

The second calculation formula is

t_meas=Tu+1v*(latho-latu)2+(longho-longu)2.

It should be further noted that, for a calculation manner based on a measurement event in a scenario in which a base station accesses the system, reference may be made to the foregoing calculation manner based on a measurement event in the mobile satellite communication system scenario and corresponding transformation is performed. Details are not described herein again.

Two implementations of the cell handover measurement indication method provided in the embodiments of this application are respectively described in detail inFIG.2andFIG.3. The following describes in detail an embodiment in which a terminal or a network device makes a cell handover decision based on indication manners inFIG.4andFIG.5.

1. Cell Handover Manner in which a Terminal Makes a Cell Handover Decision Based on the Cell Handover Measurement Indication Method.

FIG.4is a schematic diagram of an embodiment in which a terminal makes a cell handover decision according to an embodiment of this application.

401: A network device sends a measurement indication, where the measurement indication carries a measurement moment of cell handover.

402: A terminal performs cell handover measurement based on the measurement indication.

Steps401and402are respectively similar to the foregoing steps202and203. For description of step401, refer to the description of the foregoing step202. For description of step402, refer to the description of the foregoing step203. Details are not described herein again.

403: The terminal performs cell handover based on a result of the cell handover measurement.

When a measurement event is a first measurement event, that the terminal performs cell handover based on a result of the cell handover measurement includes: the terminal initiates a cell handover procedure, or the terminal skips initiating a cell handover procedure.

Specifically, if the result of the cell handover measurement indicates that cell handover needs to be performed, the terminal determines, based on the result of the cell handover measurement, that another cell with relatively high signal strength under coverage of a same communication satellite or a same base station is a target cell, and initiates a cell handover request to the target cell, so that the terminal is handed over to the target cell. Otherwise, the terminal does not initiate the cell handover procedure.

When a measurement event is a second measurement event, that the terminal performs cell handover based on a result of the cell handover measurement includes: the terminal initiates a cell handover procedure, or the terminal skips initiating a cell handover procedure.

Specifically, if the result of the cell handover measurement indicates that cell handover needs to be performed, the terminal initiates a cell handover request to a new base station or a new communication satellite based on the result of the cell handover measurement, so that the terminal is handed over to the new base station or the new communication satellite. Otherwise, the terminal does not initiate the cell handover procedure.

2. Cell Handover Manner in which a Network Device Makes a Cell Handover Decision Based on the Cell Handover Measurement Indication Method.

FIG.5is a schematic diagram of an embodiment in which a network device makes a cell handover decision according to an embodiment of this application.

501: A network device sends a measurement indication, where the measurement indication carries a measurement moment of cell handover.

502: A terminal performs cell handover measurement based on the measurement indication.

Steps501and502are respectively similar to the foregoing steps202and203. For description of step501, refer to the description of the foregoing step202. For description of step502, refer to the description of the foregoing step203. Details are not described herein again.

503: The terminal sends a measurement report.

504: The network device sends a cell handover indication.

The network device makes a cell handover decision based on the measurement report. If it is determined that cell handover needs to be performed, the network device sends, to the terminal, a cell handover indication that indicates the terminal to perform cell handover. Otherwise, the network device sends, to the terminal, a cell handover indication that indicates the terminal not to perform cell handover.

In the embodiments corresponding to the indication methods inFIG.2toFIG.5, a calculation process of a measurement moment is implemented on the network device side. Actually, the calculation process of the measurement moment may also be implemented on the terminal side. The following performs description in detail.

FIG.6is a flowchart of an embodiment in which a terminal calculates a measurement moment according to an embodiment of this application.

601: A terminal calculates a measurement moment of cell handover based on a measurement event.

A manner in which the terminal calculates the measurement moment of the cell handover based on the measurement event in step601is the same as a manner in which a network device calculates a measurement moment of cell handover based on a measurement event in step201, and details are not described herein again.

It should be noted that, different from the foregoing calculation performed on the network device side, the terminal needs to learn in advance network side information related to the measurement moment of the cell handover. Specifically, before step601, the method further includes: the terminal receives the network side information that is sent by the network device and that is related to the measurement moment of the cell handover.

602: The terminal performs cell handover measurement based on the measurement moment or directly triggers cell handover based on the measurement moment.

