CN115134747A

CN115134747A - Communication method and device

Info

Publication number: CN115134747A
Application number: CN202110334700.4A
Authority: CN
Inventors: 吴烨丹; 耿婷婷; 唐珣
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-03-29
Filing date: 2021-03-29
Publication date: 2022-09-30
Also published as: WO2022206557A1

Abstract

The application provides a communication method and a communication device, which are used for solving the problems that in a non-terrestrial network (NTN) communication system, the time required for a terminal device to carry out Radio Link Failure (RLF) judgment is increased sharply, so that the communication time delay of the terminal device is larger, and the electric quantity is wasted. The method comprises the following steps: the method comprises the steps that terminal equipment obtains the residual coverage duration of a service cell covering a first geographic area, wherein the terminal equipment is located in the first geographic area; and the terminal equipment determines that the radio link failure occurs when the residual coverage duration is less than a first time threshold. In the embodiment of the application, the terminal equipment judges whether RLF occurs or not through the residual coverage duration of the serving cell, so that the radio resource control RRC can be triggered to be reestablished in time when the coverage signal is weaker or disappears, the communication quality of the terminal equipment can be improved, and the communication delay is reduced.

Description

Communication method and device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communication method and apparatus.

Background

Currently, in a mobile communication system, after a User Equipment (UE) establishes Radio Resource Control (RRC) connection with a network device and enters an RRC connected state, if Radio Link Failure (RLF), handover failure, and other conditions occur, an RRC reestablishment procedure is triggered.

Currently, the condition for triggering the RLF is Radio Link Control (RLC) uplink maximum retransmission or random access problem (e.g. out-of-sync and re-synchronization) or T310 timeout (i.e. out-of-sync detection). The RLC uplink maximum retransmission is the maximum number of times that the RLC protocol layer retransmits to the lower protocol layer when the UE transmits uplink data. Out-of-sync re-synchronization is that the preamble (preamble) transmission reaches the maximum number of times due to the out-of-sync of the uplink Timing Advance (TA). T310 is a timer triggered after the upper protocol layer of the UE continuously receives N310 out-of-sync (out-of-sync) indications of the lower layer.

Because non-terrestrial network (NTN) communication has the characteristics of wide coverage, large time delay and the like, Round Trip Time (RTT) of communication between the UE and the network device is also relatively long, which causes a sudden increase in time required for the UE to perform RLF determination, so that the UE communication time delay is relatively large and electric quantity is relatively wasted.

Disclosure of Invention

The application provides a communication method and device, which are used for solving the problems that in an NTN communication system, the time required by UE for RLF judgment is increased greatly, the communication time delay of the UE is larger, and the electric quantity is wasted.

In a first aspect, an embodiment of the present application provides a communication method, including: the method comprises the steps that terminal equipment obtains the residual coverage duration of a service cell covering a first geographic area, wherein the terminal equipment is located in the first geographic area; and the terminal equipment determines that the radio link failure occurs when the residual coverage duration is less than a first time threshold. In the embodiment of the application, the terminal equipment judges whether RLF occurs or not through the residual coverage duration of the serving cell, so that RRC reestablishment can be triggered in time when a coverage signal is weak or disappears, the communication quality of the terminal equipment can be improved, and the communication delay is reduced.

In one possible design, the terminal device may receive coverage time information of a serving cell from the network device and determine the remaining coverage duration according to the coverage time information. Through the method, the terminal equipment can determine the residual coverage time of the serving cell, so that whether the RLF occurs can be determined according to the residual coverage time.

In one possible design, the coverage time information may be a remaining coverage duration, or the coverage time information may also be a remaining coverage time period for the serving cell to cover the first geographic area, or the coverage time information may also be a coverage time period for the serving cell. In the design, the network device may directly indicate the remaining coverage duration or indicate the coverage time period, so that the terminal device may determine the remaining coverage duration according to the current time.

In one possible design, the terminal device may determine the remaining coverage duration according to the ephemeris information and the first geographic area. Through the design, the terminal equipment can determine the residual coverage time of the serving cell by itself.

In one possible design, after the terminal device determines that the radio link failure occurs when the remaining coverage duration is less than the first time threshold, the terminal device may further determine a radio resource control RRC state after the radio link failure occurs according to cell coverage information, where the cell coverage information includes, but is not limited to, at least one of the following information: the remaining coverage duration of the serving cell, the remaining coverage durations of N neighboring cells, and the waiting durations of M neighboring cells, where the waiting duration is a duration that needs to be waited when the terminal device enters a coverage range of a neighboring cell, and M, N are integers greater than 0. Through the above design, the terminal device may select a suitable RRC state, for example, perform an RRC idle state when the remaining coverage duration of the serving cell is short and the waiting duration of the neighboring cell is long, so as to reduce signaling overhead and power consumption.

In one possible design, the determining, by the terminal device, the RRC state after the radio link failure occurs according to the cell coverage information includes: and when the residual coverage duration of the serving cell is greater than the second time threshold, the terminal equipment performs RRC reconstruction in the serving cell. Through the design, the communication quality of the terminal equipment can be improved.

In one possible design, the determining, by the terminal device, the RRC state after the radio link failure occurs according to the cell coverage information includes: and when the residual coverage duration of the service cell is not greater than the second time threshold, the terminal equipment selects the cell. Through the design, the terminal equipment can select a proper cell in time to perform RRC reestablishment, so that the communication time delay can be reduced.

In one possible design, the determining, by the terminal device, the RRC state after the radio link failure occurs according to the cell coverage information includes: and when the residual coverage duration of a first adjacent cell in the N adjacent cells is greater than a third time threshold, the terminal equipment performs RRC reconstruction in the first adjacent cell, wherein the first adjacent cell is any one of the N adjacent cells. Through the design, the communication continuity of the terminal equipment can be improved.

In one possible design, the determining, by the terminal device, the RRC state after the radio link failure occurs according to the cell coverage information includes: and when the first time difference is greater than the fourth time threshold, the terminal device performs RRC reconstruction in the second adjacent cell, wherein the first time difference is a result obtained by subtracting the residual coverage duration of the serving cell from the residual coverage duration of the second adjacent cell, and the second adjacent cell is any one of the N adjacent cells. Through the design, the terminal equipment can select the adjacent cell with longer residual coverage time to perform RRC reconstruction, so that the signal continuity can be improved.

In one possible design, the determining, by the terminal device, the RRC state after the radio link failure occurs according to the cell coverage information includes: and when the residual coverage duration of the serving cell is less than a fifth threshold and the residual coverage duration of the third neighboring cell is greater than a sixth threshold, the terminal device performs RRC reconstruction in the third neighboring cell, wherein the third neighboring cell is the cell with the longest residual coverage duration among the N neighboring cells. Through the design, the terminal equipment can select the adjacent cell with longer residual coverage time to perform RRC reconstruction, so that the signal continuity can be improved.

In one possible design, the determining, by the terminal device, the RRC state after the radio link failure occurs according to the cell coverage information includes: and when the remaining coverage time of the serving cell and the N adjacent cells are both smaller than a seventh threshold, the terminal equipment performs RRC reconstruction in a fourth adjacent cell, wherein the fourth adjacent cell is the cell with the shortest waiting time among the M adjacent cells. By the above design, communication interruption can be reduced.

In one possible design, the determining, by the terminal device, the RRC state after the radio link failure occurs according to the cell coverage information includes: and when the residual coverage time of the service cell and the N adjacent cells are both smaller than a seventh threshold value, the terminal equipment performs RRC reconstruction in a fifth adjacent cell, wherein the fifth adjacent cell is a cell which has the longest coverage time in the first geographic area and the waiting time not greater than an eighth threshold value in the M adjacent cells. Through the design, communication interruption can be reduced, and signal continuity can be guaranteed as far as possible.

In one possible design, the determining, by the terminal device, the RRC state after the radio link failure occurs according to the cell coverage information includes: and when the remaining coverage time of the serving cell and the N neighboring cells are both smaller than a seventh threshold, the terminal device performs RRC reestablishment in a sixth neighboring cell, where the sixth neighboring cell is a cell with the highest metric value among the M neighboring cells, and the metric value is determined according to the waiting time of the neighboring cells and the coverage time for covering the first geographic area. Through the design, communication interruption can be reduced, and signal continuity can be guaranteed as far as possible.

In one possible design, the determining, by the terminal device, the RRC state after the radio link failure occurs according to the cell coverage information includes: and when the residual coverage time lengths of the service cell and the N adjacent cells are both smaller than a seventh threshold value and the waiting time lengths of the M adjacent cells are both larger than an eighth threshold value, the terminal equipment enters an RRC idle state. Through the design, the terminal equipment can save resources such as signaling overhead and electric quantity.

