CN116419255A

CN116419255A - Communication method and device

Info

Publication number: CN116419255A
Application number: CN202210011231.7A
Authority: CN
Inventors: 顾志方; 娄崇; 范强; 张希
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-01-05
Filing date: 2022-01-05
Publication date: 2023-07-11

Abstract

Provided are a communication method and apparatus, the method including: the terminal equipment receives first indication information from first network equipment, the first indication information indicates the terminal equipment to communicate with second network equipment, a cell served by the first network equipment is a first cell, a cell served by the second network equipment is a second cell, and the first cell is a serving cell of the terminal equipment; receiving second indication information from the second network device, wherein the second indication information indicates that the system information of the first cell is changed; and receiving the changed system information of the first cell. When the system information of the service cell of the terminal equipment is changed, the notification of the change of the system information can be received directly through the second network equipment with better signal quality, so that the terminal equipment can receive the notification without switching back to the network equipment of the service cell, thereby being beneficial to increasing the reliability of the terminal equipment for receiving the notification and reducing the time delay.

Description

Communication method and device

Technical Field

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

Background

The fifth generation (5th generation,5G) mobile communication technology directs each signal onto the best path to the receiver by beamforming to increase signal strength, avoid signal interference, and thereby improve communication quality.

When the terminal equipment is in the coverage of the service cell and other cells, the terminal equipment is allowed to use the beam directions of the other cells for uplink and downlink communication under the condition of not switching the service cell. At this time, if the system information of the serving cell is changed, the terminal device is likely to be unable to successfully receive the notification of the change of the system information.

It is therefore desirable to provide a communication method that enables a terminal device to reliably receive notifications of the above-mentioned type in a timely manner.

Disclosure of Invention

The application provides a communication method and a communication device, so that terminal equipment can timely and reliably receive a notification of system information change.

In a first aspect, the present application provides a communication method, where the method may be performed by a terminal device, or may also be performed by a component (such as a chip, a chip system, etc.) configured in the terminal device, or may also be implemented by a logic module or software capable of implementing all or part of the functions of the terminal device, which is not limited in this application.

Illustratively, the method includes: receiving first indication information from first network equipment, wherein the first indication information indicates that terminal equipment is communicated with second network equipment, a cell served by the first network equipment is a first cell, a cell served by the second network equipment is a second cell, and the first cell is a serving cell of the terminal equipment; receiving second indication information from the second network device, wherein the second indication information indicates that the system information of the first cell is changed; and receiving the changed system information of the first cell.

Based on the above technical solution, after receiving the first indication information, the terminal device may implement cross-cell communication, that is, may communicate with a non-serving cell (e.g., a second cell) with better communication quality without switching cells, where the second cell is served by the second network device. When the system information of the service cell of the terminal equipment is changed, the notification of the change of the system information can be directly sent through the second network equipment, so that the terminal equipment can receive the notification of the change of the system information without switching back to the network equipment of the service cell, the expenditure of switching signaling can be reduced, and the terminal equipment can be prevented from frequently carrying out beam switching, thereby being beneficial to reducing time delay. On the other hand, the signal quality received by the terminal equipment in the second cell is better, and the notification is sent through the second network equipment, so that the possibility that the terminal equipment receives the notification is increased, and the terminal equipment can timely and reliably receive the notification that the system information is changed.

With reference to the first aspect, in some possible implementation manners of the first aspect, the second indication information is downlink control information (downlink control information, DCI), where the DCI is used to indicate a cell in which system information is changed.

The cell in which the system information is changed is indicated by the DCI, for example, the cell in which the system information is changed may be indicated by a bit reserved in the DCI, which is advantageous to avoid the problem that the terminal device using the second cell as the serving cell mistakenly changes the system information of the serving cell.

With reference to the first aspect, in certain possible implementation manners of the first aspect, receiving second indication information from a second network device includes: receiving DCI from a second network device based on a common physical downlink control channel (physical downlink control channel, PDCCH) reception configuration of a first cell; or receiving DCI from the second network device based on the dedicated PDCCH receiving configuration of the terminal device in the first cell; or receiving the DCI from the second network device based on a common PDCCH reception configuration of the second cell; or receiving DCI from the second network device based on a dedicated PDCCH reception configuration of the terminal device in the second cell.

The terminal device may receive the second indication information from the second network device based on the PDCCH receiving configuration, e.g. comprising the following several possible designs: a first possible design is for the terminal device to receive DCI from the second network device based on the common PDCCH reception configuration of the first cell. A second possible design is for the terminal device to receive DCI from the second network device based on the terminal device's dedicated PDCCH reception configuration in the first cell. A third possible design is for the terminal device to receive DCI from the second network device based on the common PDCCH reception configuration of the second cell. A fourth possible design is that the terminal device receives DCI from the second network device based on the terminal device's dedicated PDCCH reception configuration in the second cell. In this case, the terminal device needs to additionally configure a set of dedicated PDCCH receiving configuration in the second cell, for example, the terminal device may additionally configure a set of dedicated PDCCH receiving configuration of the terminal device in the second cell, where the set of dedicated PDCCH receiving configuration of the terminal device in the second cell may be a dedicated PDCCH receiving configuration additionally allocated to the terminal device in the second cell; the common PDCCH receiving configuration of the second cell may be used as the dedicated PDCCH receiving configuration of the terminal device in the second cell. In the above scheme, a plurality of possible designs of the PDCCH receiving configuration are provided, and the terminal device can receive the second indication information based on any one of the PDCCH receiving configuration, which is beneficial to improving flexibility.

With reference to the first aspect, in some possible implementations of the first aspect, the first indication information indicates that a beam direction of communication between the terminal device and the second network device is a beam direction of the second cell.

The first indication information indicates that the terminal device communicates with the second network device, and the terminal device may communicate with the non-serving cell (e.g., the second cell) after receiving the first indication information. One possible implementation manner is that the first indication information indicates that the beam direction of the communication between the terminal device and the second network device is the beam direction of the second cell, and the terminal device can communicate with the second network device based on the beam direction, so that the communication quality is improved.

With reference to the first aspect, in some possible implementations of the first aspect, receiving changed system information of the first cell includes: switching the direction of the received beam to the beam direction of the first cell; and receiving the changed system information from the first network equipment through the receiving beam.

After receiving the second indication information, the terminal device can automatically switch the direction of the receiving beam to the beam direction of the first cell, and receive the changed system information from the first network device through the receiving beam, in other words, the second indication information can also indicate the terminal device to switch the beam direction, without receiving other information indicating the terminal device to switch the beam direction, thereby reducing signaling overhead.

After receiving the changed system information from the first network device through the reception beam, if no new beam indication information is received, the terminal device may switch back to the beam direction of the second cell for communication, for example, switch back to the beam direction before receiving the changed system information for communication. If new beam indication information is received, communication may be based on the new beam direction. The beam indication information is used for indicating the beam direction corresponding to the reference signal with better quality.

One possible implementation manner is that after receiving the second indication information, the terminal device may start or restart a timer, where the duration of the timer may be preconfigured or predefined through a protocol. When the terminal device receives the changed system information or the new beam indication information, the timer is stopped, and when the timer is started next time, the timing is started from the initial value of the timer. If the terminal equipment does not receive the changed system information or the new beam indication information when the timer expires, the beam direction is automatically switched to the beam direction of the second cell, so that communication interruption is avoided.

With reference to the first aspect, in some possible implementations of the first aspect, receiving changed system information of the first cell includes: and receiving the changed system information from the second network equipment through the beam direction of the second cell.

Wherein the beam direction of the second cell corresponds to a transmission configuration indication (transmission configuration indication, TCI) state. The terminal equipment directly receives the changed system information from the second network equipment through the beam direction of the second cell, the beam direction does not need to be switched, the time delay is reduced, the quality of the reference signal corresponding to the beam direction of the second cell is good, and the terminal equipment is favorable for reliably receiving the changed system information.

With reference to the first aspect, in some possible implementation manners of the first aspect, the second indication information is further configured to indicate a resource carrying changed system information, and receive, through a beam direction of the second cell, the changed system information from the second network device, including: and receiving the changed system information from the second network equipment on the resource.

The second indication information also indicates resources carrying the changed system information, namely time domain resources, frequency domain resources and the like for indicating the terminal equipment to receive the changed system information, so that the terminal equipment can receive the changed system information on the resources through the beam direction of the second cell, and the terminal equipment is favorable for timely and reliably receiving the changed system information.

In a second aspect, the present application provides a communication method, where the method may be performed by the second network device, or may also be performed by a component (such as a chip, a system on a chip, etc.) configured in the second network device, or may also be implemented by a logic module or software capable of implementing all or part of the functions of the second network device, where the application is not limited to this.

Illustratively, the method includes: generating second indication information, wherein the second indication information indicates that system information of a first cell is changed, the first cell is a service cell of terminal equipment, the first cell is served by first network equipment, and a cell served by second network equipment is a second cell; and sending the second indication information to the terminal equipment.

