CN101212459A - Method, system and device for controlling media encoding rate - Google Patents

Abstract

The invention discloses a method for controlling the media coding rate in an IP multimedia session. The core of the method is that the media coding rate applied by the wireless terminal is simultaneously controlled by the network device responsible for wireless resource management in the wireless network where it is located and the wireless network of the wireless network where the communication peer is located. resource constraints. The invention also discloses a system and equipment for controlling the media coding rate in the IP multimedia session. In the present invention, the network device controls and decides the rate adjustment request of the wireless terminal, and can also dynamically allocate resources according to the request of the wireless terminal, so as to ensure that the multimedia session after the coding rate adjustment can be effectively coded, and make the media used by the wireless terminal The encoding rate is also restricted by the communication peer and wireless network resource conditions.

Description

Method, system and device for controlling media encoding rate

technical field

The present invention relates to the communication field, in particular to a method, system and equipment for controlling media coding rate.

Background technique

In the communication system, media content such as voice and video needs to be sampled and quantized into digital signals, then compressed and encoded, and then transmitted through the communication network. In mobile communication systems, due to the rapid changes in the wireless channel environment, adaptive source coding with adjustable rates is usually used to dynamically adjust the coding rate according to the quality of the wireless channel and the system load. The configuration achieves a better balance. When the system load is light, high-rate source coding is usually used to provide a high-quality communication experience, but on the other hand, because high-rate source coding occupies more bandwidth, it can only provide a lower total system capacity . Conversely, when the system load is heavy, by configuring the source coding with a lower rate, less system bandwidth can be occupied and the total number of users accommodated by the system can be increased, but the communication quality is not optimal. In UMTS (Universal Mobile Telecommunication System, universal mobile communication system), the voice uses AMR (Adaptive Multi-Rate, adaptive multi-rate coding) and AMR-WB (AMR-Wide Band, adaptive multi-rate wideband coding) coding technology, Among them, AMR supports a total of 8 rate options from 4.75kpbs to 12.2kpbs, while AMR-WB supports a total of 9 rate options from 6.60kpbs to 23.85kpbs.

The UMTS system includes two parts: UTRAN (UMTS Terrestrial Radio Access Network, UMTS Terrestrial Radio Access Network) and CN (Core Network, core network). Among them, CN includes two domains, CS (Circuit Switch, Circuit Switching) and PS (Packet Switch, Packet Switching). (Internet Protocol, Internet Protocol) packet data services. On the other hand, the mobile communication network is gradually developing in the direction of all-IP, and the 3GPP (3rd Generation Partner Project, third-generation partnership project) organization has also introduced a new IMS (IP Multimedia Subsystem, IP Multimedia Subsystem) domain in the UMTS network. , can provide conversational services based on IP, typically including VoIP (Voice Over IP, voice over IP) services.

UTRAN is composed of RNC (Radio Network Control, radio network controller) and NodeB (Node B), wherein RNC is responsible for allocating and managing radio resources, and can obtain the usage of radio resources at any time. Therefore, in UMTS network, automatic The rate adjustment and control for multi-rate speech coding is also initiated by the RNC. The uplink rate control is a process in which the RNC adjusts the coding rate applied by the UE, and the downlink rate control is a process in which the RNC notifies the CS domain CN or the communication peer to adjust the coding rate.

Specifically, the RNC sends a Transport Format Combination Control (Transport Format Combination Control) to the RRC entity of the UE through an RRC (Radio Resource Control, radio resource control) entity to perform uplink rate control. The RRC entity of the UE specifically controls the vocoder of the UE to adjust the speech coding rate according to this message, and at the same time controls the medium access control layer (MAC, Medium Access Control) entity to modify the available transmission coding format combination (TFC, Transport FormatCombination), and then The UE can then apply the new speech coding rate and use the new transmission format combination, thereby changing the data rate and speech coding rate of the UE's uplink transmission.

The downlink rate control is a process in which the RNC sends a rate control frame through the user plane protocol Iu-UP between the RNC and the CN in the CS domain. After the voice-bearing connection is established, the Iu-UP initialization process negotiates the available coding rate set between the RNC and the CS domain, and the rate control frame can modify the voice coding available in the direction opposite to the sending direction of the rate control frame rate set. In the traditional R99 (Release99) circuit domain voice conversation service, the codec converter (or vocoder) in the MSC (Mobile Switch Center, mobile switching center) will convert the voice code, and completely Different encoding methods are used for transmission. After the R4 (Release 4) version, the bearer and control are separated, the voice bearer is provided by the MGW (Media GateWay, media gateway), and the concept of TrFO (Transcoder Free Operation, operation without a codec converter) is introduced , so that the circuit domain core network does not use a vocoder on the voice bearer, that is, voice coding does not perform any conversion on the entire bearer connection. When TrFO is not applied, the CN in the CS domain always controls the transcoder according to the Iu-UP rate control process initiated by the RNC, and adjusts the encoding rate in the direction from the CN to the RNC to meet the requirements of the RNC, but it will not take the initiative in the Iu-UP rate control process. The UP initiates the rate control process to modify the available coding rate set from the RNC to the CN direction. In the case of applying TrFO, since there is no code converter in the CN, the code rate cannot be adjusted to meet the requirements of the RNC. The Iu-UP rate control frame initiated from one side of the RNC1 will be transmitted on the user plane interface between the MGWs. It is transparently transmitted, and after reaching the border of the core network, it is transmitted to RNC2 on the other side through Iu-UP. RNC2 will initiate the uplink rate control process to adjust the coding rate of the UE under its control as needed. In this case, the goal of RNC1 to perform downlink rate control is finally achieved by the RNC2 at its communication peer initiating the uplink rate control process.

