Call methods and apparatuses, network side device and readable storage medium

Abstract

The present application belongs to the technical field of communications. Disclosed are call methods and apparatuses, a network side device and a readable storage medium. A call method of the embodiments of the present application comprises: a first network node receives a first message, the first message being used for requesting a call to a second terminal; and when a first condition is satisfied, the first network node executes a first operation. The first condition comprises any one of the following: a first terminal accesses a network by means of a first satellite, and the first message comprises at least one of first indication information and a first SDP offer, the first indication information indicating at least one of the following: the first terminal supporting early media and the first terminal supporting an early session, and the first SDP offer being used for negotiation of transmitting a parameter corresponding to the early media; and the first message comprises at least one of the first indication information and the first SDP offer. The first operation comprises at least one of the following: deleting the first indication information from the first message; modifying the first indication information; and deleting the first SDP offer from the first message.

Description

Communication methods, devices, network-side equipment, and readable storage media

[0001] This application claims priority to Chinese Patent Application No. 202411454259.3, filed on October 17, 2024, entitled "Method of Communication, Apparatus, Network-Side Device and Readable Storage Medium", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application belongs to the field of communication technology, specifically relating to a call method, apparatus, network-side equipment, and readable storage medium. Background Technology

[0003] Currently, when terminal 1 calls terminal 2, terminal 1 can negotiate with terminal 2 the parameters used to transmit the data corresponding to the voice service. Terminal 1 and terminal 2 then transmit the data using the negotiated parameters. Furthermore, when media transmission is required (such as ringback tones or alert tones), terminal 1 can renegotiate the parameters used to transmit that media with the network-side device. The network-side device can then send the media to terminal 1 using the renegotiated parameters to provide the user with relevant information about terminal 2.

[0004] However, after the network-side device sends the media to terminal 1 using the renegotiated parameters, the sound quality of the media is poor when terminal 1 plays it. This may cause the user to be unable to hear the media clearly, thus affecting the media's prompting effect. Summary of the Invention

[0005] This application provides a call method, apparatus, network-side device, and readable storage medium, which can solve the problem that poor sound quality of the media affects the prompting effect of the media.

[0006] In a first aspect, a call method is provided, executed by a first network node, the method comprising: the first network node receiving a first message from a first terminal, the first message being used to request a call to a second terminal; and, upon satisfying a first condition, the first network node performing a first operation, the first condition including any one of the following: the first terminal accesses the network via a first satellite, and the first message includes at least one of first indication information and a first Session Description Protocol (SDP) request offer, the first indication information indicating at least one of the following: the first terminal supports early media, the first terminal supports early sessions, and the first SDPoffer is used to negotiate parameters corresponding to the transmission of early media; the first message includes at least one of the first indication information and the first SDPoffer; wherein the first operation includes at least one of the following: deleting the first indication information from the first message; modifying the first indication information; and deleting the first SDPoffer from the first message.

[0007] Secondly, a call method is provided, executed by a first network node, the method comprising: the first network node receiving a second SDPoffer from a third network node, the second SDPoffer being used to negotiate parameters corresponding to a fourth medium; and, upon satisfying a second condition, the first network node performing a third operation, the second condition including at least one of the following: a first terminal corresponding to the fourth medium accesses the network via a first satellite; the second SDPoffer including fifth indication information; wherein the third operation includes at least one of the following: modifying the parameters corresponding to the fourth medium in a first SDP response answer, the first SDP response being a response corresponding to the second SDPoffer; including relevant information of the second network node in the first SDP response; and sending a sixth indication information to the second network node, the sixth indication information being used to instruct the second network node to discard the received data corresponding to the fourth medium.

[0008] Thirdly, a communication device is provided, comprising: a receiving module and a processing module. The receiving module is configured to receive a first message from a first terminal, the first message being a request to call a second terminal. The processing module is configured to perform a first operation when a first condition is met, the first condition including any one of the following: the first terminal accesses a network via a first satellite, and the first message includes at least one of first indication information and a first SDPoffer, the first indication information indicating at least one of the following: the first terminal supports early media, the first terminal supports early sessions, and the first SDPoffer is used to negotiate parameters corresponding to the transmission of early media; the first message includes at least one of first indication information and a first SDP offer; wherein the first operation includes at least one of the following: deleting the first indication information from the first message; modifying the first indication information; deleting the first SDPoffer from the first message.

[0009] Fourthly, a communication device is provided, comprising: a receiving module and a processing module. The receiving module is configured to receive a second SDPoffer from a third network node, the second SDPoffer being used to negotiate parameters corresponding to a fourth medium. The processing module is configured to perform a third operation under a second condition, the second condition including at least one of the following: a first terminal corresponding to the fourth medium accesses the network via a first satellite; a second SDP offer includes fifth indication information; wherein the third operation includes at least one of the following: modifying the parameters corresponding to the fourth medium in a first SDP response answer, the first SDP response being a response to the second SDP offer; including relevant information of a second network node in the first SDP response; and sending a sixth indication information to the second network node, the sixth indication information being used to instruct the second network node to discard the received data corresponding to the fourth medium.

[0010] Fifthly, a communication device is provided, the device being configured to perform the steps of the method described in the first aspect, or to implement the steps of the method described in the second aspect.

[0011] In a sixth aspect, a network-side device is provided, the network-side device including a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the method as described in the first aspect, or implementing the steps of the method as described in the second aspect.

[0012] In a seventh aspect, a network-side device is provided, including a processor and a communication interface, wherein the communication interface is configured to receive a first message from a first terminal, the first message being used to request a call to a second terminal; the processor is configured to perform a first operation when a first condition is met, the first condition including any one of the following: the first terminal accesses the network via a first satellite, and the first message includes at least one of first indication information and a first SDP offer, the first indication information indicating at least one of the following: the first terminal supports early media, the first terminal supports early sessions, and the first SDP offer is used to negotiate parameters corresponding to the transmission of early media; the first message includes at least one of the first indication information and the first SDP offer; wherein the first operation includes at least one of the following: deleting the first indication information from the first message; modifying the first indication information; deleting the first SDP offer from the first message. Alternatively, the communication interface is used to receive a first Session Description Protocol (SDP) request offer from a third network node, the second SDP offer being used to negotiate parameters corresponding to the transmission of the fourth medium; the processor is used to perform a third operation when a second condition is met, the second condition including at least one of the following: the first terminal corresponding to the fourth medium accesses the network via a first satellite; the second SDP offer includes fifth indication information; wherein the third operation includes at least one of the following: modifying the parameters corresponding to the fourth medium in the first SDP response answer, the first SDP response being a response to the second SDP offer; including relevant information of the second network node in the first SDP response; sending a sixth indication information to the second network node, the sixth indication information being used to instruct the second network node to discard the received data corresponding to the fourth medium.

[0013] Eighthly, a readable storage medium is provided, on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the first aspect, or implement the steps of the method described in the second aspect.

[0014] In a ninth aspect, a chip is provided, the chip including a processor and a communication interface coupled to the processor, the processor being configured to run a program or instructions to implement the steps of the method described in the first aspect, or to implement the steps of the method described in the second aspect.

[0015] In a tenth aspect, a computer program / program product is provided, the computer program / program product being stored in a storage medium, the computer program / program product being executed by at least one processor to implement the steps of the method as described in the first aspect, or to implement the steps of the method as described in the second aspect.

[0016] In this embodiment of the application, a first network node receives a first message from a first terminal requesting to call a second terminal, and performs a first operation if a first condition is met; wherein, the first condition includes any one of the following: the first terminal accesses the network via a first satellite, and the first message includes at least one of a first indication information and a first SDP offer, the first indication information indicating at least one of the following: the first terminal supports early media, the first terminal supports early sessions, and the first SDP offer is used to negotiate parameters corresponding to the transmission of early media; the first message includes the first indication information and the first SDP offer; the first operation includes at least one of the following: deleting the first indication information from the first message; modifying the first indication information; deleting the first SDP offer from the first message. After receiving the first message from the first terminal requesting a call to the second terminal, the first network node can perform a first operation to delete the first indication information and / or modify the first indication information from the first message, provided that the first terminal accesses the network via the first satellite and the first message includes the first indication information and / or the first SDP offer. This allows the network-side device serving the second terminal to know, upon receiving the first message, that the first terminal may not support early media and / or early sessions. Therefore, when early media needs to be transmitted to the first terminal, the first terminal does not need to renegotiate the parameters used for media transmission with the network-side device serving the second terminal, thus avoiding a decrease in media bitrate due to changes in the 5-tuple information; and / or, perform the first operation to delete the first SDP from the first message. In this way, when the network-side device serving the second terminal receives the first message, it can confirm that the first terminal may not need to negotiate the parameters used for transmitting the media with the network-side device serving the second terminal. Therefore, when it is necessary to transmit early media to the first terminal, the first terminal does not need to re-negotiate the parameters used for transmitting the media with the network-side device serving the second terminal, thereby avoiding the decrease in media bitrate due to the change of the five-tuple information. This can further avoid the poor sound quality of the media when the first terminal plays the media, so as to avoid the user not being able to hear the media clearly. In this way, the prompting effect of the media can be improved.

[0017] In this embodiment, a first network node receives a second SDP offer from a third network node for negotiating the transmission of parameters corresponding to a fourth medium, and performs a third operation if a second condition is met; wherein the second condition includes at least one of the following: the first terminal corresponding to the fourth medium accesses the network via a first satellite; the second SDP offer includes fifth indication information; the third operation includes at least one of the following: modifying the parameters corresponding to the fourth medium in a first SDP response answer, the first SDP response being a response to the second SDP offer; including relevant information of the second network node in the first SDP response answer; sending a sixth indication information to the second network node, the sixth indication information being used to instruct the second network node to discard the received data corresponding to the fourth medium. Since the first network node, after receiving the second SDP offer from the third network node for negotiating the parameters corresponding to the fourth media, can modify the parameters corresponding to the fourth media in the first SDP response answer if the first terminal accesses the network via the first satellite, and / or if the second SDP offer includes fifth indication information, this avoids the situation where the network-side device serving the second terminal sends the fourth media to the network-side device serving the first terminal. Therefore, it reduces the need for the first terminal to renegotiate the parameters used for media transmission with the network-side device serving the first terminal, thereby reducing the decrease in media bitrate due to the change of the five-tuple information; and / or, in the first SDP... The answer contains information about the specified network node (i.e., the second network node). This allows the network-side device serving the second terminal to send the fourth media to the second network node, enabling the specified network node to directly send the fourth media to the first terminal via the established connection. This eliminates the need for the first terminal to renegotiate the parameters used for media transmission with the second network node, thus preventing a decrease in media bitrate due to changes in the 5-tuple information. Alternatively, the answer can instruct the second network node to discard the received data corresponding to the fourth media. This prevents the second network node from sending the fourth media to the first terminal, thus avoiding the need for the first terminal to renegotiate the parameters used for media transmission with the second network node, and again preventing a decrease in media bitrate due to changes in the 5-tuple information. This also prevents the first terminal from experiencing poor sound quality when playing media, ensuring the user can clearly hear the media, thereby improving the media's presentation. Attached Figure Description

[0018] Figure 1A is a schematic diagram of speech coding conversion in related technologies;

[0019] Figure 1B is one of the signaling interaction diagrams of terminal-1 calling terminal-2 in related technologies;

[0020] Figure 1C is the second schematic diagram of signaling interaction between terminal-1 and terminal-2 in the related technology;

[0021] Figure 1D is a schematic diagram of the signaling interaction for terminal-2 to initiate call hold in related technologies;

[0022] Figure 2 is a block diagram of a wireless communication system provided in an embodiment of this application;

[0023] Figure 3 is a flowchart illustrating one of the call methods provided in the embodiments of this application;

[0024] Figure 4 is a second schematic flowchart of the call method provided in the embodiments of this application;

[0025] Figure 5 is a flowchart of the call method provided in the embodiment of this application (third one).