Based on the above technical scheme, the terminal device can communicate with a non-serving cell (such as a second cell) with better signal quality, the second cell is served by the second network device, when the system information of the serving cell of the terminal device is changed, the second network device can directly send the notification of the change of the system information to the terminal device, the terminal device can receive the notification of the change of the system information without switching back the network device of the serving cell, the cost of switching signaling can be reduced, and the terminal device can be prevented from frequently performing beam switching, thereby being beneficial to reducing time delay. On the other hand, the signal quality received by the terminal equipment in the second cell is better, and the notification is sent through the second network equipment, so that the reliability of the terminal equipment for receiving the notification is improved.

With reference to the second aspect, in some possible implementations of the second aspect, the second indication information is DCI, where the DCI is used to indicate a cell in which system information is changed.

The cell in which the system information is changed is indicated by the DCI, for example, the cell in which the system information is changed may be indicated by a bit reserved in the DCI, which is advantageous for avoiding that the terminal device using the second cell as the serving cell may be mistakenly used as the own serving cell.

With reference to the second aspect, in some possible implementations of the second aspect, sending the second indication information to the terminal device includes: transmitting DCI based on the common PDCCH reception configuration of the first cell; or based on the special PDCCH receiving configuration of the terminal equipment in the first cell, transmitting DCI; or receiving and transmitting DCI based on the common PDCCH receiving configuration of the second cell; or transmitting the DCI based on a dedicated PDCCH reception configuration of the terminal device in the second cell.

The second network device may send the second indication information to the terminal device based on the PDCCH receiving configuration, e.g. comprising the following several possible designs: a first possible design is for the second network device to send DCI based on the common PDCCH reception configuration of the first cell. A second possible design is for the second network device to send DCI based on the terminal device's dedicated PDCCH reception configuration in the first cell. A third possible design is for the second network device to send DCI based on the common PDCCH reception configuration of the second cell. A fourth possible design is that the second network device transmits DCI based on the terminal device's dedicated PDCCH reception configuration in the second cell. For example, the dedicated PDCCH receiving configuration of the terminal device in the second cell may be a dedicated PDCCH receiving configuration additionally allocated to the terminal device in the second cell; the common PDCCH receiving configuration of the second cell may be used as the dedicated PDCCH receiving configuration of the terminal device in the second cell. In the above scheme, a plurality of possible designs of PDCCH receiving configuration are provided, and the second network device can send the second indication information based on any one of the above configurations, which is beneficial to improving flexibility.

With reference to the second aspect, in some possible implementations of the second aspect, before sending the changed system information of the first cell to the terminal device, the method further includes: and receiving third indication information from the first network equipment, wherein the third indication information comprises a public PDCCH receiving configuration of the first cell or a special PDCCH receiving configuration of the terminal equipment in the first cell.

The second network device may receive a common PDCCH receiving configuration from the first cell of the first network device or a dedicated PDCCH receiving configuration of the terminal device in the first cell, so that the second network device sends the second indication information to the terminal device based on the PDCCH receiving configuration.

With reference to the second aspect, in certain possible implementations of the second aspect, the method further includes: receiving changed system information of a first cell from a first network device; and sending the changed system information to the terminal equipment.

After receiving the changed system information from the first network device, the second network device can send the changed system information to the terminal device, and the terminal device does not need to be switched to the first network device to receive the changed system information, so that the terminal device can timely and reliably receive the changed system information.

With reference to the second aspect, in some possible implementations of the second aspect, the second indication information is further configured to indicate a resource that carries the changed system information, and send the changed system information to the terminal device, including: and sending the changed system information to the terminal equipment on the resources.

The second indication information also indicates resources carrying the changed system information, namely time domain resources, frequency domain resources and the like for indicating the terminal equipment to receive the changed system information, and the second network equipment sends the changed system information on the resources through the beam direction of the second cell, so that the terminal equipment can receive the changed system information timely and reliably.

In the present application, the system information change includes an emergency information change and/or a system information change other than the emergency information change. For example, the notification of the change in emergency information may be an earthquake and tsunami warning system (earthquake and tsunami warning system, ETWS) notification and/or a commercial mobile warning system (commercial mobile alert system, CMAS) notification.

In a third aspect, the present application provides a communication apparatus, which may implement the communication method in any one of the first aspect and the possible implementation manners of the first aspect. The apparatus comprises corresponding means for performing the above-described method. The units comprised by the device may be implemented in software and/or hardware.

In a fourth aspect, the present application provides a communication device, which may implement the communication method in any one of the second aspect and the possible implementation manners of the second aspect. The apparatus comprises corresponding means for performing the above-described method. The units comprised by the device may be implemented in software and/or hardware.

In a fifth aspect, the present application provides a communication device comprising a processor. The processor is coupled to the memory and operable to execute the computer program in the memory to implement the communication method of the first aspect and any one of the possible implementations of the first aspect.

In a sixth aspect, the present application provides a communication device comprising a processor. The processor is coupled to the memory and operable to execute the computer program in the memory to implement the second aspect and the communication method in any one of the possible implementations of the second aspect.

In a seventh aspect, the present application provides a communications device comprising a processor and interface circuitry for receiving signals from or transmitting signals to the processor from or to other communications devices than the device, the processor being operable to implement the communications method of the first aspect and any one of the possible implementations of the first aspect by logic circuitry or executing code instructions.

In an eighth aspect, the present application provides a communications device comprising a processor and interface circuitry for receiving signals from other communications devices than the device and transmitting signals from the processor to the processor or transmitting signals from the processor to other communications devices than the device, the processor being operable to implement the communications method of any one of the possible implementations of the second aspect and the second aspect by logic circuitry or execution of code instructions.

In a ninth aspect, the present application provides a computer readable storage medium having stored therein a computer program or instructions which, when executed, implement the communication method of the first aspect and any one of the possible implementations of the first aspect, or implement the communication method of the second aspect and any one of the possible implementations of the second aspect.

In a tenth aspect, the present application provides a computer program product comprising instructions which, when executed, implement the communication method of any one of the possible implementations of the first aspect and the first aspect, or implement the communication method of any one of the possible implementations of the second aspect and the second aspect.

In an eleventh aspect, the present application provides a chip system, where the chip system includes a processor and may further include a memory, where the memory is configured to implement the communication method in any one of the possible implementations of the first aspect and the first aspect, or implement the communication method in any one of the possible implementations of the second aspect and the second aspect. The chip system may be formed of a chip or may include a chip and other discrete devices.

In a twelfth aspect, embodiments of the present application provide a communication system, where the system includes the communication device of the third aspect, the fifth aspect, or the seventh aspect, and the communication device of the fourth aspect, the sixth aspect, or the eighth aspect.

Drawings

Fig. 1 is a schematic diagram of a network architecture of a communication system according to an embodiment of the present application;

FIG. 2 is a schematic flow chart of a communication method provided by an embodiment of the present application;

FIG. 3 is yet another schematic flow chart of a communication method provided by an embodiment of the present application;

FIG. 4 is a schematic block diagram of a communication device provided by an embodiment of the present application;

FIG. 5 is another schematic block diagram of a communication device provided by an embodiment of the present application;

fig. 6 is a schematic structural diagram of a network device according to an embodiment of the present application;

Fig. 7 is a schematic structural diagram of a terminal device provided in an embodiment of the present application.

Detailed Description

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

The technical scheme provided by the application can be applied to various communication systems, such as: global system for mobile communications (global system for mobile communications, GSM), code division multiple access (code division multiple access, CDMA) system, wideband code division multiple access (wideband code division multiple access, WCDMA) system, general packet radio service (general packet radio service, GPRS), wireless local area network (wireless local area network, WLAN), long term evolution (long term evolution, LTE) system, LTE frequency division duplex (frequency division duplex, FDD) system, LTE time division duplex (time division duplex, TDD), side-chain (sidelink) communication system, general mobile communication system (universal mobile telecommunication system, UMTS), worldwide interoperability for microwave access (worldwide interoperability for microwave access, wiMAX) communication system, 5G mobile communication system or new wireless access technology (new radio access technology, NR). The 5G mobile communication system may include a non-independent Networking (NSA) and/or an independent networking (SA), among others.

The technical scheme provided by the application can also be applied to future communication systems, such as a sixth generation (6th Generation,6G) mobile communication system and the like. The present application is not limited in this regard.

In this embodiment of the present application, the network device may be any device having a wireless transceiver function. Network devices include, but are not limited to: an evolved Node B (eNB), a radio network controller (radio network controller, RNC), a Node B (Node B, NB), a base station controller (base station controller, BSC), a base transceiver station (base transceiver station, BTS), a home base station (home evolved Node B, or home Node B, HNB, for example), a Base Band Unit (BBU), an Access Point (AP) in a Wi-Fi (wireless fidelity, wi-Fi) system, a radio relay Node, a radio backhaul Node, a transmission point (transmission point, TP), or a transmission reception point (transmission and reception point, TRP), etc., may also be a gNB or a transmission point (TRP or TP) in a 5G (such as NR) system, or one or a group (including a plurality of antenna panels) of base stations in a 5G system, or may also be a network Node constituting a gNB or a transmission point, such as a baseband unit (BBU), or a Distributed Unit (DU), etc.

