Communication method and apparatus between terminal devices

Abstract

The application discloses a communication method and device between terminal devices. The method comprises the following steps: in the case that a call request of a calling terminal is received, determining the state of an interface between a call session control function (CSCF) entity and a policy and charging rules function (PCRF) entity; in the case that the state of the interface is unavailable, performing communication by using a first communication strategy which does not use the interface; and in the case that the state of the interface is available, performing communication by using a second communication strategy which uses the interface. The application solves the technical problem that the terminal devices cannot communicate due to the interface failure between a proxy call session control function (P-CSCF) entity and a charging rules function (PCRF) entity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication, in particular to a communication method and device between terminal devices. BACKGROUND

[0002] In a voice over long-term evolution (VoLTE) network, a terminal is required to support resource reservation through a pre-reservation mechanism in a basic voice service and video service technical requirement of VoLTE. When an interface between a proxy call session control function (P-CSCF) entity and a policy and charging rules function (PCRF) entity fails, resource reservation through the precondition mechanism is not possible, which results in a failure of communication between terminal devices.

[0003] Currently, no effective solution has been proposed for the above problem. SUMMARY

[0004] Embodiments of the present application provide a communication method and device between terminal devices to at least solve the technical problem of a failure of communication between terminal devices due to an interface failure between a P-CSCF entity and a PCRF entity.

[0005] According to an aspect of an embodiment of the present application, a communication method between terminal devices is provided, including: in a case where a call request of a calling terminal is received, determining a state of an interface between a call session control function (CSCF) entity and a policy and charging rules function (PCRF) entity; in a case where the state of the interface is unavailable, performing a first communication strategy that does not use the interface to implement communication; and in a case where the state of the interface is available, performing a second communication strategy that uses the interface to implement communication.

[0006] Optionally, the CSCF entity comprises a Proxy Call Session Control Function (P-CSCF) entity, a Serving Call Session Control Function (S-CSCF) entity, the interface comprises a first interface for connecting the P-CSCF entity and the PCRF entity, a second interface for connecting the P-CSCF entity and a Diameter Routing Agent (DRA) entity, and a third interface for connecting the DRA entity and the PCRF entity, wherein the DRA entity is configured to forward information sent by the P-CSCF entity to the PCRF entity; and the method further comprises determining the state of the interface between the Call Session Control Function (CSCF) entity and the Policy and Charging Rules Function (PCRF) entity, comprising determining the state of the interface according to the state of the first interface, and determining the state of the interface according to the state of the second interface and the state of the third interface.

[0007] Optionally, the method further comprises determining the state of the interface according to the state of the first interface, comprising detecting the state of the first interface at a preset frequency, and determining the state of the interface as unavailable when the state of the first interface is unavailable, and determining the state of the interface as available when the state of the first interface is available; and determining the state of the interface according to the state of the second interface and the state of the third interface, comprising detecting the state of the second interface and the state of the third interface at a preset frequency, and determining the state of the interface as unavailable when the state of the second interface or the state of the third interface is unavailable, and determining the state of the interface as available when the state of the second interface is available and the state of the third interface is available.

[0008] Optionally, the method further comprises executing the first communication strategy without using the interface, comprising executing a deletion strategy by the P-CSCF entity in the CSCF entity, wherein the deletion strategy is configured to instruct to delete parameters related to a resource reservation mechanism in a session establishment request message, wherein the resource reservation mechanism is configured to reserve resources before a call is established between a calling terminal and a called terminal; sending the session establishment request message with the parameters related to the resource reservation mechanism deleted to the S-CSCF entity in the CSCF entity; and implementing communication based on current network resources commonly used by the S-CSCF entity.

[0009] Optionally, the method further comprises executing the deletion strategy by the P-CSCF entity, comprising determining the parameters related to the resource reservation mechanism in a Session Initiation Protocol (SIP), wherein the parameters comprise at least a pre-condition identifier in the session establishment request message and a Quality of Service (QoS) parameter used to describe a quality of service; and deleting the pre-condition identifier and the QoS parameter.

[0010] Optionally, the method further comprises executing the deletion strategy by the P-CSCF entity, comprising determining a session header of the Session Initiation Protocol (SIP), wherein the session header contains the parameters related to the resource reservation mechanism; deleting the session header, the pre-condition identifier and the QoS parameter, and adding a new session header to the Session Initiation Protocol (SIP), wherein the new session header contains basic parameters used to support a session.

[0011] Optionally, the communication is implemented by the S-CSCF entity based on current common network resources, including: determining the numbers carried in the session establishment request message after parameters related to the reservation resource mechanism are deleted; obtaining subscription information of each number, wherein the subscription information at least records a trigger priority of each number; and establishing sessions related to the numbers in sequence according to the trigger priorities of the numbers to implement the communication.

[0012] Optionally, the second communication strategy dependent on the interface is executed to implement the communication, including: establishing a dedicated bearer by a P-CSCF entity in the CSCF entity, wherein the dedicated bearer is used to provide network resources for communication between the calling terminal and the called terminal; and performing communication between the calling terminal and the called terminal based on the dedicated bearer.