[0026] Figure 6 is a fourth flowchart illustrating the call method provided in the embodiments of this application;

[0027] Figure 7 is a fifth flowchart illustrating the call method provided in the embodiments of this application;

[0028] Figure 8 is a flowchart of the call method provided in the embodiment of this application (the sixth one).

[0029] Figure 9 is a flowchart of the call method provided in the embodiment of this application (the seventh one).

[0030] Figure 10 is a flowchart of the call method provided in the embodiment of this application (the eighth one).

[0031] Figure 11 is a flowchart of the call method provided in the embodiment of this application (the ninth one).

[0032] Figure 12 is a flowchart of the tenth embodiment of the call method provided in this application;

[0033] Figure 13 is an eleventh flowchart illustrating the call method provided in an embodiment of this application;

[0034] Figure 14 is one of the structural schematic diagrams of the communication device provided in the embodiment of this application;

[0035] Figure 15 is a second structural schematic diagram of the communication device provided in an embodiment of this application;

[0036] Figure 16 is a schematic diagram of the hardware structure of the communication device provided in an embodiment of this application;

[0037] Figure 17 is one of the hardware structure diagrams of the network-side device provided in the embodiments of this application;

[0038] Figure 18 is a second schematic diagram of the hardware structure of the network-side device provided in the embodiments of this application. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0040] The terminology used in the embodiments of this application will be explained below.

[0041] 1. Satellite Access

[0042] Typically, 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 transmitted from the ground station and sending them back. Based on their operating orbit, satellite communication systems are generally classified into the following three categories:

[0043] Low Earth Orbit (LEO) satellite communication systems: located at altitudes of 500–2000 km above the Earth's surface, they have relatively low transmission latency and power consumption, but the coverage area of ​​each satellite is also relatively small.

[0044] Medium Earth Orbit (MEO) satellite communication systems: 2000-20000 km above the ground, with a longer transmission delay than low Earth orbit satellites, but also a wider coverage area.

[0045] Geosynchronous Orbit (GEO) satellite communication system: 35,800 km above the Earth, i.e., geostationary orbit. Theoretically, global coverage can be achieved using three GEO satellites.

[0046] For GEO satellites, due to their great distance from the ground, users need a large link budget to send signals to GEO satellites.

[0047] Fourth generation (4) th Generation 4G), fifth generation (5G) th Generation 5G or sixth generation (6G) thGeneration 6G communication systems all use Internet Protocol Multimedia Subsystem (IMS) voice for voice communication, such as Voice Over Long-Term Evolution (VoLTE), Voice Over New Radio (VoNR), or Voice Over 6G (Vo6G). The minimum IMS voice communication rate is 4.75 kbps. Ordinary user equipment (UE) cannot support such a high transmission rate when conducting voice communication via GEO, thus preventing the establishment of voice calls. One solution is to modify the voice codec to reduce the voice communication rate to 1.2 kbps or lower.

[0048] If Terminal-1 is a Non-Terrestrial Network (NTN) terminal (a terminal accessing the network via satellite), and Terminal-2 is a Terrestrial Network (TN) terminal (a terminal accessing the network via a terrestrial network), to avoid requiring Terminal-2 to support low-bitrate voice coding during communication between Terminal-1 and Terminal-2, thus limiting the communication range of NTN terminals, the industry has proposed a voice coding conversion scheme, as shown in Figure 1A. Terminal-1 can send low-bitrate voice to the Session Border Controller (SBC) / Proxy Call Session Control Function (P-CSCF), so that the SBC / P-CSCF can convert the low-bitrate voice into normal voice and send the normal voice to Terminal-2; or, Terminal-2 can send normal voice to the SBC / P-CSCF, so that the SBC / P-CSCF can convert the normal voice into low-bit voice and send the low-bit voice to Terminal-1.

[0049] The Session Border Controller (SBC) is a crucial network node in the IMS network, located at the network boundary and playing a vital role in connecting terminals to the IMS core network. Its main functions include access permission control, network topology hiding, Network Address Translation (NAT) and NAT traversal, Quality of Service (QoS), and bandwidth policy adjustment. An SBC can comprise both control and user plane functions, or the control and user planes can be separated. For example, the Session Border Controller Control Function (SBC-C) is used for control, while the Session Border Controller User Function (SBC-U) is used for media data transmission. SBC / P-CSCF represents an IMS network element that incorporates both SBC and P-CSCF functions; for example, an SBC with P-CSCF functionality, or an IMS network element that combines SBC and P-CSCF.

[0050] 2. Process of receiving customized alert tones (CAT) when a terminal initiates a call

[0051] Typically, as shown in Figure 1B, when a user calls terminal-2 using terminal-1, the following steps are included:

[0052] Step 1: The user of Terminal-1 dials the phone number of Terminal-2. Terminal-1 sends an Invite message, which contains information about Terminal-1's support for early media and Session Description Protocol (SDP) offer information. This Invite message is routed to Terminal-2 via the IMS core network equipment.

[0053] It should be noted that for details regarding the routing of the Invite message to terminal-2 via the IMS core network device, please refer to the specific descriptions in related technologies; the embodiments of this application will not be repeated here.

[0054] In some technologies, the Invite message is used as an example as follows:

[0055] INVITE tel: 1351234567 SIP / 2.0

[0056] P-Access-Network-Info:3GPP-NR

[0057] P-Early-Media:supported

[0058] Supported:early-session

[0059] m = audio 2400RTP / AVP97

[0060] a = rtpmap:97AMR / 8000 / 1

[0061] In this example, tel:1351234567 represents the called number as 1351234567; P-Access-Network-Info represents the access network information of terminal-1, in this example terminal-1 accesses the IMS network via 5G; P-Early-Media:supported indicates that terminal-1 supports early media; Supported:early-session indicates that terminal-1 supports early session; line m represents the media type as voice service, and 2400 represents the port number; line a represents the attribute information of this voice service: where "97" is the RTP payload type, "AMR" indicates that the encoding format is AMR, "8000" is the sampling rate, and "1" indicates mono. Lines M and a belong to SDPoffer.

[0062] In some technologies, the aforementioned SDPoffer information carries various voice coding methods supported by terminal-1.

[0063] Step 2: Terminal-2 replies with a response message, such as a 183 response message, which contains an SDP answer. The SDP answer is used to negotiate with Terminal-1 the voice encoding method to be used in this call.

[0064] In some technologies, the aforementioned SDPanswer includes the voice coding method selected by terminal-2 from the various voice coding methods mentioned above.

[0065] Step 3: Terminal-1 sends a Provisional Response ACK (PRACK) message. This PRACK message is a response to the 183 message, indicating that the 183 message has been received.

[0066] Step 4: Terminal-1 sends a 200 OK response message for PRACK.

[0067] Step 5: When Terminal-2 starts ringing, Terminal-2 replies with a 180 response message.

[0068] Step 6: The IMS application server (AS)-2, which provides services to terminal-2, determines that terminal-2 has subscribed to the ringback tone service, and then requests the Media Resource Function (MRF)-2 to reserve resources, which are used to send CAT media to terminal-1.

[0069] It should be noted that the ringback tone service is another way of expressing the CAT service, and the two are equivalent.

[0070] Step 7: AS-2 sends an SDP offer for negotiating early media to terminal-1. This SDP offer can be sent via an UPDATE message.

[0071] The UPDATE message includes P-Early-Media, whose value can be sendrecv, indicating that the network-side device supports earlymedia. The SDPoffer can be an additional m lines added to the existing m lines of the SDP (SDP negotiation in steps 1 and 2); or, a new SDP.

[0072] The following is an example of an SDPoffer:

[0073] Content-Disposition:early-session

[0074] m = audio 2500RTP / AVP98

[0075] a = rtpmap:98AMR / 8000 / 1

[0076] a = content: g.3gpp.cat

[0077] Here, Content-Disposition indicates that the SDP content is an early session; a = content:g.3gpp.cat indicates that line m is used to negotiate how to transmit CAT media; Note: early session refers to the IMS session established by the two communicating parties, which is used to transmit early media. Early media is a media stream within the early session.

[0078] Step 8: Terminal-1 responds with an SDP answer for early media, which can be sent via a 200 OK message.

[0079] Step 9: AS-2 controls MRF-2 to play CAT for terminal-1. The CAT can be music customized by terminal-2.

[0080] Step 10: AS-2 sends a 180 message to Terminal-1.

[0081] 3. Procedure for receiving call prompt tone when a terminal initiates a call

[0082] Typically, as shown in Figure 1C, when a user calls terminal-2 using terminal-1, the following steps are included:

[0083] Step 1, same as Step 1 in Figure 1B.

[0084] Step 2: AS-2 determines the status of terminal-2, such as whether terminal-2 is powered off or is in a call.

[0085] Step 3: AS-2 requests MRF-2 to reserve resources. These resources are used to send a prompt tone or music to terminal-1. The prompt tone or music is used to notify the user that terminal-2 is powered off or that terminal-2 is in a call.

[0086] Step 4: AS-2 sends an SDP offer to Terminal-1 for negotiating early media. This SDP offer can be sent via a 183 message.

[0087] The message contains P-Early-Media, where the value of P-Early-Media can be sendrecv, indicating that the network side supports early media.

[0088] Step 5: Terminal-1 replies with an SDP answer for early media, which can be sent via a PRACK message.

[0089] Step 6: AS-2 replies with a 200 OK message corresponding to PRACK.

[0090] Step 7: AS-2 controls MRF-2 to play a prompt tone or prompt music for terminal-1.

[0091] Step 8: AS-2 sends a rejection message to terminal-1, rejecting the call request and carrying the reason for the rejection.

[0092] In this context, the rejection message represents a response message that starts with 4, such as 486 or 487.

[0093] 4. Play a call hold tone during a terminal call.

[0094] Typically, as shown in Figure 1D, when terminal-1 and terminal-2 are in a call and the user initiates a call hold using terminal-2, the following steps are included:

[0095] Step 0: Terminal-1 and Terminal-2 are in a call.

[0096] Step 1: Terminal-2 initiates a call hold request. For example, Terminal-2 receives an incoming call from Terminal-2 and needs to transfer the call to Terminal-3.

[0097] Terminal-2 initiates a call hold request via a re-Invite message, carrying a sendonly or inactive indication in the SDPoffer of the Invite message, as shown in the following example:

[0098] m = audio 2400RTP / AVPF 97

[0099] a = rtpmap:97AMR

[0100] a = sendonly

[0101] Step 2: AS-2 requests MRF-2 to allocate resources, and MRF-2 allocates the IP address and port number information for transmitting the prompt tone.

[0102] Step 3: Modify the SDPoffer in AS-2. The modified SDPoffer contains the IP address and port number information of MRF-2.

[0103] Step 4: Terminal-1 sends a 200 OK response message, carrying SDPanswer.

[0104] Step 5: AS-2 controls MRF-2 to establish a Real-time Transport Protocol (RTP) connection with Terminal-1 based on the SDP answer.

[0105] Step 6: MRF-2 sends a hold prompt tone to terminal-1 according to the instruction of AS-2, such as a voice prompt or music prompt. The voice prompt or music prompt is used to prompt the communication peer (i.e., terminal-1) of terminal-2 to enable call hold.

[0106] Step 7: AS-2 sends an SDP answer to Terminal-2, controlling Terminal-2 to establish an RTP connection with MRF-2.

[0107] It should be noted that the core network devices ending in -1 in Figures 1B, 1C, and 1D are IMS core network devices providing services to terminal-1; the core network devices ending in -2 are IMS core network devices providing services to terminal-2. Figures 1B and 1C transmit ringback tones or alert sounds via early media, while Figure 1D transmits alert sounds via the normal call transmission channel.

[0108] 5. Robust Header Compression (ROHC)

[0109] Typically, ROHC is a technique for compressing the header of network data packets, primarily used in the air interface of wireless transmission to improve air interface resource utilization. The header includes static and dynamic fields, each with its own values. ROHC is usually used directly between the terminal and the base station to reduce the amount of data transmitted over the air interface. Typically, ROHC compression should only be initiated after 1-5 complete data packets have been transmitted directly over the air.

