Call establishment method, apparatus and network side device

Abstract

The present application belongs to the technical field of communications. Disclosed are a call establishment method, an apparatus and a network side device. The call establishment method in the embodiments of the present application comprises: a first core network element receives a first call establishment request message sent by a first terminal; and the first core network element sends a second call establishment request message to a second terminal, the second call establishment request message and the first call establishment request message satisfying at least one of the following: a speech coding mode carried by the second call establishment request message being different from a speech coding mode carried by the first call establishment request message, the number of parameters included in a first message header carried by the second call establishment request message being different from the number of parameters included in a first message header carried by the first call establishment request message and, when the first call establishment request message carries a second message header, the second call establishment request message not carrying a second message header.

Description

Call establishment method, device and network side equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese Patent Application No. 202310865155.0 filed in China on July 13, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application belongs to the field of communication technology, and specifically relates to a call establishment method, apparatus, and network-side equipment. Background Art

[0004] Currently, mobile communication systems (e.g., fourth generation (4G) or fifth generation (5G) communication systems) often use Internet Protocol (IP) Multimedia Subsystem (IMS) voice for voice communication, such as Voice over LTE (VoLTE) and Voice over NR (VoNR).

[0005] With the increasing application of satellite communication systems, some user equipment (UE) can conduct voice communications through satellite communication systems. Satellite communication systems typically consist of three parts: a satellite terminal, a ground terminal, and a user terminal. The satellite terminal acts as a relay station in the air, amplifying the electromagnetic waves transmitted by the ground station and then returning them to the ground station. Because the satellite terminal is often far away from the ground, the interaction between the ground equipment (UE or ground terminal) and the satellite terminal often requires a large link budget. Therefore, to meet the link budget, it is necessary to perform some specific processing on the voice communication of the UE based on satellite communication, such as using a lower voice coding method (for example, a voice coding method with a bit rate of 1.2kbps or 0.6kbps) and simplifying voice data packets. However, if the other UE does not support the voice communication after the above-mentioned specific processing, the voice call establishment will fail, and the reliability of the voice communication will be poor. Therefore, in the existing technology, the reliability of voice communication is poor when the UE conducts voice communication based on satellite.

[0006] Summary of the Invention

[0007] The embodiments of the present application provide a call establishment method, apparatus, and network-side equipment, which can improve the reliability of voice communication when a UE performs voice communication based on a satellite.

[0008] In a first aspect, a call establishment method is provided, the method comprising:

[0009] The first core network element receives a first call establishment request message sent by the first terminal; wherein the first call establishment request message is used to request establishment of a voice call between the first terminal and the second terminal;

[0010] The first core network element sends a second call establishment request message to the second terminal; wherein the second call establishment request message is determined based on the first call establishment request message, and the second call establishment request message and the first call establishment request message satisfy at least one of the following conditions:

[0011] The voice coding mode carried by the second call establishment request message is different from the voice coding mode carried by the first call establishment request message;

[0012] The number of parameters included in the first message header carried by the second call establishment request message is different from the number of parameters included in the first message header carried by the first call establishment request message;

[0013] If the first call setup request message carries the second message header, the second call setup request message does not carry the second message header. If the first call setup request message does not carry the second message header, the second call setup request message carries the second message header.

[0014] In a second aspect, a call establishment device is provided, the device comprising:

[0015] A first receiving module is configured to receive a first call establishment request message sent by a first terminal; wherein the first call establishment request message is used to request establishment of a voice call between the first terminal and a second terminal;

[0016] A first sending module is configured to send a second call establishment request message to the second terminal; wherein the second call establishment request message is determined based on the first call establishment request message, and the second call establishment request message satisfies at least one of the following conditions:

[0017] The voice coding mode carried by the second call establishment request message is different from the voice coding mode carried by the first call establishment request message;

[0018] The number of parameters included in the first message header carried by the second call establishment request message is different from the number of parameters included in the first message header carried by the first call establishment request message;

[0019] If the first call setup request message carries the second message header, the second call setup request message does not carry the second message header. If the first call setup request message does not carry the second message header, the second call setup request message carries the second message header.

[0020] In a third aspect, a network side device is provided, which includes a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the method described in the first aspect are implemented.

[0021] In a fourth aspect, a network side device is provided, comprising a processor and a communication interface, wherein the communication interface is used to receive a first call establishment request message sent by a first terminal; wherein the first call establishment request message is used to request the establishment of a voice call between the first terminal and the second terminal; and send a second call establishment request message to the second terminal; wherein the second call establishment request message is determined based on the first call establishment request message, and at least one of the following items is satisfied between the second call establishment request message and the first call establishment request message: the voice coding method carried by the second call establishment request message is different from the voice coding method carried by the first call establishment request message; the number of parameters included in the first message header carried by the second call establishment request message is different from the number of parameters included in the first message header carried by the first call establishment request message; in the case where the first call establishment request message carries a second message header, the second call establishment request message does not carry the second message header, and in the case where the first call establishment request message does not carry the second message header, the second call establishment request message carries the second message header.

[0022] In a fifth aspect, a readable storage medium is provided, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the method described in the first aspect are implemented.

[0023] In a sixth aspect, a chip is provided, comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is configured to run a program or instruction to implement the steps of the method described in the first aspect.

[0024] In a seventh aspect, a computer program / program product is provided, wherein the computer program / program product is stored in a storage medium and is executed by at least one processor to implement the steps of the method described in the first aspect.

[0025] In an embodiment of the present application, a first core network network element receives a first call establishment request message sent by a first terminal, and sends a second call establishment request message to the second terminal, the second call establishment request message is determined based on the first call establishment request message, and at least one of the following items is satisfied between the second call establishment request message and the first call establishment request message: the voice coding method carried by the second call establishment request message is different from the voice coding method carried by the first call establishment request message; the number of parameters included in the first message header carried by the second call establishment request message is different from the number of parameters included in the first message header carried by the first call establishment request message; in the case where the first call establishment request message carries a second message header, the The second call establishment request message does not carry the second message header. When the first call establishment request message does not carry the second message header, the second call establishment request message carries the second message header. That is, in an embodiment of the present application, when the first terminal or the second terminal performs voice communication through a communication satellite, the content of the first call establishment request message (that is, the voice coding mode, at least one of the first message header and the second message header) can be modified by the first core network network element to obtain a second call establishment request message adapted to the second terminal, and sent to the second terminal. This is beneficial to ensuring the successful establishment of the voice call between the two terminals when the voice communication modes supported by the terminals on both sides of the voice communication are different, improving the reliability of voice communication, and expanding the scope of application of voice communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1 is a block diagram of a wireless communication system applicable to embodiments of the present application;

[0027] FIG2 is a flowchart of a call establishment method according to an embodiment of the present application;

[0028] FIG3 is a second flowchart of a call establishment method provided in an embodiment of the present application;

[0029] FIG4 is a flowchart of a call establishment method according to an embodiment of the present application;

[0030] FIG5 is a fourth flowchart of a call establishment method provided in an embodiment of the present application;

[0031] FIG6 is a structural diagram of a call establishment device provided in an embodiment of the present application;

[0032] FIG7 is a structural diagram of a communication device provided in an embodiment of the present application;

[0033] FIG8 is a structural diagram of a network-side device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] The following will be combined with the accompanying drawings in the embodiments of this application to clearly describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0035] The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same type, and do not limit the number of objects, for example, the first object can be one or more. In addition, "or" in this application represents at least one of the connected objects. For example, "A or B" covers three options, namely, Option 1: including A but not including B; Option 2: including B but not including A; Option 3: including both A and B. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0036] The term "indication" in this application can be either a direct indication (or explicit indication) or an indirect indication (or implicit indication). A direct indication can be understood as the sender explicitly informing the receiver of specific information, the operation to be performed, or the requested result, etc. in the instruction sent; an indirect indication can be understood as the receiver determining the corresponding information based on the instruction sent by the sender, or making a judgment and determining the operation to be performed or the requested result, etc. based on the judgment result.

