Efficient interworking between circuit-switched and packet-switched multimedia services defining a maximum packet size attribute

Related application

0001This application is a US provisional application 61 / 020,982 filed on January 14, 2008, entitled "Methods and devices for interworking between circuit-switched multimedia services and packet-switched multimedia services with short latency". Issue, and US provisional application 61 / 021,163 filed on January 15, 2008, entitled "Methods and Devices for Interworking Between Circuit-Switched Multimedia Services and Packet-Switched Multimedia Services with Short Waiting Times" Claim priority over the issue. All of these contents are incorporated here by reference.

0002The present disclosure relates to a technique that provides efficient, short latency interworking between circuit-switched multimedia services and packet-switched multimedia services.

background

0003Standardized multimedia services based on packet-switched Internet Protocol (IP) networks have been developed in recent years. For example, the multimedia telephone service for the IP Multimedia System (MTSI), also referred to here as the multimedia telephone, is an IP developed by the 3rd Generation Partnership Project (3GPP) for Mobile Communications. It is a based multimedia telephone service. 3GPP TS 26.114 V7.5.0, "Technical Specification Group Services and System Aspects IP Multimedia Subsystem (IMS); Multimedia Phones; Media Handling and Dialogue," and, which are later referred to here as "3GPP Specifications." 3GPP TS See 29.163 V8.3.0, "Technical Specifications Group Core Networks and Terminals; Interworking Between IP Multimedia (IM) Core Networks (CN) Subsystems and Circuit Switching (CS) Networks (Release 8)". All of these contents are incorporated here by reference. The Packet Switching Video Phone (PSVT) specification (C.S0055-Av1.0) was also developed by the 3rd Generation Partnership Project 2 (3GPP2), the contents of which are also incorporated here by reference. Packet-switched multimedia telephones are expected to utilize the flexible data transmission mechanism provided by the Internet Protocol (IP) while providing a user experience comparable to or better than the corresponding circuit-switched telephone services. ing.

0004When transmitting media from a packet-switched terminal (such as a 3GPP MTSI terminal or a 3GPP 2PSVT terminal) to a circuit-switched terminal (such as a 3GPP CSVT terminal / 3G-324M terminal), an interworking node such as a media gateway You are requested to perform interworking between circuit-switched (CS) and packet-switched (PS) protocols. In order to deliver media packets from the PS domain through the fixed bandwidth CS domain channel, which generally show a wide range of size variations, the media gateway reshapes the buffer and fragments to carry the packet over the circuit-switched network. Data packet reformatting mechanisms such as transformation and reassembly (eg, video and / or audio) may be used. During a telephone session, such a reformatting mechanism, undesirably, results in communication breaking audiovisual (lip) synchronization requirements and / or additional end-to-end delays between terminals. May reduce the quality of service by bringing about.

0005Therefore, it would be desirable to provide a technique for signaling the maximum packet size limit on a data packet to a PS terminal, which can be transmitted without inefficient reformatting. Further, to provide a technique for allowing a PS terminal to adjust the processing of data packets of a PS terminal based on such a maximum packet size limit so as to minimize the reformatting of data packets by the interworking node. Would be desired.

Overview

0006Aspects of the present disclosure provide a method for improving the efficiency of data packet transmission between multimedia sessions, the method comprising transmitting information from an interworking node to a packet switching terminal, the information being multi. Contains parameters related to the maximum packet size negotiated with another end of the media session.

0007Another aspect of the disclosure provides a method for improving the efficiency of data packet transmission during a multimedia session, the method comprising receiving information from an interworking node at a packet switching terminal. Includes parameters related to the maximum packet size negotiated with another termination of the multimedia session.

0008Further, another aspect of the disclosure provides a packet switching device that communicates during a multimedia session, where the device provides information including parameters related to the maximum packet size negotiated with another termination of the multimedia session. It includes a receiver configured to receive and a transmitter configured to generate packets that are not larger than the maximum negotiated packet size in response to the received information.

0009Further, another aspect of the present disclosure provides a packet switching device that communicates during a multimedia session, the device comprising means for receiving information from an interworking node, and the information is another aspect of the multimedia session. Contains parameters related to the maximum packet size negotiated with the termination.

0010In addition, another aspect of the disclosure provides a computer program product for improving the efficiency of data packet transmission between multimedia sessions, where the product is the maximum packet size negotiated with another termination of the multimedia session. A computer-readable medium containing a code for causing the computer to receive information including parameters related to the above, and a code for causing the computer to generate a packet not larger than the maximum negotiated packet size in response to the received information. To do.