[0110] 6. Other terms

[0111] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, not limited in number; for example, the first object can be one or more. Furthermore, "or" in this application indicates at least one of the connected objects. For example, the scope of protection for "A or B" covers at least three scenarios: Scenario 1: including A but not B; Scenario 2: including B but not A; Scenario 3: including both A and B. In addition, the terms "A and / or B," "at least one of A and B," and "at least one of A or B" also cover at least the above three scenarios. The character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0112] The term "instruction" in this application can be either a direct instruction (or explicit instruction) or an indirect instruction (or implicit instruction). A direct instruction can be understood as one in which the sender explicitly informs the receiver of specific information, the operation to be performed, or the requested result, etc., in the instruction sent. An indirect instruction can be understood as one in which the receiver determines the corresponding information based on the instruction sent by the sender, or makes a judgment and determines the operation to be performed or the requested result, etc., based on the judgment result.

[0113] It is worth noting that the technologies described in this application are not limited to Long Term Evolution (LTE) / LTE-Advanced (LTE-A) systems, 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 this application are often used interchangeably, and the described technologies can be used with the systems and radio technologies mentioned above, as well as with other systems and radio technologies. The following description describes New Radio (NR) systems for illustrative purposes, and the term NR is used in most of the following description; however, these technologies can also be applied to systems other than NR systems, such as 6th generation (6G) radio systems. th Generation 6G communication system.

[0114] Figure 2 shows a block diagram of a wireless communication system applicable to an embodiment of this application. The wireless communication system includes a terminal 11 and a network-side device 12. The terminal 11 can be a mobile phone, tablet computer, laptop computer, notebook computer, personal digital assistant (PDA), handheld computer, netbook, ultra-mobile personal computer (UMPC), mobile internet device (MID), augmented reality (AR), virtual reality (VR) device, robot, wearable device, flight vehicle, vehicle user equipment (VUE), shipboard equipment, pedestrian user equipment (PUE), smart home (home devices with wireless communication capabilities, such as refrigerators, televisions, washing machines, or furniture), game console, personal computer (PC), ATM, or self-service machine, etc. Wearable devices include: smartwatches, smart bracelets, smart headphones, smart glasses, smart jewelry (smart bracelets, smart chains, smart rings, smart necklaces, smart anklets, smart anklets, etc.), smart wristbands, smart clothing, etc. Among these, in-vehicle devices can also be referred to as in-vehicle terminals, in-vehicle controllers, in-vehicle modules, in-vehicle components, in-vehicle chips, or in-vehicle units, etc. Furthermore, terminal 11 can be any of the terminals described above, or it can be a chip within a terminal, such as a modem chip, a system-on-chip (SoC), etc. It should be noted that the specific type of terminal 11 is not limited in this application embodiment. Network-side equipment 12 can include access network equipment or core network equipment, wherein access network equipment can also be referred to as Radio Access Network (RAN) equipment, radio access network function, or radio access network unit. Access network equipment can include base stations, Wireless Local Area Network (WLAN) access points (AS), or Wireless Fidelity (Wi-Fi) nodes, etc.In this context, a base station may be referred to as a Node B (NB), Evolved Node B (eNB), 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, Transmit / Receive Point (TRP), or any other suitable term in the relevant field, as long as the same technical effect is achieved. The base station is not limited to specific technical terms. It should be noted that in this application embodiment, only a base station in an NR system is used as an example for introduction, and the specific type of base station is not limited.

[0115] Core network equipment, also known as core network nodes, core network functions, or core network elements, includes, but is not limited to, at least one of the following: Mobility Management Entity (MME), Access and Mobility Management Function (AMF), Session Management Function (SMF), User Plane Function (UPF), Policy Control Function (PCF), Policy and Charging Rules Function (PCRF), Edge Application Server Discovery Function (EASDF), Unified Data Management (UDM), Unified Data Repository (UDR), Home Subscriber Server (HSS), Centralized Network Configuration (CNC), Network Repository Function (NRF), and Network Exposure. The core network functions include: NEF (Network Function), Local NEF (or L-NEF), Binding Support Function (BSF), Application Function (AF), Location Management Function (LMF), Gateway Mobile Location Centre (GMLC), and Network Data Analytics Function (NWDAF). It should be noted that this application only uses core network equipment in the NR system as an example and does not limit the specific type of core network equipment. If the name of the core network equipment mentioned in this application changes in subsequent protocol versions (e.g., 6G), it will still be within the scope of protection of this application.

[0116] Optionally, the core network equipment can be implemented by one or more functional modules in a single device, or by multiple devices working together; this application does not specifically limit this. It is understood that the aforementioned functional modules can be network elements in hardware devices, software functional modules running on dedicated hardware, or virtualized functional modules instantiated on a platform (e.g., a cloud platform).

[0117] The call method provided in this application can be executed by a call device, a first network node, or a functional module or entity within the first network node. This application uses the execution of the call method by a first network node as an example to illustrate the call method provided in this application.

[0118] The following description, in conjunction with the accompanying drawings, details the call method, apparatus, network-side device, and readable storage medium provided in the embodiments of this application through some examples and application scenarios.

[0119] Currently, when terminal 1 calls terminal 2, terminal 1 can negotiate with terminal 2 the parameters used to transmit the data corresponding to the voice service. Terminal 1 and terminal 2 then transmit the data using the negotiated parameters. Furthermore, when media transmission is required (such as ringback tones or alert tones), terminal 1 can renegotiate the parameters used to transmit that media with the network-side device. The network-side device can then send the media to terminal 1 using the renegotiated parameters to provide the user with relevant information about terminal 2.

[0120] However, during application, the applicant discovered that because the five-tuple information is changed during the process of terminal 1 renegotiating the parameters used for transmitting the media with the network-side device, this may cause the ROHC startup process to be restarted. Therefore, after the network-side device sends the media to terminal 1 with the renegotiated parameters, the sound quality of the media is poor when terminal 1 plays it. Furthermore, when terminal 1 accesses the network via satellite (e.g., GEO satellite), the network-side device may convert the media from a high bitrate (e.g., 64kbps) to a low bitrate (e.g., 0.6kbps), resulting in poor sound quality when terminal 1 plays the media. This may cause users to be unable to hear the media clearly, thus affecting the media's prompting effect.

[0121] To address the aforementioned problems, this application provides a call method. Figure 3 shows a flowchart of the call method provided in this application. As shown in Figure 3, the call method provided in this application may include the following steps 101 and 102.

[0122] Step 101: The first network node receives the first message from the first terminal.

[0123] In some embodiments of this application, the first network node can be a P-CSCF, or an IMS network element that includes both SBC and P-CSCF functions. For example, the first network node can be a P-CSCF with SBC functionality, or an SBC with P-CSCF functionality, or an IMS network element that combines SBC and P-CSCF. The first network node can be a network node serving the first terminal.

[0124] This application document uses P-CSCF or SBC as examples to illustrate the concept. The first network node can also be IMSAS, S-CSCF, or MRF.

[0125] In some embodiments of this application, when a user calls a second terminal using a first terminal, the first network node can receive a first message from the first terminal. It is understood that the first terminal can be the calling terminal, and the second terminal can be the called terminal.

[0126] In this embodiment of the application, the first message is used to request a call to the second terminal.

[0127] In some embodiments of this application, the first message mentioned above can be an Invite message. This Invite message may carry an SDPoffer, which can be used to negotiate the parameters used for transmitting data corresponding to voice services.

[0128] It should be noted that the first message is used to request a call to the second terminal, or it can be understood as: the first message is used to initiate a call request to the second terminal.

[0129] It should be noted that the second terminal can be a terminal device used by ordinary users; or a service device on the network side, such as a customer service center of an operator or a customer service center of a bank.

[0130] Step 102: If the first condition is met, the first network node performs the first operation.

[0131] In this embodiment of the application, the first condition mentioned above includes any one of the following:

[0132] The first terminal accesses the network via the first satellite, and the first message includes at least one of the first indication information and the first SDPoffer. The first indication information indicates at least one of the following: the first terminal supports early media, the first terminal supports early sessions, and the first SDPoffer is used to negotiate parameters corresponding to the transmission of early media.

[0133] The first message includes at least one of a first instruction message and a first SDPoffer.

[0134] In some embodiments of this application, the first satellite may be any of the following: a LEO satellite, a MEO satellite, or a GEO satellite.

[0135] In some embodiments of this application, the terminal accesses the network via satellite, which can be understood as: the terminal accesses the IMS network, 6G network, 5G network or 4G network via satellite; or, the terminal initiates or receives call requests via satellite.

[0136] In some embodiments of this application, when the first indication information indicates that the first terminal supports early media, the first indication information may specifically be P-Early-Media:supported; when the first indication information indicates that the first terminal supports early session, the first indication information may specifically be Supported:early-session.

[0137] In some embodiments of this application, when the first condition includes the first terminal accessing the network via the first satellite and the first message includes the first indication information, or when the first condition includes the first message including the first indication information, the first operation may include at least one of the following: deleting the first indication information from the first message; modifying the first indication information.

[0138] In some embodiments of this application, when the first condition includes the first terminal accessing the network via the first satellite and the first message includes the first SDPoffer, or when the first condition includes the first message including the first SDPoffer, the first operation may include: deleting the first SDPoffer from the first message.

[0139] The following example illustrates the specific scheme for determining whether the first network node meets the first condition, with the first condition including the first terminal accessing the network via the first satellite and the first message including at least one of the first indication information and the first SDPoffer.

[0140] In some embodiments of this application, the first condition includes the first terminal accessing the network via a first satellite, and the first message including at least one of a first indication information and a first SDP offer. Referring to Figure 3, as shown in Figure 4, prior to step 102, the call method provided in this application embodiment may further include the following steps 201 and 202.

[0141] Step 201: The first network node obtains the access network information corresponding to the first terminal.

[0142] In this embodiment of the application, the access network information is obtained from the first message or from the fourth network node.

[0143] In some embodiments of this application, the first message includes access network information, such as P-Access-Network-Info information, so that the first network node can directly obtain the access network information from the first message.

[0144] In some embodiments of this application, the aforementioned fourth network node may include at least one of the following: a Policy Control Function (PCF) and a Policy and Charging Rules Function (PCRF).

[0145] Step 202: The first network node determines, based on the access network information, that the first terminal accesses the network through the first satellite.

[0146] In some embodiments of this application, the first network node can determine the corresponding access network side device based on the access network information. Thus, if the access network side device is the same as the first satellite, the first network node can determine that the first terminal accesses the network through the first satellite.

[0147] In some embodiments of this application, the first network node can directly read the first message to determine whether the first message includes at least one of the first indication information and the first SDPoffer. Thus, if it is determined that the first terminal accesses the network through the first satellite and the first message includes at least one of the first indication information and the first SDPoffer, the first network node can perform the first operation.

[0148] Thus, since the first network node can directly obtain the access network information corresponding to the first terminal from the first message or from the fourth network node, and accurately determine whether the first terminal accesses the network through the first satellite using the access network information, the accuracy of the first network node in determining whether the first condition is met can be improved, thereby improving the accuracy of the first network node in performing the first operation.

[0149] In this embodiment of the application, the first operation mentioned above includes at least one of the following:

[0150] Delete the first instruction message from the first message;

[0151] Modify the first instruction information;

[0152] Delete the first SDPoffer from the first message.

[0153] In this embodiment of the application, if the first indication information is deleted from the first message, the network-side device providing services to the second terminal will determine or consider that the first terminal does not support early media and / or does not support early sessions when it receives the first message. In this way, the network-side device providing services to the second terminal will not re-negotiate SDP with the first terminal, and the network-side device providing services to the second terminal will not send the data corresponding to CAT.