Due to the existence of the Iu-UP initialization process and the Iu-UP rate control process, the RNC always knows the speech coding rate set allowed by the CS domain CN or the communication peer in the uplink direction of the RNC, that is, from the RNC to the CN. Therefore, when the RNC performs uplink rate control, it can ensure that the adjusted uplink coding rate does not exceed the limit from the CN or the communication peer.

In the UMTS network, multimedia session services such as VoIP based on the IMS domain establish an end-to-end session bearer through SIP (Session Initiation Protocol, Session Initiation Protocol) call signaling. The bearer is based on the connectionless packet chain provided by the PS domain of the UMTS network. road. Specifically, the media information coding block is encapsulated by the RTP (Real-Time Protocol, Real-Time Protocol) protocol, and the encapsulated RTP packet is generally carried out end-to-end through the UDP (User Datagram Protocol, User Datagram Protocol) protocol on the IP. send. In addition, a session can usually include an end-to-end RTCP (Real-Time Control Protocol, Real-Time Control Protocol) connection for feedback and collection of reception quality, and RTCP packets are usually transmitted using the UDP protocol. For the PS domain of UMTS, the packet link used by this bearer is no different from the packet link used by other IP services. In the network, IP packets may pass through the Iu-PS interface between UTRAN and PS domain, the Gn/Gp interface inside the PS domain core network, and possibly the Gi interface between the PS domain core network and other IP networks. Among the several interfaces mentioned above, there is no dedicated user plane protocol, but only the encoding function of IP packets is provided. Although there are other specialized control signaling between UTRAN and PS domain and within PS domain, the signaling has no control relationship with specific services over IP. In this case, the existing rate control method in the CS domain obviously cannot be applied to the VoIP multimedia session service based on the IMS domain.

A new rate control method for VoIP services is proposed in the prior art, as shown in FIG. 1 . Uplink rate control means that RNC (Radio Network Control, radio network controller) requests UE to use a new voice coding rate in the uplink through RRC signaling, but because there is no correspondence between the coding format combination and the voice coding rate in the VoIP service, Therefore, the coding format combination control message cannot be used, but a new RRC message needs to be used, and the UE controls the vocoder to apply the new speech coding rate according to the new speech coding rate indication carried in the RRC message; while the downlink rate control method is RNC The UE is notified of the new downlink voice coding rate through RRC signaling, and the RRC entity of the UE controls the AMR framing module to add in-band signaling to the voice-bearing RTP packet to notify the VoIP peer to adjust the voice coding rate. According to this in-band signaling, the vocoder is controlled to use a new speech coding rate. Typical in-band signaling is the CMR (Change Mode Request) of the RTP packet payload header (Payload Header) of AMR and AMR-WB voice. ask).

The problem with this method is that when the opposite end of VoIP is also a mobile network terminal, such as a UE in a UMTS network, the opposite end UE itself is not the controller of the radio resources of the wireless network where it is located, and therefore should not directly control the speech encoding rate. The direct adjustment of the speech coding rate of the vocoder by the peer UE may cause the speech packets encoded at the adjusted rate to be unable to be effectively transmitted through its wireless network, especially when the adjusted coding rate is higher than the currently used coding rate. case of higher rates.

Contents of the invention

The problem to be solved by the present invention is to provide a method, system and device for controlling the media coding rate, so that the media coding rate applied by the wireless terminal can be effectively controlled by the wireless resource management device of the wireless network where it is located and the communication peer network.

In order to achieve the above object, an embodiment of the present invention provides a method for controlling a media encoding rate, comprising the following steps:

After the wireless terminal establishes an Internet Protocol IP multimedia session with the communication peer, it receives a coding rate adjustment message;

judging whether to adjust the encoding rate according to the encoding rate adjustment message;

The wireless terminal applies a new coding rate or maintains the original coding rate according to the judgment result.

Another embodiment of the present invention also provides a method for controlling the media encoding rate, including the following steps:

The wireless terminal and the communication peer determine the limitation of the coding rate available for the IP multimedia session;

A network device managing the wireless terminal obtains and stores the encoding rate limit;

The network device managing the wireless terminal sends an uplink coding rate control command to the wireless terminal according to the coding rate limit to control the coding rate of the wireless terminal.

Another embodiment of the present invention also provides a method for controlling the media encoding rate, including the following steps:

The wireless terminal and the communication peer determine the limit of the available encoding rate of the IP multimedia session, and store the limit of the encoding rate;

When the wireless terminal receives a coding rate control command sent by the network device managing the wireless terminal or a coding rate set adjustment request sent by the communication peer, it updates the coding rate limit and adjusts the coding rate according to the coding rate limit. rate.

Another embodiment of the present invention also provides a system for controlling media encoding rate, including network equipment and at least one wireless terminal,

The network device, including a radio resource control entity, processes the uplink or downlink coding rate adjustment request of the wireless terminal according to the resource status of the wireless network, and sends an uplink or downlink coding rate adjustment message to the wireless terminal;

The wireless terminal, including a terminal control entity, adjusts its uplink or downlink coding rate according to the message sent by the network device and/or other wireless terminals, and sends the uplink or downlink coding rate to the network device and/or other wireless terminals Adjustment request.

Another embodiment of the present invention also provides a network device, including a terminal control entity, which processes the uplink or downlink coding rate adjustment request of the wireless terminal according to the resource status of the wireless network, and sends the uplink or downlink coding rate adjustment request to the wireless terminal. information.