[0037] It is worth noting that the technology described in the embodiments of the present application is not limited to the Long Term Evolution (LTE) / LTE-Advanced (LTE-A) system, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA) or other systems. The terms "system" and "network" in the embodiments of the present application are often used interchangeably, and the technology described can be used for the systems and radio technologies mentioned above, as well as for other systems and radio technologies. The following description describes a New Radio (NR) system for illustrative purposes, and NR terminology is used in most of the following description, but these technologies can also be applied to systems other than NR systems, such as 6th generation (6G) systems. th Generation, 6G) communication system.

[0038] FIG1 is a block diagram of a wireless communication system applicable to an embodiment of the present application. The wireless communication system includes a terminal 11 and a network-side device 12. The terminal 11 may be a mobile phone, a tablet computer (Tablet Personal Computer), a laptop computer (Laptop Computer), a notebook computer, a personal digital assistant (PDA), a handheld computer, a netbook, an ultra-mobile personal computer (UMPC), a mobile internet device (MID), an augmented reality (AR), a virtual reality (VR) device, a robot, a wearable device (Wearable Device), an aircraft (Flight Vehicle), a vehicle-mounted device (VUE), a ship-mounted device, a pedestrian user equipment (PUE), a smart home (home appliances with wireless communication capabilities, such as refrigerators, televisions, washing machines, or furniture), a game console, a personal computer (PC), an ATM, or a self-service machine, or other terminal-side devices. Wearable devices include: smart watches, smart bracelets, smart headphones, smart glasses, smart jewelry (smart bracelets, smart bracelets, smart rings, smart necklaces, smart anklets, smart anklets, etc.), smart wristbands, smart clothing, etc. Among them, the vehicle-mounted device can also be called a vehicle-mounted terminal, a vehicle-mounted controller, a vehicle-mounted module, a vehicle-mounted component, a vehicle-mounted chip or a vehicle-mounted unit, etc. In addition to the above-mentioned terminal devices, it can also be a chip in the terminal, such as a modem chip, a system-on-chip (SoC). It should be noted that the specific type of the terminal 11 is not limited in the embodiment of the present application. The network side device 12 may include an access network device or a core network device, wherein the access network device may also be called a radio access network (RAN) device, a radio access network function or a radio access network unit. The access network device may include a base station, a wireless local area network (WLAN) access point (AP) or a wireless fidelity (WiFi) node, etc.Among them, the base station can be referred to as Node B (NB), Evolved Node B (eNB), the next generation Node B (gNB), New Radio Node B (NR Node B), access point, Relay Base Station (RBS), Serving Base Station (SBS), Base Transceiver Station (BTS), radio base station, radio transceiver, Basic Service Set (BSS), Extended Service Set (ESS), Home Node B (HNB), Home Evolved Node B (home evolved Node B), Transmission Reception Point (TRP) or other appropriate terms in the field. As long as the same technical effect is achieved, the base station is not limited to specific technical vocabulary. It should be noted that in the embodiment of the present application, only the base station in the NR system is used as an example for introduction, and the specific type of the base station is not limited.

[0039] The core network equipment may include but is not limited to at least one of the following: core network node, core network function, mobility management entity (MME), access mobility management function (AMF), session management function (SMF), user plane function (UPF), policy control function (PCF), policy and charging rules function unit (PCRF), edge application service discovery function (EASDF), unified data management (UDM), unified data repository (UDR), home user server (HSS), centralized network configuration (CNC), network storage function (NRF), network exposure function (NEF), local NEF (L-NEF), binding support function (BSF), application function ( It should be noted that in the embodiments of the present application, only the core network device in the NR system is introduced as an example, and the specific type of the core network device is not limited.

[0040] For ease of understanding, some of the contents involved in the embodiments of this application are described below:

[0041] 1. Satellite communication system.

[0042] A satellite communication system consists of three parts: the satellite terminal, the ground terminal, and the user terminal. The satellite terminal acts as a relay station in the air, amplifying the electromagnetic waves sent by the ground station and then returning them to the ground station. Satellite terminals are generally divided into the following three categories based on their operating orbits:

[0043] Low Earth Orbit (LEO) satellite communication system: 500-2000 km from the ground, with relatively small transmission delay and power consumption, but the coverage range of each satellite is also relatively small.

[0044] Medium Earth Orbit (MEO) satellite communication system: 2000-20000 km from the ground, the transmission delay is greater than that of low-orbit satellites, but the coverage area is also larger.

[0045] Geostationary Earth Orbit (GEO) satellite communications system: 35,800 km above the Earth, also known as synchronous geostationary orbit. Theoretically, three high-orbit satellites can achieve global coverage.

[0046] Currently, the minimum IMS voice communication rate is 4.75 kbps. When a UE performs voice communication via a satellite communication system (e.g., GEO), the voice communication rate of the UE is reduced to 1.2 kbps or 0.6 kbps to meet the link budget.

[0047] 2. Voice Call Process

[0048] For example, the process of establishing an IMS voice call between UE-1 and UE-2 can be shown in Figure 2, where UE-1 connects to the gNB via a communication satellite and further connects to the IMS network element. As shown in Figure 2, the above voice call establishment process includes the following steps:

[0049] Step 1. UE-1 establishes a Protocol Data Unit (PDU) session for transmitting IMS services.

[0050] Step 2. UE-1 initiates an IMS call establishment request via a Session Initiation Protocol (SIP) Invite message. The Session Description Protocol (SDP) offer in the call establishment request carries information about the voice media to be established.

[0051] For example, an SDP may include the following:

[0052] m=audio 0RTP / AVP 97;

[0053] a=rtpmap:97AMR / 8000 / 1;

[0054] a=fmtp:97mode-set=0,1,2,3,4,5,6,7; mean-awb-bitrate=4750;

[0055] b=AS:22;

[0056] Among them, the m line indicates that the media type is voice service;

[0057] Line a shows the attribute information of the voice service:

[0058] Here, "97" is the Real-time Transport Protocol (RTP) payload type, "AMR" indicates the encoding format is AMR-NB, "8000" is the sampling rate, and "1" indicates mono. In the following a=fmtp line, two parameters are used to specify the encoding mode and bitrate. The "mode-set" parameter, "0,1,2,3,4,5,6,7", indicates the encoding modes supported by AMR-NB. The selected mode affects encoding efficiency and quality. mean-awb-bitrate=4750 indicates an average bitrate of 4.75kbps.

[0059] "b=AS:22" indicates that the core network bandwidth required to transmit the voice service is 22 kbps, where 22 kbps is a value calculated based on 4.75 kbps, and AS stands for Adaptive Sizing.

[0060] It should be noted that in the satellite scenario, UE-1 and gNB are directly connected via the satellite and ground terminals.

[0061] Step 3. The Session Border Controller (SBC) / Proxy Call Session Control Function (P-CSCF) sends the Invite message to the Serving Call Session Control Function (S-CSCF).

[0062] It should be noted that the P-CSCF and S-CSCF in FIG2 are both IMS network elements that provide services for UE-1, and the IMS network element that provides services for UE-2 is not shown.

[0063] It's also important to note that the SBC is a crucial network node in the IMS network. Located at the edge of the IMS network, it plays a crucial role in connecting end users to the IMS core network. The SBC's primary functions include access control, network topology hiding, Network Address Translation (NAT) and NAT traversal, Quality of Service (QoS), and bandwidth policy adjustment. An SBC can include both a control plane and a user plane, or the control and user planes can be separated. For example, an SBC-C is used for control, and an SBC-U is used for media data transmission.