[0013] According to another aspect of the embodiments of the present application, a communication device between terminal devices is further provided, including: a determination module configured to determine a state of an interface between a call session control function (CSCF) entity and a policy and charging rules function (PCRF) entity in a case that a call request of a calling terminal is received; a first execution module configured to execute a first communication strategy without using the interface to implement communication in a case that the state of the interface is unavailable; and a second execution module configured to execute a second communication strategy using the interface to implement communication in a case that the state of the interface is available.

[0014] According to another aspect of the embodiments of the present application, a non-volatile storage medium is further provided, and the non-volatile storage medium stores a computer program, wherein a device in which the non-volatile storage medium is located executes the communication method between terminal devices by running the computer program.

[0015] According to another aspect of the embodiments of the present application, an electronic device is further provided, including a memory and a processor, the memory stores a computer program, and the processor is configured to execute the communication method between terminal devices by the computer program.

[0016] According to another aspect of the embodiments of the present application, a computer program product is further provided, including computer instructions, and the computer instructions are executed by a processor to implement steps of the communication method between terminal devices.

[0017] In the embodiment of the present application, the state of the interface between the call session control function CSCF entity and the policy and charging rules function PCRF entity is determined in the case of receiving the call request of the calling terminal; in the case that the state of the interface is unavailable, the first communication strategy not using the interface is executed to realize communication; in the case that the state of the interface is available, the second communication strategy using the interface is executed to realize communication, which provides a method for realizing communication between terminal devices without relying on the reservation resource mechanism, and realizes communication between terminal devices by starting the communication strategy not relying on the reservation resource mechanism in the case that the state of the interface between the P-CSCF entity and the PCRF is unavailable, and starting the communication strategy relying on the reservation resource mechanism in the case that the state of the interface between the P-CSCF entity and the PCRF is available, so as to switch the communication strategy according to the state of the interface between the P-CSCF entity and the PCRF, thereby realizing the technical effect of ensuring that the voice service between the terminal devices is always available, and further solving the technical problem that the terminal devices cannot communicate due to the interface failure between the proxy call session control function P-CSCF entity and the charging rules function PCRF entity. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings, which are included to provide a further understanding of the present application and constitute a part of this application, illustrate certain illustrative embodiments of the present application and together with the description serve to explain the present application. In the drawings:

[0019] Figure 1 FIG. 1 is a schematic diagram of a communication system 100 according to an embodiment of the present application;

[0020] Figure 2 FIG. 2 is a step flow chart of a communication method between terminal devices according to an embodiment of the present application;

[0021] Figure 3 FIG. 3 is a schematic diagram of realizing communication between terminal devices through the reservation resource mechanism according to an embodiment of the present application;

[0022] Figure 4 FIG. 4 is a structural diagram of a communication device between terminal devices according to an embodiment of the present application;

[0023] Figure 5 FIG. 5 is a flow chart of a calling terminal executing the first communication strategy according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] In the following, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application, so that those skilled in the art can better understand the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0025] It should be noted that the terms "first", "second" and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in other than the order illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to include those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to the process, method, product or device.

[0026] In order to better understand the embodiments of the present application, the technical terms involved in the embodiments of the present application are explained as follows:

[0027] Pre-reservation network resource mechanism (preconditon mechanism): Before the establishment of a media session, the Session Initiation Protocol (SIP) allows a terminal to include a precondition in a session request message (INVITE) to indicate the resource state it expects. For example, a User Equipment (UE) can use the precondition header field in the INVITE message to request the network to reserve sufficient bandwidth and Quality of Service (QoS) resources to support high-quality voice or video communication.

[0028] In the related art, the preconditon mechanism is used for communication between terminal devices. When the interface between the P-CSCF entity and the PCRF is unavailable, the preconditon mechanism cannot be executed, resulting in that the terminal devices cannot communicate with each other, and thus there are problems such as communication interruption and influence on user experience. In order to solve the problem, the present application provides related solutions, which will be described in detail below.

[0029] According to the embodiment of the present application, a method embodiment of a communication method between terminal devices is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a group of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in a different order.

[0030] The technical solutions of the embodiments of the present application can be applied to various communication systems, for example: Voice over Long Term Evolution (VoLTE) system, Voice over New Radio (VoNR), Voice over WiFi (Vowifi), Global System of Mobile communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system or 5G system, etc.

[0031] For example, a schematic diagram of a communication system 100 to which the embodiments of the present application are applied is as shown in Figure 1As shown. The communication system 100 can include a network device 110, which can be a device communicating with a terminal device 120 (or called a communication terminal, a terminal). The network device 110 can provide communication coverage for a specific geographic area, and can communicate with terminal devices located within the coverage area. Optionally, the network device 110 can be a base station (Base Transceiver Station, BTS) in a GSM system or a CDMA system, a base station (NodeB, NB) in a WCDMA system, an evolved base station (eNB or eNodeB) in an LTE system, or a wireless controller in a cloud radio access network (Cloud Radio Access Network, CRAN), or the network device can be a mobile switching center, a relay station, an access point, a vehicle-mounted device, a wearable device, a hub, a switch, a bridge, a router, a network-side device in a 5G network, or a network device in a future evolved public land mobile network (Public Land Mobile Network, PLMN), etc.