Yet another embodiment of the present invention also provides a wireless terminal, including a terminal control entity, which adjusts its uplink or downlink coding rate according to messages sent by network equipment and/or other wireless terminals, and sends a message to network equipment and/or other wireless terminals Uplink or downlink encoding rate adjustment request.

Compared with the prior art, the present invention has the following advantages:

In the present invention, the network equipment that monitors the status of wireless resources and manages wireless resources controls and decides the rate adjustment request of the wireless terminal, and performs dynamic resource allocation to ensure that the multimedia session after the encoding rate is adjusted can be effectively encoded, avoiding Change the adverse impact of media encoding rate on network load and network wireless resource conditions, and achieve the goal of adapting to wireless resource conditions through media encoding rate control. In addition, it ensures that the media coding rate applied by the wireless terminal is restricted by the wireless resource conditions of the wireless network where the wireless terminal is located and the wireless network where the communication peer is located, effectively solving the problem that the terminal itself decides to adjust the media rate and cannot effectively transmit through the wireless network.

Description of drawings

Fig. 1 is the schematic diagram of VoIP voice coding rate control method in the prior art;

Fig. 2 is a schematic diagram of the uplink rate control process initiated by the radio network controller in the first embodiment of the present invention;

Fig. 3 is a schematic diagram of the downlink rate control process initiated by the radio network controller in the first embodiment of the present invention;

FIG. 4 is a schematic diagram of a communication peer triggering a user equipment rate adjustment process through RTCP feedback in the second embodiment of the present invention;

5 is a schematic diagram of setting a coding rate set and notifying the RNC between the user equipment and the communication peer in the third embodiment of the present invention;

FIG. 6 is a schematic diagram of the communication peer modifying the coding rate set allowed to be used by the user equipment in the uplink direction in the third embodiment of the present invention;

Fig. 7 is a schematic diagram of the process of RNC initiating uplink rate control in the fourth embodiment of the present invention;

FIG. 8 is a schematic diagram of a communication peer sending to a UE to adjust the maximum coding rate allowed to be sent in the fourth embodiment of the present invention;

9 is a schematic diagram of the downlink rate control process initiated by the RNC in the fourth embodiment of the present invention;

Fig. 10 is a schematic diagram of a system for controlling media encoding rate in the fifth embodiment of the present invention.

Detailed ways

The core of the embodiment of the present invention is that the rate adjustment request of the wireless terminal is controlled and decided by the network device that monitors the wireless resource status and is responsible for wireless resource management. The restriction of the wireless resource status of the wireless network where the terminal is located. The present invention can be applied to network equipment and wireless terminals responsible for resource control in various wireless communication networks, such as the BSC (Base Station Controller) in the CDMA (Code Division Multiple Access, Code Division Multiple Access) EvDO (Evolution Data Only) system , base station controller) and AT (Access Terminal, access terminal), or the radio network controller RNC and user equipment UE in the UMTS network. Taking the radio network controller RNC responsible for radio network resource control and the mobile user equipment in the UMTS network as an example, the method of the present invention will be further described in detail with reference to the accompanying drawings.

The first embodiment of the present invention is a procedure for the radio network controller to adjust the uplink or downlink media coding rate of the user equipment. This process specifically includes: the radio network controller monitors the radio resource status, makes a decision to adjust the uplink or downlink media coding rate of the user equipment, and sends an uplink or downlink media coding rate control command to the user equipment. The user equipment sends a request to the communication peer, requesting the peer to allow itself to adjust the encoding rate used in the direction of sending the in-band request signaling (that is, the uplink rate), or requesting the peer to adjust the direction opposite to the direction of sending the in-band request signaling The encoding rate used on the uplink (that is, the downlink rate). If the communication peer is a wireless terminal, the peer needs to request the radio network controller of the network where it is located to make a decision on the downlink or uplink rate adjustment request. According to the decision of the radio network controller, if you need to adjust the encoding rate by yourself, you can adjust it yourself. If the party that initiates the adjustment request is allowed to make adjustments, the result will be fed back to the party that initiated the adjustment request, and the requester will make corresponding adjustments. .

As shown in Figure 2, the uplink rate control process initiated by the radio network controller in the first embodiment of the present invention includes:

Step s201, RNC1 decides to change the uplink media coding rate according to the radio resource status.

Step s202, RNC1 sends an uplink rate control command to UE1 through RRC signaling, which carries the adjusted target coding rate or coding rate set.

Step s203, UE1 sends an uplink rate adjustment request to the communication peer UE2: Since the uplink rate control command sent by RNC1 may cause UE1 to apply a higher coding rate than the currently used coding rate, UE1 sends an uplink rate adjustment request to UE2 through the in-band signaling accompanying the multimedia session. The communication peer UE2 sends an uplink rate adjustment request, which carries the target coding rate or coding rate set that UE1 expects to use in the uplink.

Step s204, UE2 sends a downlink rate adjustment request to RNC2: UE2 requests RNC2 in the wireless network to adjust the downlink media coding rate through RRC signaling, which carries the desired target coding rate or coding rate set.

Step s205, RNC2 makes a decision to accept, reject or modify the downlink media coding rate adjustment request according to the radio resource status.

Step s206, RNC2 sends a downlink rate adjustment response to UE2: RNC2 returns the result to UE2 through RRC signaling, and the feedback result may include an applicable new target coding rate, or a set of available coding rates, or a rejection indication.

Step s207, UE2 sends an uplink coding rate adjustment response to UE1: UE2 sends an uplink rate adjustment response message to UE1 through in-band signaling accompanying the multimedia session, and forwards the result returned by RNC2 to UE1, which may include applicable new targets A code rate, or set of available code rates, or a reject indication.