[0064] SBC / P-CSCF refers to a network element that includes both SBC and P-CSCF functions, for example, an SBC that includes P-CSCF functions, or a P-CSCF that includes SBC functions, or a network element that is a combination of SBC and P-CSCF, that is, a network element that combines the functions of SBC and P-CSCF.

[0065] Step 4. The S-CSCF sends an Invite message to the application server (AS) providing service for UE-1.

[0066] Step 5. The AS processes the Invite message and sends it back to the S-CSCF.

[0067] Step 6. The S-CSCF sends an Invite message to UE-2.

[0068] Step 7. UE-2 replies with a 183 response message, which includes information about the voice service supported by the SDP provided by UE-2.

[0069] If UE-1 provides multiple voice coding modes in step 2, for example, supporting 4.75 kbps, 12.2 kbps, etc., UE-2 will select a voice coding mode it supports and carry it in the SDP answer of the 183 message.

[0070] It should be noted that, after receiving the 183 message, the P-CSCF providing service for UE-2 triggers the establishment of a dedicated QoS flow for transmitting voice services for UE-2, which is the same as step 11.

[0071] It should also be noted that the above description uses the QoS flow of the 5G communication system as an example, which can also be replaced by the Evolved Packet System (EPS) bearer of the 4G communication system, or other communication systems with the same concept or term as the above QoS flow or EPS bearer. This embodiment does not limit this.

[0072] Step 8. Send a 183 message to the AS via the S-CSCF.

[0073] Step 9. After processing, the AS sends a 183 message to the S-CSCF.

[0074] Step 10. The S-CSCF sends the 183 message to the SBC / P-CSCF.

[0075] Step 11. Based on the SDP answer, the P-CSCF sends a message to the 5G Policy Control Function (PCF) to establish a dedicated QoS flow for transmitting voice services.

[0076] Step 12. After the QoS flow is established, the P-CSCF sends a 183 message to UE-1.

[0077] Step 13. When UE-2 answers the call, it sends a 200 OK confirmation message to the S-CSCF.

[0078] Steps 14-16. The 200 OK message is sent to UE-1 via the AS, S-CSCF, and SBC / P-CSCF. At this point, UE-1 and UE-2 start talking.

[0079] The call establishment method provided by the embodiment of the present application is described in detail below through some embodiments and application scenarios in conjunction with the accompanying drawings.

[0080] Please refer to FIG3 , which is a flowchart of a call establishment method provided in an embodiment of the present application. The method can be performed by a first core network element, as shown in FIG3 , and includes the following steps:

[0081] Step 301: A first core network element receives a first call establishment request message sent by a first terminal; wherein the first call establishment request message is used to request establishment of a voice call between the first terminal and a second terminal.

[0082] In this embodiment, the first core network element may include, but is not limited to, at least one of an SBC, a P-CSCF, and an AS. Alternatively, the first core network element may be a new core network element, for example, one that integrates SBC and P-CSCF functions. The first terminal or the second terminal may perform voice communication via satellite, meaning that the first terminal or the second terminal may be a non-terrestrial network (NTN) terminal. In some optional embodiments, the first core network element may be a core network element dedicated to voice communication with NTN terminals.

[0083] Exemplarily, the first call establishment request message may be a SIP Invite message, which carries an SDP offer. The SDP offer may carry information about the voice media to be established. For example, the SDP offer may include some or all of the following content:

[0084] m=audio 0RTP / AVP 97;

[0085] a=rtpmap:97AMR / 8000 / 1;

[0086] a=fmtp:97mode-set=0,1,2,3,4,5,6,7; mean-awb-bitrate=1200;

[0087] b=AS:22;

[0088] Among them, line m indicates that the media type is voice service; line a indicates the attribute information of the voice service:

[0089] Here, "97" is the RTP payload type, "AMR" indicates the encoding format is AMR-NB, "8000" is the sampling rate, and "1" indicates mono. In the subsequent a=fmtp line, the "mode-set" parameter "0,1,2,3,4,5,6,7" indicates the encoding mode supported by AMR-NB. mean-awb-bitrate=1200 indicates an average bitrate of 1.2 kbps.

[0090] "b=AS:18.4" indicates that the core network bandwidth required to transmit the voice service is 18.4 kbps, where 18.4 kbps is a value calculated based on 1.2 kbps.

[0091] Step 302: The first core network element sends a second call establishment request message to the second terminal; wherein the second call establishment request message is determined based on the first call establishment request message, and the second call establishment request message satisfies at least one of the following conditions with the first call establishment request message:

[0092] The voice coding mode carried by the second call establishment request message is different from the voice coding mode carried by the first call establishment request message;

[0093] The number of parameters included in the first message header carried by the second call establishment request message is different from the number of parameters included in the first message header carried by the first call establishment request message;

[0094] If the first call setup request message carries the second message header, the second call setup request message does not carry the second message header. If the first call setup request message does not carry the second message header, the second call setup request message carries the second message header.

[0095] In this embodiment, upon receiving the first call setup request message, the first core network element may modify the content of the first call setup request message to obtain a second call setup request message, and send the second call setup request message to the second terminal. It is understood that the first core network element may send the second call setup request message to the second terminal directly or indirectly. For example, if the first core network element is an SBC or P-CSCF, the second call setup request message may be sent to the second terminal via the S-CSCF.

[0096] The following are examples to illustrate each of the above parameters:

[0097] The voice coding mode carried by the above-mentioned second call establishment request message is different from the voice coding mode carried by the first call establishment request message, which may include: the average code rate carried by the above-mentioned second call establishment request message is different from the average code rate carried by the first call establishment request message, or the bandwidth adaptation (i.e., b=AS) carried by the above-mentioned second call establishment request message is different from the bandwidth adaptation carried by the first call establishment request message, etc.

[0098] For example, if the average bit rate carried by the first call establishment request message is a value greater than or equal to 4.75kbps, then the average bit rate carried by the above-mentioned second call establishment request message can be a value less than 4.75kbps, for example, 0.6kbps or 1.2kbps, etc.; if the average bit rate carried by the above-mentioned first call establishment request message is a value less than 4.75kbps, then the average bit rate carried by the above-mentioned second call establishment request message can be a value greater than or equal to 4.75kbps.

[0099] For another example, if the bandwidth adaptation carried by the first call establishment request message is a value greater than or equal to 22, then the bandwidth adaptation carried by the second call establishment request message may be a value less than 22, for example, b=AS:18.4 or 17.6, etc.; if the bandwidth adaptation carried by the first call establishment request message is a value less than 22, then the bandwidth adaptation carried by the second call establishment request message may be a value greater than or equal to 22.

[0100] The number of parameters included in the first message header carried by the second call setup request message is different from the number of parameters included in the first message header carried by the first call setup request message, wherein the first message header may include but is not limited to at least one of a contact header, a call identification (call-ID) header, an allow header, and a from header. Exemplarily, if the first message header carried by the first call setup request message includes all corresponding parameters (i.e., the content of the first message header is complete), some parameters of the first message header carried by the first call setup request message may be deleted or simplified to obtain the first message header carried by the second call setup request message; if the first message header carried by the first call setup request message only includes some corresponding parameters (i.e., the content of the first message header is incomplete), the content of the first message header carried by the first call setup request message may be supplemented, that is, some parameters missing or not included in the first message header may be supplemented to obtain the first message header carried by the second call setup request message.

[0101] In some optional embodiments, the various parameters that the first message header should carry can be agreed upon by protocol. If the first message header carried by a call setup request message does not carry all the parameters agreed upon by protocol, the content of the first message header carried by the call setup request message is considered incomplete. If the first message header carried by a call setup request message carries all the parameters agreed upon by protocol, the content of the first message header carried by the call setup request message is considered complete. For example, for the contact header, its complete content is: Contact:<sip+xxxxxxxxxxxx@yyy.yyy.yyy.yy:zzzz> , the corresponding incomplete or simplified content is: Contact:<yyy.yyy.yyy.yy:zzzz> In addition, some of the parameters that need to be deleted or simplified can be agreed upon by the protocol.