[0032] The communication system 100 further includes at least one terminal device 120 located within the coverage of the network device 110. As used herein, a "terminal device" includes, but is not limited to, an apparatus configured to receive / transmit communication signals via a wired line connection, such as via a Public Switched Telephone Network (PSTN), a Digital Subscriber Line (DSL), a digital cable, a direct cable connection; and / or another data connection / network; and / or a wireless interface, such as for a cellular network, a Wireless Local Area Network (WLAN), a digital television network such as a DVB-H network, a satellite network, an AM-FM broadcast transmitter; and / or another terminal device; and / or an Internet of Things (IoT) device. A terminal device configured to communicate over a wireless interface can be referred to as a "wireless communication terminal", "wireless terminal" or "mobile terminal". Examples of mobile terminals include, but are not limited to, satellite or cellular phones; Personal Communications System (PCS) terminals that can combine a cellular radiotelephone with data processing, facsimile, and data communications capabilities; PDA's that can include a wireless radio telephone, a pager, Internet / Intranet access, Web browser, an organizer, a calendar, and / or a global positioning system (GPS) receiver; and conventional laptop and / or palmtop receivers or other electronic devices that include a radio telephone transceiver. A terminal device can refer to an access terminal, User Equipment (UE), subscriber unit, subscriber station, mobile station, mobile, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. An access terminal can be a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handset with wireless communication capabilities, a computing device, or other processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal device in a 5G network, or a terminal device in a future evolved PLMN, etc.

[0033] Optionally, the terminal devices 120 can communicate with each other through Device to Device (D2D) communication.

[0034] Alternatively, a 5G system or 5G network may also be referred to as a New Radio (NR) system or NR network.

[0035] This application provides a communication method between terminal devices that can operate in the above-described operating environment. Figure 2 This is a flowchart illustrating the steps of a communication method between terminal devices according to an embodiment of this application, such as... Figure 2 As shown, the method includes the following steps:

[0036] Step S202: Upon receiving a call request from the calling terminal, determine the state of the interface between the Call Session Control Function (CSCF) entity and the Policy and Charging Rules Function (PCRF) entity.

[0037] The method provided in this application embodiment can be applied to any user terminal equipment (UE). In a single communication, it can be applied to both the calling terminal and the called terminal. Figure 3 This is a diagram illustrating how terminal devices communicate through a reserved resource mechanism, such as... Figure 3 As shown, the information sent by the calling terminal is forwarded to the called terminal via the CallSession Control Function (CSCF) entity. Figure 3 It is known that during communication between terminal devices, the Call Session Control Function (CSCF) entity is responsible for handling and controlling SIP-based multimedia sessions. The reserved resource mechanism needs to be implemented based on the interface between the CSCF entity and the PCRF entity. When the interface between the CSCF entity and the PCRF entity is unavailable, the reserved resource mechanism cannot be implemented. The method provided in this application determines whether to adopt a communication strategy that relies on the reserved resource mechanism to realize communication between terminal devices based on the status of the interface. Therefore, in step S202, after receiving a session request sent by the calling terminal, the status of the interface between the CSCF entity and the PCRF entity is first determined to further determine which communication strategy to adopt.

[0038] According to an optional embodiment of the present application, the CSCF entity comprises a Proxy Call Session Control Function (P-CSCF) entity, a Serving Call Session Control Function (S-CSCF) entity, the interfaces comprise a first interface for connecting the P-CSCF entity and the PCRF entity, a second interface for connecting the P-CSCF entity and a Diameter Routing Agent (DRA) entity, and a third interface for connecting the DRA entity and the PCRF entity, wherein the DRA entity is used for forwarding information sent by the P-CSCF entity to the PCRF entity; determining the state of the interface between the Call Session Control Function (CSCF) entity and the Policy and Charging Rules Function (PCRF) entity comprises determining the state of the interface according to the state of the first interface and determining the state of the interface according to the state of the second interface and the state of the third interface.