In one possible design, the terminal device sends an RRC reestablishment report, where the RRC reestablishment report carries an RRC reestablishment cause, and the RRC reestablishment cause is related to a coverage time of the serving cell. Through the design, the network equipment can determine the reason of RRC reestablishment of the terminal equipment.

In a second aspect, an embodiment of the present application provides a communication method, including: the method comprises the steps that the terminal equipment determines N suitable cells, the suitable cells meet a coverage condition, the coverage condition is that the residual coverage time for covering a first geographic area is greater than a first time threshold or the waiting time is less than a second time threshold, the terminal equipment is located in the first geographic area, the waiting time is the time required to wait when the terminal equipment enters the coverage area of the cells, and N is an integer greater than 0; the terminal device performs cell selection or cell reselection among the N suitable cells.

In the embodiment of the application, the coverage duration or the waiting duration of the cell is considered when the suitable cell is selected, so that the terminal equipment can select the cell with longer coverage time or the cell with shorter waiting time to camp on, thereby improving the stability of communication and improving the communication quality.

In one possible design, the terminal device determines N suitable cells, including: the terminal equipment selects N cells with the residual coverage duration being greater than a first time threshold as suitable cells; or when the remaining coverage time of the cells covering the first geographic area is less than the first time threshold, the terminal device selects N cells with the waiting time less than the second time threshold as the suitable cells. Through the design, the terminal device can preferentially select the cell which covers the service cell of the first geographic area and has the residual coverage duration satisfying the condition as the appropriate cell.

In one possible design, the terminal device performs cell selection or cell reselection among N suitable cells, including: and the terminal equipment performs cell selection or cell reselection in the N suitable cells based on the S criterion or the R criterion, wherein the remaining coverage time or the waiting time is an offset value in the S criterion or the R criterion. In the above design, by introducing the remaining coverage duration parameter or the waiting duration parameter into the S criterion or the R criterion, a cell with a longer remaining coverage duration or a shorter waiting duration may be preferentially selected.

In a third aspect, the present application provides a communication apparatus, which may be a terminal device, or a chip set in the terminal device. The apparatus may include a processing unit and a memory unit.

When the apparatus is a terminal device, the processing unit may be a processor, and the storage unit may be a memory. The apparatus may further include a transceiving unit for communicating with the network device. The transceiver unit may be a transceiver. The storage unit is configured to store an instruction, and the processing unit executes the instruction stored in the storage unit, so as to enable the terminal device to perform the corresponding function of the first aspect or the second aspect.

When the apparatus is a chip or a chipset in a terminal device, the processing unit may be a processor, and the storage unit may be a storage unit (e.g., a register, a cache, etc.) in the chip or the chipset, or a storage unit (e.g., a read-only memory, a random access memory, etc.) external to the chip or the chipset. The apparatus may further include a transceiving unit for communicating with the network device. The transceiving unit may be an input/output interface, a pin or a circuit, etc. The storage unit is configured to store instructions, and the processing unit executes the instructions stored by the storage unit to enable the terminal device to perform corresponding functions in the first aspect or the second aspect.

In a fourth aspect, embodiments of the present application provide a communication apparatus, which includes a communication interface and a processor, where the communication interface is used for the apparatus to communicate with other devices, for example, to receive and transmit data or signals. Illustratively, the communication interface may be a transceiver, circuit, bus, module, or other type of interface, and the other device may be a network device. The processor is configured to invoke a set of programs, instructions or data to perform the method of the first aspect or each of the possible design descriptions of the first aspect, or to perform the method of the second aspect or each of the possible design descriptions of the second aspect. The apparatus may also include a memory for storing programs, instructions or data called by the processor. The memory is coupled to the processor, and the processor, when executing the instructions or data stored in the memory, may implement the method described in the first aspect or the possible design description of the first aspect, or may implement the method described in the second aspect or the possible design description of the second aspect.

In a fifth aspect, this embodiment also provides a computer-readable storage medium, in which computer-readable instructions are stored, which, when executed on a computer, cause the method as described in any one of the first to second aspects and in various possible designs to be performed.

In a sixth aspect, an embodiment of the present application provides a chip system, where the chip system includes a processor and may further include a memory, and is configured to implement the method described in any one of the first aspect to the second aspect and in each possible design. The chip system may be formed by a chip, and may also include a chip and other discrete devices.

In a seventh aspect, embodiments of the present application provide a computer program product comprising instructions which, when run on a computer, cause a method as described in the first or second aspect and various possible designs to be performed.

In an eighth aspect, an embodiment of the present application provides a communication apparatus, including a processor, a memory, and a transceiver, where the transceiver is configured to receive a signal or transmit a signal; the memory for storing program code or instructions; the processor is configured to call the program code or instructions from the memory to perform the method according to the first or second aspect.

In a ninth aspect, embodiments of the present application provide a communication apparatus, which includes a processor and an interface circuit, where the interface circuit is configured to receive computer program codes or instructions and transmit the computer program codes or instructions to the processor; the processor executes the computer program code or instructions to perform the respective method as described in the first or second aspect above.

In a tenth aspect, an embodiment of the present application provides a communication apparatus, which may be a chip, and includes: logic circuits and input-output interfaces. The input and output interface is used for the device to communicate with network equipment, such as receiving coverage time information and the like. The logic circuitry is configured to execute computer program code or instructions to perform the respective methods as described in the first or second aspects above.

For technical effects brought by any implementation manner of the third aspect to the tenth aspect, reference may be made to the above-provided beneficial effects in the corresponding method, and details are not repeated here.

Drawings

Fig. 1 is a schematic diagram of RRC state transition according to an embodiment of the present application;

fig. 2 is a schematic diagram of a satellite according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of another satellite provided by an embodiment of the present application;

fig. 4 is a schematic structural diagram of a network device according to an embodiment of the present application;

fig. 5 is a schematic diagram of an NTN application scenario provided in an embodiment of the present application;

fig. 6 is a schematic diagram of another NTN application scenario provided in the embodiment of the present application;

fig. 7 is a schematic diagram of another NTN application scenario provided in an embodiment of the present application;

fig. 8 is a schematic interface diagram provided in an embodiment of the present application;

fig. 9 is a schematic diagram of another NTN application scenario provided in the embodiment of the present application;

fig. 10 is a schematic diagram of another NTN application scenario provided in an embodiment of the present application;

fig. 11 is a flowchart illustrating a communication method according to an embodiment of the present application;

FIG. 12 is a schematic diagram of a time comparison RLF provided in an embodiment of the present application;

fig. 13 is a schematic flowchart of cell reselection according to an embodiment of the present application;

fig. 14 is a flowchart illustrating another communication method according to an embodiment of the present application;

fig. 15 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 16 is a schematic structural diagram of another communication device according to an embodiment of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

Hereinafter, some terms in the present application are explained to facilitate understanding by those skilled in the art.

Radio Resource Control (RRC) state of a terminal device

In a New Radio (NR), the RRC state of the terminal device includes a CONNECTED state (RRC _ CONNECTED), a deactivated state or a third state (RRC _ INACTIVE), and an IDLE state (RRC _ IDLE), where when the terminal device is in the RRC _ CONNECTED state, the terminal device establishes a link with the network device and the core network, and when data arrives at the network, the data may be directly transmitted to the terminal device; when the terminal device is in the RRC _ INACTIVE state, it indicates that a link is established between the terminal device and the network device and between the terminal device and the core network, but the link from the terminal device to the network device is released, and although the link is released, the network device stores the context of the terminal device, and when there is data to be transmitted, the network device can recover the link in time; when the terminal device is in the RRC _ IDLE state, there is no link between the terminal device and the network device and between the terminal device and the network device, and when there is data to be transmitted, a link from the terminal device to the network device and to the core network needs to be established. The three states transition as shown in fig. 1.

Second, cell selection

When the terminal device is powered on or a radio link failure occurs, the terminal device executes a cell search process and selects a suitable cell (capable cell) as soon as possible to camp on, and the process is called cell selection. And the terminal equipment evaluates whether the cell is the suitable cell according to the condition of the suitable cell, completes the cell selection process if the cell is the suitable cell, and searches the suitable cell if the cell is not the suitable cell.

Suitable cells are generally provided with the following conditions:

1) a Public Land Mobile Network (PLMN) identification (PLMN ID) of the cell belongs to one of a selected PLMN (selected PLMN), a Registered PLMN (RPLMN), or an Equivalent PLMN (EPLMN).

2) The cell satisfies the S criterion.