[0102] In the case where the first call establishment request message carries a second message header, the second call establishment request message does not carry the second message header; in the case where the first call establishment request message does not carry the second message header, the second call establishment request message carries the second message header, wherein the above-mentioned second message header may include but is not limited to at least one of a supported header, a min-Session Expiration (min-SE) header, and a via header. Exemplarily, in the case where the first call establishment request message does not include the second message header, the first core network network element may add the second message header to the first call establishment request message to obtain the second call establishment request message; in the case where the first call establishment request message includes the second message header, the first core network network element may delete the second message header from the first call establishment request message to obtain the second call establishment request message.

[0103] It should be noted that, in this embodiment, the first terminal and the second terminal may perform voice communication in different ways. For example, one of the first terminal and the second terminal may be an NTN terminal and the other may be a terrestrial network (TN) terminal. Furthermore, the content carried in the first call establishment request message (e.g., voice coding mode, first message header, second message header, etc.) may be content adapted or supported for parsing by the first terminal, and the content carried in the second call establishment request message may be content adapted or supported for parsing by the second terminal.

[0104] In the following, taking the first terminal as an NTN terminal and the second terminal as a terrestrial network (TN) terminal as an example, the first core network device receives a first call establishment request message from the first terminal, wherein the average bit rate carried by the first call establishment request message is 1.2 kbps, and the bandwidth adaptation carried by the first call establishment request message is 18.4. The first core network device can modify the average bit rate of the first call establishment request message to 4.75 kbps, or modify the bandwidth adaptation of the first call establishment request message to 22, and send the call establishment request message after the modified average bit rate or bandwidth adaptation to the second terminal. Since the second terminal supports the modified average bit rate or bandwidth adaptation, the second terminal can reply with a response message to the first core network device to confirm that it agrees to establish a voice call with the first terminal.

[0105] The call establishment method provided in the embodiment of the present application can modify the content of the first call establishment request message (i.e., at least one of the voice coding mode, the first message header, and the second message header) through the first core network network element to obtain a second call establishment request message adapted to the second terminal, and send it to the second terminal when the first terminal or the second terminal conducts voice communication via a communication satellite. This is conducive to ensuring the successful establishment of the voice call between the two terminals when the voice communication modes supported by the terminals on both sides are different, improving the reliability of voice communication, and expanding the scope of application of voice communication.

[0106] Optionally, the first message header includes at least one of the following:

[0107] Contact header, Call Identification header, Allow header, From header.

[0108] Optionally, the second message header includes at least one of the following: a support header, a minimum expiration time header, and a passing header.

[0109] Optionally, the voice coding mode carried in the second call establishment request message is a voice coding mode supported by the second terminal.

[0110] Exemplarily, if the second terminal is an NTN terminal, the average bit rate carried by the above-mentioned second call establishment request message can be a value less than 4.75kbps, for example, 0.6kbps or 1.2kbps, etc., or the bandwidth adaptation carried by the above-mentioned second call establishment request message can be a value less than 22, for example, b=AS:18.4 or 17.6, etc.; if the second terminal is a TN terminal, the average bit rate carried by the above-mentioned second call establishment request message can be a value greater than or equal to 4.75kbps, or the bandwidth adaptation carried by the above-mentioned second call establishment request message can be a value greater than or equal to 22, for example, b=AS:22.

[0111] Optionally, the method further includes:

[0112] When the first core network element receives the first response information sent by the second terminal, it sends a second response information to the first terminal; wherein the first response message is used to respond to the second call establishment request message, and the second response information is used to respond to the first call establishment request message.

[0113] In this embodiment, after receiving the first response information sent by the second terminal, the first core network network element can immediately send the second response information to the first terminal. Compared with the prior art in which the first core network network element sends the second response information to the first terminal after establishing a bearer for transmitting voice services for the first terminal, the call establishment delay can be shortened.

[0114] Optionally, when receiving the first response information sent by the second terminal, the first core network element does not establish a bearer for transmitting voice services for the first terminal.

[0115] In this embodiment, the first core network element may not establish a bearer for transmitting voice services for the first terminal. For example, the voice services may be transmitted through the bearer of IMS signaling, which not only saves resource overhead but also shortens the call establishment delay.

[0116] Optionally, the method further includes:

[0117] Upon receiving the first call establishment request message sent by the first terminal, the first core network element performs at least one of the following:

[0118] Establishing a bearer for transmitting voice services for the first terminal;

[0119] A third response message is sent to the first terminal, where the third response message is used to respond to the first call establishment request message.

[0120] In this embodiment, upon receiving a first call establishment request message sent by a first terminal, the first core network element establishes a bearer for transmitting voice services for the first terminal, for example, establishing a QoS flow, an Evolved Packet System (EPS) bearer, etc. for transmitting voice services for the first terminal; or, the first core network element sends a third response message to the first terminal, where the third response message is used to respond to the first call establishment request message, for example, sending a 183 message, a 180 message, or a 200 OK message carrying an SDP response to the first terminal. The following description takes the third response message being a 183 message as an example.

[0121] It is understandable that in the prior art, it is necessary to establish a bearer for transmitting voice services for the first terminal and to feed back the 183 message to the first terminal only after receiving the 183 message returned by the second terminal, as shown in Figure 2. This results in a longer call delay. In this embodiment, the first core network network element can directly establish a bearer for transmitting voice services for the first terminal or send a first response message to the first terminal after receiving the first call establishment request message sent by the first terminal, which is conducive to shortening the call establishment delay.

[0122] Optionally, the bearer for transmitting voice services includes at least one of the following: Quality of Service QoS flow, Evolved Packet System EPS bearer.

[0123] Optionally, the first core network element sending a second call establishment request message to the second terminal includes:

[0124] When determining that the target terminal is connected to the network via a communication satellite, the first core network element sends a second call establishment request message to the second terminal; wherein the target terminal includes the first terminal or the second terminal.

[0125] In this embodiment, the target terminal is connected to the network via a communication satellite, that is, the target terminal performs voice communication via the communication satellite. The target terminal may also be referred to as an NTN terminal. It will be understood that this embodiment is applicable to scenarios where the calling terminal (i.e., the first terminal) communicates via a communication satellite, and is also applicable to scenarios where the called terminal (i.e., the second terminal) communicates via a communication satellite.

[0126] Exemplarily, in the scenario where the above-mentioned first core network element is used for both NTN terminals and TN terminals for voice communication, the first core network element can determine whether the first terminal or the second terminal is connected to the network via a communication satellite when receiving a first call establishment request message. When it is determined that the first terminal or the second terminal is connected to the network via a communication satellite, a second call establishment request message is sent to the second terminal to ensure that voice communication is possible between the first terminal and the second terminal.

[0127] Optionally, the target terminal includes the first terminal;

[0128] The method further comprises:

[0129] The first core network element determines, based on the first information, that the first terminal is connected to the network via a communication satellite;

[0130] The first information includes at least one of the following:

[0131] an access type carried in the first call establishment request message;

[0132] The voice coding mode carried by the first call establishment request message;

[0133] message content carried by the first call establishment request message;

[0134] Access information of the first terminal pre-stored by the first core network element;

[0135] The first core network element receives the access type of the first terminal from the second core network element.

[0136] The following are examples for each of the above parameters:

[0137] For the access type carried in the first call setup request message, for example, when the access type carried in the first call setup request message is satellite access (for example, access-type=3GPP-NR-SAT), it can be determined that the first terminal is connected to the network via a communication satellite. It should be noted that the access type may be included in the access network information (P-Access-Network-Info) header of the IMS message.