[0154] For example, suppose the first message includes:

[0155] INVITE tel: 1351234567 SIP / 2.0

[0156] P-Access-Network-Info:3GPP-NR

[0157] P-Early-Media:supported

[0158] Supported: precondition, early-session

[0159] m = audio 2400RTP / AVP97

[0160] a = rtpmap:97AMR / 8000 / 1;

[0161] After the first network node deletes the first instruction information from the first message, it will look like this:

[0162] INVITE tel: 1351234567 SIP / 2.0

[0163] P-Access-Network-Info:3GPP-NR

[0164] Supported: precondition

[0165] m = audio 2400RTP / AVP97

[0166] a = rtpmap:97AMR / 8000 / 1;

[0167] Among them, the precondition represents the first terminal supporting the precondition feature.

[0168] In some embodiments of this application, the first operation described above includes modifying the first instruction information. Referring to FIG3 and FIG5, the above step 102 can be specifically implemented by the following step 102a.

[0169] Step 102a: If the first condition is met, and if the first instruction information indicates that the first terminal supports early media, the first network node modifies the first instruction information to the second instruction information.

[0170] In this embodiment of the application, the above-mentioned second indication information indicates at least one of the following: the first terminal does not support early media, or the first terminal does not support early sessions.

[0171] For example, suppose the first message includes:

[0172] INVITE tel: 1351234567 SIP / 2.0

[0173] P-Access-Network-Info:3GPP-NR

[0174] P-Early-Media:supported

[0175] Supported:early-session

[0176] m = audio 2400RTP / AVP97

[0177] a = rtpmap:97AMR / 8000 / 1;

[0178] The first network node can then modify the first indication information to the second indication information. For example, it can change P-Early-Media:supported to P-Early-Media:not supported, where P-Early-Media:not supported indicates that the first terminal does not support early media; and / or change Supported:precondition,early-session to Supported:precondition, where Supported:precondition indicates that the first terminal does not support early sessions. Here, the precondition represents that the first terminal supports the precondition feature.

[0179] In this embodiment of the application, if the first SDP offer is deleted from the first message, the network-side device serving the second terminal can assume that the first terminal did not request to renegotiate the parameters for transmitting the early media when it receives the first message. Therefore, the network-side device of the second terminal will not renegotiate the parameters for transmitting the early media with the first terminal.

[0180] This application provides a call method in which a first network node receives a first message from a first terminal requesting a call to a second terminal, and performs a first operation when a first condition is met. The first condition includes any one of the following: the first terminal accesses the network via a first satellite, and the first message includes at least one of first indication information and a first SDP offer. The first indication information indicates at least one of the following: the first terminal supports early media; the first terminal supports early sessions; the first SDP offer is used to negotiate parameters corresponding to the early media transmission. The first message includes the first indication information and the first SDP offer. The first operation includes at least one of the following: deleting the first indication information from the first message; modifying the first indication information; deleting the first SDP offer from the first message. After receiving the first message from the first terminal requesting a call to the second terminal, the first network node can perform a first operation to delete and / or modify the first indication information from the first message, provided that the first terminal accesses the network via the first satellite and the first message includes first indication information and / or a first SDP offer, or if the first message includes first indication information and / or a first SDP offer. This allows the network-side device serving the second terminal to know, upon receiving the first message, that the first terminal may not support early media and / or early sessions. Therefore, when early media needs to be transmitted to the first terminal, the first terminal does not need to renegotiate the parameters used for media transmission with the network-side device serving the second terminal, thus avoiding a decrease in media bitrate due to changes in the 5-tuple information; and / or, perform the first operation to delete the first SDP from the first message. In this way, when the network-side device serving the second terminal receives the first message, it can confirm that the first terminal may not need to negotiate the parameters used for transmitting the media with the network-side device serving the second terminal. Therefore, when it is necessary to transmit early media to the first terminal, the first terminal does not need to re-negotiate the parameters used for transmitting the media with the network-side device serving the second terminal, thereby avoiding the decrease in media bitrate due to the change of the five-tuple information. This can further avoid the poor sound quality of the media when the first terminal plays the media, so as to avoid the user not being able to hear the media clearly. In this way, the prompting effect of the media can be improved.

[0181] Furthermore, since the first network node can delete and / or modify the first instruction information from the first message, the network-side device serving the second terminal can know, upon receiving the first message, that the first terminal may not support early media and / or early sessions; and / or, the first network node can delete the first SDP offer from the first message, thus the network-side device serving the second terminal can confirm, upon receiving the first message, that the first terminal may not need to negotiate the parameters used for transmitting the media with the network-side device serving the second terminal; therefore, the network-side device will not transcode the high-bitrate early media to be transmitted into low-bitrate early media and send the low-bitrate early media to the first terminal, thereby avoiding poor sound quality of the early media when the first terminal plays it, so as to avoid the user not being able to hear the media clearly, thus improving the media prompting effect.

[0182] In some embodiments of this application, after step 102 described above, the call method provided in the embodiments of this application may further include step 203 as described below.

[0183] Step 203: The first network node sends a second message to the second terminal.

[0184] In this embodiment of the application, the second message is used to request a call to the second terminal.

[0185] In some embodiments of this application, the first network node can send a second message to the second terminal through S-CSCF-1 (i.e., the S-CSCF serving the first terminal), AS-1 (i.e., the AS serving the first terminal), S-CSCF-2 (i.e., the S-CSCF serving the second terminal) and AS-2 (i.e., the AS serving the second terminal).

[0186] In this embodiment of the application, if the first operation includes deleting the first indication information from the first message, the second message does not include the first indication information; or, if the first operation includes modifying the first indication information, the second message includes the second indication information; the second indication information indicates at least one of the following: the first terminal does not support early media, or the first terminal does not support early sessions; if the first operation includes deleting the first SDPoffer from the first message, the second message does not include the first SDPoffer.

[0187] Thus, since the first network node can also send a second message to the second terminal, which is obtained by the first network node performing the first operation on the first message, the network-side device forwarding the second message can know that the first terminal does not support early media and / or does not support early sessions, and / or the first terminal does not need to renegotiate the parameters for transmitting early media with the network-side device. In this way, when it is necessary to transmit early media to the first terminal, the first terminal does not need to renegotiate the parameters used for transmitting the media with the network-side device, thereby avoiding the decrease in media bitrate due to the change of the five-tuple information. Furthermore, since the network-side device forwarding the second message can know that the first terminal does not support early media and / or does not support early sessions, the network-side device will not transcode the high bitrate early media to be transmitted into low bitrate early media and send the low bitrate early media to the first terminal. This can avoid the first terminal playing the media with poor sound quality, thus preventing the user from not being able to listen to the media clearly.

[0188] In some embodiments of this application, after step 203 described above, the call method provided in this application may further include steps 204 and 205 as described below.

[0189] Step 204: The first network node receives a third message from the second terminal or the third network node.

[0190] In some embodiments of this application, the aforementioned third network node can be AS-2 (i.e., the AS serving the second terminal). Of course, the third network node can also be other network nodes, and this application does not limit this.

[0191] In this embodiment of the application, the aforementioned third message is used to indicate ringing or to indicate call failure.

[0192] It should be noted that when the third message is used to indicate ringing, the third message can be a 180 response message.

[0193] In some embodiments of this application, when the first network node receives a third message from the second terminal, the third message can be used to indicate that the second terminal is ringing; or when the first network node receives a third message from the third network node, the third message can be used to indicate that the call has failed.

[0194] Step 205: The first network node performs the second operation based on the third message.

[0195] In this embodiment of the application, the second operation includes at least one of the following:

[0196] Send a third instruction message to the second network node, the third instruction message being used to instruct the first terminal to send the first medium;

[0197] A fourth instruction message is sent to the first terminal, which instructs the first terminal to play the second media.

[0198] A fourth message is sent to the first terminal, which instructs the first terminal to play the third media.

[0199] In some embodiments of this application, the second network node can be an access gateway (AGW). Of course, the second network node can also be other network nodes, such as an MRF, and this application does not limit this.

[0200] In some embodiments of this application, the first medium can be a predetermined medium corresponding to the third message. For example, when the third message is used to indicate ringing, the first medium can be a predetermined medium in the second network node, and the predetermined medium can be a "beep beep" audio signal. Alternatively, when the third message is used to indicate a call failure, the first medium can be a predetermined medium in the second network node, and the predetermined medium can be an audio signal saying "Sorry, the user you are calling is switched off" or "Sorry, the user you are calling is currently on another call".

[0201] In some embodiments of this application, the first media may be a low bitrate media (e.g., media with a bitrate below a predetermined threshold).

[0202] In some embodiments of this application, after the first network node sends third instruction information to the second network node, the second network node can use the RTP connection with the first terminal for transmitting voice to send the first media.

[0203] In some embodiments of this application, the second medium can be a predetermined medium corresponding to the third message. For example, when the third message is used to indicate ringing, the second medium can be a predetermined medium in the first terminal, which can be a "beep beep" audio signal. Alternatively, when the third message is used to indicate a call failure, the second medium can be a predetermined medium in the first terminal, which can be an audio signal saying "Sorry, the user you are calling is switched off" or "Sorry, the user you are calling is currently on another call".

[0204] In some embodiments of this application, the second medium may be a low bitrate medium (e.g., a medium with a bitrate below a predetermined threshold).

[0205] In some embodiments of this application, the fourth message may include a third message and an instruction message. The instruction message is used to instruct the first terminal to determine the playback of a predetermined medium based on the third message. Thus, the first terminal can determine and play the third medium based on the message name of the third message or the call failure reason value carried in the third message.

[0206] In some embodiments of this application, the aforementioned third medium can be a predetermined medium corresponding to the third message. For example, when the third message is used to indicate ringing, the third medium can be a predetermined medium in the first terminal, which can be a "beep beep" audio signal. Alternatively, when the third message is used to indicate a call failure, the third medium can be a predetermined medium in the first terminal, which can be an audio signal saying "Sorry, the user you are calling is switched off" or "Sorry, the user you are calling is currently on another call".

[0207] In some embodiments of this application, the aforementioned third media may be low bitrate media (e.g., media with a bitrate below a predetermined threshold).

[0208] Therefore, upon receiving the third message—that is, upon learning that the second terminal is ringing or the call has failed—the first network node can instruct the second network node to send the first media to the first terminal. This allows the second network node to directly use the RTP connection with the first terminal to send the first media without needing to renegotiate the parameters used to transmit the first media. Thus, the existing ROHC state can be reused, avoiding the problem of poor sound quality of the first media caused by ROHC restart. And / or, the first terminal can be instructed to play the second media. This allows the first terminal to play the second media pre-stored in its own memory without needing to receive and play media from the network-side device. Therefore, the network-side device can avoid converting the second media into low-bitrate media, thereby improving the sound quality of the second media played by the first terminal. And / or, a fourth message can be sent to the first terminal, enabling it to determine and play the third media based on the fourth message. Therefore, the accuracy of playing the third media can be improved, as can the sound quality of the third media played by the first terminal.

[0209] In some embodiments of this application, the first medium includes a medium corresponding to a ringback tone or a notification tone; or, the second medium includes a medium corresponding to a ringback tone or a notification tone; or, the third medium includes a medium corresponding to a ringback tone or a notification tone.

[0210] Thus, since the embodiments of this application specify the specific content included in the first media, the second media, or the third media, the first network node can accurately instruct the second network node and / or the first terminal based on the specific content, thereby enabling the first terminal to accurately play the media corresponding to the third message.

[0211] The following will use specific examples to illustrate the complete process of the call method provided in the embodiments of this application.

[0212] Example 1: The third message indicates a ringing.

[0213] As shown in Figure 6, the call method provided in this application embodiment may include the following steps:

[0214] Step 1: The user of the first terminal dials the phone number of the second terminal. The first terminal sends an Invite message (e.g., the first message in the above embodiment) to the first network node (e.g., P-CSCF-1 / SBC). The first network node receives the Invite message, which may carry at least one of the first indication information and the first SDP offer.

[0215] It should be noted that Figure 6 illustrates the Invite message carrying the first SDP offer (i.e., the SDP offer).

[0216] Step 2: The first network node performs the first operation if the first condition is met;

[0217] The first condition includes:

[0218] The first terminal accesses the network via satellite or via GEO satellite, and the first message carries first indication information (e.g., P-Early-Media:supported, or Supported:early-session).