Step602is similar to step203. For description of step602, refer to the description in step203. Details are not described herein again.

It should be noted that, a specific cell handover procedure and a cell handover operation mentioned in this embodiment of this application are consistent with a conventional cell handover procedure and cell handover operation. For the specific cell handover procedure and cell handover operation, refer to related documents. Details are not described in this embodiment of this application.

It should be noted that, for brief description, the foregoing method embodiments are represented as a series of actions. However, a person skilled in the art should appreciate that this application is not limited to the described order of the actions, because according to this application, some steps may be performed in other orders or simultaneously. It should be further appreciated by a person skilled in the art that the embodiments described in this specification, and the involved actions and modules are not necessarily required by this application.

To better implement the foregoing solutions in the embodiments of this application, the following further provides a related apparatus for implementing the foregoing solutions.

FIG.7is a schematic structural diagram of a network device according to an embodiment of this application. A network device700includes a processing module701and a sending module702.

The processing module701is configured to calculate a measurement moment of cell handover based on a measurement event, where the measurement event is a location relationship between a terminal and the network device.

The sending module702is configured to send a measurement indication, where the measurement indication carries the measurement moment, and the measurement indication is used to indicate the terminal to perform cell handover measurement.

In some embodiments of this application, the measurement event includes at least one of the following: a first measurement event or a second measurement event. The first measurement event is that a distance between the terminal and a center point of a serving cell is greater than a first threshold, where the serving cell is a cell that provides a service for the terminal. The second measurement event is that a distance between the terminal and the network device is greater than a second threshold.

In some embodiments of this application, the measurement moment includes at least one of the following: a measurement start moment, a measurement end moment, or a time offset, where the time offset is a time difference between the measurement start moment and the measurement end moment.

In some embodiments of this application, the sending module702is specifically configured to send the measurement indication by using a radio resource control message or downlink control information.

In some embodiments of this application, the sending module702is specifically configured to send the measurement indication in a manner of reusing a field or adding a new field.

In some embodiments of this application, the measurement indication includes the measurement moment of one or more cells, where the one or more cells include the serving cell.

In some embodiments of this application, when the network device is a communication satellite, the first threshold and/or the second threshold may be determined based on at least one of a first cell handover delay, a cell diameter corresponding to the serving cell, an orbit height of the communication satellite, a motion speed of the communication satellite, or a service type of the terminal, where the first cell handover delay includes a delay of handover between cells covered by a same communication satellite, or a delay of handover between cells covered by different communication satellites.

In some embodiments of this application, when the network device is a base station, the first threshold and/or the second threshold may be determined based on at least one of a second cell handover delay, a cell diameter corresponding to the serving cell, or a service type of the terminal, where the second cell handover delay includes a delay of handover between cells covered by a same base station, or a delay of handover between cells covered by different base stations.

In some embodiments of this application, the network device700further includes a receiving module703, configured to receive a measurement report sent by the terminal, where the measurement report is generated based on a result of the cell handover measurement.

FIG.8is a schematic structural diagram of a terminal according to an embodiment of this application. A terminal800includes a receiving module801and a processing module802.

The receiving module801is configured to receive a measurement indication, where the measurement indication is used to indicate the terminal to perform cell handover measurement, the measurement indication carries a measurement moment of cell handover, the measurement moment is obtained by a network device through calculation based on a measurement event, and the measurement event is a location relationship between the terminal and the network device.

The processing module802is configured to perform the cell handover measurement based on the measurement indication.

In some embodiments of this application, the measurement event includes at least one of the following: a first measurement event or a second measurement event. The first measurement event is that a distance between the terminal and a center point of a serving cell is greater than a first threshold, where the serving cell is a cell that provides a service for the terminal. The second measurement event is that a distance between the terminal and the network device is greater than a second threshold.

In some embodiments of this application, the measurement moment includes at least one of the following: a measurement start moment, a measurement end moment, or a time offset, where the time offset is a time difference between the measurement start moment and the measurement end moment.

In some embodiments of this application, the receiving module801is specifically configured to receive the measurement indication by using a radio resource control message or downlink control information.

In some embodiments of this application, the receiving module801is specifically configured to receive the measurement indication in a manner of reusing a field or adding a new field.

In some embodiments of this application, the measurement indication includes the measurement moment of one or more cells, where the one or more cells include the serving cell.