In some deployments, the gNB may include a Centralized Unit (CU) and DUs. Illustratively, a CU implements part of the functionality of the gNB, and a DU implements part of the functionality of the gNB, e.g., the CU is responsible for handling non-real time protocols and services, implementing radio resource control (radio resource control, RRC), packet data convergence layer protocol (packet data convergence protocol, PDCP) layer functions; the DUs may include functions of a radio link control (radio link control, RLC) layer, functions of a medium access control (media access control, MAC) layer, and partial functions of a Physical (PHY) layer.

Illustratively, the DU may include functionality of higher layers in the PHY layer. Among other things, the functions of the higher layers in the PHY layer may include cyclic redundancy check (cyclic redundancy check, CRC) functions, channel coding, rate matching, scrambling, modulation, and layer mapping; alternatively, the functions of higher layers in the PHY layer may include cyclic redundancy check, channel coding, rate matching, scrambling, modulation, layer mapping, and precoding. The functions of the lower layer in the PHY layer may be implemented by another network entity independent of the DUs, where the functions of the lower layer in the PHY layer may include precoding, resource mapping, physical antenna mapping, and radio frequency functions; alternatively, the functions of lower layers in the PHY layer may include resource mapping, physical antenna mapping, and radio frequency functions. The embodiment of the application does not limit the functional division of the upper layer and the bottom layer in the PHY layer. When the functions of the lower layers in the PHY layer can be implemented in another network entity independent of the DU, the DU transmits data or information to other communication devices (e.g., terminal equipment, core network equipment), it can be understood that: the DU performs functions of the RLC layer, the MAC layer, and part of functions of the PHY layer. For example, after the functions of the RLC layer and the MAC layer are completed, and cyclic redundancy check, channel coding, rate matching, scrambling, modulation, layer mapping, the remaining functions of mapping and transmitting on physical resources are performed by the network entity independent of the DUs, which performs the functions of the lower layer in the PHY layer.

The network device provides services for the cell, and the terminal device communicates with the cell through transmission resources (e.g., frequency domain resources, or spectrum resources) allocated by the network device, where the cell may belong to a macro base station (e.g., macro eNB or macro gNB, etc.), or may belong to a base station corresponding to a small cell (small cell), where the small cell may include: urban cells (metro cells), micro cells (micro cells), pico cells (pico cells), femto cells (femto cells) and the like, and the small cells have the characteristics of small coverage area and low transmitting power and are suitable for providing high-rate data transmission services.

In the embodiments of the present application, the terminal device may also be referred to as a User Equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user equipment.

The terminal device may be a device providing voice/data connectivity to a user, e.g., a handheld device with wireless connectivity, an in-vehicle device, etc. Currently, some examples of terminal devices may be: a mobile phone (mobile phone), a tablet (pad), a computer with wireless transceiver function (e.g., a notebook, a palm, etc.), a mobile internet device (mobile internet device, MID), a Virtual Reality (VR) device, an augmented reality (augmented reality, AR) device, a wireless terminal in an industrial control (industrial control), a wireless terminal in an unmanned (self-driving) device, an unmanned aerial vehicle, a wireless terminal in a remote medical (remote medium), a wireless terminal in a smart grid (smart grid), a wireless terminal in a transportation security (transportation safety), a wireless terminal in a smart city (smart city), a wireless terminal in a smart home (smart home), a cellular phone, a cordless phone, a session initiation protocol (session initiation protocol, SIP) phone, a wireless local loop (wireless local loop, WLL) station, a personal digital assistant (personal digital assistant, PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a wireless terminal in a vehicle-mounted device, a future evolution land-based terminal (PLMN) device, a mobile terminal in a mobile phone (35G) or a future-developed network (public land mobile network) device, etc.

The wearable device can also be called as a wearable intelligent device, and is a generic name for intelligently designing daily wearing and developing wearable devices by applying a wearable technology, such as glasses, gloves, watches, clothes, shoes and the like. The wearable device is a portable device that is worn directly on the body or integrated into the clothing or accessories of the user. The wearable device is not only a hardware device, but also can realize a powerful function through software support, data interaction and cloud interaction. The generalized wearable intelligent device includes full functionality, large size, and may not rely on the smart phone to implement complete or partial functionality, such as: smart watches or smart glasses, etc., and focus on only certain types of application functions, and need to be used in combination with other devices, such as smart phones, for example, various smart bracelets, smart jewelry, etc. for physical sign monitoring.

Furthermore, the terminal device may also be a terminal device in an internet of things (internet of things, ioT) system. IoT is an important component of future information technology development, and its main technical feature is to connect an item with a network through a communication technology, so as to implement man-machine interconnection and an intelligent network for object interconnection. IoT technology may enable massive connectivity, deep coverage, and terminal power saving through, for example, narrowband (NB) technology.

In addition, the terminal device may further include sensors such as an intelligent printer, a train detector, and a gas station, and the main functions include collecting data (part of the terminal device), receiving control information and downlink data of the network device, and transmitting electromagnetic waves to transmit uplink data to the network device.

It should be appreciated that the roles of the network device and the terminal device may be relative, e.g., the drone may be configured to move the network device, for which the drone is a network device for those terminal devices that access the network through the drone; but for network devices that the drone accesses, the drone is a terminal device.

It should also be understood that the present application is not limited to any particular form of network device or terminal device.

In order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first", "second", etc. are used to distinguish the same item or similar items having substantially the same function and effect. For example, the first indication information and the second indication information are for distinguishing different indication information, and the sequence of the first indication information and the second indication information is not limited. It will be appreciated by those of skill in the art that the words "first," "second," and the like do not limit the amount and order of execution, and that the words "first," "second," and the like do not necessarily differ.

In order to better understand the communication method provided in the embodiments of the present application, the terms referred to in the present application will be briefly described first.

1. Cell-crossing communication: when the terminal equipment is in the coverage of the service cell and other cells, the terminal equipment is allowed to use the beam directions of the other cells for uplink and downlink communication under the condition of not switching the service cell. For example, the terminal device is located in the coverage area of the cell #1 and the cell #2, where the cell #1 is a serving cell of the terminal device, and the terminal device may perform uplink and downlink communications using the beam direction of the cell #2 without switching the cells. The cross-cell communication may be understood as a manner of multi-cell communication, and in this embodiment of the present application, the cross-cell communication is used to describe a communication scenario where a terminal device is located, and is not limited to a specifically used multi-cell communication technology.

2. Cell: the cells are described by a higher layer from the point of view of resource management or mobility management or service units. The coverage area of each network device may be divided into one or more cells, and each cell may correspond to one or more frequency points, or each cell may be considered as an area formed by the coverage area of one or more frequency points.

It should be noted that a cell may be an area within a coverage area of a wireless network of a network device. In the embodiment of the present application, different cells may correspond to the same or different network devices, and the description below uses the network devices as base stations. For example, the network device to which the cell #1 belongs and the network device to which the cell #2 belongs may be different base stations, that is, the cell #1 and the cell #2 may be managed by different base stations. Alternatively, for another example, cell #1 and cell #2 may be managed by the same base station, having the same baseband processing unit and intermediate frequency processing unit, but having different radio frequency processing units. Alternatively, for another example, cell #1 and cell #2 may be managed by the same base station, in which case, it may be referred to as cell #1 and cell #2 co-sited. The present application is not particularly limited thereto.

It should be understood that, for a terminal device capable of performing cross-cell communication, the beam direction of the serving cell may be used for uplink and downlink communication, or the beam direction of the assisting cell may be used for uplink and downlink communication. The name of the assisting cell is not particularly limited, and the terminal device may consider the beam resource of the assisting cell as the beam resource outside the serving cell. For example, the terminal device may use the beam direction corresponding to trp#1 to perform uplink and downlink communication with the serving cell, or may use the beam direction corresponding to trp#2 of the assisting cell to perform uplink and downlink communication with the assisting cell. The cell served by TRP#1 is a serving cell of the terminal equipment, and the cell served by TRP#2 is a assisting cell. On the other hand, the terminal device may consider the beam resources of the assisting cell as part of the beam resources of the serving cell, for example, the terminal device may be configured with two sets of beam resources, where the first set of beam resources corresponds to the beam direction of trp#1 and the second set of beam resources corresponds to the beam direction of trp#2, and the terminal device does not consider that the serving cell is changed when switching from the first set of beam resources to the beam direction of the second set of beam resources in the communication process.

3. Beam: it is understood as a spatial filter or spatial parameter. The beam used to transmit the signal may be referred to as a transmit beam and may be a spatial transmit filter or spatial transmit parameter; the beam used to receive the signal may be referred to as a receive beam and may be a spatial receive filter or spatial receive parameter.