Wherein the formula of the S criterion is as follows: if the S value of the cell is greater than 0, the cell is a suitable cell, wherein the S value of the cell can be Srxlev of the cell or Squal of the cell;

Srxlev＝Q _rxlevmeas –(Q _rxlevmin +Q _{rxlevminoffset} )–P _compensation -Qoffset _temp

Squal＝Q _qualmeas –(Q _qualmin +Q _{qualminoffset} )-Qoffset _temp ；

wherein:

srxlev refers to a level value (dB) calculated in a cell selection/reselection process;

Q _rxlevmeas the Reference Signal Received Power (RSRP) is a received signal strength value measured by a terminal device, and the value is measured reference signal received power (dBm);

Q _rxlevmin refers to the minimum required received signal strength value of the cell, which can be indicated by system information block 1 (SIB 1);

P _compensation max (PEMAX-PUMAX, 0) (dB), where PEMAX is the maximum allowed transmission power set by the system when the terminal device accesses the cell; PUMAX refers to the maximum output power specified by the terminal equipment class.

Q _{rxlevminOffset} The parameter is valid only when the user normally resides in a VPLMN and periodically searches a high-priority PLMN for cell selection evaluation, and the parameter carries out certain bias on the Qrxlevmin.

Squal is the received signal quality value calculated in the cell selection/reselection process;

Q _qualmeas the Reference Signal Received Quality (RSRQ) refers to the downlink measurement of the cell;

Q _qualmin refers to the RSRQ of the cell minimum requirement;

Q _{qualminOffset} only normally residing in a VPLMN, periodically searching for a high priorityIs valid for cell selection evaluation, this parameter biases Qqualmin.

Qoffset _temp Is an offset value.

Srxlev and Squal can be referred to the relevant description in TS38.304 section 5.2.3.2 of the 3GPP protocol and will not be described here.

3) The cell does not prohibit access by the terminal device.

4) The PLMN ID of the cell is within the forbidden TA on the premise that condition 1) is satisfied.

Cell reselection (cell reselection)

Cell reselection refers to a process in which a terminal device selects a best cell to provide a service signal by monitoring signal qualities of a neighboring cell and a current service cell in an idle mode. Different frequencies with different priorities and reselection criteria among different systems.

If the cell priority of the neighboring cell of the inter-radio access technology (inter-RAT) is higher than the cell priority of the current serving cell, if the current serving cell carries threshServingLowQ in the system information (SIB2), where threshServingLowQ is a reselection threshold value corresponding to the neighboring cell of which the cell priority is smaller than the current serving cell. Reselection is triggered when the following conditions are met: the terminal device resides in the current serving cell for more than a preset time (for example, 1 second); at a time interval (T) _{reselectionRAT} ) The adjacent area in the neighborhood satisfies Squal>Thresh _X,HighQ . If the current serving cell does not carry threshServingLowQ in the system information (SIB2), reselection is triggered when the following conditions are met: at a time interval (T) _{reselectionRAT} ) The adjacent region in the neighborhood satisfies Srxlev>Thresh _X,HighP (ii) a The terminal device resides in the current serving cell for more than a preset time (e.g., 1 second).

If the cell priority of the neighboring cell of the inter-radio access technology (inter-RAT) is equal to the cell priority of the current serving cell, the terminal device may perform cell reselection according to the R criterion. The R rule is that an R (rank) value is calculated for each adjacent cell and the current service cell according to the signal quality of the cellAnd then sorting according to the R value, wherein the R value is larger than that of the current service cell, meets the reselection standard, and if a plurality of R values are met, the best R value is selected. In the time interval (Treselection) _RAT ) The intra-neighboring cell always satisfies the R criterion, and the residence time of the terminal device in the current serving cell exceeds a preset time duration (e.g., 1 second). The terminal device initiates reselection to the neighboring cell. R value R of serving cell _s May conform to the following formula, or, R value R of the serving cell _s Can be determined by the following formula:

R _s ＝Q _meas,s +Q _hyst -Qoffset _temp ；

wherein Q is _meas,s The signal quality of the current serving cell can be measured by the terminal equipment.

Q _hyst A reselection hysteresis value for the current serving cell. Q _hyst The larger the value, the larger the border of the serving cell, the lower the probability of reselecting to the neighbor cell.

Qoffset is an R-criterion calculation parameter. Under the same-frequency reselection scene, the Qoffset can be equal to the Qoffset, and the Qoffset can be acquired from SIB 3; in the case of inter-frequency reselection, Qoffset may be equal to the sum of QoffsetCell and QoffsetFreq, which may be obtained from SIB 4.

Qoffset _temp The parameters calculated for the R-criterion may be obtained from SIB 1.

R value R of adjacent region _n Can conform to the following formula, or R value R of the adjacent region _n Can be determined by the following formula:

R _n ＝Q _meas,n –Qoffset-Qoffset _temp ；

wherein Q is _meas,n The signal quality of the neighboring cell can be measured by the terminal device.

R value R of serving cell _s And R value R of adjacent region _n Reference may be made to the relevant description in TS38.304 of the 3GPP protocol, which is not further described here.

If the cell priority of the adjacent cell of the inter-radio access technology (inter-RAT) is lower than the cell priority of the current service cell, if the current service cell is the inter-RATThe serving cell carries threshServingLowQ in the system information (SIB2), and reselection is triggered when the following conditions are met: the neighboring cell with the cell priority higher than that of the current service cell does not conform to the corresponding reselection criterion; the cell priority is equal to that the adjacent cell of the current service cell does not accord with the corresponding reselection criterion; serving cell satisfies Squal<Thresh _Serving,LowQ (ii) a Neighbor cell time interval (Treselection) _RAT ) During which the Squal is satisfied>Thresh _X,LowQ (ii) a The terminal device resides in the current serving cell for more than a preset time (e.g., 1 second). If the current serving cell does not carry threshServingLowQ in the system information (SIB2), reselection is triggered when the following conditions are met: the neighboring cell with the cell priority higher than that of the current service cell does not conform to the corresponding reselection criterion; the cell priority is equal to that the adjacent cell of the current service cell does not accord with the corresponding reselection criterion; serving cell satisfies Squal<Thresh _Serving,LowP (ii) a Neighbor cell time interval (Treselection) _RAT ) During which the Squal is satisfied>Thresh _X,LowP (ii) a The terminal device resides in the current serving cell for more than a preset time (e.g., 1 second).

Four, non-terrestrial network (NTN) communication

NTN communications may also be referred to as satellite communications. The satellite communication architecture is divided into two major categories, namely a transparent forwarding (transparent) architecture, and at the moment, the satellite only performs relay or amplifier, and can perform radio frequency filtering, amplification and the like to regenerate signals; the second is a regenerative architecture, where the satellite may be a new generation node B (gbb), a Distributed Unit (DU), and a relay, where the relay is different from the relay in the first class, and is no longer a simple relay, and has a signal processing function, similar to an Integrated Access and Backhaul (IAB) node or other relay nodes. When the satellite is used as a gNB, DU, IAB or other relay node, the function of the satellite is similar to that of a common gNB, DU, IAB or other relay node.

The NTN communication provides seamless coverage for the terminal device by deploying the functions of the access network device or a part of the access network device on a non-ground device (such as an aerial platform or a satellite), and because the non-ground device is less affected by natural disasters, the reliability of the communication system can be improved. For convenience of description and understanding of the solution of the embodiment of the present application, the following description will use an NTN communication system in which access network devices are deployed on satellites as an example. For convenience of description, in the following description, the "access network device on the satellite" is described instead of the "satellite", and the "NTN communication" is described instead of the "satellite communication". That is, the communication between the terminal device and the satellite referred to in the following of the present application actually refers to the communication between the terminal device and the access network device on the satellite. The description is unified here and will not be repeated later.

The satellite system can be divided into a High Elliptic Orbit (HEO) satellite, a Geosynchronous (GEO) satellite, a Medium Earth Orbit (MEO) satellite, and a low-earth orbit (LEO) satellite according to the satellite altitude, i.e., the satellite orbital altitude, as shown in fig. 2 or fig. 3. In addition, the NTN system may further include an air network device such as a High Altitude Platform (HAPS) communication system, and the network device related to the present invention is not limited to the above example.

It should be noted that as technology develops, the terminology of the embodiments of the present application may vary, but all are within the scope of the present application.

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in further detail with reference to the accompanying drawings.

The network element related in the embodiment of the application comprises network equipment and terminal equipment.

The network device may be an access network device. An access network device is an entity in a network side, such as a new generation base station (gdnodeb), for transmitting or receiving signals. The access network device may be a device for communicating with the mobile device. The access network device may be an Access Point (AP) in a Wireless Local Area Network (WLAN), an evolved Node B (eNB) or eNodeB) in Long Term Evolution (LTE), an integrated access Node and backhaul (IAB) in a relay station, an access point or an access backhaul, or an access network device in a vehicle-mounted device, a wearable device, and a 5G network or an access network device in a Public Land Mobile Network (PLMN) network in future evolution, or a gNB in an NR system. In addition, in this embodiment of the present application, the access network device provides a service for a cell, and the terminal device communicates with the access network device through transmission resources (for example, frequency domain resources or spectrum resources) used by the cell.