[0219] The first operation includes:

[0220] Remove P-Early-Media:supported; and / or remove Supported:early-session; and / or change P-Early-Media:supported to P-Early-Media:not supported; and / or change Supported:early-session to Supported:.

[0221] The first network node can determine whether the first terminal accesses the network via satellite or via GEO satellite based on the access network information carried in the first message; or, the first network node can obtain the access network information corresponding to the first terminal from the fourth network node (e.g., PCF or PCRF) and determine whether the first terminal accesses the network via satellite or via GEO satellite based on the access network information.

[0222] Step 3: The first network node sends a modified Invite message (e.g., the second message in the above embodiment) to the second terminal, which carries an SDP offer.

[0223] Step 4: The second terminal replies with a 183 message, carrying the SDP answer.

[0224] Step 5: The second terminal replies with a 180 message (e.g., the third message in the above embodiment), which indicates that the second terminal is ringing.

[0225] Step 6a: The first network node instructs the second network node (e.g., AGW) to send a ringback tone (e.g., the first media in the above embodiment) to the first terminal according to the 180 message.

[0226] The AGW can send a ringback tone using an RTP connection with the first terminal for transmitting voice. This ringback tone can be a low-bitrate (low-data-rate) ringback tone.

[0227] Step 6b: The first network node sends an 180 message to the first terminal, which instructs the first terminal to play a local ringback tone (e.g., the second or third media in the above embodiment).

[0228] It should be noted that the first network node may execute only step 6a, only step 6b, or both steps 6a and 6b. This application embodiment does not limit this.

[0229] It is understandable that, by executing the steps in the above process, on the one hand, the first network node deletes the first indication information, thus preventing the called network-side device (e.g., MRF-2) from sending a ringback tone (e.g., a custom ringback tone). On the other hand, the second network node (e.g., AGW) uses an RTP connection for voice transmission to send the ringback tone, reusing the existing ROHC state and avoiding the poor playback quality caused by ROHC restart. Furthermore, the second network node plays a low-bitrate ringback tone, avoiding the problem of poor playback quality of transcoded media caused by voice transcoding. Finally, the first terminal plays a local ringback tone, preventing the propagation of the ringback tone and thus ensuring playback quality.

[0230] Example 2: The third message indicates that the call failed.

[0231] As shown in Figure 7, the call method provided in this embodiment may include the following steps:

[0232] Steps 1-3 are the same as steps 1-3 in Figure 6.

[0233] Step 4: AS-2 (i.e., the AS serving the second terminal) determines the status of the second terminal, such as whether the second terminal is powered off or is in a call.

[0234] Step 5: AS-2 sends a rejection message (e.g., the third message in the above embodiment) to the first terminal. The rejection message indicates that the call failed and carries the reason for the failure.

[0235] 6a. Based on the rejection message, the first network node (e.g., P-CSCF-1 / SBC) instructs the second network node (e.g., AGW) to send a prompt tone (e.g., the first media) to the first terminal.

[0236] P-CSCF-1 can instruct the second network node to play a prompt tone to the first terminal based on the rejection message or the reason value carried by the rejection message.

[0237] Step 6b: The first network node instructs the first terminal to play a local prompt tone.

[0238] The first terminal can determine the prompt tone to be played based on the rejection message or the reason value carried in the rejection message.

[0239] Figure 8 shows a flowchart of the call method provided in an embodiment of this application. As shown in Figure 8, the call method provided in an embodiment of this application may include the following steps 301 and 302.

[0240] Step 301: The first network node receives the second SDP offer from the third network node.

[0241] In some embodiments of this application, the first network node can be a P-CSCF or an IMS network element that includes both SBC and P-CSCF functions. For example, the first network node can be a P-CSCF with SBC functionality, or an SBC with P-CSCF functionality, or an IMS network element that combines SBC and P-CSCF. The first network node can be a network node serving the first terminal.

[0242] This application document uses P-CSCF or SBC as examples to illustrate the concept. The first network node can also be IMSAS, S-CSCF, or MRF.

[0243] In some embodiments of this application, the aforementioned third network node can be AS-2 (i.e., the AS serving the second terminal). Of course, the third network node can also be other network nodes, and this application does not limit this.

[0244] In this embodiment of the application, the second SDP offer is used to negotiate the parameters corresponding to the transmission of the fourth medium.

[0245] In some embodiments of this application, the aforementioned fourth medium may be an earlier medium or may not be an earlier medium.

[0246] In some embodiments of this application, the aforementioned fourth media includes at least one of the following: media corresponding to the ringback tone, media corresponding to the prompt tone, and media corresponding to CAT.

[0247] Thus, since the embodiments of this application specify the specific content that the fourth medium may include, the first network node can accurately determine the role of the second SDP offer based on the specific content, and accurately determine the corresponding SDP answer based on the second SDP offer.

[0248] In some embodiments of this application, the second SDPoffer is specifically used to negotiate the media parameters corresponding to the transmission of the fourth media.

[0249] In some embodiments of this application, the second SDPoffer is also used to request to maintain the call connection between the second terminal and the first terminal.

[0250] Thus, since the embodiments of this application also specify the possible functions of the second SDP offer, the first network node can accurately determine the function of the second SDP offer and determine the corresponding SDP answer when it receives the second SDP offer.

[0251] In some embodiments of this application, the first network node may receive an UPDATE message from a third network node, the UPDATE message carrying a second SDP offer. Alternatively, the first network node may receive a call hold request message from a second terminal, the call hold request message carrying a second SDPoffer. It is understood that when the second SDPoffer is carried by the call hold request message, the second SDPoffer can be used to request to maintain the call connection between the second terminal and the first terminal.

[0252] Step 302: If the second condition is met, the first network node performs the third operation.

[0253] In this embodiment of the application, the second condition includes at least one of the following:

[0254] The first terminal corresponding to the fourth medium accesses the network via the first satellite;

[0255] The second SDPoffer includes the fifth instruction information.

[0256] In some embodiments of this application, the first terminal corresponding to the fourth media can be understood as: the first terminal is the terminal that will play the fourth media.

[0257] In some embodiments of this application, the first satellite may be any of the following: a LEO satellite, a MEO satellite, or a GEO satellite.

[0258] In some embodiments of this application, the aforementioned fifth indication information is used to indicate at least one of the following:

[0259] The second SDPoffer is used to negotiate the early session;

[0260] The fourth medium corresponds to CAT media;

[0261] The second SDPoffer is used to negotiate the transmission of CAT media;

[0262] The second SDPoffer is used to perform call hold.

[0263] Thus, since the embodiments of this application specify the possible specific content of the fifth indication information, the first network node can accurately determine whether the second SDPoffer includes the fifth indication information based on the specific content, so as to accurately determine whether the second condition is met.

[0264] In some embodiments of this application, the second condition mentioned above includes the first terminal accessing the network via a first satellite. Referring to Figure 8 and Figure 9, prior to step 302, the call method provided in this application embodiment may further include steps 401 and 402 as described below.

[0265] Step 401: The first network node obtains the access network information corresponding to the first terminal from the fourth network node.

[0266] In some embodiments of this application, the aforementioned fourth network node may include at least one of the following: a Policy Control Function (PCF) and a Policy and Charging Rules Function (PCRF).

[0267] Step 402: The first network node determines, based on the access network information, that the first terminal accesses the network through the first satellite.

[0268] In some embodiments of this application, the first network node can determine the corresponding access network side device based on the access network information. Thus, if the access network side device is the same as the first satellite, the first network node can determine that the first terminal accesses the network through the first satellite.

[0269] Thus, since the first network node can directly obtain the access network information corresponding to the first terminal from the fourth network node, and accurately determine whether the first terminal accesses the network through the first satellite using this access network information, the accuracy of the first network node in determining whether the second condition is met can be improved, thereby improving the accuracy of the first network node in performing the first operation.

[0270] In this embodiment of the application, the third operation includes at least one of the following:

[0271] Modify the parameter corresponding to the fourth media in the first SDP response answer; the first SDP response answer is the response to the second SDP offer.

[0272] The first SDP answer contains information about the second network node;

[0273] A sixth instruction message is sent to the second network node, which instructs the second network node to discard the data corresponding to the received fourth media.

[0274] In some embodiments of this application, the first SDP answer can be determined by a first network node. It is understood that the first network node can determine the first SDP answer on behalf of the first terminal.

[0275] In some embodiments of this application, the second network node can be an access gateway (AGW). Of course, the second network node can also be other network nodes, and this application does not limit this.

[0276] In some embodiments of this application, the relevant information of the second network node may include: IP address, port number, etc.

[0277] In some embodiments of this application, the first SDP answer described above can also be used to instruct a second network node to discard the received data.

[0278] In some embodiments of this application, the third operation described above includes modifying the parameters corresponding to the fourth medium. Step 302 can be implemented specifically through at least one of steps 302a and 302b described below.

[0279] Step 302a: If the second condition is met, the first network node sets the port number corresponding to the fourth media in the first SDP answer to zero.

[0280] Thus, since the first network node can set the port number corresponding to the fourth media in the first SDPanswer to zero, it can avoid the called network device from sending media. Therefore, it can avoid the calling network device from transcoding the received media and sending it to the first terminal, thereby avoiding the situation where the sound quality of the media is poor when the first terminal plays the media.

[0281] Step 302b: If the second condition is met, the first network node sets the port number corresponding to the voice service between the first terminal and the second terminal in the first SDP answer to zero.

[0282] Thus, since the first network node can set the port number corresponding to the voice service between the first terminal and the second terminal in the first SDPanswer to zero, it can avoid the called network device from sending media. Therefore, it can avoid the calling network device from transcoding the received media and sending it to the first terminal, thereby avoiding the situation where the sound quality of the media is poor when the first terminal plays the media.

[0283] This application provides a call method in which a first network node receives a second SDPoffer from a third network node for negotiating parameters corresponding to a fourth medium, and performs a third operation if a second condition is met. The second condition includes at least one of the following: a first terminal corresponding to the fourth medium accesses the network via a first satellite; the second SDPoffer includes fifth indication information; and the third operation includes at least one of the following: modifying the parameters corresponding to the fourth medium in a first SDP response (answer), where the first SDP response is the response to the second SDPoffer; including relevant information about the second network node in the first SDP response; and sending sixth indication information to the second network node, which instructs the second network node to discard the received data corresponding to the fourth medium. Since the first network node, after receiving the second SDPoffer from the third network node for negotiating the parameters corresponding to the fourth media, can modify the parameters corresponding to the fourth media in the first SDP reply answer if the first terminal accesses the network via the first satellite, and / or if the second SDPoffer includes fifth indication information, this avoids the situation where the network-side device serving the second terminal sends the fourth media to the network-side device serving the first terminal. Therefore, it reduces the need for the first terminal to renegotiate the parameters used for media transmission with the network-side device serving the first terminal, thereby reducing the decrease in media bitrate due to the change of the five-tuple information; and / or, by including the relevant information of the specified network node (i.e., the second network node) in the first SDP answer, the network serving the second terminal... The side device can send a fourth medium to the second network node, enabling the designated network node to directly send the fourth medium to the first terminal through the established connection without requiring the first terminal to renegotiate the parameters used for transmitting the medium with the second network node. This avoids a decrease in the medium's bitrate due to changes in the 5-tuple information. Alternatively, it can instruct the second network node to discard the data corresponding to the received fourth medium. This avoids the second network node sending the fourth medium to the first terminal, thus preventing the first terminal from renegotiating the parameters used for transmitting the medium with the second network node, and again avoiding a decrease in the medium's bitrate due to changes in the 5-tuple information. This also prevents the first terminal from experiencing poor sound quality when playing the medium, ensuring the user can clearly hear it, thereby improving the media's presentation.