The technique of forming the beam may be a beamforming technique or other technique. For example, the beamforming technique may specifically be a digital beamforming technique, an analog beamforming technique, or a hybrid digital/analog beamforming technique, etc. The transmit beam may refer to a distribution of signal strengths formed in spatially different directions after a signal is transmitted through an antenna, and the receive beam may refer to a signal strength distribution of a wireless signal received from the antenna in spatially different directions.

In the NR protocol, the beam may be, for example, a spatial filter. It should be understood that this application does not exclude the possibility of defining other terms in future protocols to represent the same or similar meanings.

In the embodiment of the present application, the beam is associated with a reference signal, or different reference signals may be transmitted using different beam directions, each corresponding to a beam direction.

4. System information: specifically, a master information block (master information block, MIB) and a system message block SIB (system information block, SIB) may be included. The MIB may be used to instruct the terminal device to further receive information required for system information (e.g., SIB 1), etc. SIBs are classified into various types, for example, in LTE, the SIBs may be classified into SIB type (type) 1 to SIB type 29. For another example, in NR, SIBs may be classified into SIB type 1 to SIB type 14. It should be understood that the types of SIBs listed herein are merely examples, and as protocols evolve, the present application does not exclude the possibility of other SIBs being defined in future protocols.

For convenience of distinction and explanation herein, SIB type X is denoted as SIBX, which may be a positive integer. For example, SIB type 1 is denoted SIB1.

Different types of SIBs function differently. For example, in NR, SIB1 defines scheduling of other system information blocks and contains information required for initial access. SIB2 contains cell reselection information, mainly related to the serving cell. SIB3 contains information about service frequencies and intra-frequency neighboring cells related to cell reselection (e.g., including frequency-shared cell reselection parameters as well as cell-specific reselection parameters). SIB4 contains information about other NR frequencies and inter-frequency neighbor cells related to cell reselection (e.g., including frequency-shared cell reselection parameters as well as cell-specific reselection parameters). SIB5 contains information about the evolved universal terrestrial radio access (evolved universal terrestrial radio access, E-UTRA) frequency and E-UTRA neighbor cells associated with cell reselection (e.g., including frequency-shared cell reselection parameters as well as cell-specific reselection parameters). SIB6 contains ETWS primary notification. SIB7 contains ETWS assisted notification. SIB8 contains CMAS alert notifications. SIB9 contains information related to global positioning system (global positioning system, GPS) time and coordinated universal time (universal time coordinated, UTC). For brevity, the description of the different types of SIBs is not listed here.

In the embodiment of the present application, the notification of the change of the system information may be a notification of the change of the emergency information, for example, an ETWS notification and/or a CMAS notification, or may be a notification of the change of the system information other than the emergency information, or may be a notification of the change of the emergency information and a notification of the change of the system information other than the emergency information, which is not limited in the embodiment of the present application. The notification of the change of the emergency information and/or the emergency information may also be referred to as public warning system information. The second indication information may be used to indicate that the system information is changed, and the third indication information may be used to indicate the changed system information. When the second indication information indicates that the emergency information is changed, the third indication information indicates the specific content of the emergency information, for example, the level of the earthquake, etc. When the second indication information is used for indicating that the system information except the emergency information is changed, the third indication information indicates the changed system information.

5. DCI: DCI has multiple uses, and DCI of different uses has different formats. The present embodiments focus on DCI for indicating a system message change, the format of such DCI is described below: the device is mainly divided into three parts, namely a first part, a second part and a third part.

The first part is Short Message (Short Message) indication information, and occupies 2 bits. For example, the first part is 01 indicating that only scheduling information of paging messages exists in the DCI, i.e., only the third part exists. The first part being 10 indicates that only Short Message exists in the DCI, i.e. only the second part exists. The first part is 11 indicating that there is scheduling information and Short Message of the paging Message in the DCI, i.e. there are both the second and third parts. The first part being 00 is denoted as reserved bits.

The second part is Short Message, occupying 8 bits. When the second portion is not present, the 8 bits are reserved bits; when the second portion is present, the 8 bits may be denoted b1 to b8.

Wherein, when b1 is 1, system information change except SIB6/7/8 is indicated; when b2 is 1, an ETWS notification and/or a CMAS notification is indicated. Wherein the ETWS primary notification information is carried in SIB6, the ETWS secondary notification information is carried in SIB7, and the CMAS information is carried in SIB 8; when b3 is set to 1, in the shared spectrum scene, indicating the terminal equipment to stop monitoring paging on paging occasion; b4 to b8 are reserved bits.

The third part is the scheduling information of the paging message, and the occupied bit number is not fixed. When the third portion is not present, the number of bits is reserved bits; when the third portion exists, the number of bits indicates scheduling information of the paging message, including: frequency domain resource allocation, time domain resource allocation, modulation and coding modes and other information.

In order to facilitate understanding of the communication method provided in the embodiments of the present application, a system architecture suitable for the method provided in the embodiments of the present application will be described below. It can be understood that the system architecture described in the embodiments of the present application is for more clearly describing the technical solutions of the embodiments of the present application, and does not constitute a limitation on the technical solutions provided by the embodiments of the present application.

Fig. 1 is a schematic diagram of a network architecture of a communication system according to an embodiment of the present application. As shown in fig. 1, the communication system 100 includes terminal devices and network devices, such as network device 110, network device 120, terminal device 130, and terminal device 140 shown in the figure. Wherein the terminal device 130 and the terminal device 140 may be mobile or fixed. The network device 110 and the network device 120 may be micro base stations, TRP, or other types of network devices, which are not limited in this embodiment of the present application. Each network device may provide communication coverage for a particular geographic area and may communicate over a wireless link with terminal devices located within that coverage area (cell). For example, the cell served by the network device 110 is denoted as cell #1, cell #1 is the serving cell of the terminal device 130, the cell served by the network device 120 is denoted as cell #2, and cell #2 is the assisting cell of the terminal device 130. The terminal device 130 may communicate with the network device 110 of the serving cell using the beam direction of the serving cell or with the network device 120 of the assisting cell using the beam direction of the assisting cell. The terminal device 140 may be a terminal device that does not perform cross-cell beam management, and its serving cell is cell #2.

Alternatively, the communication system shown in the communication system 100 may include more or fewer network devices, and may include other numbers of terminal devices within the coverage area of each network device, which is not limited in this embodiment.

As can be seen from fig. 1, when the terminal device is within the coverage of the serving cell and other cells, the terminal device can perform uplink and downlink communication using the beam directions of the other cells without switching cells. In some cases, for example, the quality of the reference signal corresponding to the beam direction of a certain cell is higher than the quality of the reference signal of the serving cell, and the terminal device may perform uplink and downlink communications using the beam direction in the cell. At this time, if the system information of the serving cell is changed, a notification of the change of the system information may be transmitted to the terminal device through the network device of the serving cell. Specifically, the terminal device needs to switch the beam direction back to the beam direction of the serving cell, and then the network device of the serving cell sends a notification of the system information change to the terminal device.

In order to solve the above problems, the present application provides a communication method, in which a terminal device can communicate with a network device of a non-serving cell, and when system information of a serving cell of the terminal device changes, the terminal device can directly receive a notification of the change of the system information from the network device of the non-serving cell, without switching back to the network device of the serving cell, so that the possibility of receiving the notification by the terminal device is improved, and the terminal device does not need to switch back to the network device of the serving cell, which is beneficial to reducing signaling overhead and delay.

It should be noted that, in the embodiment of the present application, the network device that the terminal device switches back to the serving cell means that the beam direction that the terminal device switches back to the serving cell communicates with the network device of the serving cell, and the network device does not represent that the terminal device switches to the cell, that is, the terminal device may use the beam directions of other cells to perform uplink and downlink communications under the condition that the terminal device does not switch to the cell.

The communication method provided in the embodiment of the present application will be described in detail below with reference to the accompanying drawings. It should be appreciated that the embodiments shown below describe the method from the point of view of terminal device, first network device and second network device interactions. Wherein the terminal device may be the terminal device 130 shown in fig. 1, the first network device may be the network device 110 shown in fig. 1, and the second network device may be the network device 120 shown in fig. 1.

It should also be understood that the embodiments shown below are described by taking the example of terminal device, first network device and second network device interactions, but should not constitute any limitation as to the execution bodies of the methods. The method provided by the embodiments of the present application can be executed as long as the program recorded with the code of the method provided by the embodiments of the present application can be executed. For example, the terminal device may be replaced with a component (e.g., a chip system, etc.) configured in the terminal device, or other functional modules capable of calling a program and executing the program, the first network device may be replaced with a component (e.g., a chip system, etc.) configured in the first network device, or other functional modules capable of calling a program and executing the program, and the second network device may be replaced with a component (e.g., a chip system, etc.) configured in the second network device, or other functional modules capable of calling a program and executing the program. The embodiments of the present application are not limited in this regard.