0011<figref num="1">Figure 1 illustrates the system for MTSI according to the 3GPP specification.</figref><figref num="2">Figure 2 illustrates an exemplary embodiment of a mechanism for communicating CS terminal restrictions to PS terminals, where the IP Multimedia Core Network (IM CN) initiates a session and preconditions are used on the IMS side.</figref><figref num="3">Figure 3 illustrates a further exemplary embodiment of the mechanism for communicating CS terminal restrictions to PS terminals, where the IM CN initiates a session and no preconditions are used on the IMS side.</figref><figref num="4">FIG. 4 illustrates an exemplary embodiment of a mechanism for communicating CS terminal restrictions to PS terminals, where the CS network initiates a session.</figref><figref num="5">FIG. 5 illustrates an exemplary embodiment of a computer program product that improves the efficiency of data packet transmission during multimedia sessions in accordance with the present disclosure.</figref>

Detailed explanation

0012The detailed description described below in connection with the accompanying drawings is intended to illustrate exemplary hands-on embodiments of the invention and is not intended to provide only one exemplary embodiment in which the invention can be practiced. .. The term "exemplary" as used throughout this description means "acting as an example, as an instance, or as an example" and should necessarily be construed as preferred or effective over other embodiments. is not it. The detailed description includes specific details for the purpose of providing a complete understanding of the exemplary embodiments of the invention. It will be apparent to those skilled in the art that exemplary embodiments of the invention may be practiced without these particular details. In some instances, well-known structures and devices are shown in the form of block diagrams to avoid obscuring the novelty of the exemplary embodiments presented herein.

0013In the specification and claims, when an element is referred to as "connected" or "bonded" to another element, it is directly connected or connected to the other element. There may be intervening elements. In contrast, when an element is referred to as being "directly connected" or "directly connected" to another element, there are no intervening elements.

0014As a reminder for ease of discussion, various exemplary embodiments of the present disclosure are described with reference to implementations according to the 3GPP specification. However, such description does not imply limiting the technology of the present disclosure to multimedia telephone implementations in accordance with the 3GPP specification. Those skilled in the art may readily derive changes to the technology, thereby providing alternatives, such as systems implemented according to the 3GPP2 specification or specifications made by the Internet Engineering Task Force (IETF). Changes may be applied to the system. Such alternative exemplary embodiments are intended to be within the scope of the present disclosure.

0015Figure 1 illustrates System 100 for MTSI, according to the 3GPP specification. In FIG. 1, communication system 100 comprises a packet-switched (PS) terminal 110 configured to accept multimedia inputs from (not shown) users and / or deliver multimedia outputs to users. ing. Such multimedia inputs and outputs may be communicated to or from other terminals during a multimedia session. Within this specification and claims, it will be appreciated that a multimedia session may refer to a session containing one or more types of media streams. For example, a multimedia session may include both video and audio media streams, as shown in FIG. Alternatively, the multimedia session may include video streams only, audio streams only, text streams only, or any combination of such media streams.

0016The PS terminal 110 may use the transmitter and receiver modules 111 to transmit multimedia data to the interworking node 120 through the PS channel 112 and receive multimedia data from the interworking node 120. The interworking node 120 may include a media gateway (MGW) 130 and a media gateway control function (MGCF) 125. Transmission of multimedia data to and from PS terminal 110 over PS channel 112 involves using a transmission protocol to encapsulate the media in the form of packets.

0017In FIG. 1, the interworking node 120 further communicates with the circuit-switched (CS) terminal 140 through the CS channel 142. Like the PS terminal 110, the CS terminal 140 is also configured to accept multimedia inputs from the user and / or deliver multimedia outputs to the user. However, unlike the PS terminal 110, the CS terminal 140 does not send or receive multimedia data in the form of packets of varying sizes. Rather, CS terminal 140 uses a dedicated session through CS channel 142, which has a fixed bandwidth guaranteed for the session, and uses transmitter and receiver 141 to send and receive data through CS channel 142.

0018When transmitting media from the PS terminal 110 to the CS terminal 140, the MGW 130 may perform the necessary interworking between the PS and CS protocols. For example, during a unit time, a dedicated CS channel may only support service data units (SDUs) below a fixed maximum SDU size. However, the PS terminal 110 may generate application layer protocol data units (PDUs) of arbitrary size. Therefore, the size of the PDU generated by the PS terminal 110 may cause the corresponding SDU size to exceed the maximum SDU size of the CS channel 142.