[0284] Furthermore, after receiving the second SDP offer from the third network node for negotiating the parameters corresponding to the fourth media, the first network node can modify the parameters corresponding to the fourth media in the first SDP response answer if the first terminal accesses the network via the first satellite, and / or if the second SDP offer includes the fifth indication information. This avoids the situation where the network-side device serving the second terminal sends the fourth media to the network-side device serving the first terminal. Therefore, it avoids the situation where the network-side device serving the first terminal converts the fourth media into low-bitrate media and sends the low-bitrate media to the first terminal, thus avoiding poor sound quality of the media when the first terminal plays it. And / or, it instructs the second network node to discard the received data corresponding to the fourth media. This avoids the situation where the second network node converts the fourth media into low-bitrate media and sends the low-bitrate media to the first terminal, thus avoiding poor sound quality of the media when the first terminal plays it. In this way, the media prompting effect can be improved.

[0285] In some embodiments of this application, after step 302 above, the call method provided in the embodiments of this application may further include step 403 below.

[0286] Step 403: The first network node performs the fourth operation.

[0287] In this embodiment of the application, the fourth operation includes at least one of the following:

[0288] Send a seventh instruction message to the second network node, the seventh instruction message being used to instruct the first terminal to send the fifth medium;

[0289] Send an eighth instruction message to the first terminal, the eighth instruction message being used to instruct the first terminal to play the sixth media;

[0290] A ninth instruction message is sent to the second network node, which instructs the second network node to transmit the fourth media or the seventh media using a first Real-Time Transport Protocol (RTP) connection; wherein the first RTP connection is an RTP connection between the first terminal and the second network node, and the seventh media is the media after transcoding the fourth media.

[0291] In some embodiments of this application, the aforementioned fifth medium can be a pre-defined medium in the second network node, corresponding to the fourth medium. It is understood that the voice content corresponding to the fifth medium can be matched with the voice content corresponding to the fourth medium.

[0292] It should be noted that the above "matching" can be understood as identical, or the similarity between the two is greater than or equal to the similarity threshold.

[0293] In some embodiments of this application, the aforementioned fifth medium may be a low bitrate (low bit rate) medium.

[0294] In some embodiments of this application, the aforementioned sixth medium may be a predetermined medium in the first terminal, which corresponds to the fourth medium.

[0295] In some embodiments of this application, the aforementioned sixth medium may be a low bitrate (low bit rate) medium.

[0296] In some embodiments of this application, the second network node can receive the fourth medium and transcode the fourth medium to obtain the seventh medium.

[0297] Therefore, since the first network node can instruct the second network node to send the fifth media to the first terminal, the second network node can directly use the RTP connection with the first terminal to send the first media without renegotiating the parameters used to transmit the first media. This allows reuse of the existing ROHC state, avoiding the problem of poor sound quality of the first media caused by ROHC restart. And / or, the first terminal can be instructed to play the sixth media, allowing it to play the sixth media pre-stored in the first terminal without receiving and playing media from the network-side device. This avoids the network-side device converting the sixth media into low-bitrate media, thus improving the sound quality of the sixth media played by the first terminal. And / or, the second network node can be instructed to directly use the RTP connection with the first terminal to send the fourth or seventh media without renegotiating the parameters used to transmit the first media. This also allows reuse of the existing ROHC state, avoiding the problem of poor sound quality of the first media caused by ROHC restart.

[0298] In some embodiments of this application, before step 403 above, the call method provided in the embodiments of this application may further include steps 404 and 405 below, and step 403 above can be specifically implemented by step 403a below.

[0299] Step 404: The first network node sends the first SDP answer to the third network node.

[0300] In this embodiment of the application, the first SDP answer indicates acceptance of negotiated transmission of a fourth medium.

[0301] Step 405: The first network node receives the fifth message from the third network node.

[0302] In this embodiment of the application, the fifth message is used to indicate ringing.

[0303] Step 403a: The first network node performs the fourth operation based on the fifth message.

[0304] Thus, since the first network node can send the first SDP answer to the third network node and, upon learning that the second terminal is ringing, can perform the fourth operation to enable the first terminal to play the fourth media and / or media corresponding to the fourth media, it can accurately notify the user that the second terminal is ringing, thereby improving the media notification effect.

[0305] The following will use specific examples to illustrate the complete process of the call method provided in the embodiments of this application.

[0306] Example 3: After receiving the request to establish early media, the first network node processes the SDP answer on behalf of the first terminal.

[0307] As shown in Figure 10, the call method provided in this embodiment may include the following steps:

[0308] Steps 1-7 are the same as steps 1-7 in Figure 1B.

[0309] It should be noted that in step 1 of Figure 10, the Invite message can carry a second SDP offer (i.e., the SDP offer in Figure 10).

[0310] Step 8: When the first network node (e.g., P-CSCF-1 / SBC) determines that the second condition is met, the third operation is performed.

[0311] The second condition includes: the first terminal accesses the network via satellite or via a GEO satellite;

[0312] The SDP offer contains a fifth instruction; for example, the fifth instruction is used to indicate that the second SDP offer is for negotiating an early session, and the fifth instruction can be Content-Disposition:early-session; and / or, the fifth instruction is used to indicate that the fourth media corresponds to the CAT media, and the fifth instruction can be a=content:g.3gpp.cat.

[0313] The third operation includes at least one of the following:

[0314] The first network node determines the first SDP answer on behalf of the first terminal and modifies the parameters corresponding to the fourth medium in the first SDP answer; for example, it sets the port number corresponding to the fourth medium to zero.

[0315] The first SDP answer carries relevant information about the second network node (e.g., AGW) (e.g., IP address, port number, etc.);

[0316] The first network node instructs the second network node to discard the data corresponding to the received fourth media.

[0317] Steps 9-11 are the same as steps 8-10 in Figure 1B, except that in Figure 10, the first network node (i.e., P-CSCF-1) replaces the first terminal in sending the SDP answer.

[0318] Step 12, at least one of steps 6a and 6b in Figure 6; or, at least one of steps 6a and 6b in Figure 7.

[0319] It is understandable that by executing the steps in the above process, on the one hand, the first network node refuses to establish early media on behalf of the first terminal (i.e., sets the port number to zero), thus preventing the called network device from sending ringback tones or prompts; on the other hand, the first network node instructs the second network node to discard the data corresponding to the received fourth media, thus preventing the second network node from transcoding the received ringback tones or prompts and sending them to the first terminal; furthermore, the second network node uses an RTP connection for voice transmission to send media, which can reuse the existing ROHC state and avoid the problem of poor media playback quality caused by ROHC restart; and finally, the first terminal can play locally scheduled media without media transmission, thus ensuring the playback quality of the media played by the first terminal.

[0320] Example 4

[0321] As shown in Figure 11, the call method provided in this embodiment may include the following steps:

[0322] Steps 1-7 are the same as steps 1-7 in Figure 1B.

[0323] Step 8: When the first network node determines that the second condition is met, the third operation is performed.

[0324] The second condition includes: the first terminal accesses the network via satellite or via a GEO satellite;

[0325] The SDP offer contains a fifth instruction; for example, the fifth instruction is used to indicate that the second SDP offer is for negotiating an early session, and the fifth instruction can be Content-Disposition:early-session; and / or, the fifth instruction is used to indicate that the fourth media corresponds to the CAT media, and the fifth instruction can be a=content:g.3gpp.cat.

[0326] The third operation includes: the first network node responding to the first SDP answer on behalf of the first terminal, and the first SDP answer carrying relevant information of the second network node (such as IP address, port number, etc.).

[0327] Steps 9-11 are the same as steps 9-11 in Figure 10.

[0328] Step 12: Based on the received 180 message, the first network node instructs the second network node to transcode the message and send it through the RTP connection used for voice transmission between the first terminal and the second network node.

[0329] Step 13: MRF-2 sends a fourth medium (e.g., a ringback tone) to the second network node.

[0330] Step 14: After receiving the fourth media, the second network node transcodes and packages it into a five-tuple corresponding to the voice RTP, and sends the transcoded media, i.e. the transcoded ringback tone (e.g., the seventh media), through the RTP connection.

[0331] Understandably, compared to Example 3, the second network node does not need to play the fourth or seventh media, thus simplifying its execution process. Furthermore, the second network node uses an RTP connection for voice to send the transcoded seventh media, avoiding a ROHC restart.

[0332] Example 5: After receiving the call hold request, the first network node processes the SDP answer on behalf of the first terminal.

[0333] As shown in Figure 12, the call method provided in this embodiment may include the following steps:

[0334] Steps 1-3 are the same as steps 1-3 in Figure 1D.

[0335] Step 4: When the first network node (e.g., P-CSCF-1 / SBC) determines that the second condition is met, the third operation is performed.

[0336] The second condition includes: the first terminal accesses the network via satellite or via a GEO satellite;

[0337] The SDP offer contains a fifth instruction message; this fifth instruction message is used to instruct the second SDPoffer to perform call holding, for example, the fifth instruction message is a = sendonly.

[0338] The third operation includes at least one of the following:

[0339] The first network node responds to the first SDP answer on behalf of the first terminal and rejects the second SDP offer. That is, in the first SDP answer, the port number corresponding to the voice service between the first terminal and the second terminal is set to zero.

[0340] The first SDP answer carries relevant information about the second network node (e.g., AGW) (e.g., IP address, port number, etc.);

[0341] The first network node instructs the second network node to discard the data corresponding to the received fourth media.

[0342] Of course, the first network node can also send a re-Invite message to the first terminal, carrying a sendonly instruction, to modify the IP address and port number of the MRF to the IP address and port number of the SBC (i.e., the IP address and port number of the voice RTP).

[0343] Steps 5-6 are the same as steps 5 and 7 in Figure 1D.

[0344] Step 7, at least one of steps 6a and 6b in Figure 6; or, at least one of steps 6a and 6b in Figure 7.

[0345] It is understandable that by executing the steps in the above process, on the one hand, the first network node refuses to establish a prompt tone on behalf of the first terminal (i.e., sets the port number to zero), thus preventing the called network device from sending a prompt tone; on the other hand, the first network node instructs the second network node to discard the data corresponding to the received fourth media, thus preventing the second network node from sending the received prompt tone code back to the first terminal; furthermore, the second network node uses an RTP connection for transmitting voice to send the media, which can reuse the existing ROHC state and avoid the problem of poor media playback quality caused by ROHC restart; furthermore, the second network node can play a low-bitrate prompt tone, thus avoiding the problem of poor playback quality of transcoded media caused by voice transcoding; and finally, the first terminal can play locally pre-defined media to avoid media transmission, thereby ensuring the playback quality of the media played by the first terminal.

[0346] Example 6

[0347] As shown in Figure 13, the call method provided in this embodiment may include the following steps:

[0348] Steps 1-3 are the same as steps 1-3 in Figure 12.

[0349] Step 4: When the first network node (e.g., P-CSCF-1 / SBC) determines that the second condition is met, the third operation is performed.

[0350] The second condition includes: the first terminal accesses the network via satellite or via a GEO satellite;

[0351] The SDP offer contains a fifth instruction message; this fifth instruction message is used to instruct the second SDPoffer to perform call holding, for example, the fifth instruction message is a = sendonly.

[0352] The third operation includes: the first network node responding to the first SDP answer on behalf of the first terminal, carrying relevant information of the second network node (e.g., AGW) in the first SDP answer (e.g., the IP address and port number assigned by the second network node), and instructing the second network node to transcode the data corresponding to the fourth media and send it through the RTP connection used for voice transmission between the second and first terminals when it receives the data.

[0353] Of course, the first network node can also send a re-Invite message to the first terminal, carrying a sendonly instruction, to change the IP address and port number of the MRF to the IP address and port number of the SBC.

[0354] Steps 5-6 are the same as steps 5 and 6 in Figure 12.

[0355] Steps 8-9: After receiving the fourth media, the second network node transcodes and packages it into a five-tuple corresponding to the voice RTP, and sends the transcoded seventh media through the RTP channel used for voice transmission.

[0356] The call method provided in this application can be executed by a call device. This application uses a call device executing the call method as an example to illustrate the call device provided in this application.