[0138] For the voice coding mode carried by the first call establishment request message, for example, when the voice coding mode carried by the first call establishment request message is a specific voice coding mode (for example, mean-awb-bitrate = 1200 or 600; or, b = AS: 18.4 or 17.6), it can be determined that the first terminal is connected to the network via a communication satellite.

[0139] Regarding the message content carried by the first call establishment request message, for example, if the message content carried by the first call establishment request message is specific message content, it is determined that the first terminal is connected to the network via a communications satellite. For example, the message content carried by the first call establishment request message is simplified message content. The simplified message content may include, but is not limited to, message content excluding a voice coding mode and message content excluding an access type. It should be noted that since some NTN UEs only support one voice coding transmission mode, the voice coding mode may not be carried in the SDP to reduce the amount of IMS signaling transmission. For another example, the message content carried by the first call establishment request message includes special indication information, which is used to indicate that the first terminal is connected to the network via a communications satellite.

[0140] For the access information of the first terminal pre-stored in the first core network network element, exemplarily, when the first terminal performs IMS registration, it carries information that it is connected to the network via satellite, for example, access-type = 3GPP-NR-SAT, and the first core network network element records the access information of the first terminal, for example, records the access method corresponding to the public identity identifier of the first terminal. When a call initiated by the terminal identified by the public identity identifier is received, or a call is sent to the terminal identified by the public identity identifier, it can be determined that the first terminal is connected to the network via satellite based on the locally stored access information of the first terminal.

[0141] For the access type of the first terminal received by the first core network element from the second core network element, exemplarily, the P-CSCF requests the access type of the first terminal from the PCF or PCRF, for example, NR_GEO, NR_MEO, etc.; or, the AS instructs the P-CSCF to request the access type of the first terminal from the PCF or PCRF, for example, NR_GEO, NR_MEO, etc.; or, the AS obtains the access type of the first terminal from the HSS / UDM, or the AS instructs the S-CSCF to obtain the access type of the first terminal from the HSS / UDM, for example, access-type=3GPP-NR-SAT; or, when the SBC / P-CSCF determines that the first terminal is accessed via satellite based on the locally stored access information, it requests the access type of the first terminal from the PCF / PCRF.

[0142] It can be understood that the above-mentioned parameter items can be reasonably combined according to actual needs. For example, when the first information includes the access type carried by the first call establishment request message and the voice coding method carried by the first call establishment request message, it can be determined whether the first terminal is connected to the network via a communication satellite based on the access type carried by the first call establishment request message; when the first information includes the voice coding method carried by the first call establishment request message and the pre-stored access information of the first terminal, it can be determined whether the first terminal is connected to the network via a communication satellite based on the voice coding method carried by the first call establishment request message.

[0143] Optionally, the target terminal includes the second terminal;

[0144] The method further comprises:

[0145] The first core network element determines, based on the second information, that the second terminal is connected to the network via a communication satellite;

[0146] The second information includes at least one of the following:

[0147] access information of the second terminal pre-stored by the first core network element;

[0148] The first core network element receives the access type of the second terminal from the second core network element.

[0149] In this embodiment, for the access information of the second terminal pre-stored by the first core network network element, for example, when the second terminal performs IMS registration, it carries information that it is connected to the network via satellite, for example, access-type = 3GPP-NR-SAT, and the first core network network element records the access information of the second terminal, for example, records the access method corresponding to the public identity identifier of the second terminal. When a call initiated by the terminal identified by the public identity identifier is received, or a call is sent to the terminal identified by the public identity identifier, it can be determined that the second terminal is connected to the network via satellite based on the locally stored access information of the second terminal.

[0150] For the access type of the second terminal received by the first core network element from the second core network element, exemplarily, the P-CSCF requests the access type of the second terminal from the PCF or PCRF, for example, NR_GEO, NR_MEO, etc.; or, the AS instructs the P-CSCF to request the access type of the second terminal from the PCF or PCRF, for example, NR_GEO, NR_MEO, etc.; or, the AS obtains the access type of the second terminal from the HSS / UDM, or the AS instructs the S-CSCF to obtain the access type of the second terminal from the HSS / UDM, for example, access-type=3GPP-NR-SAT; or, when the SBC / P-CSCF determines that the second terminal is accessed via satellite based on the locally stored access information, it requests the access type of the second terminal from the PCF / PCRF.

[0151] Optionally, the first core network element is a session border controller SBC or a proxy call session control function P-CSCF.

[0152] The following example illustrates the first core network element being an SBC or a P-CSCF with reference to FIG4 :

[0153] As shown in FIG4 , the call establishment method provided in this embodiment includes the following steps:

[0154] Step a1. UE-1 establishes a PDU session for transmitting IMS services.

[0155] Step a2. UE-1 sends an Invite message carrying an SDP offer to the SBC / P-CSCF.

[0156] Step a3. When the SBC / P-CSCF determines that UE-1 or UE-2 is connected to the network via satellite, it directly initiates the process of establishing a dedicated QoS flow for transmitting voice services without waiting for the 183 message returned by UE-2.

[0157] Step a4. When the SBC / P-CSCF determines that UE UE-1 or UE-2 is connected to the network via satellite, the SBC / P-CSCF modifies the voice coding mode in the SDP offer and sends an invite message carrying the SDP offer with the modified voice coding mode (i.e., Modified SDP Offer) to the S-CSCF, which then sends it to UE-2 via the S-CSCF.

[0158] For example, the SBC / P-CSCF modifies the mean-awb-bitrate of the SDP offer from 1200 to 4750, or modifies b=AS from 18.4 to 22.

[0159] Step a5. After the dedicated QoS flow is established, the SBC / P-CSCF sends a 183 message to UE-1, carrying the SDP answer.

[0160] Step a6. The S-CSCF sends an Invite message to the AS that provides service for UE-1.

[0161] Step a7. The AS processes the Invite message and sends it back to the S-CSCF.

[0162] Step a8. The S-CSCF sends an Invite message to UE-2.

[0163] Step a9. UE-2 replies with a 183 response message, which includes information about the voice service supported by the SDP provided by UE-2.

[0164] Step a10: Send a 183 message to the AS via the S-CSCF.

[0165] Step a11. After processing, the AS sends a 183 message to the S-CSCF.

[0166] Step a12: The S-CSCF sends the 183 message to the SBC / P-CSCF.

[0167] Step a13. When UE-2 answers the call, it sends a 200 OK confirmation message to the S-CSCF.

[0168] Step a14-16. The 200 OK message is sent to UE-1 via the AS, S-CSCF, and SBC / P-CSCF. At this time, UE-1 and UE-2 start talking.

[0169] It should be noted that the execution order of the above steps a3 and a4 is not particular, and they can be executed simultaneously. In addition, the execution order of the above steps a5 and a6 is not particular, and they can be executed simultaneously.

[0170] It should also be noted that Figure 4 is illustrated using UE-1 as the calling party. For UE-1 being called, the SBC / P-CSCF receives a call establishment request message sent to UE-1. If it is determined that UE-1 accesses the network via satellite, it can directly reply to the initiator with a 183 message carrying an SDP answer.

[0171] As can be seen from the above, in this embodiment, the SBC / P-CSCF performs voice coding mode conversion when it is determined that UE-1 or UE-2 is connected to the network via a satellite, and directly initiates the process of establishing a dedicated QoS flow for transmitting voice services. In this way, not only can voice communication between the two terminals be guaranteed when the voice coding modes supported by the terminals on both sides of the voice communication are different, the reliability of voice communication is improved, the scope of application of voice communication is expanded, but also the delay of voice calls can be shortened.

[0172] Optionally, the method further includes:

[0173] The first core network element sends a third call establishment request message to a media resource function (MRF); wherein the third call establishment request message is determined according to the first call establishment request message;

[0174] The first core network element receives a fourth response message from the MRF, where the fourth response message is used to respond to the third call establishment request message.