It should be noted that, for convenience of distinction, a cell served by the first network device is denoted as a first cell, a cell served by the second network device is denoted as a second cell, the first cell is a serving cell of the terminal device, and the second cell may be regarded as an assisting cell of the terminal device. Without being specifically described, the terminal device described below is a terminal device using the first cell as a serving cell.

Fig. 2 is a schematic flow chart of a communication method provided in an embodiment of the present application. The method 200 shown in fig. 2 may include S210 to S230. The various steps in method 200 are described in detail below.

S210, the first network device sends first indication information to the terminal device, wherein the first indication information indicates the terminal device to communicate with the second network device. Accordingly, the terminal device receives the first indication information from the first network device.

The cell served by the first network device is a first cell, the cell served by the second network device is a second cell, the first cell is a serving cell of the terminal device, and the second cell can be regarded as an assisting cell of the terminal device. When the quality of the reference signal corresponding to the beam direction of the second cell is higher than the quality of the reference signal corresponding to the beam direction of the first cell, the first network device may send first indication information to the terminal device to indicate the terminal device to communicate with the second network device. It is readily apparent that the first indication information indicates that the terminal device communicates with the second network device, i.e. that the terminal device may perform cross-cell communication, in other words, that the terminal device may communicate with other cells than the serving cell without switching the serving cell. After receiving the first indication information, the terminal equipment can communicate with the second network equipment, so that the communication quality is improved.

One possible design is that the first indication information may indicate a beam direction of the terminal device communicating with the second network device, where the beam direction is a beam direction of the second cell. For example, the first indication information may include a TCI state, and the first network device may indicate the beam direction through the TCI state, where the TCI state has a correspondence with the reference signal. The terminal device may determine the reference signal based on the TCI state, where the reference signal corresponds to the beam direction one by one, and the terminal device determines the beam direction for communicating with the second network device based on the reference signal.

S220, the second network equipment sends second indication information to the terminal equipment, wherein the second indication information indicates that the system information of the first cell is changed. Accordingly, the terminal device receives the second indication information from the second network device.

The system information may be changed in emergency, or may be changed in system information other than emergency, or may be changed in emergency or changed in system information other than emergency. For example, the emergency information may be an ETWS notification and/or a CMAS notification, or may be other types of emergency information, which is not limited in this embodiment of the present application.

Optionally, before the second network device sends the second indication information to the terminal device, the first network device may send a notification of the change of the system information of the first cell to the second network device, so that the second network device sends the second indication information to the terminal device. The second network device may directly send the notification to the terminal device after receiving the notification of the change of the system information from the first network device.

The second network device sends second indication information to the terminal device to indicate the system information of the first cell of the terminal device to change. One possible design may be that the second indication information may be DCI. The second network device sends DCI to the terminal device to indicate that the system information is changed, e.g., the system information may be indicated to be changed through a Short Message in the second portion of the DCI.

Several possible designs for the second network device to send the second indication information to the terminal device are described in detail below, wherein the second indication information may be DCI, for example.

A first possible design is that the second network device sends the second indication information to the terminal device based on the common PDCCH reception configuration of the first cell. The common PDCCH receiving configuration of the first cell refers to a PDCCH receiving configuration that can be used by terminal devices of the first cell, in other words, the terminal devices of the first cell can receive the second indication information based on the common PDCCH receiving configuration.

A second possible design is that the second network device sends the second indication information to the terminal device based on the dedicated PDCCH receiving configuration of the terminal device in the first cell. For example, the second network device sends the second indication information to the terminal device based on the terminal device's dedicated search space and the dedicated control resource set (control resource set, CORESET) configuration in the first cell. For another example, the second network device sends the second indication information to the terminal device based on a search space configuration specific to the first cell and a common CORESET configuration of the first cell.

A third possible design is that the second network device sends the second indication information to the terminal device based on the common PDCCH receiving configuration of the second cell. Since the terminal device is located within the coverage of the second cell, the terminal device may also receive the second indication information from the second network device based on the common PDCCH receiving configuration of the second cell.

A fourth possible design is that the second network device sends the second indication information to the terminal device based on the dedicated PDCCH receiving configuration of the terminal device in the second cell. For example, the terminal device may additionally configure a set of dedicated PDCCH receiving configuration of the terminal device in the second cell, where the dedicated PDCCH receiving configuration of the terminal device in the second cell may be a dedicated receiving configuration additionally allocated to the terminal device by the second cell; the common PDCCH receiving configuration of the second cell may be used as the dedicated PDCCH receiving configuration of the terminal device in the second cell, in other words, the common PDCCH receiving configuration of the second cell may be used as the dedicated PDCCH receiving configuration of the terminal device in the second cell.

In the above design, the PDCCH receiving configuration may include, for example, one or more of the following: a common search space configuration, a common CORESET configuration, a paging cycle configuration, a paging slot configuration, a DCI format configuration, a scrambled radio network temporary identity (radio network temporary identifier, RNTI), a dedicated search space configuration for a terminal device, and a dedicated CORESET configuration for a terminal device.

It will be appreciated that when the second network device sends the second indication information to the terminal device based on the first or second possible designs described above, the second network device needs to know the common PDCCH receiving configuration of the first cell or the dedicated PDCCH receiving configuration of the terminal device in the first cell. One possible implementation manner is that the first network device and the second network device store the PDCCH receiving configuration of the opposite cell in advance. Another possible implementation is that the second network device determines the PDCCH receiving configuration described above through communication with the first network device. For example, the first network device sends third indication information to the second network device, where the third indication information includes a common PDCCH receiving configuration of the first cell or a dedicated PDCCH receiving configuration of the terminal device in the first cell.

As is known from the foregoing, the system information change includes an emergency information change and/or a system information change other than the emergency information change. Thus, it is possible that the second indication information indicates that the system information of the first cell, which is system information other than the emergency information, is changed. Another possibility is that the second indication information indicates an emergency information change. It is also possible that the second indication information indicates an emergency information change and a change of system information of the first cell other than the emergency information.

It will be appreciated that the change in emergency information may be a change over a larger area, such as an earthquake, tsunami, etc., and that both the first cell and the second cell may occur, thus eliminating the need to distinguish which cell is. Since the system information change other than the emergency information is specific to a certain cell, it is necessary to distinguish which cell the system information change has occurred. In order to avoid that the terminal device taking the second cell as the serving cell changes the system information of the serving cell by mistake after receiving the second indication information, two possible ways are given below for example to distinguish the cells where the system information changes.

It should be understood that, unless specifically stated otherwise, reference herein to a terminal device refers to a terminal device having a first cell as a serving cell. In the following description, in order to facilitate distinguishing between a terminal device having a first cell as a serving cell and a terminal device having a second cell as a serving cell, the terminal device having the first cell as a serving cell may be referred to as a first terminal device, and the terminal device having the second cell as a serving cell may be referred to as a second terminal device.

One possible way is to use, as the second indication information, DCI including an indication bit for indicating a cell in which the system information change has occurred. The second network device may indicate the cell in which the system information change occurred by a reserved bit of the second part in the DCI, for example. For example, when b4 is 1, the system information of the serving cell of the first terminal device is instructed to be changed, that is, the system information of the first cell is changed, and after the second terminal device receives the second instruction information, the second terminal device considers that the system information of the second cell is not changed, thereby avoiding the problem that the second terminal device taking the second cell as the serving cell mistakenly changes the system information of the serving cell.

Another possibility is to send the second indication information by different PDCCH reception configurations and different cell correspondence, so that the terminal device can distinguish between them. The specific content included in the PDCCH receiving configuration is as described above, and will not be described here. The PDCCH reception configurations of different cells are different, that is, there are differences in one or more of the following in the PDCCH reception configurations of different cells: a common search space configuration, a common CORESET configuration, a paging cycle configuration, a paging slot configuration, a DCI format configuration, a scrambled RNTI, a dedicated search space configuration for a terminal device, and a dedicated CORESET configuration for a terminal device. Transmitting the second indication information based on different PDCCH reception configurations may enable terminals having different cells as serving cells to receive DCI based on different PDCCH reception configurations. For example, the PDCCH receiving configuration of the first cell is designated as configuration #1, the PDCCH receiving configuration of the second cell is designated as configuration #2, the content in configuration #1 and configuration #2 are not identical, and the second network device sends the second indication information to the first terminal device based on configuration #1, so that the second terminal device does not receive the second indication information, thereby avoiding the problem that the second terminal device using the second cell as the serving cell mistakenly changes the system information of the serving cell.

S230, the second network equipment sends the changed system information of the first cell to the terminal equipment. Accordingly, the terminal device receives the changed system information from the first cell of the second network device.

And the second network equipment sends the changed system information to the terminal equipment through the beam direction of the second cell. Illustratively, the beam direction of the second cell corresponds to TCI. As is known from the foregoing, the system information is changed, including the emergency information or the system information other than the emergency information, and thus, the system information after the change may be specific content of the emergency information, such as a level of an earthquake or a tsunami, or may be the system information after the change other than the emergency information.