The access network device in the embodiment of the present application may refer to a Central Unit (CU) or a DU. Alternatively, the access network device may be composed of CUs and DUs, for example, as shown in fig. 4. The CU and the DU may be physically separated or disposed together, which is not specifically limited in this embodiment of the application. One CU can be connected to one DU, or a plurality of DUs can share one CU, which can save cost and facilitate network expansion.

The terminal device may be a wireless terminal device capable of receiving access network device scheduling and indication information, which may be a device providing voice and/or data connectivity to a user, or a handheld device having wireless connection capability, or other processing device connected to a wireless modem. Wireless terminal devices, which may be mobile terminal devices such as mobile telephones (or "cellular" telephones), computers, and data cards, such as portable, pocket, hand-held, computer-included, or vehicle-mounted mobile devices, may communicate with one or more core networks or the internet via a radio access network (e.g., a RAN). For example, devices such as Personal Communication Services (PCS) phones, cordless phones, Session Initiation Protocol (SIP) phones, Wireless Local Loop (WLL) stations, Personal Digital Assistants (PDAs), tablet computers (pads), and computers with wireless transceiving functions. A wireless terminal device may also be referred to as a system, a subscriber unit (subscriber unit), a subscriber station (subscriber station), a mobile station (mobile station), a Mobile Station (MS), a remote station (remote station), an Access Point (AP), a remote terminal device (remote terminal), an access terminal device (access terminal), a user terminal device (user terminal), a user agent (user agent), a Subscriber Station (SS), a user terminal device (CPE), a terminal (terminal), a User Equipment (UE), a Mobile Terminal (MT), etc. The wireless terminal device may also be a wearable device as well as a next generation communication system, e.g. a terminal device in a 5G network or a terminal device in a future evolved PLMN network, a terminal device in an NR communication system, etc.

In addition, the embodiment of the application can also be applied to other communication technologies facing the future. The network architecture and the service scenario described in this application are for more clearly illustrating the technical solution of this application, and do not constitute a limitation to the technical solution provided in this application, and it can be known by those skilled in the art that the technical solution provided in this application is also applicable to similar technical problems along with the evolution of the network architecture and the appearance of new service scenarios.

It should be noted that the embodiments of the present application do not limit the types and systems of the above communication systems. For example: the communication system may be: the 5th Generation (5G) communication system, an LTE communication system, a 6G communication system, and The like.

The embodiments of the present application may be applied to the fourth generation mobile communication system (4G) system, a 5G system, an NTN system, a vehicle-to-everything (V2X), a long term evolution-vehicle networking (LTE-vehicle, LTE-V), a vehicle-to-vehicle (V2V), a vehicle networking, a Machine Type Communication (MTC), an internet of things (internet of things, IoT), a long term evolution-Machine to Machine (LTE-Machine to Machine, LTE-M), a Machine-to-Machine (M2M), or a future mobile communication system.

For example, in the application scenario shown in fig. 5, the satellite may serve as a base station to establish an N2 or Ng connection with an AMF entity in the core network, so as to provide a wireless access service for the terminal device.

For example, in a communication system, an X2 or Xn connection may be established between two base stations in the RAN to transmit data such as cell information, thereby implementing cell reselection and handover of a terminal device. For example, the two base stations in the RAN that establish the connection may be: the satellite as the base station and the satellite as the base station, the satellite as the base station and the conventional base station, the base station composed of a plurality of partial functions and the conventional base station, or the base station composed of a plurality of partial functions and the satellite as the base station, and the like. In the application scenario shown in fig. 6, a connection may be established between two satellites serving as base stations to perform data and signaling interaction.

Illustratively, in a communication system supporting carrier aggregation, a dual-connection (DC) technology may be introduced to implement, thereby providing a higher rate and improving spectrum efficiency for a user, and in the communication system, a terminal device supporting dual-connection may simultaneously connect two base stations to increase the throughput rate of a single user. Two base stations simultaneously connected to the terminal device also need to establish a connection through a corresponding interface to perform data and signaling interaction, as shown in fig. 7. When it is required to be described, one of two base stations to which the terminal device is simultaneously connected serves as a main base station, and the other serves as a secondary base station. When the core networks connected to the base stations are different and the types of the two base stations are different, the interfaces between the AMF entity and the base stations and the interfaces between the two base stations may also change accordingly, as shown in each interface schematic diagram in fig. 8.

For example, in the application scenario shown in fig. 9, the satellite may also be used as a relay device between the terminal device and the base station or as a Remote Radio Unit (RRU) of the base station. In this scenario, the satellite is primarily responsible for L1 relaying for physical layer forwarding and is not visible to higher layers.

For example, in the application scenario shown in fig. 10, a base station in a RAN is split into two functional parts, namely a DU and a CU, where a satellite can serve as the DU. In this application scenario, the interface between DU and CU is the F1 interface.

It should be further noted that the application scenarios shown in fig. 5 to fig. 10 above are only examples of application scenarios to which the present application is applicable, and a satellite is taken as an example in the above examples.

Currently, in a mobile communication system, after a User Equipment (UE) establishes Radio Resource Control (RRC) connection with a network device and enters an RRC connection state, if Radio Link Failure (RLF), handover failure, and other conditions occur, an RRC reestablishment procedure is triggered.

Currently, the condition for triggering the RLF is Radio Link Control (RLC) uplink maximum retransmission or random access problem (out-of-sync and re-synchronization) or T310 timeout (i.e. out-of-sync detection).

The RLC uplink maximum retransmission is the maximum number of times that the RLC protocol layer retransmits to the lower protocol layer when the UE transmits uplink data.

Out-of-sync re-synchronization is that the preamble (preamble) transmission reaches the maximum number of times due to the out-of-sync of the uplink Timing Advance (TA). The terminal equipment does not receive a TA command in TA to cause desynchronization, at the moment, if uplink data exist, resynchronization is triggered, namely a random access process is carried out, and if preamble (preamble) is sent for the maximum times, the terminal equipment judges that RLF occurs.

T310 is a timer triggered after the upper protocol layer of the UE continuously receives N310 out-of-sync (out-of-sync) indications of the lower layer. N310 may be network configured, for example, configured as 6, and when the upper layer protocol layer receives the physical layer out-of-sync indication for 6 consecutive times, T310 is turned on. When T310 times out, RLF is judged to occur. The relevant description of T310 can be found in table 1.

TABLE 1

As non-terrestrial network (NTN) communication has the characteristics of wide coverage, large delay and the like, Round Trip Time (RTT) of communication between the UE and the network device is also relatively long. When the NTN device cannot provide a communication service for the terminal device, the terminal device needs any one of the RLF determination conditions to determine the RLF, and because the RTT of communication between the UE and the NTN device is relatively long, the time required for the UE to perform RLF determination increases dramatically, so that the UE communication delay is relatively long, and electric quantity is relatively wasted. Taking the RLC maximum retransmission as an example, assuming that the number of RLC retransmissions is T at most, RTT in the terrestrial communication system is T1, so the time taken by the terminal device to determine RLF is T × T1, whereas RTT in the NTN communication system is T2, so the time taken by the terminal device to determine RLF is T × T2, and since T2 is much longer than T1, the time taken by the terminal device to determine RLF is long. For example, in GEO scenarios, RTT is 500 milliseconds or more, whereas in general terrestrial communication scenarios, RTT is only about 5 milliseconds.

Furthermore, due to the fast flight speed of LEO satellites, the terminal equipment may be intermittently without signal coverage, especially early, with imperfect coverage. Since the RTT of communication between the UE and the NTN device is relatively long, the terminal device may not satisfy the RLF determination condition during a time period without signal coverage. For example, taking the RLC maximum retransmission as an example, the terminal device has a time duration of T1 without signal coverage, since the RTT in the terrestrial communication system is relatively short, the number of RLC retransmissions occurring within the time duration of T1 reaches the maximum value, the terminal device can trigger RRC reestablishment in time, and the RTT in the NTN communication system is relatively long, and the number of RLC retransmissions occurring within the time duration of T1 does not reach the maximum value, so that the terminal device cannot trigger RRC reestablishment in time.

Based on this, embodiments of the present application provide a communication method and apparatus, so as to solve the problems that, in an NTN communication system, time required for a UE to perform RLF determination increases dramatically, so that UE communication delay is large, and electric power is wasted. The method and the device are based on the same technical conception, and because the principles of solving the problems of the method and the device are similar, the implementation of the device and the method can be mutually referred, and repeated parts are not repeated.