[0357] This application provides a calling device. As an example, the calling device can be a communication device or a component within a communication device, such as a chip. The communication device can be a terminal, a network-side device, or a server, etc. Exemplarily, the terminal can be, but is not limited to, the type of terminal 11 listed above, and the network-side device can be, but is not limited to, the type of network-side device 12 listed above. This application does not impose specific limitations.

[0358] The communication device includes a receiving module, a transmitting module, and a processing module. These modules can be implemented in software or hardware. When implemented in hardware, the processing module can be implemented by a processor. For example, the processor can include general-purpose processors, special-purpose processors, such as a Central Processing Unit (CPU), microprocessor, Digital Signal Processor (DSP), Artificial Intelligence (AI) processor, Graphics Processing Unit (GPU), Application Specific Integrated Circuit (ASIC), Network Processor (NP), Field Programmable Gate Array (FPGA), or other programmable logic devices, gate circuits, transistors, discrete hardware components, etc. The receiving and transmitting modules can be implemented by a communication interface, which can include one or more of the following: transceiver, pins, circuits, bus, radio frequency unit, etc.

[0359] Specifically, referring to Figure 14, when the communication device is a network-side device or a component of a network-side device, the communication device 50 includes: a receiving module 51 and a processing module 52.

[0360] The receiving module 51 is configured to receive a first message from a first terminal, the first message being used to request a call to a second terminal. The processing module 52 is configured to perform a first operation when a first condition is met, the first condition including any one of the following: the first terminal accesses the network via a first satellite, and the first message includes at least one of first indication information and a first SDP offer, the first indication information indicating at least one of the following: the first terminal supports early media, the first terminal supports early sessions, and the first SDP offer is used to negotiate parameters corresponding to the transmission of early media; the first message includes at least one of the first indication information and the first SDP offer; wherein the first operation includes at least one of the following: deleting the first indication information from the first message; modifying the first indication information; deleting the first SDP offer from the first message.

[0361] This application provides a calling device. After receiving a first message from a first terminal requesting to call a second terminal, the calling device can perform a first operation to delete the first indication information and / or modify the first indication information from the first message, either when the first terminal accesses the network via a first satellite and the first message includes first indication information and / or a first SDP offer, or when the first message includes first indication information and / or a first SDP offer. This allows the network-side device serving the second terminal to know, upon receiving the first message, that the first terminal may not support early media and / or early sessions. Therefore, when early media needs to be transmitted to the first terminal, the first terminal does not need to renegotiate the parameters used for media transmission with the network-side device serving the second terminal, thereby avoiding a decrease in media bitrate due to changes in the 5-tuple information; and / or, perform the first operation to delete the first SDP from the first message. In this way, when the network-side device serving the second terminal receives the first message, it can confirm that the first terminal may not need to negotiate the parameters used for transmitting the media with the network-side device serving the second terminal. Therefore, when it is necessary to transmit early media to the first terminal, the first terminal does not need to re-negotiate the parameters used for transmitting the media with the network-side device serving the second terminal, thereby avoiding the decrease in media bitrate due to the change of the five-tuple information. This can further avoid the poor sound quality of the media when the first terminal plays the media, so as to avoid the user not being able to hear the media clearly. In this way, the prompting effect of the media can be improved.

[0362] In one possible implementation, the first operation includes modifying the first indication information. Specifically, the processing module 52 is configured to modify the first indication information to second indication information when the first indication information indicates that the first terminal supports early media; wherein the second indication information indicates at least one of the following: the first terminal does not support early media, or the first terminal does not support early sessions.

[0363] In one possible implementation, the calling device 50 provided in this application embodiment may further include a sending module. The sending module is configured to send a second message to a second terminal, the second message being used to request a call to the second terminal. Where the first operation includes deleting first indication information from the first message, the second message does not include the first indication information; or, where the first operation includes modifying the first indication information, the second message includes the second indication information; the second indication information indicates at least one of the following: the first terminal does not support early media; the first terminal does not support early sessions; where the first operation includes deleting the first SDP offer from the first message, the second message does not include the first SDP offer.

[0364] In one possible implementation, the receiving module 51 is further configured to receive a third message from the second terminal or the third network node, the third message being used to indicate ringing or to indicate call failure. The processing module 52 is further configured to perform a second operation based on the third message received by the receiving module 51, the second operation including at least one of the following: sending a third indication message to the second network node, the third indication message being used to indicate sending a first medium to the first terminal; sending a fourth indication message to the first terminal, the fourth indication message being used to indicate that the first terminal plays a second medium; and sending a fourth message to the first terminal, the fourth message being used to indicate that the first terminal plays a third medium.

[0365] In one possible implementation, the first medium includes a medium corresponding to a ringback tone or a notification tone; or, the second medium includes a medium corresponding to a ringback tone or a notification tone; or, the third medium includes a medium corresponding to a ringback tone or a notification tone.

[0366] In one possible implementation, the first condition includes the first terminal accessing the network via the first satellite, and the first message includes at least one of first indication information and a first SDP offer. The processing module 52 is further configured to obtain access network information corresponding to the first terminal; and determine, based on the access network information, that the first terminal accesses the network via the first satellite; wherein the access network information is obtained from the first message or from the fourth network node.

[0367] Referring to Figure 15, when the communication device is a network-side device or a component of a network-side device, the communication device 60 includes: a receiving module 61 and a processing module 62.

[0368] The receiving module 61 is configured to receive a second SDP offer from a third network node, which is used to negotiate parameters corresponding to the fourth medium. The processing module 62 is configured to perform a third operation if a second condition is met, the second condition including at least one of the following: the first terminal corresponding to the fourth medium accesses the network via a first satellite; the second SDP offer includes fifth indication information; wherein the third operation includes at least one of the following: modifying the parameters corresponding to the fourth medium in a first SDP response, the first SDP response being a response to the second SDP offer; including relevant information about the second network node in the first SDP response; and sending a sixth indication information to the second network node, the sixth indication information instructing the second network node to discard the received data corresponding to the fourth medium.

[0369] This application provides a communication device. After receiving a second SDP offer from a third network node for negotiating parameters corresponding to a fourth medium, the communication device can, if the first terminal accesses the network via a first satellite, and / or if the second SDP offer includes fifth indication information, modify the parameters corresponding to the fourth medium in the first SDP response. This avoids the network-side device serving the second terminal sending the fourth medium to the network-side device serving the first terminal. Therefore, it reduces the need for the first terminal to renegotiate the parameters used for media transmission with the network-side device serving the first terminal, thereby reducing the decrease in media bitrate due to changes in the five-tuple information; and / or, in the first SDP... The answer contains information about the specified network node (i.e., the second network node). This allows the network-side device serving the second terminal to send the fourth media to the second network node, enabling the specified network node to directly send the fourth media to the first terminal via the established connection. This eliminates the need for the first terminal to renegotiate the parameters used for media transmission with the second network node, thus preventing a decrease in media bitrate due to changes in the 5-tuple information. Alternatively, the answer can instruct the second network node to discard the received data corresponding to the fourth media. This prevents the second network node from sending the fourth media to the first terminal, thus avoiding the need for the first terminal to renegotiate the parameters used for media transmission with the second network node, and again preventing a decrease in media bitrate due to changes in the 5-tuple information. This also prevents the first terminal from experiencing poor sound quality when playing media, ensuring the user can clearly hear the media, thereby improving the media's presentation.

[0370] In one possible implementation, the aforementioned fifth instruction information is used to indicate at least one of the following: the second SDP offer is used to negotiate an early session; the fourth media corresponds to a custom tone CAT media; the second SDP offer is used to negotiate the transmission of CAT media; and the second SDP offer is used to perform call hold.

[0371] In one possible implementation, the aforementioned second SDP offer is also used to request that the call connection between the second terminal and the first terminal be maintained.

[0372] In one possible implementation, the third operation described above includes modifying the parameters corresponding to the fourth media. The processing module 62 is specifically used for at least one of the following: setting the port number corresponding to the fourth media in the first SDP answer to zero; setting the port number corresponding to the voice service between the first terminal and the second terminal in the first SDP answer to zero.

[0373] In one possible implementation, the processing module 62 is further configured to perform a fourth operation, which includes at least one of the following: sending a seventh instruction message to a second network node, the seventh instruction message being used to instruct the first terminal to send a fifth medium; sending an eighth instruction message to the first terminal, the eighth instruction message being used to instruct the first terminal to play a sixth medium; and sending a ninth instruction message to the second network node, the ninth instruction message being used to instruct the second network node to transmit the fourth medium or the seventh medium using a first Real-Time Transport Protocol (RTP) connection; wherein the first RTP connection is an RTP connection between the first terminal and the second network node, and the seventh medium is a medium after transcoding the fourth medium.

[0374] In one possible implementation, the calling device 50 provided in this application embodiment may further include a sending module. The sending module is configured to send a first SDP answer to a third network node, the first SDP answer indicating acceptance of negotiated transmission of a fourth medium. The receiving module 61 is further configured to receive a fifth message from the third network node, the fifth message indicating ringing. The processing module 62 is specifically configured to perform a fourth operation based on the fifth message.

[0375] In one possible implementation, the second condition includes the first terminal accessing the network via the first satellite. The receiving module 61 is further configured to obtain access network information corresponding to the first terminal from the fourth network node. The processing module 62 is further configured to determine, based on the access network information received by the receiving module 61, that the first terminal accesses the network via the first satellite.

[0376] In one possible implementation, the aforementioned fourth media includes at least one of the following: media corresponding to the ringback tone, media corresponding to the prompt tone, and media corresponding to CAT.

[0377] The communication device provided in this application embodiment can implement the various processes implemented in the method embodiments of Figures 3 to 13 and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0378] As shown in Figure 16, this application embodiment also provides a communication device 70, including a processor 71 and a memory 72. The memory 72 stores a program or instructions that can be executed on the processor 71. For example, when the communication device 70 is a network-side device, when the program or instructions are executed by the processor 71, they implement the various steps of the above-described call method embodiment and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0379] This application also provides a network-side device, including a processor and a communication interface. The communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the steps of the method embodiments shown in Figures 3 to 13. This network-side device embodiment corresponds to the above-described network-side device method embodiment. All implementation processes and methods of the above-described method embodiments can be applied to this network-side device embodiment and achieve the same technical effects.

[0380] Specifically, this application embodiment also provides a network-side device, which can be the communication device shown in FIG14 or FIG15. As shown in FIG17, the network-side device 80 includes: an antenna 81, a radio frequency device 82, a baseband device 83, a processor 84, and a memory 85. The antenna 81 is connected to the radio frequency device 82. In the uplink direction, the radio frequency device 82 receives information through the antenna 81 and sends the received information to the baseband device 83 for processing. In the downlink direction, the baseband device 83 processes the information to be transmitted and sends it to the radio frequency device 82. The radio frequency device 82 processes the received information and transmits it through the antenna 81.

[0381] The method executed by the network-side device in the above embodiments can be implemented in the baseband device 83, which includes a baseband processor.

[0382] The baseband device 83 may include at least one baseband board, on which multiple chips are disposed, as shown in FIG17. One of the chips is, for example, a baseband processor, which is connected to the memory 85 via a bus interface to call the program in the memory 85 and execute the network device operation shown in the above method embodiment.

[0383] The network-side device may also include a network interface 86, such as a Common Public Radio Interface (CPRI).

[0384] Specifically, the network-side device 80 in this application embodiment further includes: instructions or programs stored in memory 85 and executable on processor 84. Processor 84 calls the instructions or programs in memory 85 to execute the methods executed by the modules shown in FIG14 or FIG15 and achieve the same technical effect. To avoid repetition, it will not be described in detail here.

[0385] Specifically, this application also provides a network-side device. As shown in FIG18, the network-side device 90 includes a processor 91, a network interface 92, and a memory 93. The network-side device may be the communication device shown in FIG14 or FIG15. The network interface 92 is, for example, a Common Public Radio Interface (CPRI).

[0386] Specifically, the network-side device 90 in this application embodiment further includes: instructions or programs stored in memory 93 and executable on processor 91. Processor 91 calls the instructions or programs in memory 93 to execute the methods executed by each module shown in FIG14 or FIG15 and achieve the same technical effect. To avoid repetition, it will not be described in detail here.