[0175] Exemplarily, before performing the first operation, the first core network element may send a third call establishment request message to the MRF, for example, an Invite message carrying an SDP offer, wherein the message content carried by the third call establishment request message may be the same as the message content (for example, SDP offer) carried by the first call establishment request message. Upon receiving the third call establishment request message, the MRF may reply to the first core network device with a response message to the third call establishment request message, for example, a 200 OK message carrying an SDP answer.

[0176] It should be noted that, in this embodiment, after the first core network network element sends the third call establishment request message to the MRF and receives a response message to the third call establishment request message from the MRF, it can further send a response message to the first terminal for the above-mentioned third call establishment request message to establish an RTP connection between the first terminal and the MRF for transmitting voice, and the RTP connection supports the transmission of the voice code stream encoded by the voice encoding method supported by the first terminal, so that the voice code stream of the first terminal can be first transmitted to the MRF through the above-mentioned RTP connection, and then transmitted to the second terminal after processing by the MRF.

[0177] Optionally, the first operation includes sending a second call establishment request message to the second terminal;

[0178] The method further comprises:

[0179] The first core network element sends a fourth call establishment request message to the MRF;

[0180] The first core network element receives a fifth response message from the MRF;

[0181] The fifth response message is used to respond to the fourth call establishment request message, the fourth call establishment request message is determined based on the first call establishment request message, and the fourth call establishment request message and the first call establishment request message satisfy at least one of the following conditions:

[0182] The voice coding mode carried by the fourth call establishment request message is different from the voice coding mode carried by the first call establishment request message;

[0183] The number of parameters included in the first message header carried by the fourth call establishment request message is different from the number of parameters included in the first message header carried by the first call establishment request message;

[0184] If the first call setup request message carries the second message header, the fourth call setup request message does not carry the second message header; if the first call setup request message does not carry the second message header, the fourth call setup request message carries the second message header.

[0185] In this embodiment, for the fourth call establishment request message, reference may be made to the relevant description of the second call establishment request message, which will not be elaborated herein.

[0186] Exemplarily, the first core network element may send a fourth call establishment request message to the MRF, for example, an Invite message carrying an SDP offer. Upon receiving the fourth call establishment request message, the MRF may reply to the first core network device with a response message for the fourth call establishment request message, for example, a 200 OK message carrying an SDP answer.

[0187] It should be noted that, in this embodiment, after the first core network network element sends the fourth call establishment request message to the MRF and receives the response message of the fourth call establishment request message from the MRF, it can further send a fifth call establishment request message to the second terminal and receive a response message for the fifth call establishment request message returned by the second terminal. For example, the first core network network element can send the fifth call establishment request message to the second terminal via the S-CSCF, and receive a response message for the fifth call establishment request message from the second terminal via the S-CSCF to establish an RTP connection for voice transmission between the second terminal and the MRF, and the RTP connection supports the transmission of the voice code stream encoded by the voice coding method supported by the second terminal. In this way, the above-mentioned MRF can realize the conversion of the voice coding method between the first terminal and the second terminal, thereby ensuring the call between the first terminal and the second terminal.

[0188] Optionally, the method further includes:

[0189] In a case where the first core network element receives the fourth response message from the MRF, the first core network element sends a sixth response message to the SBC or P-CSCF, where the sixth response message is determined according to the fourth response message.

[0190] In this embodiment, when the first core network network element receives the fourth response message from the MRF, it directly sends a sixth response message to the SBC or P-CSCF. In this way, the SBC or P-CSCF can directly establish a bearer for transmitting voice services for the first terminal when it receives the sixth response message. For example, it initiates a process of establishing a dedicated QoS flow for transmitting voice services, and sends a response message to the first terminal when the bearer for transmitting voice services is established. In this way, compared with establishing a bearer for transmitting voice services for the first terminal after receiving a response message returned by the second terminal, the delay of the voice call can be shortened.

[0191] Optionally, the first core network element is an application server AS.

[0192] The following example illustrates the first core network element being an AS with reference to FIG5 :

[0193] As shown in FIG5 , the call establishment method provided in this embodiment includes the following steps:

[0194] Step b1. UE-1 establishes a PDU session for transmitting IMS services.

[0195] Step b2. UE-1 sends an Invite message carrying an SDP offer to the SBC / P-CSCF.

[0196] Step b3. The SBC / P-CSCF sends the Invite message to the S-CSCF.

[0197] Step b4. The S-CSCF sends an Invite message to the AS providing service for UE-1.

[0198] Step b5. When the AS determines that UE-1 or UE-2 is connected to the network via satellite, the AS sends an Invite message to the MRF, carrying the SDP offer of the Invite message sent by UE-1.

[0199] Step b6. The MRF returns a response message, for example, a 200 OK or 183 message, carrying an SDP answer.

[0200] Step b7. The AS sends a 183 message to the S-CSCF, carrying the SDP answer.

[0201] Step b8. The S-CSCF sends a 183 message to the SBC / P-CSCF.

[0202] Step b9: The SBC / P-CSCF directly initiates the process of establishing a dedicated QoS flow for transmitting voice services.

[0203] Step b10: After the dedicated QoS flow is established, the SBC / P-CSCF sends a 183 message to UE-1, carrying the SDP answer.

[0204] Step b11. The AS sends an invite message carrying the SDP offer with the modified voice coding mode (ie, Modified SDP offer) to the MRF.

[0205] For example, the AS modifies the mean-awb-bitrate of the SDP offer from 1200 to 4750, or modifies b=AS from 18.4 to 22.

[0206] Step b12: The MRF replies with a response message, such as a 200 OK or 183 message, carrying an SDP answer.

[0207] Step b13: The AS sends an invite message to the S-CSCF, carrying the SDP offer with the modified voice coding mode.

[0208] Step b14: The S-CSCF sends an invite message to UE-2, carrying the SDP offer with the modified voice coding mode.

[0209] Step b15. UE-2 sends a 183 message carrying an SDP answer to the S-CSCF.

[0210] Step b16: The S-CSCF sends a 183 message carrying an SDP answer to the AS.

[0211] Step b17: When UE-2 answers the call, it sends a 200 OK confirmation message to the S-CSCF.

[0212] Step b18-20. The 200 OK message is sent to UE-1 via the AS, S-CSCF, and SBC / P-CSCF. At this time, UE-1 and UE-2 start talking.

[0213] It should be noted that the execution order of the above steps b7 and b11 is not particular, and they can be executed simultaneously. In addition, the execution order of the above steps b8 and b12 is not particular, and they can be executed simultaneously.

[0214] It should also be noted that Figure 5 is illustrated using UE-1 as the calling party. For UE-1 being called, the AS receives a request sent to UE-1. If it determines that UE-1 accesses the network via satellite, it can directly reply to the call initiator with a 183 message carrying an SDP answer.

[0215] As can be seen from the above, in this embodiment, when the AS determines that UE-1 or UE-2 is connected to the network via satellite, it establishes an RTP connection between UE-1 and the MRF based on the voice coding method supported by UE-1, and establishes an RTP connection between UE-2 and the MRF based on the voice coding method supported by UE-2. In this way, transcoding between UE-1 and UE-2 can be achieved through the MRF, ensuring the voice call between UE-1 and UE-2. In addition, the AS directly sends a 183 message carrying an SDP answer to UE-1, allowing the SBC / P-CSCF to initiate the process of establishing a dedicated QoS flow for transmitting voice services based on the 183 message, without waiting for the 183 message returned by UE-2 to initiate again, thereby shortening the latency of the voice call.

[0216] It should be noted that the call establishment method provided in the embodiments of the present application can be executed by a call establishment device, or a control module in the call establishment device for executing the call establishment method. In the embodiments of the present application, the call establishment device provided in the embodiments of the present application is described by taking the call establishment method executed by the call establishment device as an example.