Step s208, UE1 sends an uplink rate control response message to RNC1: the response message may include the applied target coding rate, or the set of available coding rates, or a rejection indication.

Step s209, UE1 controls its vocoder to maintain the original or apply the new media encoding rate, and transmit the media packet data encoded at the new rate on the multimedia session bearer.

In the above steps, if the uplink rate control command sent by RNC1 in step s203 causes UE1 to apply a lower coding rate than the currently used coding rate, UE1 can also directly accept the control command and end without sending the coding rate to the communication peer. Adjustment request. Of course, in this case, still according to the above steps s203 to s209, it is entirely possible for the communication peer to judge whether to adjust the encoding rate.

As shown in FIG. 3, the downlink rate control process initiated by the radio network controller in the first embodiment of the present invention includes:

Step s301, RNC1 decides to change the downlink media coding rate according to the radio resource status.

Step s302, RNC1 sends a downlink rate control message to UE1, which carries the adjusted target coding rate or coding rate set.

Step s303, UE1 sends a downlink rate adjustment request to the communication peer UE2: UE1 sends a downlink rate adjustment request to the communication peer UE2 through in-band signaling accompanying the multimedia session, which carries the target coding rate or coding rate that UE1 expects to use in the downlink set.

Step s304, UE2 sends an uplink rate adjustment request to RNC2: Since the downlink rate adjustment request sent by UE1 may cause UE2 to apply a higher coding rate than the currently used coding rate, UE2 requests the RNC2 of the wireless network where it is located to adjust the uplink rate through RRC signaling Media encoding rate, which carries the desired target encoding rate or encoding rate set.

Step s305, RNC2 makes a decision to accept, reject or modify the uplink media coding rate adjustment request of UE2 according to the radio resource status.

Step s306, RNC2 sends an uplink rate adjustment response to UE2: RNC2 returns the result to UE2 through RRC signaling, and the feedback result may include an applicable new target coding rate, or a set of available coding rates, or a rejection indication.

Step s307, UE2 sends a downlink coding rate adjustment response to UE1: UE2 sends a downlink rate adjustment response message to UE1 through in-band signaling accompanying the multimedia session, and forwards the result returned by RNC2 to UE1, which may include applicable new targets A code rate, or set of available code rates, or a reject indication.

Step s308, UE2 controls its vocoder to maintain the original or apply the new media encoding rate, and transmit the media packet data encoded at the new rate on the multimedia session bearer.

Step s309, UE1 sends a downlink rate control response message to RNC1: the response message may include the applied target coding rate, or the set of available coding rates, or a rejection indication.

In the above steps, if the downlink rate adjustment request sent by UE1 in step s304 causes UE2 to apply a lower coding rate than the currently used coding rate, UE2 can also directly accept the control command and end without sending a coding rate to RNC2 that manages UE2. Rate adjustment request. Of course, in this case, still according to the above steps s304 to s309, it is entirely possible for the network device managing the communication peer to determine whether to adjust the encoding rate.

In the first embodiment, when the RNC sends to the UE to adjust the set of encoding rates allowed to be sent, the indicated encoding rate set can be represented by the maximum encoding rate among them. The processing method of this case is the same as that described in the first embodiment The process is the same and will not be repeated here.

In the solution described in the first embodiment above, the uplink or downlink encoding rate adjustment request or response message may be transmitted through the RTP header extension. Specifically: according to RFC (Request For Comment, Internet Protocol Group specification document) 3550, set the X field of the RTP header to 1, and fill the header extension in the part immediately following the RTP header. The RTP header extension contains 16 bits of custom information, followed by a length indication field, followed by the specific content of the header extension. The length indication field indicates length information in units of 32 bits from the end of the length indication field to the beginning of the RTP payload part. The in-band signaling described in the present invention can be included in the specific content part of the header extension, which should include at least the following information: the message type field, typically, can be a binary number of 2 bits, and the values 0 to 3 respectively represent uplink Coding rate adjustment request, uplink coding rate adjustment response, downlink coding rate adjustment request, and downlink coding rate adjustment response; followed by the specific expected target coding rate or available coding rate set, usually the maximum value in the coding rate set can also be used Implicitly represents the set of encoding rates that do not exceed this maximum value. Typically, the target coding rate or the maximum coding rate in the coding rate set can be represented by a 4-bit binary number, and it is pre-specified that 1111 in the response message, that is, the decimal value 15 means rejection, and other values starting from 0 to N-1 N values represent N media coding rates from low to high, N is the number of different coding rates supported by a specific media coding method, N<=15, of course, more bits can be used to represent the coding rate, so as to support more More code rate numbers, but still use all 1 binary bit sequence to indicate rejection. In addition, a list of multiple 4-bit binary numbers can be used to represent a coding rate set, and the corresponding relationship between each 4-bit binary number and the media coding rate is as described above. An empty list can be used to indicate rejection, or an additional Bits indicate acceptance or rejection, instead of 1111 for rejection.

In particular, for speech coding using AMR or AMR-WB, the in-band signaling of the downlink coding rate adjustment request can be transmitted using the CMR field of the payload header (Payload Header) of AMR or AMR-WB carried by RTP. According to the payload format of RTP carrying AMR and AMR-WB defined by RFC 3267, the header of the payload only includes a 4-bit CMR field, and CMR=15 indicates that there is no preferred speech coding rate. When AMR is carried, the CMR values from 0 to 7 correspond to 8 preferred speech coding rates of AMR4.75kbps to 12.2kbps respectively, as shown in Table 1 for details. When carrying AMR-WB, when the value of CMR is 0 to 8, it corresponds to 9 preferred speech coding rates of AMR-WB 6.60kbps to 23.85kpbs, as shown in Table 2. The preferred speech coding rate is also the target coding rate or the maximum rate value in the coding rate set.