[0387] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described call method embodiments and achieve the same technical effect. To avoid repetition, they will not be described again here.

[0388] The processor mentioned above is the processor in the terminal described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk. In some examples, the readable storage medium may be a non-transient readable storage medium.

[0389] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above-described call method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0390] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0391] This application also provides a computer program / program product, which is stored in a storage medium and executed by at least one processor to implement the various processes of the above-described call method embodiments, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0392] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0393] From the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of computer software products plus necessary general-purpose hardware platforms, and of course, they can also be implemented by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes several instructions to cause the terminal or network-side device to execute the methods described in the various embodiments of this application.

[0394] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other implementations under the guidance of this application without departing from the spirit and scope of the claims. All of these implementations are within the protection scope of this application.

Claims

1. A method for making a call, comprising: The first network node receives a first message from the first terminal, the first message being used to request a call to the second terminal; If a first condition is met, the first network node performs a first operation, wherein the first condition includes any one of the following: The first terminal accesses the network via the first satellite, and the first message includes at least one of the first indication information and the first Session Description Protocol (SDP) request offer. The first indication information indicates at least one of the following: the first terminal supports early media, the first terminal supports early sessions, and the first SDP offer is used to negotiate parameters corresponding to the transmission of early media. The first message includes at least one of the first instruction information and the first SDP offer; The first operation includes at least one of the following: Delete the first instruction information from the first message; Modify the first instruction information; Delete the first SDP offer from the first message.

2. The method according to claim 1, wherein, The first operation includes modifying the first instruction information; The first network node performs a first operation, including: If the first indication information indicates that the first terminal supports early media, the first network node will modify the first indication information to the second indication information; The second indication information indicates at least one of the following: the first terminal does not support early media, or the first terminal does not support early sessions.

3. The method according to claim 1, wherein, The method further includes: The first network node sends a second message to the second terminal, the second message being used to request a call to the second terminal; Where the first operation includes deleting the first indication information from the first message, the second message does not include the first indication information; or, If the first operation includes modifying the first indication information, the second message includes second indication information; the second indication information indicates at least one of the following: the first terminal does not support early media, or the first terminal does not support early sessions; If the first operation includes deleting the first SDP offer from the first message, the second message does not include the first SDP offer.

4. The method according to claim 3, wherein, The method further includes: The first network node receives a third message from the second terminal or the third network node, the third message being used to indicate ringing or to indicate call failure; The first network node performs a second operation based on the third message, the second operation including at least one of the following: Send a third instruction message to the second network node, the third instruction message being used to instruct the first terminal to send the first medium; Send a fourth instruction message to the first terminal, the fourth instruction message being used to instruct the first terminal to play the second media; A fourth message is sent to the first terminal, the fourth message being used to instruct the first terminal to play third media.

5. The method according to claim 4, wherein, The first media includes media corresponding to a ringback tone or a notification tone; or, The second medium includes the medium corresponding to the ringback tone or notification tone; or, The third media includes media corresponding to the ringback tone or notification tone.

6. The method according to any one of claims 1 to 5, wherein, The first condition includes the first terminal accessing the network via the first satellite, and the first message includes at least one of the first indication information and the first SDP offer; the method further includes: The first network node obtains the access network information corresponding to the first terminal; The first network node determines, based on the access network information, that the first terminal accesses the network via the first satellite; The access network information is obtained from the first message or from the fourth network node.

7. A method for making a call, comprising: The first network node receives a second SDP offer from the third network node, which is used to negotiate the parameters corresponding to the transmission of the fourth medium. If the second condition is met, the first network node performs the third operation, wherein the second condition includes at least one of the following: The first terminal corresponding to the fourth media accesses the network via the first satellite; The second SDP offer includes the fifth instruction information; The third operation includes at least one of the following: Modify the parameter corresponding to the fourth media in the first SDP response answer, where the first SDP response is the response to the second SDP offer; The first SDP answer contains information about the second network node; A sixth indication message is sent to the second network node, the sixth indication message being used to instruct the second network node to discard the data corresponding to the received fourth media.

8. The method according to claim 7, wherein, The fifth instruction information is used to indicate at least one of the following: The second SDP offer is used to negotiate an early session; The fourth media corresponds to the custom prompt sound CAT media; The second SDP offer is used to negotiate the transmission of CAT media; The second SDP offer is used to perform call hold.

9. The method according to claim 7, wherein, The second SDP offer is also used to request that the call connection between the second terminal and the first terminal be maintained.

10. The method according to any one of claims 7 to 9, wherein, The third operation includes modifying the parameters corresponding to the fourth media; the first network node performs the third operation, including at least one of the following: The first network node sets the port number corresponding to the fourth media in the first SDP answer to zero; The first network node sets the port number corresponding to the voice service between the first terminal and the second terminal in the first SDP answer to zero.

11. The method according to any one of claims 7 to 10, wherein, The method further includes: The first network node performs a fourth operation, which includes at least one of the following: Send a seventh indication message to the second network node, the seventh indication message being used to instruct the first terminal to send the fifth medium; Send an eighth instruction message to the first terminal, the eighth instruction message being used to instruct the first terminal to play a sixth medium; A ninth instruction message is sent to the second network node, the ninth instruction message being used to instruct the second network node to transmit the fourth media or the seventh media using a first Real-Time Transport Protocol (RTP) connection; wherein, the first RTP connection is an RTP connection between the first terminal and the second network node, and the seventh media is a media after transcoding the fourth media.

12. The method according to claim 11, wherein, The method further includes: The first network node sends the first SDP answer to the third network node, and the first SDP answer indicates acceptance of the negotiated transmission of the fourth medium; The first network node receives a fifth message from the third network node, the fifth message being used to indicate ringing; The first network node performs a fourth operation, including: The first network node performs the fourth operation based on the fifth message.

13. The method according to any one of claims 7 to 12, wherein, The second condition includes the first terminal accessing the network via a first satellite; the method further includes: The first network node obtains the access network information corresponding to the first terminal from the fourth network node; The first network node determines, based on the access network information, that the first terminal accesses the network via the first satellite.

14. The method according to any one of claims 7 to 13, wherein, The fourth media includes at least one of the following: media corresponding to the ringback tone, media corresponding to the prompt tone, and media corresponding to CAT.

15. A communication device, the communication device comprising: Receive module and processing module; The receiving module is used to receive a first message from the first terminal, the first message being used to request a call to the second terminal; The processing module is configured to perform a first operation when a first condition is met, wherein the first condition includes any one of the following: The first terminal accesses the network via the first satellite, and the first message includes at least one of the first indication information and the first SDP offer. The first indication information indicates at least one of the following: the first terminal supports early media, the first terminal supports early sessions, and the first SDP offer is used to negotiate parameters corresponding to the transmission of early media. The first message includes at least one of the first instruction information and the first SDP offer; The first operation includes at least one of the following: Delete the first instruction information from the first message; Modify the first instruction information; Delete the first SDP offer from the first message.

16. The apparatus according to claim 15, wherein, The first operation includes modifying the first instruction information; The processing module is specifically used to modify the first indication information to the second indication information when the first indication information indicates that the first terminal supports early media. The second indication information indicates at least one of the following: the first terminal does not support early media, or the first terminal does not support early sessions.

17. The apparatus according to claim 15, wherein, The communication device further includes: a transmitting module; The sending module is used to send a second message to the second terminal, the second message being used to request a call to the second terminal; Where the first operation includes deleting the first indication information from the first message, the second message does not include the first indication information; or, If the first operation includes modifying the first indication information, the second message includes second indication information; the second indication information indicates at least one of the following: the first terminal does not support early media, or the first terminal does not support early sessions.

18. The apparatus according to claim 17, wherein, The receiving module is further configured to receive a third message from the second terminal or the third network node, the third message being used to indicate ringing or to indicate call failure; The processing module is further configured to perform a second operation based on the third message received by the receiving module, the second operation including at least one of the following: Send a third instruction message to the second network node, the third instruction message being used to instruct the first terminal to send the first medium; Send a fourth instruction message to the first terminal, the fourth instruction message being used to instruct the first terminal to play the second media; A fourth message is sent to the first terminal, the fourth message being used to instruct the first terminal to play third media.

19. The apparatus according to claim 18, wherein, The first media includes media corresponding to a ringback tone or a notification tone; or, The second medium includes the medium corresponding to the ringback tone or notification tone; or, The third media includes media corresponding to the ringback tone or notification tone.

20. The apparatus according to any one of claims 15 to 19, wherein, The first condition includes the first terminal accessing the network via the first satellite, and the first message including the first indication information; The processing module is further configured to obtain access network information corresponding to the first terminal; and determine, based on the access network information, that the first terminal accesses the network through the first satellite; The access network information is obtained from the first message or from the fourth network node.

21. A communication device, the communication device comprising: Receive module and processing module; The receiving module is used to receive a second SDP offer from a third network node, the second SDP offer being used to negotiate parameters corresponding to the transmission of the fourth medium; The processing module is configured to perform a third operation if a second condition is met, wherein the second condition includes at least one of the following: The first terminal corresponding to the fourth media accesses the network via the first satellite; The second SDP offer includes the fifth instruction information; The third operation includes at least one of the following: Modify the parameter corresponding to the fourth media in the first SDP response answer, where the first SDP response is the response to the second SDP offer; The first SDP answer contains information about the second network node; A sixth indication message is sent to the second network node, the sixth indication message being used to instruct the second network node to discard the data corresponding to the received fourth media.

22. The apparatus according to claim 21, wherein, The fifth instruction information is used to indicate at least one of the following: The second SDP offer is used to negotiate an early session; The fourth media corresponds to the custom prompt sound CAT media; The second SDP offer is used to negotiate the transmission of CAT media; The second SDP offer is used to perform call hold.

23. The apparatus according to claim 21, wherein, The second SDP offer is also used to request that the call connection between the second terminal and the first terminal be maintained.

24. The apparatus according to any one of claims 21 to 23, wherein, The third operation includes modifying the parameters corresponding to the fourth media; The processing module is specifically used for at least one of the following: Set the port number corresponding to the fourth media mentioned in the first SDP answer to zero; Set the port number corresponding to the voice service between the first terminal and the second terminal in the first SDP answer to zero.

25. The apparatus according to any one of claims 21 to 24, wherein, The processing module is further configured to perform a fourth operation, the fourth operation including at least one of the following: Send a seventh indication message to the second network node, the seventh indication message being used to instruct the first terminal to send the fifth medium; Send an eighth instruction message to the first terminal, the eighth instruction message being used to instruct the first terminal to play a sixth medium; A ninth instruction message is sent to the second network node, the ninth instruction message being used to instruct the second network node to transmit the fourth media or the seventh media using a first Real-Time Transport Protocol (RTP) connection; wherein, the first RTP connection is an RTP connection between the first terminal and the second network node, and the seventh media is a media after transcoding the fourth media.

26. The apparatus according to claim 25, wherein, The communication device further includes: a transmitting module; The sending module is used to send the first SDP answer to the third network node, wherein the first SDP answer indicates acceptance of the negotiated transmission of the fourth medium; The receiving module is further configured to receive a fifth message from the third network node, the fifth message being used to indicate ringing; The processing module is specifically used to execute the fourth operation based on the fifth message.

27. The apparatus according to any one of claims 21 to 26, wherein, The second condition includes the first terminal accessing the network via the first satellite; The receiving module is further configured to obtain access network information corresponding to the first terminal from the fourth network node; The processing module is further configured to determine, based on the access network information received by the receiving module, that the first terminal accesses the network via the first satellite.

28. The apparatus according to any one of claims 21 to 27, wherein, The fourth media includes at least one of the following: media corresponding to the ringback tone, media corresponding to the prompt tone, and media corresponding to CAT.

29. A network-side device comprising a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the call method as described in any one of claims 1 to 14.

30. A readable storage medium storing a program or instructions that, when executed by a processor, implement the steps of the call method as described in any one of claims 1 to 14.

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