0019To address this issue, the MGW 130 may fragment such PDUs for subsequent reassembly by the CS terminal 140 prior to transmission to the CS terminal 140. For more details on the fragmentation and reassembly mechanism, see Section 12.2.4.6, Packet Size Review of 3GPP TS 26.114 V7.5.0, referenced here earlier. However, undesirably, such fragmentation and reassembly results in communication breaking audiovisual (lip) synchronization requirements and / or resulting in additional end-to-end delays between terminals. This may reduce the quality of service.

0020According to aspects of this disclosure, the MGW 130 communicates the packet size limit of CS channel 142 or CS terminal 140 to PS terminal 110, whereby PS terminal 110 is best suited for the maximum SDU size supported by the CS network. A technique for controlling the size of packets generated by the PS terminal 110 is provided so as to adapt to the above. In the present disclosure, the technology is illustrated in the context of a communication system operating according to the 3GPP specification. However, those skilled in the art will appreciate that the technique can be easily applied to systems operating according to other specifications. Such alternative exemplary embodiments are also intended to be within the scope of the present disclosure.

0021Figure 2 illustrates an exemplary embodiment of a mechanism for communicating CS terminal restrictions to PS terminals, where the IP Multimedia Core Network (IM CN) initiates a session and preconditions are used on the IMS side. Steps 201-210 and 212-213 illustrate the dialogue between the H.245 or MONA procedure, well known in the prior art, and Session Initiation Protocol (SIP) / SDP. For example, see Figure E.2.3.1.1.1 in 3GPP TS 29.163 V8.3.0, which was referenced earlier, and the accompanying instructions.

0022According to the present disclosure, in step 211 of the message exchange, the a line following the m line related to the video flow in the SDP message sent from the networking node 120 to the PS terminal 110 is the relevant number maximum A12 SDU size. May include a "maximum RecvSDU size" attribute with. This attribute may indicate, for video flow, the maximum SDU size (eg in bytes) negotiated by MGCF125 with CS terminal 140. In FIG. 2, the maximum A12 SDU size has an exemplary value of 400. Those skilled in the art will appreciate that the video codec "MP4V-ES" is related to the video flow shown in Figure 2, but other video codecs are also readily available.

0023Step 211 of the message exchange may further include specifying the "maximum RecvSDU size" attribute following the "m" line associated with the audio flow. This attribute may have the relevant numerical maximum A13 SDU size indicating the maximum SDU size negotiated with CS terminal 140 by MGCF125 for audio flow. In FIG. 2, the maximum A13 SDU size has an exemplary value of 48. Such signaling is intended to be within the scope of the present disclosure. Those skilled in the art will correctly recognize that the audio codec "AMR" is related to the audio flow shown in Figure 2, but other audio codecs are also readily available.

0024In an alternative exemplary embodiment (not shown), the a line in the SDP message in step 211 indicates an additional a indicating that the terminal is communicating with a 3G-324M CS terminal. Attribute 3G-324M may be further included.

0025In an exemplary embodiment, the PS terminal 110 ensures that the generated SDU size is smaller than the signaled maximum allowed SDU size, based on the value of the maximum RecvSDU size attribute signaled by the interworking node 120. In addition, its own packet processing may be optionally adapted. This minimizes the fragmentation and reassembly of data packets that need to be performed by Internet node 120. In an exemplary embodiment, the PS terminal 110 may remove the attribute "a" in the subsequent SIP message.

0026In an alternative exemplary embodiment, if the ability to adapt to the maximum RecvSDU size attribute is not supported by the PS terminal 110, the PS terminal 110 simply provides information about the CS channel limitation signaled by the interworking node 120. It can be ignored and may rely on the normal reformatting scheme of interworking node 120 to convey data to CS terminal 140.

0027In an exemplary embodiment, the maximum SDU size limit to be signaled by the interworking node 120 is from the interworking node 120, eg, from the (not shown) H.223 bearer capacity exchange between CS terminal 140 and MGCF125. It may be decided. Such bearer capacity exchange is technically well known and will not be further discussed here.

0028In an alternative exemplary embodiment (not shown), the interworking node 120 also provides the PS terminal 110 with an SDU reception interval that corresponds to how often SDU is expected to be delivered through the CS channel. May be shown.

0029Figure 3 illustrates a further exemplary embodiment of the mechanism for communicating CS terminal restrictions to PS terminals, where the IM CN initiates a session and the preconditions are not used on the IMS side. Steps 301-308 illustrate the procedures and Session Initiation Protocol (SIP) / SDP that are well known in the prior art. For example, see Figure E.2.3.2.1.1 in 3GPP TS 29.163 V8.3.0, which was referenced earlier, and the accompanying description. In step 309, the maximum RecvSDU size parameter is signaled according to the principles disclosed above, and the maximum RecvSDU size parameter will be apparent to those of skill in the art given the description of FIG. 2 provided above.