Table 1, the corresponding relationship between the value of CMR and the preferred AMR speech coding rate

CMR AMR speech coding rate

0 AMR 4, 75kbit/s 1 AMR 5, 15kbit/s 2 AMR 5, 90kbit/s 3 AMR 6, 70kbit/s (PDC-EFR) 4 AMR 7, 40kbit/s (TDMA-EFR) 5 AMR 7, 95kbit/s 6 AMR 10, 2kbit/s 7 AMR 12, 2kbit/s(GSM-EFR)

Table 2, the corresponding relationship between the value of CMR and the preferred AMR-WB speech coding rate

CMR AMR-WB speech coding rate 0 AMR-WB 6.60kbit/s 1 AMR-WB 8.85kbit/s 2 AMR-WB 12.65kbit/s 3 AMR-WB 14.25kbit/s 4 AMR-WB 15.85kbit/s 5 AMR-WB 18.25kbit/s 6 AMR-WB 19.85kbit/s 7 AMR-WB 23.05kbit/s 8 AMR-WB 23.85kbit/s

As mentioned above, in the IMS domain session service, there may also be an RTCP connection accompanying the RTP session, and RTCP provides a mechanism for implicitly requesting the communication peer to adjust the coding rate by sending a receiving status report. The receiving end counts the receiving quality information mainly including packet loss rate, jitter, etc., generates a receiving status report and sends it to the communication peer through the RTCP connection accompanying the multimedia session. Specifically, it is sent through an RTCP packet of the sender report (Sender Report, SR) or receiver report (Receiver Report, RR) type, or through a combined RTCP packet containing SR or RR. The end receiving the SR or RR judges whether the currently used encoding rate is appropriate based on the packet loss rate and jitter information included therein, and may make corresponding adjustments. Therefore, the communication peer can also send a receiving status report through RTCP to request rate adjustment. In some systems, when the communication peer is a wireless terminal, the wireless device that controls the communication disconnection can also directly initiate the RTCP receiving status in the name of the communication peer. Report. In the above case, the RTCP receiving status report is the rate adjustment message from the communication peer. The second embodiment of the present invention is a process in which the communication peer triggers the user equipment to adjust the rate through RTCP feedback, as shown in FIG. 4 , specifically including the following steps:

In step s401, the user equipment UE1 receives a reception report fed back by the communication peer UE2 through RTCP.

Step s402, according to the report, the user equipment UE1 derives the coding rate information that needs to be applied in the uplink or downlink direction of the session in order to improve the receiving quality of the communication peer.

Step s403, the user equipment UE1 sends a rate adjustment request to the radio network controller RNC1, which carries the derived coding rate information.

Step s404, the radio network controller RNC1 decides to accept, reject or modify the request of the user equipment according to the radio resource status.

Step s405, the radio network controller RNC1 feeds back the result to the user equipment UE1 through a rate adjustment response.

Step s406 , the user equipment UE1 receiving the rate adjustment response adjusts the encoding rate it uses for encoding the media.

In step s407, the UE1 forwards the response of the RNC1 to the communication peer UE2 through the in-band signaling accompanying the session.

The third embodiment of the present invention is a process in which the radio network controller stores the specific selected media coding predetermined by the user equipment and the communication peer, and adjusts the uplink or downlink media coding rate of the user equipment. This process specifically includes the following Steps: First, during the establishment of a multimedia session, the UE and the communication peer negotiate to determine the specific media coding and the available coding rate set, and the UE reports the coding rate set to the RNC through RRC signaling, and the RNC saves this encoding rate set.

As shown in FIG. 5, in the third embodiment of the present invention, the process of setting the coding rate set between the user equipment and the communication peer and notifying the RNC includes:

Step s501, establishing a multimedia session: UE1 and the communication peer establish an IP session through SIP signaling, wherein the SIP signaling can carry an SDP description, and the user equipment and the communication peer use the media encoding format and the corresponding encoding rate set carried in the SDP description Conduct initial encoding negotiation to determine the encoding format and available encoding rate set used in the session.

Step s502 , UE1 sends an uplink allowable rate set report to RNC1 : UE1 sends to RNC1 the encoding rate set negotiated with the communication peer in the above multimedia session establishment phase to RNC1 through RRC signaling.

In step s503, RNC1 saves the allowed uplink coding rate set and ends.

Then, during the multimedia session, the communication peer can modify the encoding rate set that the UE is allowed to use in the uplink direction through in-band signaling, and when receiving the encoding rate set, the UE also reports it to the RNC through RRC signaling , if the coding rate currently used by the UE exceeds the coding rate range limited by the communication peer, the UE should also adjust its own coding rate to ensure that it does not exceed the limit of the communication peer; the RNC updates the saved coding rate set to the value reported by the UE, If the code rate range allowed after the update is larger than before the update, the RNC further judges whether the UE is allowed to use the new code rate in the uplink according to the radio resource status, and if yes, the RNC initiates the uplink rate control process.

As shown in FIG. 6, in the third embodiment of the present invention, the process for the above-mentioned communication peer to modify the encoding rate set allowed to be used by the user equipment in the uplink direction includes:

In step s601, the communication peer sends an instruction to adjust the set of coding rates allowed to be sent to UE1 through in-band signaling.