[0217] Please refer to FIG. 6 , which is a structural diagram of a call establishment device provided in an embodiment of the present application. The call establishment device can be applied to a first core network element. As shown in FIG. 6 , the call establishment device 600 includes:

[0218] A first receiving module 601 is configured to receive a first call establishment request message sent by a first terminal; wherein the first call establishment request message is used to request establishment of a voice call between the first terminal and a second terminal;

[0219] The first sending module 602 is configured to send a second call establishment request message to the second terminal; wherein the second call establishment request message is determined based on the first call establishment request message, and the second call establishment request message satisfies at least one of the following conditions:

[0220] The voice coding mode carried by the second call establishment request message is different from the voice coding mode carried by the first call establishment request message;

[0221] The number of parameters included in the first message header carried by the second call establishment request message is different from the number of parameters included in the first message header carried by the first call establishment request message;

[0222] If the first call setup request message carries the second message header, the second call setup request message does not carry the second message header. If the first call setup request message does not carry the second message header, the second call setup request message carries the second message header.

[0223] Optionally, the first message header includes at least one of the following:

[0224] Contact header, Call Identification header, Allow header, From header.

[0225] Optionally, the second message header includes at least one of the following: a support header, a minimum expiration time header, and a passing header.

[0226] Optionally, the voice coding mode carried in the second call establishment request message is a voice coding mode supported by the second terminal.

[0227] Optionally, the device further comprises:

[0228] The second sending module is used to send a second response message to the first terminal when receiving the first response message sent by the second terminal; wherein the first response message is used to respond to the second call establishment request message, and the second response message is used to respond to the first call establishment request message.

[0229] Optionally, when receiving the first response information sent by the second terminal, the first core network element does not establish a bearer for transmitting voice services for the first terminal.

[0230] Optionally, the device further comprises:

[0231] an execution module, configured to, upon receiving a first call establishment request message sent by the first terminal, execute at least one of the following:

[0232] Establishing a bearer for transmitting voice services for the first terminal;

[0233] A third response message is sent to the first terminal, where the third response message is used to respond to the first call establishment request message.

[0234] Optionally, the bearer for transmitting voice services includes at least one of the following: Quality of Service QoS flow, Evolved Packet System EPS bearer.

[0235] Optionally, the first sending module is specifically configured to:

[0236] In the case of determining that the target terminal is connected to the network via a communication satellite, a second call establishment request message is sent to the second terminal; wherein the target terminal includes the first terminal or the second terminal.

[0237] Optionally, the target terminal includes the first terminal;

[0238] The device further comprises:

[0239] a first determining module, configured to determine, based on first information, that the first terminal is connected to a network via a communication satellite;

[0240] The first information includes at least one of the following:

[0241] the access type carried by the first call establishment request message;

[0242] The voice coding mode carried by the first call establishment request message;

[0243] message content carried by the first call establishment request message;

[0244] Access information of the first terminal pre-stored by the first core network element;

[0245] The first core network element receives the access type of the first terminal from the second core network element.

[0246] Optionally, the target terminal includes the second terminal;

[0247] The device further comprises:

[0248] a second determining module, configured to determine, based on the second information, that the second terminal is connected to the network via a communication satellite;

[0249] The second information includes at least one of the following:

[0250] pre-stored access information of the second terminal;

[0251] The access type of the second terminal is received from the second core network element.

[0252] Optionally, the first core network element is a session border controller SBC or a proxy call session control function P-CSCF.

[0253] Optionally, the device further comprises:

[0254] A third sending module is configured to send a third call establishment request message to the media resource function MRF; wherein the third call establishment request message is determined according to the first call establishment request message;

[0255] The second receiving module is configured to receive a fourth response message from the MRF, where the fourth response message is used to respond to the third call establishment request message.

[0256] Optionally, the device further comprises:

[0257] A fourth sending module, configured to send a fourth call establishment request message to the MRF;

[0258] A third receiving module, configured to receive a fifth response message from the MRF;

[0259] The fifth response message is used to respond to the fourth call establishment request message, the fourth call establishment request message is determined based on the first call establishment request message, and the fourth call establishment request message and the first call establishment request message satisfy at least one of the following conditions:

[0260] The voice coding mode carried by the fourth call establishment request message is different from the voice coding mode carried by the first call establishment request message;

[0261] The number of parameters included in the first message header carried by the fourth call establishment request message is different from the number of parameters included in the first message header carried by the first call establishment request message;

[0262] If the first call setup request message carries the second message header, the fourth call setup request message does not carry the second message header; if the first call setup request message does not carry the second message header, the fourth call setup request message carries the second message header.

[0263] Optionally, the device further comprises:

[0264] The fifth sending module is configured to send a sixth response message to the SBC or P-CSCF when the fourth response message is received from the MRF, where the sixth response message is determined according to the fourth response message.

[0265] Optionally, the first core network element is an application server AS.

[0266] The call establishment device in the embodiments of the present application can be an electronic device, such as an electronic device with an operating system, or a component of an electronic device, such as an integrated circuit or chip. The electronic device can be a network-side device, or a device other than a network-side device. For example, the network-side device can include, but is not limited to, the types of network-side devices 12 listed above. Other devices can include servers, network attached storage (NAS), etc., and are not specifically limited in the embodiments of the present application.

[0267] The call establishment device provided in the embodiment of the present application can implement the various processes implemented in the method embodiment of Figure 3 and achieve the same technical effects. To avoid repetition, they will not be described here.

[0268] Optionally, as shown in Figure 7, an embodiment of the present application also provides a communication device 700, including a processor 701 and a memory 702, and the memory 702 stores a program or instruction that can be run on the processor 701. When the program or instruction is executed by the processor 701, the various steps of the above-mentioned call establishment method embodiment are implemented and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0269] The embodiment of the present application also provides a network-side device, including a processor and a communication interface, the communication interface being configured to receive a first call establishment request message sent by a first terminal; wherein the first call establishment request message is used to request the establishment of a voice call between the first terminal and a second terminal; and send a second call establishment request message to the second terminal; wherein the second call establishment request message is determined based on the first call establishment request message, and the second call establishment request message and the first call establishment request message satisfy at least one of the following conditions: the voice coding mode carried by the second call establishment request message is different from the voice coding mode carried by the first call establishment request message; the number of parameters included in the first message header carried by the second call establishment request message is different from the number of parameters included in the first message header carried by the first call establishment request message; if the first call establishment request message carries the second message header, the second call establishment request message does not carry the second message header, and if the first call establishment request message does not carry the second message header, the second call establishment request message carries the second message header. This network-side device embodiment corresponds to the above-mentioned method embodiment, and each implementation process and implementation method of the above-mentioned method embodiment can be applied to this network-side device embodiment and can achieve the same technical effect.

[0270] Specifically, the embodiment of the present application further provides a network side device. As shown in Figure 8, the network side device 800 includes: a processor 801, a network interface 802, and a memory 803. The network interface 802 is, for example, a common public radio interface (CPRI).

[0271] Specifically, the network side device 800 of the embodiment of the present application also includes: instructions or programs stored in the memory 803 and can be run on the processor 801. The processor 801 calls the instructions or programs in the memory 803 to execute the methods executed by each module shown in Figure 6 and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0272] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the various processes of the above-mentioned call establishment method embodiment are implemented and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0273] The processor is the processor in the terminal described in the above embodiment. The readable storage medium includes a computer-readable storage medium, such as a computer read-only memory (ROM), random access memory (RAM), a magnetic disk, or an optical disk. In some examples, the readable storage medium may be a non-transitory readable storage medium.