It should be understood that "at least one" in the embodiments of the present application means one or more, "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a alone, both A and B, and B alone, where A, B may be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a and b, a and c, b and c, or a, b and c, wherein a, b and c can be single or multiple.

It is to be understood that the terms "first," "second," and the like in the description of the present application are used for descriptive purposes only and not for purposes of indicating or implying relative importance, nor for purposes of indicating or implying order.

It should be noted that, before initiating RRC reestablishment, the network device that establishes connection last may be referred to as a serving network device, an anchor network device (anchor gbb), a source network device, and the like, and the cell that connects last before initiating RRC reestablishment is referred to as a source cell.

The communication method provided by the present application is specifically described below with reference to the drawings.

The embodiment of the application provides two communication methods. The method may be applied, but is not limited to, the following scenarios: the LEO/GEO is used as an independent base station and is connected with a core network; the LEO/GEO is used as a relay base station and is connected with a ground base station; LEO is used as DU and connected with the ground CU; the terminal device communicates with the satellites of the remaining various orbits.

The first embodiment is as follows:

as shown in fig. 11, an embodiment of the present application provides a communication method. The method can be applied to a terminal device, or a chip set, or a functional module in a chip and the like for executing the method. Taking the terminal device as an example, the communication process may specifically include:

s1101, the terminal device obtains the remaining coverage duration of the service cell covering the first geographic area, and the terminal device is located in the first geographic area.

In one embodiment, the network device may send coverage time information of the serving cell to the terminal device, and the terminal device may determine, according to the coverage time information, a remaining coverage duration in which the serving cell covers the first geographic area.

For example, the coverage time information may be a remaining coverage time for the serving cell to cover the first geographic area. Alternatively, the coverage time information may also be a remaining coverage time period for which the serving cell covers the first geographical area, e.g., the coverage time information includes a start time and an end time of the remaining coverage time. So that the terminal device can determine the remaining coverage duration according to the remaining coverage time period. Alternatively, the coverage time information may also be a coverage time period of the serving cell, for example, the coverage time information includes a start time and an end time of the coverage time. So that the terminal device can determine the remaining coverage duration according to the coverage time period and the current time.

Optionally, the network device may send the coverage time information of the serving cell to the terminal device through a system message, RRC signaling, or NAS signaling.

In another implementation manner, the terminal device may determine the remaining coverage duration according to at least one of the following information: ephemeris information, a first geographical area, a coverage of a serving cell. Illustratively, the ephemeris information may include at least one of: the service cell corresponds to the information of the position, the operation track, the operation speed, the operation direction and the like of the network equipment.

In an example, taking the ephemeris information including the operation speed and the operation direction of the network device corresponding to the serving cell as an example, the terminal device may determine the remaining coverage duration of the serving cell according to the operation speed and the operation direction of the network device corresponding to the serving cell, the coverage of the serving cell, and the location of the first geographic area where the terminal device is located.

Optionally, the network device may send information such as ephemeris information and coverage of the serving cell to the terminal device through system message, RRC signaling, or NAS signaling. The ephemeris information and the coverage area of the serving cell may be sent through the same signaling or through different signaling.

1102, the terminal device determines that a radio link failure occurs when the remaining coverage duration is less than a first time threshold.

In the embodiment of the application, the terminal equipment judges whether RLF occurs or not through the residual coverage duration of the serving cell, so that RRC reestablishment can be triggered in time when a coverage signal is weak or disappears, the communication quality of the terminal equipment can be improved, and the communication delay is reduced. For example, as shown in fig. 12, the time for determining the RLF according to the remaining coverage duration of the serving cell is earlier than the time for determining the RLF according to the timeout of T310, so that the terminal device can determine the RLF in time, thereby saving signaling transmission and power consumption.

In some embodiments, the remaining coverage duration of the serving cell covering the first geographical area may be used in combination with the three current determination conditions (see the background introduction). For example, the occurrence of the RLF is determined when the RLC uplink maximum retransmission occurs and the remaining coverage duration of the serving cell covering the first geographical area is less than a first threshold. As another example, RLF is determined to occur when out-of-sync resynchronization is performed and the remaining coverage duration of the serving cell covering the first geographic area is less than the first threshold. As another example, when T310 times out and the remaining coverage duration of the serving cell covering the first geographic area is less than the first threshold, it is determined that RLF occurs.

Optionally, after determining that the radio link failure occurs, the terminal device may determine, according to cell coverage information, an RRC state after the radio link failure occurs, where the cell coverage information includes at least one of the following information: the remaining coverage duration of the serving cell, the remaining coverage durations of N neighboring cells, and the waiting durations of M neighboring cells, where the waiting duration is a duration that needs to be waited when the terminal device enters a coverage range of a neighboring cell, and M, N are integers greater than 0.

In one implementation, if the remaining coverage duration of the serving cell is greater than the second time threshold, the terminal device performs RRC reestablishment in the serving cell.

In another implementation manner, if the remaining coverage duration of the serving cell is not greater than the second time threshold, the terminal device performs cell selection.

In another implementation manner, if the remaining coverage duration of a first neighboring cell of the N neighboring cells is greater than a third time threshold, the terminal device performs RRC reestablishment in the first neighboring cell, where the first neighboring cell is any one of the N neighboring cells.

In another implementation, if the first time difference is greater than the fourth time threshold, the terminal device performs RRC reestablishment in the second neighboring cell, where the first time difference is a result of subtracting the remaining coverage duration of the serving cell from the remaining coverage duration of the second neighboring cell, and the second neighboring cell is any one of the N neighboring cells.

In another implementation manner, if the remaining coverage duration of the serving cell is less than the fifth threshold and the remaining coverage duration of the third neighboring cell is greater than the sixth threshold, the terminal device performs RRC reestablishment in the third neighboring cell, where the third neighboring cell is a cell with the longest remaining coverage time among the N neighboring cells.

In another implementation manner, if the remaining coverage duration of the serving cell is less than the fifth threshold, the terminal device performs RRC reestablishment in a third neighboring cell, where the third neighboring cell is a cell with the longest remaining coverage duration among the N neighboring cells.

In another implementation manner, if the remaining coverage durations of the serving cell and the N neighboring cells are both less than the seventh threshold, the terminal device performs RRC reestablishment in a fourth neighboring cell, where the fourth neighboring cell is a cell with the shortest waiting duration among the M neighboring cells.

In another implementation manner, if the remaining coverage durations of the serving cell and the N neighboring cells are both less than the seventh threshold, the terminal device performs RRC reestablishment in a fifth neighboring cell, where the fifth neighboring cell is a cell with the longest coverage duration in the first geographic area and the waiting duration in the M neighboring cells is not greater than the eighth threshold.

In another implementation, if the remaining coverage durations of the serving cell and the N neighboring cells are both less than the seventh threshold, the terminal device performs RRC reestablishment in a sixth neighboring cell, where the sixth neighboring cell is a cell with the highest metric among the M neighboring cells, and the metric is determined according to the waiting duration of the neighboring cells and the coverage duration covering the first geographic area.

For example, the metric value may be a waiting time length, a weighted value of a coverage time length, and the like.

In another implementation manner, if the remaining coverage durations of the serving cell and the N neighboring cells are both less than the seventh threshold and the waiting durations of the M neighboring cells are both greater than the eighth threshold, the terminal device enters the RRC idle state.

In another implementation, if the remaining coverage duration of the serving cell is less than the fifth threshold, the terminal device performs RRC reestablishment in a seventh neighboring cell, where the seventh neighboring cell is a cell in which any remaining coverage duration of the N neighboring cells is greater than the eighth threshold.

Optionally, the manner of acquiring the remaining coverage duration and the waiting duration of the neighboring cell by the terminal device is similar to the manner of acquiring the remaining coverage duration of the serving cell by the terminal device, and details are not repeated here.

Illustratively, the terminal device may perform RRC reestablishment through the following procedures, as shown in fig. 13:

s1301, the terminal device sends an RRC Reestablishment Request message (RRC Request) to the first network device. The first network device may be a network device corresponding to a serving cell, or may also be a network device corresponding to a neighboring cell, for example, a network device corresponding to a first neighboring cell, a network device corresponding to a second neighboring cell, a network device corresponding to a third neighboring cell, and the like.

S1302, the first network device sends a UE Context recovery Request message (Retrieve UE Context Request) to the second network device. The second network device may be a network device corresponding to the serving cell.

S1303, the second network device sends a resume UE Context request Response (Retrieve UE Context Response) to the first network device.

And if the second network equipment does not have the CONTEXT of the terminal equipment, sending a UE CONTEXT recovery FAILURE message (RETRIEVE UE CONTEXT FAILURE) to the first network equipment.

It should be noted that steps S1302 and S1303 are not necessarily performed, for example, when the first network device is a network device corresponding to the serving cell, step S1302, S1303 may not be performed.