[0039] In the embodiment of the present application, the CSCF entity is a network entity composed of a P-CSCF entity and a Serving Call Session Control Function (S-CSCF) entity, that is, the P-CSCF entity and the S-CSCF entity are contained in the CSCF entity. In the embodiment, the reserved resource mechanism is executed starting from the P-CSCF entity and the PCRF entity, and the interface that needs to be determined is the interface between the P-CSCF entity and the PCRF entity. The interface between the P-CSCF entity and the PCRF entity includes two transmission modes when transmitting messages, one is that the P-CSCF entity and the PCRF entity directly transmit information, and the other is that a Diameter Routing Agent (DRA) entity is used to forward messages between the P-CSCF entity and the PCRF entity to realize information transmission. Therefore, the interface (the interface that needs to be determined) between the P-CSCF entity and the PCRF entity includes an interface (the first interface) that transmits information, one end of which is connected to the P-CSCF entity and the other end of which is connected to the PCRF entity; an interface (the second interface) that one end of which is connected to the DRA entity and the other end of which is connected to the P-CSCF entity; and an interface (the third interface) that one end of which is connected to the DRA entity and the other end of which is connected to the PCRF entity. When detecting whether the interface is available, different detection methods are used according to different networking modes. Specifically, when the network does not contain the DRA entity, the P-CSCF entity and the PCRF entity transmit information through the directly connected interface (the first interface), and at this time, the state of the first interface is the state of the interface between the P-CSCF entity and the PCRF entity that needs to be determined. If the network contains the DRA entity, the P-CSCF entity and the PCRF entity forward information through the second interface and the third interface, and at this time, the state of the interface between the P-CSCF entity and the PCRF entity is determined according to the state of the second interface and the state of the third interface.

[0040] Optionally, determining the state of the interface according to the state of the first interface comprises: detecting the state of the first interface according to a preset frequency; in the case that the state of the first interface is unavailable, determining the state of the interface as unavailable; in the case that the state of the first interface is available, determining the state of the interface as available; determining the state of the interface according to the state of the second interface and the state of the third interface comprises: detecting the state of the second interface and the state of the third interface according to a preset frequency; in the case that the state of the second interface or the state of the third interface is unavailable, determining the state of the interface as unavailable; in the case that the state of the second interface is available and the state of the third interface is available, determining the state of the interface as available.

[0041] As mentioned in the above embodiments, there are two transmission modes between the P-CSCF entity and the PCRF entity when transmitting messages. Since the reserved resource mechanism needs to rely on the information transmission between the P-CSCF entity and the PCRF entity to be implemented, the way of implementing the reserved resource mechanism also includes two ways. When the P-CSCF entity and the PCRF entity transmit information through the first interface, the reserved resource mechanism is implemented based on the first interface. When the P-CSCF entity and the PCRF entity transmit information through the DRA entity forwarding messages, i.e., through the second interface and the third interface, the reserved resource mechanism is implemented based on the second interface and the third interface. When the P-CSCF entity and the PCRF entity transmit information through the first interface, a communication strategy is selected according to the state of the first interface. Specifically, if the state of the first interface is available, a communication strategy based on the reserved resource mechanism (i.e., the second communication strategy) is adopted, and if the state of the first interface is unavailable, a communication strategy without enabling the reserved resource mechanism (i.e., the first communication strategy) is adopted. When the P-CSCF entity and the PCRF entity transmit information through the DRA entity forwarding messages, a communication strategy is selected according to the state of the second interface and the state of the third interface. Specifically, if the state of the second interface is available, it means that the DRA entity can receive the messages sent by the P-CSCF entity, and if the state of the third interface is available, it means that the PCRF entity can receive the messages forwarded by the DRA entity. Therefore, when selecting a communication strategy according to the state of the second interface and the state of the third interface, if the states of the second interface and the third interface are both available, a communication strategy based on the reserved resource mechanism (i.e., the second communication strategy) is adopted, and if the state of any one of the second interface and the third interface is unavailable, a communication strategy without enabling the reserved resource mechanism (i.e., the first communication strategy) is adopted. It should be noted that no matter which way is used to determine the state of the interface between the P-CSCF entity and the PCRF entity, the detection frequency can be preset to detect the state of the first interface according to the preset detection frequency, or the state of the second interface and the state of the third interface according to the preset detection frequency.

[0042] Step S204, in the case that the state of the interface is unavailable, the first communication strategy not using the interface is implemented to realize the communication.

[0043] If the state of the interface between the CSCF entity and the PCRF entity is completely blocked (i.e. unavailable), it is determined that the reserved resource mechanism cannot be implemented through the interface, at this time, in step S204, the communication strategy not using the reserved resource mechanism (i.e. the first communication strategy) is implemented to realize the communication between the calling terminal and the corresponding called terminal, wherein the reserved resource mechanism is not enabled using the interface between the CSCF entity and the PCRF entity when the first communication strategy is used; the reasons causing the state of the interface between the CSCF entity and the PCRF entity to be completely blocked include network failure, hardware failure, software error, configuration problem, etc., when the interface is completely blocked, the data exchange between the CSCF entity and the PCRF entity cannot be performed, and the communication between the terminal devices based on the reserved resource mechanism cannot be realized.

[0044] According to an optional embodiment of the present application, the first communication strategy not using the interface is implemented to realize the communication, including: performing a deletion strategy by a P-CSCF entity in the CSCF entity, wherein the deletion strategy is used to instruct to delete the parameters related to the reserved resource mechanism in the session establishment request message, wherein the reserved resource mechanism is used to realize the function of reserving resources before the calling terminal and the called terminal start a session; sending the session establishment request message after the parameters related to the reserved resource mechanism are deleted to an S-CSCF entity in the CSCF entity; and realizing the communication based on the current general network resources by the S-CSCF entity.