[0274] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned call establishment method embodiment and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0275] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0276] An embodiment of the present application further provides a computer program / program product, which is stored in a storage medium. The computer program / program product is executed by at least one processor to implement the various processes of the above-mentioned call establishment method embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0277] An embodiment of the present application also provides a call establishment system, including: a first terminal, a second terminal, and a network-side device. The network-side device is used to execute the various processes shown in Figure 3 and the above-mentioned method embodiments, and can achieve the same technical effects. To avoid repetition, it will not be repeated here.

[0278] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0279] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of a computer software product plus a necessary general-purpose hardware platform, or of course, by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes a number of instructions for enabling a terminal or network-side device to execute the methods described in each embodiment of the present application.

[0280] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms of implementation methods without departing from the purpose of this application and the scope of protection of the claims. These implementation methods are all within the protection of this application.

Claims

1. A call establishment method, comprising: The first core network element receives a first call establishment request message sent by the first terminal; wherein the first call establishment request message is used to request to establish a voice call between the first terminal and the second terminal; The first core network element sends a second call establishment request message to the second terminal; wherein the second call establishment request message is determined according to the first call establishment request message, and the second call establishment request message and the first call establishment request message satisfy at least one of the following: The voice coding mode carried by the second call establishment request message is different from the voice coding mode carried by the first call establishment request message; The number of parameters included in the first message header carried by the second call establishment request message is different from the number of parameters included in the first message header carried by the first call establishment request message; In the case where the first call establishment request message carries the second message header, the second call establishment request message does not carry the second message header; in the case where the first call establishment request message does not carry the second message header, the second call establishment request message carries the second message header.

2. The method according to claim 1, wherein: The first message header includes at least one of the following: Contact header, Call Identity header, Allow header, From header.

3. The method according to claim 1 or 2, wherein: The second message header includes at least one of the following: a support header, a minimum expiration time header, and a passing header.

4. The method according to any one of claims 1 to 3, wherein: The voice coding mode carried in the second call establishment request message is a voice coding mode supported by the second terminal.

5. The method according to any one of claims 1 to 4, further comprising: When receiving the first response information sent by the second terminal, the first core network element sends a second response information to the first terminal; wherein the first response message is used to respond to the second call establishment request message, and the second response information is used to respond to the first call establishment request message.

6. The method according to any one of claims 1 to 5, wherein: When receiving the first response information sent by the second terminal, the first core network element does not establish a bearer for transmitting voice services for the first terminal.

7. The method according to any one of claims 1 to 4, further comprising: When receiving the first call establishment request message sent by the first terminal, the first core network element performs at least one of the following: Establishing a bearer for transmitting a voice service for the first terminal; A third response message is sent to the first terminal, where the third response message is used to respond to the first call establishment request message.

8. The method according to claim 7, wherein: The bearer used to transmit the voice service includes at least one of the following: Quality of Service QoS flow, Evolved Packet System EPS bearer.

9. The method according to any one of claims 1 to 8, wherein: The first core network element sending a second call establishment request message to the second terminal includes: When determining that the target terminal is connected to the network via a communication satellite, the first core network element sends a second call establishment request message to the second terminal; wherein the target terminal includes the first terminal or the second terminal.

10. The method according to claim 9, wherein: The target terminal includes the first terminal; The method further comprises: The first core network element determines, according to the first information, that the first terminal is connected to a network via a communication satellite; The first information includes at least one of the following: The access type carried by the first call establishment request message; The voice coding mode carried by the first call establishment request message; message content carried by the first call establishment request message; The access information of the first terminal pre-stored by the first core network element; The first core network element receives the access type of the first terminal from the second core network element.

11. The method according to claim 9, wherein the target terminal comprises the second terminal; The method further comprises: The first core network element determines, according to the second information, that the second terminal is connected to the network via a communication satellite; The second information includes at least one of the following: The access information of the second terminal pre-stored by the first core network element; The access type of the second terminal received by the first core network element from the second core network element.

12. The method according to any one of claims 1 to 11, wherein: The first core network element is a session border controller SBC or a proxy call session control function P-CSCF.

13. The method according to any one of claims 1 to 11, further comprising: The first core network element sends a third call establishment request message to the media resource function MRF; wherein the third call establishment request message is determined according to the first call establishment request message; The first core network element receives a fourth response message from the MRF, where the fourth response message is used to respond to the third call establishment request message.

14. The method according to claim 13, further comprising: The first core network element sends a fourth call establishment request message to the MRF; The first core network element receives a fifth response message from the MRF; The fifth response message is used to respond to the fourth call establishment request message, the fourth call establishment request message is determined according to the first call establishment request message, and the fourth call establishment request message and the first call establishment request message satisfy at least one of the following conditions: The voice coding mode carried by the fourth call establishment request message is different from the voice coding mode carried by the first call establishment request message; The number of parameters included in the first message header carried by the fourth call establishment request message is different from the number of parameters included in the first message header carried by the first call establishment request message; In the case where the first call establishment request message carries the second message header, the fourth call establishment request message does not carry the second message header; in the case where the first call establishment request message does not carry the second message header, the fourth call establishment request message carries the second message header.

15. The method according to claim 13 or 14, further comprising: In a case where the first core network element receives the fourth response message from the MRF, the first core network element sends a sixth response message to the SBC or P-CSCF, where the sixth response message is determined according to the fourth response message.

16. The method according to any one of claims 13 to 15, wherein: The first core network element is an application server AS.

17. A call establishment device, applied to a first core network element, comprising: A first receiving module, configured to receive a first call establishment request message sent by a first terminal; wherein the first call establishment request message is used to request to establish a voice call between the first terminal and a second terminal; A first sending module is configured to send a second call establishment request message to the second terminal; wherein the second call establishment request message is determined according to the first call establishment request message, and at least one of the following conditions is satisfied between the second call establishment request message and the first call establishment request message: The voice coding mode carried by the second call establishment request message is different from the voice coding mode carried by the first call establishment request message; The number of parameters included in the first message header carried by the second call establishment request message is different from the number of parameters included in the first message header carried by the first call establishment request message; In the case where the first call establishment request message carries the second message header, the second call establishment request message does not carry the second message header; in the case where the first call establishment request message does not carry the second message header, the second call establishment request message carries the second message header.

18. The device according to claim 17, wherein: The first message header includes at least one of the following: Contact header, Call Identity header, Allow header, From header.

19. The device according to claim 17 or 18, wherein: The second message header includes at least one of the following: a support header, a minimum expiration time header, and a passing header.

20. The device according to any one of claims 17 to 19, wherein: The voice coding mode carried in the second call establishment request message is a voice coding mode supported by the second terminal.

21. The device according to any one of claims 17 to 20, further comprising: The second sending module is used to send a second response message to the first terminal when receiving the first response message sent by the second terminal; wherein the first response message is used to respond to the second call establishment request message, and the second response message is used to respond to the first call establishment request message.

22. The device according to any one of claims 17 to 21, wherein: When receiving the first response information sent by the second terminal, the first core network element does not establish a bearer for transmitting voice services for the first terminal.

23. The device according to any one of claims 17 to 20, further comprising: An execution module, configured to execute at least one of the following items when receiving a first call establishment request message sent by the first terminal: Establishing a bearer for transmitting a voice service for the first terminal; A third response message is sent to the first terminal, where the third response message is used to respond to the first call establishment request message.

24. The device according to any one of claims 17 to 23, wherein the first sending module is specifically configured to: When it is determined that the target terminal is connected to the network via a communication satellite, a second call establishment request message is sent to the second terminal; wherein, The target terminal includes the first terminal or the second terminal.

25. A network side device, comprising a processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the call establishment method according to any one of claims 1 to 16 are implemented.

26. A readable storage medium storing a program or an instruction, wherein the program or the instruction, when executed by a processor, implements the steps of the call establishment method according to any one of claims 1 to 16.

Images