One possible implementation manner is that the second network device receives the changed system information from the first network device, and then directly sends the changed system information to the terminal device. It should be noted that, if the changed system information refers to the specific content of the emergency information, and the emergency information is the emergency information for a larger area, for example, the whole area including the first cell and the second cell, the second network device does not need to obtain the changed system information from the first network device. For example, if the first cell and the second cell are both in the area where they are located, the second network device does not need to acquire the changed system information from the first network device.

Several possible designs of the second network device transmitting the changed system information to the terminal device through the beam direction of the second cell will be described in detail below.

One possible design is that the second indication information is further used to indicate a resource carrying the changed system information, and the second network device sends the changed system information to the terminal device on the resource. Wherein, the resources for carrying the changed system information include one or more of the following: time domain resources, frequency domain resources, and spatial domain resources. Illustratively, the third portion of the DCI includes the above-mentioned resources to instruct the terminal device how to receive the changed system information.

Another possible design is that the second network device does not need to send the second indication information, and directly sends the changed system information through RRC dedicated signaling. Specific embodiments are described with reference to known techniques and will not be described in detail herein.

Another possible design is that the second network device sends a system message (system information, SI) -RNTI scrambled PDCCH to the terminal device, the PDCCH indicating resources carrying SIB1, the SIB1 indicating resources carrying changed system information. After receiving the PDCCH, the terminal equipment can determine the resources carrying the SIB1, and after receiving the SIB1 on the resources, the terminal equipment can determine the resources carrying the changed system information. For example, taking a system information change except for emergency information as an example, after receiving the PDCCH, the terminal device receives SIB1 on a corresponding resource indicated by the PDCCH, determines resources carrying other SIBs (such as SIB 2) based on the received SIB1, and receives SIB2 on the corresponding resource, so as to obtain the changed system information. In another example, taking a modification of the emergency information as an example, after receiving the PDCCH, the terminal device receives SIB1 on a corresponding resource indicated by the PDCCH, determines resources carrying other SIBs (such as SIB 6) based on the received SIB1, and receives SIB6 on the corresponding resource, so as to obtain specific content of the emergency information, such as a level of an earthquake.

Alternatively, the terminal device may configure a plurality of sets of system information reception configurations for receiving the changed system information. Wherein the system information receiving configuration comprises a period and/or a window length of the system information. Each set of system information receiving configuration corresponds to one cell, and the terminal equipment can use the system information receiving configuration of the cell (such as the second cell) corresponding to the current activated beam direction to receive the changed system information.

For example, the system information receiving configuration of the first cell is denoted as configuration #1, the system information receiving configuration of the second cell is denoted as configuration #2, and if the current activated beam direction of the terminal device is the beam direction of the second cell, the terminal device may receive the changed system information through the beam direction based on the system information receiving configuration corresponding to the second cell.

Based on the above technical solution, the terminal device can communicate with a non-serving cell (e.g. a second cell) with better signal quality. If the system information of the serving cell of the terminal device is changed, the terminal device can directly receive the notification of the change of the system information and the changed system information through the network device of the non-serving cell, so that the terminal device can receive the notification and the changed system information without switching back to the network device of the serving cell, the cost of switching signaling can be reduced, and the terminal device can be prevented from frequently performing beam switching, thereby being beneficial to reducing time delay. On the other hand, the signal quality received by the terminal equipment in the second cell is better, and the notification is sent through the second network equipment, so that the reliability of the terminal equipment for receiving the notification is improved.

Fig. 3 is a further schematic flow chart of a communication method provided by an embodiment of the present application. The method 300 shown in fig. 3 may include S310 to S330. The various steps in method 300 are described in detail below.

S310, the first network device sends first indication information to the terminal device, wherein the first indication information indicates the terminal device to communicate with the second network device. Accordingly, the terminal device receives the first indication information from the first network device.

This step is the same as S210 in the embodiment shown in fig. 2, and is not repeated here for brevity.

S320, the second network device sends second indication information to the terminal device, wherein the second indication information indicates that the system information of the first cell is changed. Accordingly, the terminal device receives the second indication information from the second network device.

This step is the same as S220 in the embodiment shown in fig. 2, and is not repeated here for brevity.

S330, the first network device sends the changed system information of the first cell to the terminal device. Accordingly, the terminal device receives the changed system information from the first cell of the first network device.

Unlike the embodiment shown in fig. 2, the second network device sends the second indication information to the terminal device, and after the system information of the first cell is indicated to be changed, the first network device sends the changed system information to the terminal device, in other words, the terminal device needs to switch back to the beam direction of the first cell to communicate with the first network device.

One possible implementation manner is that after receiving the second indication information, the terminal device automatically switches the direction of the receiving beam to the beam direction of the first cell, and receives the changed system information from the first network device through the receiving beam. In other words, the second indication information implicitly indicates that the terminal device switches beam directions. Alternatively, the beam direction of the first cell may be a beam direction used by the terminal device in the first cell before communicating with the second network device.

The process by which the terminal device receives the changed system information from the first network device based on the above-described reception beam is described in detail below.

One possibility is that the change of the system information refers to a change of the system information other than the emergency information. In this case, the terminal device receives SIB1 in the next system information modification period, where SIB1 includes resources carrying other SIBs (e.g., SIB 2), and the terminal device receives the changed system information on the resources. The system information modification period refers to how often the system information is modified at intervals.

Another possibility is that the change of system information refers to a change of emergency information. At this time, the terminal device immediately starts to receive SIB1, where SIB1 includes resources for carrying other SIBs (e.g., SIB 6), and receives specific contents of emergency information, such as a seismic hierarchy, on the resources.

After receiving the changed system information, if no new beam indication information is received, the terminal device may switch back to the beam direction of the second cell for communication, for example, switch back to the beam direction before receiving the changed system information for communication. If new beam indication information is received, communication may be based on the new beam direction. The beam indication information is used for indicating the beam direction corresponding to the reference signal with better quality.

Optionally, the method further comprises: after receiving the second indication information, the terminal device starts or restarts a timer, and the duration of the timer can be preconfigured or predefined through a protocol. When the terminal device receives the changed system information or the new beam indication information, the timer is stopped, and when the timer is started next time, the timing is started from the initial value of the timer. If the terminal equipment does not receive the changed system information or the new beam indication information when the timer expires, the beam direction is automatically switched to the beam direction of the second cell, so that communication interruption is avoided.

Optionally, the terminal device may be further configured with a discontinuous reception (discontinuous reception, DRX) parameter, DRX referring to the terminal device discontinuously receiving the PDCCH signal, the DRX parameter being used to indicate a period of on reception and a period of off reception. After receiving the second indication information, the terminal device can be in a period of starting the receiving in a next period of time, so that the terminal device can conveniently and quickly receive the changed system information. Illustratively, the terminal device starts or restarts a timer (e.g., DRX inactivity timer) after receiving the second indication information, and before the timer expires, the terminal device is in a state of starting receiving the PDCCH. After the timer expires, the terminal equipment decides the time period for starting and closing the reception according to the DRX parameter, so that the terminal equipment can quickly receive the specific content of the emergency information in the emergency scenes such as earthquake or tsunami.

Based on the technical scheme, the terminal equipment can communicate with the non-serving cell with better signal quality, when the system information of the serving cell of the terminal equipment is changed, the network equipment of the non-serving cell can send the second indication information to indicate the system information of the serving cell of the terminal equipment to be changed, and the first network equipment of the serving cell receives the changed system information, so that the terminal equipment can timely and reliably receive the second indication information.

Fig. 4 to fig. 7 are schematic structural diagrams of a possible communication device according to an embodiment of the present application.

Fig. 4 is a schematic block diagram of a communication device 400 provided by an embodiment of the present application.

As shown in fig. 4, the communication apparatus 400 includes a processing unit 410 and a transceiving unit 420.

The apparatus 400 may be used to implement the functions of the terminal device in the method embodiment shown in fig. 2, or the apparatus 400 may include a module for implementing any of the functions or operations of the terminal device in the method embodiment shown in fig. 2, where the module may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. The apparatus 400 is configured to implement the functions of the first network device in the method embodiment shown in fig. 2, or the apparatus 400 may include a module configured to implement any of the functions or operations of the first network device in the method embodiment shown in fig. 2, where the module may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. The apparatus 400 is configured to implement the functions of the second network device in the method embodiment shown in fig. 2, or the apparatus 400 may include a module configured to implement any of the functions or operations of the second network device in the method embodiment shown in fig. 2, where the module may be implemented in whole or in part by software, hardware, firmware, or any combination thereof.