[0045] In the embodiment, since the parameters related to the reserved resource mechanism are contained in the session request message (INVITE) sent by the terminal device, when the strategy not enabling the reserved resource mechanism (i.e. the first communication strategy) is used to realize the communication between the calling terminal and the corresponding called terminal, first, the deletion strategy is performed by the P-CSCF entity, wherein the deletion strategy value is used to instruct to delete the parameters related to the reserved resource mechanism in the session request message, and the session request message (INVITE) after the parameters related to the reserved resource mechanism are deleted is sent to the S-CSCF entity by the P-CSCF entity; further, the communication between the calling terminal and the called terminal is realized by the S-CSCF entity according to the current used network resources; wherein in the embodiment of the present application, if the reserved resource mechanism is enabled, the specific QoS is set for the communication between the calling terminal and the called terminal; in the case that the reserved resource mechanism is not enabled, the network performs the equal processing mechanism for all data packets; the general network resources refer to the network resources not specially used for the communication between the calling terminal and the called terminal.

[0046] Optionally, the deleting strategy is executed by the P-CSCF entity, comprising: determining parameters related to the reservation resource mechanism in the session initiation protocol, wherein the parameters at least include: a precondition identifier in a session establishment request message, and a quality of service parameter used to describe quality of service; and deleting the precondition identifier and the quality of service parameter.

[0047] In the embodiment, the parameters related to the reservation resource mechanism at least include the following parameters: a precondition extension identifier (i.e. precondition identifier) added in the SIP signaling to indicate support of the resource reservation function, and the following quality of service parameters related to quality of service: a=curr:qos local none (the local caller's (curr:) quality of service (qos) resource now has no resource reservation), a=curr:qos remote none (the remote called party's (curr:) quality of service (qos) resource now has no resource reservation), a=des:qos mandatory local sendrecv (the local caller's (local) expected (des) quality of service (qos) resource is a bidirectional (sendrecv) resource reservation, and the resource reservation cannot be successfully reserved, and the session will not be established), and a=des:qos optional remote sendrecv (the remote called party's (remote) expected (des) quality of service (qos) resource is a bidirectional resource reservation, but it is not determined whether the called user really needs to reserve (none)). When the P-CSCF entity executes the deleting strategy, the precondition extension identifier (i.e. precondition identifier) and the quality of service parameter contained in the session initiation protocol (SIP) can be deleted.

[0048] According to another optional embodiment of the present application, the deleting strategy is executed by the P-CSCF entity, further comprising: determining a session header of the session initiation protocol, wherein the session header contains the parameters related to the reservation resource mechanism; deleting the session header, the precondition identifier and the quality of service parameter, and adding a new session header to the session initiation protocol, wherein the new session header contains basic parameters used to support the session.

[0049] In some embodiments, the parameters related to the reservation resource mechanism can include, in addition to the quality of service parameters mentioned above, the related parameters recorded in the session header of the Session Initiation Protocol (SIP), such as 100rel recorded in the supported header field of the session header, the reliable transmission mechanism of the provisional response is defined in the standard document of the SIP, the negotiation mechanism of "100rel" is introduced, and the 100rel extension provides the corresponding mechanism for the reliable transmission of the 100 class response message. In the case that the parameters related to the reservation resource mechanism include the precondition identifier and the quality of service parameters in the previous embodiment and the 100rel in the supported header field mentioned above, when the P-CSCF entity performs the deletion policy, the precondition identifier and the quality of service parameters and the session header are deleted at the same time. However, since the supported header field contains the parameters necessary for the basic call (i.e., the basic parameters for supporting the session), such as timer, replaces, histinfo and tdialog, wherein the timer is used to indicate whether the session refresh function is supported; the replaces message header is used to indicate that the current SIP session is replaced by a new SIP session. The histinfo message header is used to record the processing history of the redirected request message, so as to correctly provide services for the subsequent session. When the request message is redirected, the old routing information of the request message can be lost, so that the subsequent session cannot be processed in the original defined manner. The History-Info message header can be used to collect the processing history of the request message to provide services for the subsequent session; tdialog is the target dialog, and the Require header field of the SIP carries the tdialog identifier, indicating that the SCC AS (Session Continuity Controller Application Server) supports the Target-Dialog header field, and the Target-Dialog represents the original Dialog ID of the to-be-switched session, including: the identifier of the original session (Call-ID), the remote device user instance (remote-tag), and the local device user instance (local-tag); therefore, if the P-CSCF entity deletes the precondition identifier and the quality of service parameters and the session header when performing the deletion policy, a new session header containing the timer, replaces, histinfo and tdialog mentioned above needs to be generated to realize the communication between the calling terminal and the called terminal.