S1304, the first network device sends an RRC reestablishment message to the terminal device.

Optionally, the first network device may send an RRC reconfiguration message after sending the RRC reestablishment message to the terminal device.

S1305, the terminal device sends an RRC reestablishment complete message to the first network device.

Optionally, the terminal device sends an RRC reconfiguration complete message to the first network device.

S1306, the first network device sends a data forwarding address indication to the second network device.

If the second network device side has downlink data to be sent to the terminal device, the downlink data can be forwarded to the first network device after the data forwarding address is obtained.

S1307, the first network device sends a path switching request message to an access and mobility management function (AMF), which instructs the AMF to send downlink data to the first network device.

S1308, the AMF sends a path switching request response message to the first network device.

S1309, the first network device notifies the second network device to release the context of the terminal device.

It should be understood that the RRC reestablishment procedure is only an exemplary illustration, and in a specific implementation, only a part of the steps in the procedure may be performed, or steps other than the procedure may be performed.

In addition, the terminal device may further send an RRC reestablishment report, where the RRC reestablishment report carries an RRC reestablishment reason, and the RRC reestablishment reason is related to the coverage time of the serving cell, for example, the remaining coverage time of the serving cell is less than the first time threshold for the RRC reestablishment reason, and for example, the remaining coverage time of the serving cell is 0 for the RRC reestablishment reason.

Alternatively, the RRC reestablishment reason may also be related to the coverage time of the target cell.

Optionally, the terminal device may receive neighboring cell information sent by the network device after determining that the RLF occurs, for example, cell identification (cell ID) of a neighboring cell, Physical Cell Identification (PCI), frequency point, and other information. The terminal device may perform RRC reestablishment in the cell corresponding to the neighboring cell information. In this manner, the terminal device may skip the process of cell selection to perform RRC reestablishment in the cell.

The neighbor cell information may be sent by the network device through a system message or RRC signaling.

In one implementation, the network device may determine a neighboring cell that is to cover the terminal device according to the ephemeris information and the neighboring cell management information, where the neighboring cell management information may include information of at least one neighboring cell of the terminal device, where the at least one neighboring cell may include a current neighboring cell and may further include a future neighboring cell as the satellite moves. The ephemeris information may include operation information of the at least one neighbor cell, and the operation information may include at least one of: running track, running speed, real-time position and running direction. In the foregoing manner, the network device may determine, according to the ephemeris information, a neighboring cell that is about to cover the terminal device in the neighboring cells included in the neighboring cell management information, so as to send the neighboring cell information of the neighboring cell to the terminal device.

In the embodiment of the application, the terminal device judges whether RLF occurs or not through the residual coverage duration of the serving cell, so that RRC reestablishment can be triggered in time or an RRC idle state can be entered when a coverage signal is weak or disappears, electric quantity and signaling overhead can be saved, communication quality of the terminal device is improved, and communication delay is reduced.

Example two:

as shown in fig. 14, another communication method provided in the embodiments of the present application is provided. The method can be applied to a terminal device, or a chip set, or a functional module in a chip and the like for executing the method. Taking the terminal device as an example, the communication process may specifically include:

s1401, the terminal device determines N suitable cells, where the suitable cells may satisfy a coverage condition, and the coverage condition may optionally be that a remaining coverage duration covering a first geographic area is greater than a first time threshold or a waiting duration is less than a second time threshold, where the terminal device is located in the first geographic area, the waiting duration is a duration that the terminal device needs to wait when entering a coverage area of the cell, and N is an integer greater than 0.

For example, the manner in which the terminal device obtains the remaining coverage duration or the waiting duration of the cell may refer to the manner in which the terminal device obtains the remaining coverage duration that the serving cell covers the first geographic area in the foregoing embodiment, and details are not repeated here.

In one implementation, the terminal device may select N cells with the remaining coverage duration greater than the first time threshold as the suitable cells.

In another implementation manner, if the remaining coverage duration of the cell covering the first geographic area is smaller than the first time threshold, the terminal device may select N cells with the waiting duration smaller than the second time threshold as the suitable cells.

S1402, the terminal device performs cell selection or cell reselection among the N suitable cells.

In one implementation, the terminal device may perform cell selection or cell reselection among N suitable cells based on an S-criterion or an R-criterion, where the remaining coverage duration or the waiting duration (or a reduced value of the remaining coverage duration or the waiting duration) is an offset value in the S-criterion or the R-criterion. For example, the remaining coverage duration or waiting duration (or a reduced value of the remaining coverage duration or waiting duration) is used as Qoffset in the S-criterion or R-criterion _temp 。

One example is:

Srxlev＝Q _rxlevmeas -(Q _rxlevmin +Q _{rxlevminOffset} )-P _compensation +Qoffset _temp ；

Squal＝Q _qualmeas -(Q _qualmin +Q _{qualminOffset} )+Qoffset _temp ；

R _s ＝Q _meas,s +Q _hyst +Qoffset _temp ；

wherein Qoffset _temp For the remaining coverage duration or waiting duration, or Qoffset _temp The converted value of the remaining coverage duration or the converted value of the waiting duration, for example, the remaining coverage duration minus a threshold value or the waiting duration minus a threshold value.

Another example is:

Srxlev＝Q _rxlevmeas -(Q _rxlevmin +Q _{rxlevminOffset} )-P _compensation -Qoffset _temp ；

Squal＝Q _qualmeas -(Q _qualmin +Q _{qualminOffset} )-Qoffset _temp ；

R _s ＝Q _meas,s +Q _hyst -Qoffset _temp ；

wherein Qoffset _temp Is the inverse of the remaining coverage duration or the inverse of the waiting duration, or Qoffset _temp The converted value of the remaining coverage duration or the converted value of the waiting duration is, for example, a value obtained by subtracting the remaining coverage duration from a threshold or a value obtained by subtracting the waiting duration from a threshold.

As another example, Qoffset _temp As a first offset in the S-criterion or the R-criterion, the remaining coverage duration or the waiting duration (or a reduced value of the remaining coverage duration or the waiting duration) is a second offset in the S-criterion or the R-criterion.

One example is:

Srxlev＝Q _rxlevmeas -(Q _rxlevmin +Q _{rxlevminOffset} )-P _compensation -Qoffset _temp +Qoffset _time ；

Squal＝Q _qualmeas -(Q _qualmin +Q _{qualminOffset} )-Qoffset _temp +Qoffset _time ；

R _s ＝Q _meas,s +Q _hyst -Qoffset _temp +Qoffset _time ；

wherein Qoffset _temp Qoffset, defined for the present protocol _time For remaining coverage duration or the likeWait time, or Qoffset _time The converted value of the remaining coverage duration or the converted value of the waiting duration, for example, the remaining coverage duration minus a threshold value or the waiting duration minus a threshold value.

Another example is:

Srxlev＝Q _rxlevmeas -(Q _rxlevmin +Q _{rxlevminOffset} )-P _compensation -Qoffset _temp -Qoffset _time ；

Squal＝Q _qualmeas -(Q _qualmin +Q _{qualminOffset} )-Qoffset _temp -Qoffset _time ；

R _s ＝Q _meas,s +Q _hyst -Qoffset _temp -Qoffset _time ；

wherein Qoffset _temp May be the inverse of the remaining coverage duration or the inverse of the waiting duration, or Qoffset _temp The reduced value of the remaining coverage duration or the reduced value of the waiting duration may also be considered, for example, a value obtained by subtracting the remaining coverage duration from a threshold value or a value obtained by subtracting the waiting duration from a threshold value.

Based on the same technical concept as the method embodiment, the embodiment of the application provides a communication device. The communication apparatus may include a processing unit 1501 and a transmitting/receiving unit 1502 as shown in fig. 15. The communication apparatus may be specifically configured to implement the method executed by the terminal device in the foregoing embodiment, and the apparatus may be the terminal device itself, or may also be a chip or a chip set in the terminal device, or a part of the chip for executing the function of the relevant method.

In one implementation, the transceiver 1502 is configured to transmit and receive information. The processing unit 1501 is configured to: acquiring the residual coverage duration of a current service cell of a communication device covering a first geographical area through information received and transmitted by a receiving and transmitting unit, wherein the communication device is positioned in the first geographical area; and determining that the radio link failure occurs when the residual coverage duration is less than a first time threshold.

In an implementation manner, the transceiving unit 1502 may be specifically configured to receive coverage time information of a serving cell from a network device. The corresponding processing unit 1501 is specifically configured to determine the remaining coverage duration according to the coverage time information when obtaining the remaining coverage duration that the serving cell covers the first geographic area.

For example, the coverage time information may be a remaining coverage time, or the coverage time information may also be a remaining coverage time period during which the serving cell covers the first geographic area, or the coverage time information may also be a coverage time period of the serving cell.