When the apparatus 400 is used to implement the function of the terminal device in the method embodiment shown in fig. 2, the transceiver unit 420 may be configured to receive first indication information from a first network device, where the first indication information indicates that the terminal device communicates with a second network device, and a cell served by the first network device is a first cell, and a cell served by the second network device is a second cell, and the first cell is a serving cell of the terminal device; receiving second indication information from the second network equipment, wherein the second indication information indicates that the system information of the first cell is changed; and receiving the changed system information of the first cell.

When the apparatus 400 is used to implement the function of the first network device in the method embodiment shown in fig. 2, the transceiver unit 420 may be configured to send first indication information to the terminal device, where the first indication information indicates that the terminal device communicates with the second network device, and a cell served by the first network device is a first cell, and a cell served by the second network device is a second cell, and the first cell is a serving cell of the terminal device.

When the apparatus 400 is used to implement the function of the second network device in the method embodiment shown in fig. 2, the transceiver unit 420 may be configured to send second indication information to the terminal device, where the second indication information indicates that the system information of the first cell is changed; and sending the changed system information to the terminal equipment.

The apparatus 400 may be configured to implement the functions of the terminal device in the method embodiment shown in fig. 3, or the apparatus 400 may include a module configured to implement any of the functions or operations of the terminal device in the method embodiment shown in fig. 3, where the module may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. The apparatus 400 is configured to implement the functions of the first network device in the method embodiment shown in fig. 3, or the apparatus 400 may include a module configured to implement any of the functions or operations of the first network device in the method embodiment shown in fig. 3, where the module may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. The apparatus 400 is configured to implement the functions of the second network device in the method embodiment shown in fig. 3, or the apparatus 400 may include a module configured to implement any of the functions or operations of the second network device in the method embodiment shown in fig. 3, where the module may be implemented in whole or in part by software, hardware, firmware, or any combination thereof.

When the apparatus 400 is used to implement the function of the terminal device in the method embodiment shown in fig. 3, the transceiver unit 420 may be configured to receive first indication information from a first network device, where the first indication information indicates that the terminal device communicates with a second network device, and a cell served by the first network device is a first cell, and a cell served by the second network device is a second cell, and the first cell is a serving cell of the terminal device; receiving second indication information from the second network equipment, wherein the second indication information indicates that the system information of the first cell is changed; and receiving the changed system information of the first cell.

When the apparatus 400 is used to implement the function of the first network device in the method embodiment shown in fig. 3, the transceiver unit 420 may be configured to send first indication information to the terminal device, where the first indication information indicates that the terminal device communicates with the second network device, and a cell served by the first network device is a first cell, and a cell served by the second network device is a second cell, and the first cell is a serving cell of the terminal device; and sending the changed system information to the terminal equipment.

When the apparatus 400 is used to implement the function of the second network device in the method embodiment shown in fig. 3, the transceiver unit 420 may be configured to send second indication information to the terminal device, where the second indication information indicates that the system information of the first cell is changed.

The above-mentioned more detailed descriptions of the processing unit 410 and the transceiver unit 420 may be directly obtained by referring to the related descriptions in the method embodiments shown in fig. 2 or fig. 3, which are not repeated herein.

It should be understood that the division of the units in the embodiments of the present application is illustrative, and is merely a logic function division, and there may be another division manner in actual implementation. In addition, each functional unit in the embodiments of the present application may be integrated in one processor, or may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

Fig. 5 is another schematic block diagram of a communication device 500 provided by an embodiment of the present application. The apparatus 500 may be a chip system, or may be an apparatus configured with a chip system to implement the communication function in the foregoing method embodiment. In the embodiments of the present application, the chip system may be formed by a chip, and may also include a chip and other discrete devices.

As shown in fig. 5, the apparatus 500 may include a processor 510 and a communication interface 520. Wherein communication interface 520 may be used to communicate with other devices via a transmission medium such that apparatus 500 may communicate with the other devices. The communication interface 520 may be, for example, a transceiver, an interface, a bus, a circuit, or a device capable of implementing a transceiver function. Processor 510 may input and output data using communication interface 520 and may be used to implement the communication methods described in the corresponding embodiments of fig. 2 or fig. 3. In particular, the apparatus 500 may be configured to implement the functions of the first network device, the second network device, or the terminal device in the above-described method embodiment.

When the apparatus 500 is used to implement the method shown in fig. 2 or fig. 3, the processor 510 is used to implement the functions of the processing unit 410, and the communication interface 520 is used to implement the functions of the transceiver unit 420.

Optionally, the apparatus 500 further comprises at least one memory 530 for storing program instructions and/or data. Memory 530 is coupled to processor 510. The coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units, or modules, which may be in electrical, mechanical, or other forms for information interaction between the devices, units, or modules. Processor 510 may operate in conjunction with memory 530. Processor 510 may execute program instructions stored in memory 530. At least one of the at least one memory may be included in the processor.

The specific connection medium between the processor 510, the communication interface 520, and the memory 530 is not limited in the embodiments of the present application. The present embodiment is illustrated in fig. 5 as being coupled between processor 510, communication interface 520, and memory 530 via bus 540. The connection of the bus 540 to other components is shown by a bold line in fig. 5, and is merely illustrative and not limiting. The buses may be classified as address buses, data buses, control buses, etc. For ease of illustration, only one thick line is shown in fig. 5, but not only one bus or one type of bus.

Fig. 6 is a schematic structural diagram of a network device provided in the embodiment of the present application, for example, may be a schematic structural diagram of a base station. The base station 600 may perform the functions of the network device in the above-described method embodiments. As shown in fig. 6, the base station 600 may include one or more radio frequency units, such as a remote radio frequency unit (remote radio unit, RRU) 610 and one or more baseband units (BBU) (also referred to as a Distributed Unit (DU)) 620. The RRU 610 may be referred to as a transceiver unit, corresponding to the transceiver unit 420 in fig. 4. Alternatively, the RRU 610 may also be referred to as a transceiver, transceiving circuitry, or transceiver, etc., which may include at least one antenna 611 and a radio frequency unit 612. Alternatively, the RRU 610 may include a receiving unit, which may correspond to a receiver (or receiver, receiving circuit), and a transmitting unit, which may correspond to a transmitter (or transmitter, transmitting circuit). The RRU 610 is mainly configured to receive and transmit radio frequency signals and convert radio frequency signals to baseband signals, for example, to send configuration information to a terminal device. The BBU 620 is mainly configured to perform baseband processing, control a base station, and the like. The RRU 610 and BBU 620 may be physically located together or physically separate, i.e., distributed base stations.

The BBU 620 is a control center of the base station, and may also be referred to as a processing unit, and may correspond to the processing unit 410 in fig. 4, and is mainly configured to perform baseband processing functions, such as channel coding, multiplexing, modulation, spreading, and so on. For example, the BBU (processing unit) may be configured to control the base station to perform the operation procedures described in the above method embodiments with respect to the network device.

In one example, the BBU 620 may be configured by one or more single boards, where the multiple single boards may support radio access networks of a single access system (such as an LTE network), or may support radio access networks of different access systems (such as an LTE network, a 5G network, or other networks). The BBU 620 further comprises a memory 621 and a processor 622. The memory 621 is used to store necessary instructions and data. The processor 622 is configured to control the base station to perform necessary actions, for example, to control the base station to perform the operation procedure of the method embodiment described above with respect to the first network device. The memory 621 and processor 622 may serve one or more boards. That is, the memory and the processor may be separately provided on each board. It is also possible that multiple boards share the same memory and processor. In addition, each single board can be provided with necessary circuits.

It should be understood that the base station 600 shown in fig. 6 is capable of implementing various processes involving network devices in the method embodiments shown in fig. 2 or 3. The operations and/or functions of the respective modules in the base station 600 are respectively for implementing the respective flows in the above-described method embodiments. Reference is specifically made to the description in the above method embodiments, and detailed descriptions are omitted here as appropriate to avoid repetition.

The BBU 620 described above may be used to perform the actions described in the method embodiments as being implemented internally by the network device, while the RRU 610 may be used to perform the actions described in the method embodiments as being sent to or received from the terminal device by the network device. Please refer to the description of the foregoing method embodiments, and details are not repeated herein.

Fig. 7 is a schematic structural diagram of a terminal device provided in an embodiment of the present application. The terminal device 700 has the function of the terminal device in the embodiment shown in fig. 2 or fig. 3, and the terminal device 700 is applicable to the communication system 100 shown in fig. 1. As shown in fig. 7, the terminal device 700 includes a processor 701 and a transceiver 702. Optionally, the terminal device 700 further comprises a memory 703. Wherein the processor 701, the transceiver 702 and the memory 703 can communicate with each other via an internal connection path for transmitting control and/or data signals, the memory 703 is used for storing a computer program, and the processor 701 is used for calling and running the computer program from the memory 703 to control the transceiver 702 to transmit and receive signals. Optionally, the terminal device 700 may further include an antenna 704 for transmitting uplink data or uplink control signaling output by the transceiver 702 through a wireless signal. Optionally, the terminal device 700 further comprises a Wi-Fi module 711 for accessing the wireless network.