[0050] Based on the above embodiments, in the embodiments of the present application, when the parameters related to the reservation mechanism are deleted, there are two cases, one is to delete a=curr:qos local none, a=curr:qos remote none, a=curr:qos remote none, a=des:qos mandatory local sendrecv and 100rel; the other is to delete only a=curr:qos local none, a=curr:qos remote none, a=curr:qos remote none and a=des:qos mandatory local sendrecv. Wherein, whether to delete 100rel is determined according to the preset network management strategy, if the preset network strategy indicates that 100rel is deleted when the state of the interface between the P-CSCF entity and the PCRF entity is unavailable, 100rel is deleted.

[0051] In addition, the session header of the SIP can further include a Require header field in addition to the supported header field, the Require header field is used to specify the characteristics that the receiver must use or support in the SIP request, the Require header field contains a precondition identifier (precondition); when the parameters related to the reservation mechanism are deleted, the following cases can also exist: 1) delete the precondition identifier (precondition extension identifier) of the supported header field, 100rel, the quality of service parameter in the SDP, and delete the Require header field and the precondition identifier (precondition extension identifier) of the Require header field at the same time. 2) delete the precondition identifier (precondition extension identifier) of the supported header field, the quality of service parameter in the SDP, the Require header field and the precondition identifier (precondition extension identifier) of the Require header field.

[0052] According to some optional embodiments of the present application, the communication is realized by the S-CSCF entity based on the current general network resources, including: determining the numbers carried in the session establishment request message after the parameters related to the reservation resource mechanism are deleted; obtaining the subscription information of each number, wherein the subscription information at least records the trigger priority of each number; and establishing the session related to the number according to the trigger priority of the number in turn to realize the communication.

[0053] As mentioned in the above embodiment, the communication strategy without enabling the reservation resource mechanism (i.e. the first communication strategy) finally enables the S-CSCF entity to implement the communication between the calling terminal and the called terminal. Specifically, in this embodiment, the S-CSCF entity triggers the service according to the initial filter criteria (IFC) of the number subscription; and connects the called terminal; wherein the IFC of each number, i.e. the subscription information of each number, at least records the priority of service triggering, the condition of service triggering and the like. Therefore, when implementing the communication between the calling terminal and the called terminal, the S-CSCF entity can first acquire the numbers recorded in the session invitation information (the parameters related to the reservation resource mechanism in the session invitation information at this time have been deleted), further acquire the subscription information (including the IFC) of each number, set the triggering order for the multiple numbers according to the triggering priority recorded in the subscription information of each number, and sequentially connect the calling terminal or the called terminal corresponding to the number according to the above triggering order, to establish the session between the calling terminal and the called terminal, so as to implement the communication between the calling terminal and the called terminal. In this embodiment, the number can be the calling number or the called number. In the calling process, the IFC of the calling number is triggered by the S-CSCF entity on the calling side, and in the called process, the IFC of the called number is triggered by the S-CSCF entity on the called side. Since the number can be the calling number or the called number, the session related to the number includes: 1) the session between the calling terminal and the called terminal when the number is the calling number; and 2) the session between the calling terminal and the called terminal when the number is the called number.

[0054] In step S206, if the state of the interface is available, the second communication strategy using the interface is executed to implement the communication.

[0055] On the contrary, if the state of the interface between the CSCF entity and the PCRF entity is available, the data exchange between the CSCF entity and the PCRF entity can be performed through the interface, and the reservation resource mechanism can be enabled. Therefore, in step S206, if it is determined that the interface between the CSCF entity and the PCRF entity is used, the communication between the calling terminal and the called terminal corresponding to the calling terminal is implemented by using the communication strategy based on the reservation mechanism (i.e. the second communication strategy); wherein when the second communication strategy is used, the reservation resource mechanism needs to be enabled based on the interface.

[0056] Optionally, the second communication strategy depending on the interface is executed to implement the communication, including: establishing a dedicated bearer by the P-CSCF entity in the CSCF entity, wherein the dedicated bearer is used to provide network resources for the communication between the calling terminal and the called terminal; and performing the communication between the calling terminal and the called terminal based on the dedicated bearer.

[0057] As mentioned in step S206, when the state of the interface between the CSCF entity and the PCRF entity is available, the reserved resource mechanism is enabled, and a communication strategy based on the reserved resource mechanism (i.e., the second communication strategy) is used to implement the communication between the calling terminal and the called terminal. In this embodiment, when the second communication strategy is used, the reserved resource mechanism is enabled, and a dedicated bearer is established by the P-CSCF entity to provide network resources for the communication between the calling terminal and the called terminal. After the dedicated bearer is established, the calling terminal and the called terminal communicate with each other only through the dedicated bearer.

[0058] Through the above steps, the scheme of selecting a communication strategy according to the state of the interface between the CSCF entity and the PCRF entity can be implemented. Specifically, when the state of the interface between the CSCF entity and the PCRF entity is available, the communication strategy based on the reserved resource mechanism (i.e., the second communication strategy) is used; and when the state of the interface between the CSCF entity and the PCRF entity is unavailable, the communication strategy without the reserved resource mechanism (i.e., the first communication strategy) is used. Thus, the technical effect that the terminal devices can still communicate with each other when the interface between the CSCF entity and the PCRF entity is unavailable is achieved, and the implementation of basic voice services is ensured. In addition, the strategy can be switched in the communication process without the user of the terminal device being aware, the communication between the terminal devices is not interrupted, and the technical effect of improving the user experience is also achieved.