In some embodiments of this application, when the network device is a communication satellite, the first threshold and/or the second threshold may be determined based on at least one of a first cell handover delay, a cell diameter corresponding to the serving cell, an orbit height of the communication satellite, a motion speed of the communication satellite, or a service type of the terminal, where the first cell handover delay includes a delay of handover between cells covered by a same communication satellite, or a delay of handover between cells covered by different communication satellites.

In some embodiments of this application, when the network device is a base station, the first threshold and/or the second threshold may be determined based on at least one of a second cell handover delay, a cell diameter corresponding to the serving cell, or a service type of the terminal, where the second cell handover delay includes a delay of handover between cells covered by a same base station, or a delay of handover between cells covered by different base stations.

In some embodiments of this application, the terminal800further includes a sending module803, configured to send a measurement report, where the measurement report is generated based on a result of the cell handover measurement. Alternatively, the processing module802is further configured to perform the cell handover based on a result of the cell handover measurement.

It should be noted that content such as information exchange between the modules/units of the apparatus and the execution processes thereof is based on the same idea as the method embodiments of this application, and produces the same technical effects as the method embodiments of this application. For the specific content, refer to the foregoing description in the method embodiments of this application. Details are not described herein again.

An embodiment of this application further provides a computer storage medium. The computer storage medium stores a program, and the program performs some or all of the steps described in the foregoing method embodiments.

The following describes another network device according to an embodiment of this application. Referring toFIG.9, a network device900includes:

a receiver901, a transmitter902, a processor903, and a memory904(where there may be one or more processors903in the network device900, and one processor is used as an example inFIG.9). In some embodiments of this application, the receiver901, the transmitter902, the processor903, and the memory904may be connected by using a bus or in another manner. InFIG.9, a connection by using the bus is used as an example.

The memory904may include a read-only memory and a random access memory, and provide instructions and data to the processor903. A part of the memory904may further include a non-volatile random access memory (NVRAM). The memory904stores an operating system and an operation instruction, an executable module or a data structure, or a subset thereof, or an extended set thereof. The operation instruction may include various operation instructions to implement various operations. The operating system may include various system programs to implement various basic services and process hardware-based tasks.

The processor903controls an operation of the network device, and the processor903may also be referred to as a central processing unit (CPU). In specific application, components of the network device are coupled together by using a bus system. In addition to a data bus, the bus system may further include a power bus, a control bus, and a status signal bus. However, for clear description, various types of buses in the figure are marked as the bus system.

The methods disclosed in the embodiments of this application may be applied to the processor903, or implemented by the processor903. The processor903may be an integrated circuit chip and has a signal processing capability. In an implementation process, the steps in the foregoing methods can be implemented by using a hardware integrated logical circuit in the processor903, or by using instructions in a form of software. The processor903may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or another programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The processor903may implement or perform the methods, the steps, and logical block diagrams that are disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor or the like. The steps of the methods disclosed with reference to the embodiments of this application may be directly executed and accomplished by using a hardware decoding processor, or may be executed and accomplished by using a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium mature in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, or a register. The storage medium is located in the memory904, and the processor903reads information in the memory904and completes the steps in the foregoing methods in combination with hardware of the processor.

The receiver901may be configured to receive input digital or character information, and generate signal input related to setting and function controls of the network device. The transmitter902may include a display device such as a display screen, and the transmitter902may be configured to output digital or character information by using an external interface.

In this embodiment of this application, the processor903is configured to perform the foregoing cell handover measurement indication method performed by a network device.

The following describes another terminal according to an embodiment of this application. Referring toFIG.10, a terminal1000includes:

a receiver1001, a transmitter1002, a processor1003, and a memory1004(where there may be one or more processors1003in the terminal1000, and one processor is used as an example inFIG.10). In some embodiments of this application, the receiver1001, the transmitter1002, the processor1003, and the memory1004may be connected by using a bus or in another manner. InFIG.10, a connection by using the bus is used as an example.

The memory1004may include a read-only memory and a random access memory, and provide instructions and data to the processor1003. A part of the memory1004may further include a non-volatile random access memory (non-volatile random access memory, NVRAM). The memory1004stores an operating system and an operation instruction, an executable module or a data structure, or a subset thereof, or an extended set thereof. The operation instruction may include various operation instructions to implement various operations. The operating system may include various system programs to implement various basic services and process hardware-based tasks.