In step s602, UE1 judges whether the coding rate currently used by it is greater than the maximum value in the coding rate set limited by the communication peer.

Step s603, UE1 maintains the original or applies a new media encoding rate: when the encoding rate currently used by UE1 is greater than the maximum value in the encoding rate set limited by the communication peer, it automatically adjusts to a new encoding rate so as not to exceed the limit of the communication peer; When the encoding rate currently used by UE1 is lower than the maximum value in the set of encoding rates limited by the communication peer, the original encoding rate is maintained.

Step s604, UE1 sends an uplink allowable rate set report to RNC1.

Step s605, RNC1 updates the set of uplink allowed coding rates.

Step s606, if the allowed coding rate range after the update is larger than that before the update, then RNC1 further judges whether UE1 is allowed to use the new coding rate in uplink according to the radio resource conditions, and if so, RNC initiates the uplink rate control process.

In addition, during the multimedia session, RNC1 monitors the wireless resource status in real time, and decides whether to adjust the uplink allowed media coding rate set or the downlink allowed media coding rate set according to the change of the wireless resource status, that is, initiates the uplink or downlink rate control process .

The uplink rate control process is: the RNC sends an uplink rate control message to the UE through RRC signaling, which carries a target coding rate or a set of allowed uplink coding rates. The UE adjusts its vocoder according to the RNC command to use the target coding rate specified by the RNC or the coding rate that does not exceed the coding rate set limit given by the RNC; when adjusting the uplink media coding rate, the RNC guarantees that the adjusted target coding rate will not Exceeded the limit of the saved upstream allowed encoding rate set. The downlink rate control process is as follows: RNC sends a downlink rate control message to UE through RRC signaling, which carries the allowed downlink coding rate set; UE notifies the communication peer of the allowed sending coding rate set through in-band signaling accompanying the multimedia session. If the communication peer is a UE, the UE of the communication peer also needs to perform corresponding processing according to the method from step s601 to step s606.

In the third embodiment, when the communication peer sends to the UE through in-band signaling to adjust the set of encoding rates allowed to be sent, the indicated encoding rate set can be represented by the maximum encoding rate among them. The processes described in the three embodiments are the same and will not be repeated here.

The fourth embodiment of the present invention is a process in which the user equipment pre-stores the maximum uplink coding rate allowed by the communication peer and the radio network controller, and the radio network controller adjusts the uplink or downlink media coding rate. The process specifically includes the following Several steps: First, set the uplink coding rate limit controlled by the variable RNC (hereinafter denoted as rate limit 1) and the uplink coding rate limit required by the communication peer (hereinafter denoted as rate limit 2) in the UE. During the establishment of a multimedia session, the UE and the communication peer determine the specific media encoding and the available encoding rate set through negotiation, and initialize the values of rate limit 1 and rate limit 2 to the maximum value in the encoding rate set .

The RNC monitors the status of radio resources, and adjusts the maximum encoding rate allowed for uplink or downlink according to changes in the status of radio resources. On the other hand, during a multimedia session, the communication peer can notify the UE of the maximum encoding rate allowed to be sent through in-band signaling, and the UE always guarantees to use the maximum encoding rate allowed by the RNC of the wireless network at the same time. and the maximum encoding rate allowed to be sent restricted by the communication peer.

As shown in Figure 7, in the fourth embodiment of the present invention, the uplink rate control process initiated by the RNC specifically includes:

Step s701, RNC1 decides to change the maximum coding rate allowed in the uplink according to the change of the radio resource status.

Step s702, RNC1 sends an uplink rate control message to UE1: RNC1 sends an uplink rate control message to UE1 through RRC signaling, which carries the maximum uplink coding rate.

Step s703, UE1 changes the value of rate limit 1: UE1 updates the saved value of rate limit 1 as the maximum uplink coding rate indicated by RNC according to the command of RNC1.

Step s704, UE1 maintains the original or applies a new media coding rate: after updating, UE1 reselects a coding rate that does not exceed rate limit 1 and rate limit 2 according to the updated value.

As shown in FIG. 8, in the fourth embodiment of the present invention, the process of the communication peer sending to the UE to adjust the maximum encoding rate allowed to be sent specifically includes:

Step s801, the communication peer sends a message to UE1 to adjust the maximum coding rate allowed to be sent: the communication peer notifies UE1 of the maximum coding rate allowed to be sent through the in-band signaling accompanying the multimedia session.

Step s802 , UE1 updates the value of rate limit 2: UE1 updates the stored rate limit 2 as the maximum uplink coding rate indicated by the communication peer according to the instruction of the communication peer.

Step s803, UE1 maintains the original or applies a new media coding rate: UE1 reselects a coding rate that does not exceed rate limit 1 and rate limit 2 according to the updated value.

As shown in Figure 9, in the fourth embodiment of the present invention, the downlink rate control process initiated by the RNC specifically includes:

In step s901, RNC1 decides to change the maximum coding rate allowed in the downlink according to the change of the radio resource status.

Step s902, RNC1 sends a downlink rate control message to UE1: RNC sends a downlink rate control message to UE through RRC signaling, which carries the maximum allowed downlink coding rate.

Step s903, UE1 sends an instruction message for adjusting the maximum encoding rate allowed to be sent to the communication peer: UE1 notifies the communication peer of the maximum code rate allowed to be sent through the in-band signaling accompanying the multimedia session. If the communication peer is a UE, the processing process performed by the UE at the communication peer is the same as the process described in step s801 to step 803.