The processor 701 and the memory 703 may be combined into a single processing device, and the processor 701 is configured to execute the program code stored in the memory 703 to implement the functions. In particular, the memory 703 may also be integrated into the processor 701 or may be separate from the processor 701. The processor 701 may correspond to the processing unit 410 in fig. 4 or the processor 510 in fig. 5.

The transceiver 702 may correspond to the transceiver unit 420 of fig. 4 or the communication interface 520 of fig. 5. The transceiver 702 may include a receiver (or receiver, receiving circuitry) and a transmitter (or transmitter, transmitting circuitry). Wherein the receiver is for receiving signals and the transmitter is for transmitting signals.

Optionally, the terminal device 700 may further comprise a power supply 705 for providing power to various devices or circuits in the terminal device 700.

In addition to this, the terminal device 700 may further comprise one or more of an input unit 706, a display unit 707, audio circuitry 708, which may further comprise a speaker 708a, a microphone 708b, etc., a camera 709, a sensor 710, etc., in order to make the functionality of the terminal device more complete.

It will be appreciated that the terminal device 700 shown in fig. 7 is capable of carrying out the various processes involving the terminal device in the method embodiments shown in fig. 2 or 3. The operations and/or functions of the respective modules in the terminal device 700 are respectively for implementing the corresponding flows in the above-described method embodiments. Reference is specifically made to the description in the above method embodiments, and detailed descriptions are omitted here as appropriate to avoid repetition.

When the terminal device 700 is used to perform the operation flow related to the terminal device in the above method embodiment, the processor 701 may be used to perform the actions described in the previous method embodiment as being implemented inside the terminal device, and the transceiver 702 may be used to perform the actions described in the previous method embodiment as being transmitted to or received from the network device by the terminal device. Please refer to the description of the foregoing method embodiments, and details are not repeated herein.

The present application also provides a computer program product comprising: a computer program (which may also be referred to as code, or instructions), which when executed, causes a computer to perform the method performed by the terminal device, or the method performed by the first network device, or the method performed by the second network device in the embodiments shown in fig. 2 or 3.

The present application also provides a computer-readable storage medium storing a computer program (which may also be referred to as code, or instructions). The computer program, when executed, causes the computer to perform the method performed by the terminal device in the embodiment shown in fig. 2 or fig. 3, or the method performed by the first network device, or the method performed by the second network device.

The embodiment of the application provides a communication system, which comprises the terminal equipment, first network equipment and second network equipment.

It should be appreciated that the processor in the embodiments of the present application may be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above method embodiments may be implemented by integrated logic circuits of hardware in a processor or instructions in software form. The processor may be a general purpose processor, a digital signal processor (digital signal processor, DSP), an application specific integrated circuit (application specific integrated circuit, ASIC), a field programmable gate array (field programmable gate array, FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components. The disclosed methods, steps, and logic blocks in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present application may be embodied directly in hardware, in a decoded processor, or in a combination of hardware and software modules in a decoded processor. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in a memory, and the processor reads the information in the memory and, in combination with its hardware, performs the steps of the above method.

It should also be appreciated that the memory in embodiments of the present application may be either volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The nonvolatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. The volatile memory may be random access memory (random access memory, RAM) which acts as an external cache. By way of example, and not limitation, many forms of RAM are available, such as Static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous DRAM (SLDRAM), and direct memory bus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

The terms "unit," "module," and the like as used in this specification may be used to refer to a computer-related entity, either hardware, firmware, a combination of hardware and software, or software in execution. The units and modules in the embodiment of the application have the same meaning and can be used in a crossed manner.

Those of ordinary skill in the art will appreciate that the various illustrative logical blocks (illustrative logical block) and steps (steps) described in connection with the embodiments disclosed herein can be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application. In the several embodiments provided in this application, it should be understood that the disclosed apparatus, device, and method may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

In the above-described embodiments, the functions of the respective functional units may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions (programs). When the computer program instructions (program) are loaded and executed on a computer, the processes or functions described in accordance with the embodiments of the present application are fully or partially produced. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a digital versatile disk (digital video disc, DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), or the like.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: a usb disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk, etc.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A communication method, wherein the method is applied to a terminal device, the method comprising:

receiving first indication information from first network equipment, wherein the first indication information indicates that the terminal equipment is in communication with second network equipment, a cell served by the first network equipment is a first cell, a cell served by the second network equipment is a second cell, and the first cell is a serving cell of the terminal equipment;

receiving second indication information from the second network equipment, wherein the second indication information indicates that the system information of the first cell is changed;

and receiving the changed system information of the first cell.

2. The method of claim 1, wherein the second indication information is downlink control information, DCI, the DCI indicating a cell in which the system information is changed.

3. The method of claim 2, wherein the receiving the second indication information from the second network device comprises:

receiving the DCI from the second network device based on a common Physical Downlink Control Channel (PDCCH) receiving configuration of the first cell; or (b)

Receiving the DCI from the second network device based on a dedicated PDCCH reception configuration of the terminal device in the first cell; or (b)

Receiving the DCI from the second network device based on a common PDCCH reception configuration of the second cell; or (b)

And receiving the DCI from the second network equipment based on the special PDCCH receiving configuration of the terminal equipment in the second cell.

4. A method according to any of claims 1 to 3, wherein the first indication information indicates that the beam direction in which the terminal device communicates with the second network device is the beam direction of the second cell.

5. The method according to any of claims 1 to 4, wherein the receiving the changed system information of the first cell comprises:

switching the direction of a received beam to the beam direction of the first cell;

and receiving the changed system information from the first network equipment through the receiving beam.

6. The method according to any of claims 1 to 4, wherein the receiving the changed system information of the first cell comprises:

and receiving the changed system information from the second network equipment through the beam direction of the second cell.

7. The method of claim 6, wherein the second indication information is further used to indicate resources carrying the changed system information, and

the receiving, by the beam direction of the second cell, the changed system information from the second network device, including:

and receiving the changed system information from the second network device on the resource.

8. A method of communication, the method being applied to a second network device, the method comprising:

generating second indication information, wherein the second indication information indicates that system information of a first cell is changed, the first cell is a service cell of terminal equipment, the first cell is served by first network equipment, and a cell served by second network equipment is a second cell;

and sending the second indication information to the terminal equipment.

9. The method of claim 8, wherein the second indication information is downlink control information, DCI, the DCI indicating a cell in which the system information is changed.

10. The method of claim 9, wherein the sending the second indication information to the terminal device comprises:

Transmitting the DCI based on a common Physical Downlink Control Channel (PDCCH) receiving configuration of the first cell; or (b)

Transmitting the DCI based on a dedicated PDCCH receiving configuration of the terminal equipment in the first cell; or (b)

Receiving and transmitting DCI based on a common PDCCH receiving configuration of the second cell; or (b)

And transmitting the DCI based on the special PDCCH receiving configuration of the terminal equipment in the second cell.

11. The method of claim 10, wherein prior to the sending the changed system information for the first cell to the terminal device, the method further comprises:

and receiving third indication information from the first network equipment, wherein the third indication information comprises a public PDCCH receiving configuration of the first cell or a special PDCCH receiving configuration of the terminal equipment in the first cell.

12. The method of claim 11, wherein the method further comprises:

receiving changed system information of the first cell from the first network device;

and sending the changed system information to the terminal equipment.

13. The method of claim 12, wherein the second indication information is further for indicating resources carrying the changed system information, and

The sending the changed system information to the terminal equipment comprises the following steps:

and sending the changed system information to the terminal equipment on the resource.

14. A communication device comprising means for performing the method of any of claims 1 to 7.

15. A communication device comprising a processor and a memory, the processor and the memory being coupled, the processor being configured to control the device to implement the method of any one of claims 1 to 7.

16. A communication device comprising a processor and interface circuitry for receiving signals from other communication devices than the device and transmitting signals from the processor to the processor or sending signals from the processor to other communication devices than the device, the processor being operable to implement the method of any one of claims 1 to 7 by logic circuitry or executing code instructions.

17. A communication device comprising means for performing the method of any of claims 8 to 13.

18. A communication device comprising a processor and a memory, the processor and the memory being coupled, the processor being configured to control the device to implement the method of any one of claims 8 to 13.

19. A communication device comprising a processor and interface circuitry for receiving signals from other communication devices than the device and transmitting signals from the processor to the processor or sending signals from the processor to other communication devices than the device, the processor being operable to implement the method of any one of claims 8 to 13 by logic circuitry or executing code instructions.

20. A communication system comprising an apparatus as claimed in any one of claims 14 to 16 and an apparatus as claimed in any one of claims 17 to 19.

21. A computer readable storage medium, characterized in that the storage medium has stored therein a computer program or instructions which, when executed by a computer, implement the method of any one of claims 1 to 7 or the method of any one of claims 8 to 13.

22. A computer program product comprising instructions which, when executed by a computer, implement the method of any one of claims 1 to 7 or the method of any one of claims 8 to 13.