The processor1003controls an operation of the terminal, and the processor1003may also be referred to as a central processing unit (CPU). In specific application, components of the terminal are coupled together by using a bus system. In addition to a data bus, the bus system may further include a power bus, a control bus, and a status signal bus. However, for clear description, various types of buses in the figure are marked as the bus system.

The methods disclosed in the embodiments of this application may be applied to the processor1003, or implemented by the processor1003. The processor1003may be an integrated circuit chip and has a signal processing capability. In an implementation process, the steps in the foregoing methods can be implemented by using a hardware integrated logical circuit in the processor1003, or by using instructions in a form of software. The processor1003may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or another programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The processor1003may implement or perform the methods, the steps, and logical block diagrams that are disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor or the like. The steps of the methods disclosed with reference to the embodiments of this application may be directly executed and accomplished by using a hardware decoding processor, or may be executed and accomplished by using a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium mature in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, or a register. The storage medium is located in the memory1004, and the processor1003reads information in the memory1004and completes the steps in the foregoing methods in combination with hardware of the processor.

The receiver1001may be configured to receive input digital or character information, and generate signal input related to related setting and function control of the terminal. The transmitter1002may include a display device such as a display screen, and the transmitter1002may be configured to output digital or character information by using an external interface.

In this embodiment of this application, the processor1003is configured to perform the foregoing cell handover measurement indication method performed by a terminal.

In another possible design, a chip includes a processing unit and a communication unit. The processing unit may be, for example, a processor, and the communication unit may be, for example, an input/output interface, a pin, or a circuit. The processing unit may execute a computer executable instruction stored in a storage unit, so that the chip in the terminal performs the foregoing cell handover measurement indication method performed by a terminal or a network device. Optionally, the storage unit is a storage unit in the chip, for example, a register or a buffer. Alternatively, the storage unit may be a storage unit that is in the terminal and that is located outside the chip, for example, a read-only memory (ROM), or another type of static storage device that can store static information and instructions, or a random access memory (RAM).

The processor mentioned anywhere above may be a general-purpose central processing unit, a microprocessor, an ASIC, or one or more integrated circuits for controlling program execution of the method in the first aspect.

In addition, it should be noted that the described apparatus embodiments are merely examples. The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the objectives of the solutions of the embodiments. In addition, in the accompanying drawings of the apparatus embodiments provided by this application, connection relationships between modules indicate that the modules have communication connections with each other, which may be specifically implemented as one or more communication buses or signal cables.

Based on the description of the foregoing implementations, a person skilled in the art may clearly understand that this application may be implemented by software in addition to necessary universal hardware, or by dedicated hardware including an application-specific integrated circuit, a dedicated CPU, a dedicated memory, a dedicated component, and the like. Generally, any function that can be performed by a computer program can be easily implemented by corresponding hardware. Moreover, a specific hardware structure used to achieve a same function may be in various forms, for example, in a form of an analog circuit, a digital circuit, a dedicated circuit, and the like. However, for this application, software program implementation is a better implementation in most cases. Based on such an understanding, the technical solutions of this application essentially or the part contributing to the prior art may be implemented in a form of a software product. The software product is stored in a readable storage medium, such as a floppy disk, a USB flash drive, a removable hard disk, a ROM, a RAM, a magnetic disk, or a CD-ROM of a computer, and includes several instructions for instructing a computer device (which may be a personal computer, a server, a network device, or the like) to perform the methods described in the embodiments of this application.

All or some of the foregoing embodiments may be implemented by using software, hardware, firmware, or any combination thereof. When software is used to implement the embodiments, all or some of the embodiments may be implemented in a form of a computer program product.

The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, all or some of the procedures or functions according to the embodiments of this application are generated. The computer may be a general-purpose computer, a dedicated computer, a computer network, or another programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or may be transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired (for example, a coaxial cable, an optical fiber, or a digital subscriber line (DSL)) or wireless (for example, infrared, radio, or microwave) manner. The computer-readable storage medium may be any usable medium accessible by a computer, or a data storage device, such as a server or a data center, integrating one or more usable media. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, or a magnetic tape), an optical medium (for example, a DVD), a semiconductor medium (for example, a solid-state drive (SSD)), or the like.