[0059] Figure 4 is a structural diagram of a communication device between terminal devices according to an embodiment of the present application, as shown in Figure 4 The communication device between terminal devices includes a determination module 40 configured to determine the state of an interface between a call session control function (CSCF) entity and a policy and charging rules function (PCRF) entity when a call request of a calling terminal is received; a first execution module 42 configured to implement communication by using a first communication strategy without the interface when the state of the interface is unavailable; and a second execution module 44 configured to implement communication by using a second communication strategy with the interface when the state of the interface is available.

[0060] It should be noted that Figure 4 The preferred embodiments of the embodiments shown in Figure 2 will not be described here.

[0061] Figure 5 is a flowchart of the calling terminal implementing the first communication strategy, as shown in Figure 5As shown, the network architecture on the side of the calling terminal when the calling terminal establishes communication with the called terminal includes terminal equipment (UE), base station (eNodeB), mobility management entity (MME), service gateway (S-GW), packet data network gateway (P-GW), PCRF, and CSCF including P-CSCF and S-CSCF. In the procedure of UE triggered Service Request, after the P-CSCF entity receives the session invitation information (i.e. INVITE (Offer)) sent by the UE as the calling terminal and containing parameters related to the reservation resource mechanism, the P-CSCF entity deletes the parameters related to the reservation resource mechanism (i.e. precondition related parameters) in the session invitation information and sends the session invitation information (i.e. INVITE) from which the precondition related parameters are deleted to the S-CSCF entity. The S-CSCF entity returns a temporary response information (100 trying) to the UE to inform the UE that the information sent by the UE has been received. The INVITE continues to be transmitted to the called terminal. When the INVITE reaches the called terminal, the called terminal sends a temporary response information (180 ringing) to the S-CSCF entity of the calling terminal to inform the calling terminal that the called terminal has received the INVITE. After a period of time, if the called terminal receives the request, the called terminal returns a final response information (200 OK) to the calling terminal. After the calling terminal receives the final response information (200 OK), the calling terminal establishes a session with the called terminal and can start communication. When the communication ends, the calling terminal sends a session stop information (BYE) to the called terminal. When the session is successfully stopped, the called terminal returns a session stop success information (BYE 200) to the calling terminal.

[0062] The embodiment of the present application further provides a non-volatile storage medium, and the non-volatile storage medium stores a computer program. When a device in which the non-volatile storage medium is located executes the computer program, the communication method between terminal devices described above is implemented.

[0063] The non-volatile storage medium described above is used for storing a program for implementing the following functions: determining the state of an interface between a call session control function CSCF entity and a policy and charging rules function PCRF entity in the case that a call request of a calling terminal is received; implementing a first communication strategy that does not use the interface to implement communication in the case that the state of the interface is unavailable; and implementing a second communication strategy that uses the interface to implement communication in the case that the state of the interface is available.

[0064] The embodiment of the present application further provides an electronic device, which comprises a memory and a processor. The memory stores a computer program, and the processor is configured to execute the communication method between terminal devices described above by using the computer program.

[0065] The processor in the electronic device is configured to run a program for performing the following functions: determining a state of an interface between a call session control function (CSCF) entity and a policy and charging rules function (PCRF) entity upon receiving a call request of a calling terminal; implementing communication by using a first communication strategy that does not use the interface when the state of the interface is unavailable; and implementing communication by using a second communication strategy that uses the interface when the state of the interface is available.

[0066] The embodiment of the present application further provides a computer program product, comprising computer instructions, which, when executed by a processor, implement the steps of the communication method between terminal devices.

[0067] It should be noted that each module in the communication device between terminal devices can be a program module (for example, a program instruction set for implementing a certain specific function) or a hardware module, and the hardware module can be in the following forms, but is not limited thereto: each module is in the form of a processor, or the functions of each module are implemented by a processor.

[0068] The serial numbers of the embodiments of the present application are only for description, and do not represent the advantages or disadvantages of the embodiments.

[0069] In the above embodiments of the present application, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0070] In the several embodiments provided by the present application, it should be understood that the disclosed technology can be implemented in other ways. Of course, the device embodiment described above is only illustrative, and for example, the division of the units can be a logical function division, and actual implementation can have another division manner, for example, a plurality of units or entities can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units or modules shown or discussed can be indirect coupling or communication connection through some interface, unit or module, and can be electrical or other forms.

[0071] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on multiple units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0072] In addition, each function unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software function unit.

[0073] When the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or the part that contributes to the related art, or all or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The foregoing storage medium includes: a U disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0074] The above is only the preferred embodiment of the present application, and it should be pointed out that, for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be considered as the protection scope of the present application.