In another implementation manner, the transceiver 1502 may be specifically configured to receive ephemeris data from a network device; correspondingly, the processing unit 1501 is specifically configured to determine the remaining coverage duration according to the ephemeris information and the first geographic area when obtaining the remaining coverage duration that the serving cell covers the first geographic area.

Optionally, the processing unit 1501 is further configured to: after the radio link failure is determined to occur when the remaining coverage duration is less than the first time threshold, determining a Radio Resource Control (RRC) state after the radio link failure occurs according to cell coverage information, wherein the cell coverage information comprises at least one of the following information: the remaining coverage duration of the serving cell, the remaining coverage durations of N neighboring cells, and the waiting durations of M neighboring cells, where the waiting duration is a duration that needs to be waited when the terminal device enters a coverage range of a neighboring cell, and M, N are integers greater than 0.

When determining the RRC state after the radio link failure occurs according to the cell coverage information, the processing unit 1501 may specifically perform the following different operations according to the circumstances, and may of course perform other operations, which is not limited herein:

when the residual coverage duration of the serving cell is greater than a second time threshold, performing RRC reconstruction in the serving cell;

when the residual coverage duration of the serving cell is not greater than the second time threshold, cell selection is carried out;

when the remaining coverage duration of a first neighbor cell in the N neighbor cells is greater than a third time threshold, the terminal device performs RRC reestablishment in the first neighbor cell, where the first neighbor cell is any one of the N neighbor cells;

when the first time difference is greater than a fourth time threshold, performing RRC reconstruction in a second adjacent cell, wherein the first time difference is a result obtained by subtracting the residual coverage duration of the serving cell from the residual coverage duration of the second adjacent cell, and the second adjacent cell is any one of the N adjacent cells;

when the residual coverage duration of the serving cell is less than a fifth threshold and the residual coverage duration of a third neighboring cell is greater than a sixth threshold, performing RRC reconstruction in the third neighboring cell, wherein the third neighboring cell is the cell with the longest residual coverage time among the N neighboring cells;

when the remaining coverage time of the serving cell and the N neighbor cells are both smaller than a seventh threshold, performing RRC reconstruction in a fourth neighbor cell, wherein the fourth neighbor cell is a cell with the shortest waiting time among the M neighbor cells;

when the remaining coverage time of the serving cell and the N adjacent cells are both smaller than a seventh threshold, performing RRC reconstruction in a fifth adjacent cell, wherein the fifth adjacent cell is a cell with the longest coverage time in the first geographic area and the waiting time in the M adjacent cells is not larger than an eighth threshold;

when the remaining coverage duration of the serving cell and the N neighboring cells are both smaller than a seventh threshold, performing RRC reestablishment in a sixth neighboring cell, where the sixth neighboring cell is a cell with the highest metric value among the M neighboring cells, and the metric value is determined according to the waiting duration of the neighboring cells and the coverage duration covering the first geographic area;

and when the residual coverage time lengths of the service cell and the N adjacent cells are both smaller than a seventh threshold value and the waiting time lengths of the M adjacent cells are both larger than an eighth threshold value, entering an RRC idle state.

The transceiver unit 1502 may further be configured to send an RRC reestablishment report, where the RRC reestablishment report carries an RRC reestablishment reason, and the RRC reestablishment reason is related to the coverage time of the serving cell.

In another implementation, the transceiving unit 1502 is configured to transceive information; a processing unit 1501, configured to determine N suitable cells, where the suitable cells meet a coverage condition that a remaining coverage duration covering a first geographic area is greater than a first time threshold or a waiting duration is less than a second time threshold, where a terminal device is located in the first geographic area, the waiting duration is a duration that the terminal device needs to wait when entering a coverage area of a cell, and N is an integer greater than 0; cell selection or cell reselection is performed among the N suitable cells by the transceiving unit 1502.

The processing unit 1501, when determining N suitable cells, may specifically select N cells whose remaining coverage duration is greater than the first time threshold as suitable cells; or when the residual coverage time of the cells covering the first geographic area is smaller than the first time threshold, selecting N cells with the waiting time smaller than the second time threshold as the suitable cells.

Optionally, when the processing unit 1501 performs cell selection or cell reselection in N suitable cells, specifically, the transceiving unit 1502 may perform cell selection or cell reselection in the N suitable cells based on an S criterion or an R criterion, where the remaining coverage duration or the waiting duration is an offset value in the S criterion or the R criterion.

The division of the modules in the embodiments of the present application is schematic, and only one logical function division is provided, and in actual implementation, there may be another division manner, and in addition, each functional module in each embodiment of the present application may be integrated in one processor, may also exist alone physically, or may also be integrated in one module by two or more modules. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. It is to be understood that the functions or implementations of the respective modules in the embodiments of the present application may further refer to the related description of the method embodiments.

In one possible approach, the communication device may be as shown in fig. 16. The communication device may include a processor 1601, a communication interface 1603, and optionally, a memory 1602. The processing unit 1501 may be the processor 1601. The transceiving unit 1502 may be a communication interface 1603.

The processor 1601 may be a Central Processing Unit (CPU), a digital processing unit, or the like. Communication interface 1603 may be a transceiver, or may be an interface circuit such as a transceiver circuit, or may be a transceiver chip, or the like. A memory 1602 for storing programs executed by the processor 1601. The memory 1602 may be a non-volatile memory, such as a Hard Disk Drive (HDD) or a solid-state drive (SSD), and may also be a volatile memory (RAM), such as a random-access memory (RAM). The memory 1602 is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to such.

The processor 1601 is configured to execute the program codes stored in the memory 1602, and is specifically configured to perform the actions of the processing unit 1501, which are not described herein again. The communication interface 1603 is specifically configured to perform the operations of the transceiver 1502, which will not be described herein again.

The embodiment of the present application does not limit the specific connection medium among the communication interface 1603, the processor 1601 and the memory 1602. In the embodiment of the present application, the memory 1602, the processor 1601 and the communication interface 1603 are connected by the bus 1604 in fig. 16, the bus is indicated by a thick line in fig. 16, and the connection manner between other components is merely schematically illustrated and is not limited thereto. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 16, but that does not indicate only one bus or one type of bus.

The embodiment of the present invention further provides a computer-readable storage medium, which is used for storing computer software instructions required to be executed for executing the processor, and which contains a program required to be executed for executing the processor.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A method of communication, comprising:

the method comprises the steps that terminal equipment obtains the residual coverage duration of a service cell covering a first geographic area, wherein the terminal equipment is located in the first geographic area;

and the terminal equipment determines that the radio link failure occurs when the residual coverage duration is less than a first time threshold.

2. The method of claim 1, wherein the obtaining, by the terminal device, the remaining coverage duration for the serving cell to cover the first geographic area comprises:

the terminal equipment receives the coverage time information of the serving cell from network equipment;

and the terminal equipment determines the residual coverage duration according to the coverage time information.

3. The method of claim 2, wherein the coverage time information is the remaining coverage duration, or wherein the coverage time information is a remaining coverage time period for the serving cell to cover the first geographic area, or wherein the coverage time information is a coverage time period for the serving cell.

4. The method of claim 1, wherein the obtaining, by the terminal device, the remaining coverage duration for the serving cell to cover the first geographic area comprises:

and the terminal equipment determines the residual coverage duration according to the ephemeris information and the first geographical area.

5. The method of any of claims 1-4, wherein after the terminal device determines that a radio link failure has occurred when the remaining coverage duration is less than a first time threshold, the method further comprises:

the terminal equipment determines the Radio Resource Control (RRC) state after a radio link failure occurs according to cell coverage information, wherein the cell coverage information comprises at least one of the following information:

the remaining coverage duration of the serving cell, the remaining coverage durations of N neighboring cells, and the waiting durations of M neighboring cells, where the waiting duration is a duration that needs to be waited when the terminal device enters the coverage area of the neighboring cell, and M, N are integers greater than 0.