In this solution, the UE can also save the set of available uplink coding rates restricted by the RNC and the set of available uplink coding rates restricted by the communication peer, and initialize to the set of coding rates negotiated during the session establishment process. Then when the RNC controls the uplink and downlink rates, it also sends the corresponding rate set information, and the UE can forward the rate set information through in-band signaling. When the UE receives the rate set information from the RNC or the communication peer, it always updates the corresponding variables and ensures that the encoding rate that exceeds the limit of the rate set is not used.

The fifth embodiment of the present invention provides a system for controlling the media encoding rate in an IP multimedia session. As shown in FIG. 10 , the system includes a network device 10 and at least one user device 20,

The network device 10 specifically includes a radio resource control entity 101 and a coding rate storage entity 102 . Wherein, the radio resource control entity 101 processes the uplink or downlink coding rate adjustment request of the user equipment 20 according to the resource status of the wireless network where the network device 10 is located, and sends an uplink or downlink coding rate adjustment message to the user equipment. The coding rate storage entity 102 is connected to the radio resource control entity 101, and stores the set of available coding rates preset by each user equipment 20 and the communication peer during the IP session establishment process.

The user equipment 20 specifically includes a terminal control entity 201 , a terminal storage entity 202 , a vocoder 203 and an AMR framing module 204 . Wherein, the terminal control entity 201 adjusts its uplink or downlink coding rate according to the message sent by the network device 10 or other user equipment, and sends an uplink or downlink coding rate adjustment request to the network device 10 or other user equipment when necessary. The terminal storage entity 202 is connected to the terminal control entity 201, and stores the set of uplink or downlink coding rates allowed by the network device 10 or the communication peer. The vocoder 203 converts the speech and code received by the user equipment 20 under the control of the terminal control entity 201, and uses a new speech coding rate when the coding rate needs to be adjusted. The AMR framing module 204, under the control of the terminal control entity 201, sends a request for adjusting the voice frequency adjustment to the communication peer, and receives the voice frequency adjustment request sent by the communication peer.

The above disclosures are only a few specific embodiments of the present invention, however, the present invention is not limited thereto, and any changes conceivable by those skilled in the art shall fall within the protection scope of the present invention.

Claims (26)