Claims

1. A method of communication between terminal devices, characterized in that, Comprise: In the case of receiving a call request of a calling terminal, determining the state of an interface between a call session control function (CSCF) entity and a policy and charging rules function (PCRF) entity; In the case of the state of the interface being unavailable, implementing communication by a first communication strategy which does not use the interface, comprising: executing a deletion policy by a P-CSCF entity in the CSCF entity, wherein the deletion policy is used to instruct to delete parameters related to a reserved resource mechanism in a session establishment request message, wherein the reserved resource mechanism is used to implement a function of reserving resources before a session between the calling terminal and a called terminal starts; sending the session establishment request message with the parameters related to the reserved resource mechanism deleted to an S-CSCF entity in the CSCF entity; and implementing communication by the S-CSCF entity based on current common network resources; In the case of the state of the interface being available, implementing communication by a second communication strategy which uses the interface.

2. The method of claim 1, wherein, The CSCF entity comprises a proxy call session control function (P-CSCF) entity and a serving call session control function (S-CSCF) entity, and the interface comprises a first interface for connecting the P-CSCF entity and the PCRF entity, a second interface for connecting the P-CSCF entity and a routing agent (DRA) entity, and a third interface for connecting the DRA entity and the PCRF entity, wherein the DRA entity is used to forward information sent by the P-CSCF entity to the PCRF entity. Determining the state of the interface between the CSCF entity and the PCRF entity comprises determining the state of the interface according to the state of the first interface and determining the state of the interface according to the state of the second interface and the state of the third interface.

3. The method of claim 2, wherein, Determining the state of the interface according to the state of the first interface comprises: Detecting the state of the first interface at a preset frequency, and determining that the state of the interface is unavailable in the case of the state of the first interface being unavailable, and determining that the state of the interface is available in the case of the state of the first interface being available; Determining the state of the interface according to the state of the second interface and the state of the third interface comprises: detecting the state of the second interface and the state of the third interface at the preset frequency, and determining that the state of the interface is unavailable in the case of the state of the second interface or the state of the third interface being unavailable, and determining that the state of the interface is available in the case of the state of the second interface being available and the state of the third interface being available.

4. The method of claim 1, wherein, Executing the deletion policy by the P-CSCF entity comprises: Determining the parameters related to the reserved resource mechanism in a session initiation protocol, wherein the parameters at least comprise a precondition identifier in the session establishment request message and a quality of service parameter used to describe quality of service; and deleting the precondition identifier and the quality of service parameter.

5. The method of claim 4, wherein, Executing the deletion policy by the P-CSCF entity further comprises: determining a session header of the session initiation protocol, wherein the session header contains the parameter related to the reservation resource mechanism; deleting the session header, the precondition identification and the quality of service parameter, and adding a new session header to the session initiation protocol, wherein the new session header contains basic parameters for supporting a session.

6. The method of claim 1, wherein, implementing communication based on current common network resources through the S-CSCF entity, including: determining numbers carried by the session establishment request message after the parameter related to the reservation resource mechanism is deleted; obtaining subscription information of each of the numbers, wherein the subscription information at least records a triggering priority of each of the numbers; establishing sessions related to the numbers in sequence according to the triggering priorities of the numbers to implement communication.

7. The method of claim 1, wherein, implementing communication according to a second communication strategy dependent on the interface, including: establishing a dedicated bearer through a P-CSCF entity in the CSCF entity, wherein the dedicated bearer is used to provide network resources for communication between the calling terminal and the called terminal; implementing communication between the calling terminal and the called terminal based on the dedicated bearer.

8. A communication apparatus between terminal devices, characterized by, including: a determining module, configured to determine a state of an interface between a call session control function (CSCF) entity and a policy and charging rules function (PCRF) entity when a call request of a calling terminal is received; a first executing module, configured to implement communication according to a first communication strategy not using the interface when the state of the interface is unavailable, including: executing a deletion strategy through a P-CSCF entity in the CSCF entity, wherein the deletion strategy is used to instruct to delete a parameter related to a reservation resource mechanism in a session establishment request message, wherein the reservation resource mechanism is used to implement a function of reserving resources before a session between the calling terminal and a called terminal is started; sending the session establishment request message after the parameter related to the reservation resource mechanism is deleted to an S-CSCF entity in the CSCF entity; and implementing communication based on current common network resources through the S-CSCF entity; a second executing module, configured to implement communication according to a second communication strategy using the interface when the state of the interface is available.

9. A non-volatile storage medium, characterized by, The non-volatile storage medium stores a computer program, wherein a device in which the non-volatile storage medium is located implements the communication method between terminal devices according to any one of claims 1 to 7 by running the computer program.

10. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to implement the communication method between terminal devices according to any one of claims 1 to 7 by running the computer program.

11. A computer program product comprising computer instructions, characterized in that, The computer instructions are executed by the processor to implement the steps of the communication method between terminal devices according to any one of claims 1 to 7.

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