6. The method of claim 5, wherein the determining, by the terminal device, the RRC state after the radio link failure occurs according to the cell coverage information comprises:

when the residual coverage duration of the serving cell is greater than a second time threshold, the terminal device performs RRC reestablishment in the serving cell; or alternatively

When the residual coverage duration of the service cell is not greater than a second time threshold, the terminal equipment performs cell selection; or alternatively

When the remaining coverage duration of a first neighbor cell of the N neighbor cells is greater than a third time threshold, the terminal device performs RRC reestablishment in the first neighbor cell, where the first neighbor cell is any one of the N neighbor cells; or

When a first time difference is greater than a fourth time threshold, the terminal device performs RRC reestablishment in a second neighboring cell, where the first time difference is a result of subtracting the remaining coverage duration of the serving cell from the remaining coverage duration of the second neighboring cell, and the second neighboring cell is any one of the N neighboring cells; or

When the remaining coverage duration of the serving cell is less than a fifth threshold and the remaining coverage duration of a third neighboring cell is greater than a sixth threshold, the terminal device performs RRC reestablishment in the third neighboring cell, where the third neighboring cell is a cell with the longest remaining coverage duration among the N neighboring cells; or alternatively

When the remaining coverage duration of the serving cell and the N neighboring cells are both smaller than a seventh threshold, the terminal device performs RRC reestablishment in a fourth neighboring cell, where the fourth neighboring cell is a cell with the shortest waiting duration among the M neighboring cells; or

When the remaining coverage time of the serving cell and the N neighboring cells are both less than a seventh threshold, the terminal device performs RRC reestablishment in a fifth neighboring cell, where the fifth neighboring cell is a cell with a longest coverage time in the first geographic area and a waiting time that is not greater than an eighth threshold among the M neighboring cells; or

When the remaining coverage duration of the serving cell and the N neighboring cells are both less than a seventh threshold, the terminal device performs RRC reestablishment in a sixth neighboring cell, where the sixth neighboring cell is a cell with the highest metric value among the M neighboring cells, and the metric value is determined according to the waiting duration of the neighboring cells and the coverage duration covering the first geographic area; or

And when the residual coverage time of the serving cell and the N adjacent cells are both smaller than a seventh threshold value and the waiting time of the M adjacent cells are both larger than an eighth threshold value, the terminal equipment enters an RRC idle state.

7. The method of any one of claims 1-6, further comprising:

and the terminal equipment sends an RRC reestablishment report, wherein the RRC reestablishment report carries an RRC reestablishment reason, and the RRC reestablishment reason is related to the coverage time of the serving cell.

8. A method of communication, comprising:

the method comprises the steps that a terminal device determines N suitable cells, the suitable cells meet a coverage condition, the coverage condition is that the residual coverage time for covering a first geographic area is greater than a first time threshold or the waiting time is less than a second time threshold, the terminal device is located in the first geographic area, the waiting time is the time required to wait when the terminal device enters the coverage area of the cells, and N is an integer greater than 0;

and the terminal equipment performs cell selection or cell reselection in the N suitable cells.

9. The method of claim 8, wherein the terminal device determining N suitable cells comprises:

the terminal equipment selects N cells with the residual coverage duration being greater than the first time threshold as suitable cells; or

And when the residual coverage time of the cells covering the first geographic area is smaller than the first time threshold, the terminal equipment selects N cells with the waiting time smaller than the second time threshold as suitable cells.

10. The method of claim 8 or 9, wherein the terminal device performing cell selection or cell reselection among the N suitable cells comprises:

and the terminal equipment performs cell selection or cell reselection in the N suitable cells based on an S criterion or an R criterion, wherein the remaining coverage time or the waiting time is an offset value in the S criterion or the R criterion.

11. A communications apparatus, comprising:

a transceiving unit for transceiving information;

a processing unit to:

acquiring the residual coverage duration of a current service cell of the communication device covering a first geographical area through information received and transmitted by the receiving and transmitting unit, wherein the communication device is positioned in the first geographical area;

and determining that radio link failure occurs when the residual coverage duration is less than a first time threshold.

12. The apparatus as claimed in claim 11, wherein said transceiver unit is specifically configured to: receiving coverage time information of the serving cell from a network device;

the processing unit is specifically configured to determine the remaining coverage duration according to the coverage time information when the remaining coverage duration that the serving cell covers the first geographic area is obtained.

13. The apparatus of claim 12, wherein the coverage time information is the remaining coverage duration, or wherein the coverage time information is a remaining coverage time period for the serving cell to cover the first geographic area, or wherein the coverage time information is a coverage time period for the serving cell.

14. The apparatus of claim 11, wherein the transceiver unit is specifically configured to receive ephemeris data from a network device;

the processing unit, when obtaining the remaining coverage length of the communication device when the current serving cell covers the first geographic area, is specifically configured to: and determining the residual coverage duration according to the ephemeris information and the first geographical area.

15. The apparatus of any of claims 11-14, wherein the processing unit is further to:

after the radio link failure is determined to occur when the residual coverage duration is less than a first time threshold, determining a Radio Resource Control (RRC) state after the radio link failure occurs according to cell coverage information, wherein the cell coverage information comprises at least one of the following information:

16. The apparatus as claimed in claim 15, wherein the processing unit, when determining the RRC state after the radio link failure occurs according to the cell coverage information, is specifically configured to:

when the residual coverage duration of the serving cell is greater than a second time threshold, performing RRC reconstruction in the serving cell; or alternatively

When the residual coverage duration of the serving cell is not greater than a second time threshold, cell selection is carried out; or

When the remaining coverage duration of a first neighbor cell of the N neighbor cells is greater than a third time threshold, the terminal device performs RRC reestablishment in the first neighbor cell, where the first neighbor cell is any one of the N neighbor cells; or alternatively

When a first time difference is greater than a fourth time threshold, performing RRC reconstruction in a second adjacent cell, wherein the first time difference is a result of subtracting the remaining coverage duration of the serving cell from the remaining coverage duration of the second adjacent cell, and the second adjacent cell is any one of the N adjacent cells; or alternatively

When the remaining coverage duration of the serving cell is less than a fifth threshold and the remaining coverage duration of a third neighboring cell is greater than a sixth threshold, performing RRC reestablishment in the third neighboring cell, where the third neighboring cell is a cell with the longest remaining coverage duration among the N neighboring cells; or

When the remaining coverage time of the serving cell and the N neighbor cells are both smaller than a seventh threshold, performing RRC reconstruction in a fourth neighbor cell, wherein the fourth neighbor cell is a cell with the shortest waiting time among the M neighbor cells; or

When the remaining coverage time of the serving cell and the N neighboring cells are both less than a seventh threshold, performing RRC reestablishment in a fifth neighboring cell, where the fifth neighboring cell is a cell with a longest coverage time in the first geographic area and a wait time not greater than an eighth threshold among the M neighboring cells; or

When the remaining coverage duration of the serving cell and the N neighboring cells are both less than a seventh threshold, performing RRC reestablishment in a sixth neighboring cell, where the sixth neighboring cell is a cell with the highest metric value among the M neighboring cells, and the metric value is determined according to the waiting duration of the neighboring cells and the coverage duration covering the first geographic area; or

And when the residual coverage time of the service cell and the N adjacent cells are both smaller than a seventh threshold value and the waiting time of the M adjacent cells are both larger than an eighth threshold value, entering an RRC idle state.

17. The apparatus according to any of claims 11-16, wherein the transceiver unit is further configured to:

and sending an RRC reestablishment report, wherein the RRC reestablishment report carries an RRC reestablishment reason, and the RRC reestablishment reason is related to the coverage time of the serving cell.

18. A communications apparatus, comprising:

a transceiving unit for transceiving information;

a processing unit to:

determining N suitable cells, wherein the suitable cells meet a coverage condition, the coverage condition is that the remaining coverage time for covering a first geographic area is greater than a first time threshold or the waiting time is less than a second time threshold, a terminal device is located in the first geographic area, the waiting time is the time required to wait when the terminal device enters the coverage area of the cells, and N is an integer greater than 0;

and performing cell selection or cell reselection among the N suitable cells through the transceiver unit.

19. The apparatus as claimed in claim 18, wherein said processing unit, when determining N suitable cells, is specifically configured to:

selecting N cells with the residual coverage duration being greater than the first time threshold as suitable cells; or

And when the residual coverage time of the cells covering the first geographic area is smaller than the first time threshold, selecting N cells with the waiting time smaller than the second time threshold as suitable cells.

20. The apparatus according to claim 18 or 19, wherein the processing unit, when performing cell selection or cell reselection among the N suitable cells through the transceiver unit, is specifically configured to:

performing, by the transceiver unit, cell selection or cell reselection in the N suitable cells based on an S-criterion or an R-criterion, wherein the remaining coverage duration or the waiting duration is an offset value in the S-criterion or the R-criterion.

21. A communication device, characterized in that the communication device comprises a transceiver, a processor and a memory; the memory has stored therein program instructions; the program instructions, when executed, cause the communication device to perform the method of any of claims 1 to 7 or cause the communication device to perform the method of any of claims 8 to 10.

22. A chip coupled to a memory in an electronic device such that the chip, when executed, invokes program instructions stored in the memory to implement the method of any of claims 1 to 7 or the method of any of claims 8 to 10.

23. A computer-readable storage medium, comprising program instructions which, when run on a device, cause the device to perform the method of any of claims 1 to 7 or to implement the method of any of claims 8 to 10.