1. A method for controlling media encoding rate, comprising the following steps: After the wireless terminal establishes an Internet Protocol IP multimedia session with the communication peer, it receives a coding rate adjustment message; judging whether to adjust the encoding rate according to the encoding rate adjustment message; The wireless terminal applies a new coding rate or maintains the original coding rate according to the judgment result. 2. The method for controlling the media coding rate according to claim 1, wherein the coding rate adjustment message includes a downlink coding rate adjustment request sent by a communication peer or an uplink coding rate sent by a network device managing the wireless terminal control commands. 3. The method for controlling the media encoding rate according to claim 2, wherein when the encoding rate adjustment message is an uplink encoding rate control command sent by a network device managing the wireless terminal, the judgment whether to adjust the encoding rate The steps specifically include: The wireless terminal judges whether the coding rate control information carried in the uplink coding rate control command is greater than the currently used uplink coding rate, and if not, accepts the uplink coding rate control command and ends, otherwise sends an uplink encoding rate adjustment request; The communication peer judges whether to allow the wireless terminal to adjust the uplink coding rate; The communication peer sends an adjustment response to the wireless terminal; According to the adjustment response, the wireless terminal determines whether to adjust the uplink coding rate. 4. The method for controlling the media encoding rate according to claim 2, wherein when the encoding rate adjustment message is an uplink encoding rate control command sent by a network device managing the wireless terminal, the judgment whether to adjust the encoding rate The steps specifically include: The wireless terminal sends an uplink coding rate adjustment request to the communication peer; The communication peer judges whether to allow the wireless terminal to adjust the uplink coding rate; The communication peer sends an adjustment response to the wireless terminal; According to the adjustment response, the wireless terminal determines whether to adjust the uplink coding rate. 5. The method for controlling the media coding rate according to claim 3 or 4, wherein when the communication peer is a wireless terminal, the step of determining whether the communication peer is allowed to adjust the uplink coding rate specifically includes: The communication peer sends a downlink coding rate adjustment request to the network device managing the communication peer; The network device managing the communication peer judges the request, and sends an adjustment response to the communication peer; According to the adjustment response, the communication peer judges whether to allow the wireless terminal to adjust the uplink coding rate. 6. The method for controlling the media encoding rate according to claim 2, wherein when the encoding rate adjustment message is a downlink encoding rate adjustment request sent by the communication peer, the step of determining whether to adjust the encoding rate specifically comprises: The wireless terminal judges whether the coding rate control information carried in the downlink coding rate adjustment request is greater than the currently used uplink coding rate, and if not, then accepts the downlink coding rate adjustment request and ends, otherwise reports to the management of the wireless terminal The network device sends an uplink coding rate adjustment request; A network device managing the wireless terminal judges the request, and sends an adjustment response to the wireless terminal; According to the adjustment response, the wireless terminal determines whether to adjust the uplink coding rate. 7. The method for controlling the media encoding rate according to claim 2, wherein when the encoding rate adjustment message is a downlink encoding rate adjustment request sent by the communication peer, the step of determining whether to adjust the encoding rate specifically comprises: The wireless terminal sends an uplink coding rate adjustment request to a network device managing the wireless terminal; A network device managing the wireless terminal judges the request, and sends an adjustment response to the wireless terminal; According to the adjustment response, the wireless terminal determines whether to adjust the uplink coding rate. 8. The method for controlling the media encoding rate according to claim 1, wherein the IP multimedia session is a voice over IP (VoIP) session. 9. The method for controlling a media encoding rate according to claim 1 or 2, wherein the encoding rate adjustment message carries one of a target encoding rate, an encoding rate set, and a maximum encoding rate. 10. The method for controlling the media encoding rate according to claim 3, 4, 6 or 7, wherein the adjustment response includes one of a rejection indication, an acceptance indication, a target encoding rate, an encoding rate set, and a maximum encoding rate kind. 11. The method for controlling the media coding rate as claimed in claim 2, 6 or 7, characterized in that, between the wireless terminal and the communication peer, the mode request field of the header of the real-time protocol or the real-time control The receiving status report of the protocol sends the downlink coding rate adjustment request implicitly or through one of header extensions of the real-time protocol. 12. The method for controlling the media coding rate according to claim 3 or 4, characterized in that, the uplink coding rate adjustment request and the uplink coding rate adjustment request are sent between the wireless terminal and the communication peer through the header extension of the real-time protocol. Adjust the response described above. 13. A method for controlling media encoding rate, comprising the following steps: The wireless terminal and the communication peer determine the limitation of the coding rate available for the IP multimedia session; A network device managing the wireless terminal obtains and stores the encoding rate limit; The network device managing the wireless terminal sends an uplink coding rate control command to the wireless terminal according to the coding rate limit to control the coding rate of the wireless terminal. 14. The method for controlling the media encoding rate according to claim 13, wherein the uplink encoding rate control command carries a target encoding rate, a maximum encoding rate, or a set of encoding rates within the constraint range of the encoding rate limit. A sort of. 15. The method for controlling the media coding rate according to claim 13, wherein after the network device obtains and stores the coding rate limit, it further includes updating the coding rate limit according to a rate adjustment message sent by the communication peer : The wireless terminal receives the encoding rate adjustment request sent by the communication peer; The wireless terminal reports the coding rate limit information of the coding rate adjustment request to the network device; The network device managing the wireless terminal updates the stored encoding rate limit according to the encoding rate limit information in the encoding rate adjustment request sent by the communication peer; When the coding rate currently used by the wireless terminal exceeds the coding rate limit information sent by the communication peer, adjust the coding rate of the wireless terminal so that it does not exceed the coding rate limit. 16. A method for controlling media encoding rate, comprising the following steps: The wireless terminal and the communication peer determine the limit of the available encoding rate of the IP multimedia session, and store the limit of the encoding rate; When the wireless terminal receives a coding rate control command sent by the network device managing the wireless terminal or a coding rate set adjustment request sent by the communication peer, it updates the coding rate limit and adjusts the coding rate according to the coding rate limit. rate. 17. The method for controlling the encoding rate of media according to claim 16, wherein the encoding rate limit comprises an encoding rate limit of a network device managing the wireless terminal and/or an encoding rate limit of a communication peer. 18. The method for controlling the media coding rate according to claim 17, wherein when the wireless terminal receives an uplink coding rate control command sent by a network device managing the wireless terminal, the wireless terminal adjusts the uplink coding rate The steps specifically include: The wireless terminal updates the stored coding rate limit of the network device according to the target coding rate, the maximum coding rate or the coding rate set in the uplink coding rate control command sent by the network device; The wireless terminal adjusts its uplink coding rate according to the coding rate limit, so as not to exceed the coding rate limit of the network device and the coding rate limit of the communication peer. 19. The method for controlling a media coding rate according to claim 17, wherein when the wireless terminal receives the coding rate set adjustment request sent by the communication peer, the step of adjusting the coding rate by the wireless terminal specifically includes : The wireless terminal updates the stored coding rate limit of the communication peer according to the coding rate limit information in the coding rate adjustment request sent by the communication peer; The wireless terminal adjusts its encoding rate according to the encoding rate limit, so as not to exceed the encoding rate limit of the communication peer and the encoding rate limit of the network device managing the wireless terminal. 20. A system for controlling media coding rate, characterized in that it includes network equipment and at least one wireless terminal, The network device, including a radio resource control entity, processes the uplink or downlink coding rate adjustment request of the wireless terminal according to the resource status of the wireless network, and sends an uplink or downlink coding rate adjustment message to the wireless terminal; The wireless terminal, including a terminal control entity, adjusts its uplink or downlink coding rate according to the message sent by the network device and/or other wireless terminals, and sends the uplink or downlink coding rate to the network device and/or other wireless terminals Adjustment request. 21. The system for controlling the media coding rate according to claim 20, wherein the network device also includes a coding rate storage entity, connected to the radio resource control entity, and storing the available coding rates of each wireless terminal in a session set. 22. The system for controlling media coding rate according to claim 20, characterized in that, the wireless terminal further comprises a terminal storage entity, connected to the terminal control entity, storing the network equipment and/or other wireless terminal allowed Uplink or downlink encoding rate set. 23. A network device, characterized in that it includes a terminal control entity, which processes an uplink or downlink coding rate adjustment request of a wireless terminal according to the resource status of the wireless network, and sends an uplink or downlink coding rate adjustment message to the wireless terminal. 24. The network device according to claim 23, further comprising a coding rate storage entity, connected to the radio resource control entity, and storing the coding rate set available for each wireless terminal in an IP session. 25. A wireless terminal, characterized in that it includes a terminal control entity, which adjusts its uplink or downlink coding rate according to messages sent by network equipment and/or other wireless terminals, and sends uplink or downlink code rates to network equipment and/or other wireless terminals Encoding rate adjustment request. 26. The wireless terminal according to claim 25, further comprising a terminal storage entity, connected to the terminal control entity, and storing the uplink or downlink coding rate set allowed by network equipment and/or other wireless terminals.

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