0030FIG. 4 illustrates an exemplary embodiment of a mechanism for communicating CS terminal restrictions to PS terminals, where the CS network initiates a session. Steps 401-412, and 414 illustrate procedures and Session Initiation Protocol (SIP) / SDP that are well known in the prior art. See 3GPP TS 29.163, Figure E.2.4.1.1.1 in V8.3.0, and the accompanying instructions referenced above. In step 414, the maximum RecvSDU size parameter is signaled according to the principles disclosed above, and the maximum RecvSDU size parameter will be apparent to those of skill in the art given the description of FIG. 2 provided above.

0031The technology for communicating the restrictions of the CS terminal to the PS terminal is disclosed above. Further disclosed below is a technique in which the PS terminal adjusts the packet processing of the PS terminal so as to adapt to the information communicated regarding the CS terminal restriction. The techniques for PS terminal processing disclosed below need not be combined with the techniques for signaling the restrictions of CS terminals disclosed above, and are realized separately and independently in an alternative exemplary embodiment of the present disclosure. Please note that you may.

0032In an exemplary embodiment, the PS terminal may adapt the choice of packet loss feedback mechanism between the PS terminal and the MGW in response to being notified that the terminal is communicating with the CS terminal. Good. For example, when a PS terminal knows that the other side is a CS terminal, the PS terminal loses packets because the CS terminal operates widely using the Picture Loss Display (PLI) mechanism for packet loss feedback. PLI may be dynamically selected as the preferred mechanism compared to other forms of feedback.

0033In another exemplary embodiment, in response to being notified of the maximum SDU size limit supported by the CS terminal, the PS terminal ensures that its self-generated packets remain smaller than the maximum SDU size limit. You may do so. This enables efficient packetization of data packets in MGW, and similarly enables timely delivery of packets to CS terminals.

0034An exemplary embodiment of the present disclosure in which a PS terminal communicates with a CS terminal according to a signaled packet size limit of the CS terminal has been described, but the scope of this disclosure is the communication between the PS terminal and the CS terminal. Not limited to. For example, the present technology may generally be applied to communication between a PS terminal and any other terminal having the maximum supported packet size (including non-circuit switched terminals). Such alternative exemplary embodiments are intended to be within the scope of the present disclosure.

0035FIG. 5 illustrates an exemplary embodiment of Computer Program Product 500 that improves the efficiency of data packet transmission between multimedia sessions in accordance with the present disclosure. It should be noted that Computer Program Product 500 is shown for illustrative purposes only and is not intended to limit the scope of this disclosure to any particular exemplary embodiment of Computer Program Product.

0036In FIG. 5, the packet switching (PS) terminal 110 as described above with reference to FIG. 1 is coupled to the computer program product 500. The computer program product 500 includes a computer-readable medium 510 that stores code for causing a computer to perform a certain function.

0037In particular, the computer-readable medium 510 includes code 511 for causing the computer to receive information including parameters related to the maximum packet size negotiated with another termination of the multimedia session.

0038The computer-readable medium 510 further includes a code 512 for causing the computer to generate packets that are not greater than the maximum negotiated packet size in response to the information received.

0039Those skilled in the art will appreciate that information and signals may be represented using any of a variety of different techniques and techniques. For example, the data, instructions, commands, information, signals, bits, symbols and chips referenced throughout the description above are voltages, currents, electromagnetic waves, magnetic fields or particles, light fields or particles, and any combination thereof. It may be represented by a thing.

0040The various exemplary logic blocks, modules, circuits and algorithm steps described in connection with the exemplary embodiments disclosed herein are realized as electronic hardware, computer software, or a combination of both. Those skilled in the art will recognize that it is acceptable. To clearly illustrate this interchangeability of hardware and software, various exemplary components, blocks, modules, circuits, and steps have been described above with respect to these features in general. Whether such functionality is implemented as hardware or software depends on the design constraints imposed on the particular application and system as a whole. One of ordinary skill in the art may realize the functions described in a manner that varies for each particular application, but the determination of such realization deviates from the scope of the exemplary embodiments of the invention. It should not be interpreted as causing it.

0041The various exemplary logical blocks, modules and circuits described in connection with the exemplary embodiments disclosed herein are general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), and field programmable. Achieved by a gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these designed to perform the functions disclosed herein. Or it may be executed. The general purpose processor may be a microprocessor, but instead, the processor may be any traditional processor, controller, microcontrol or state machine. Processors are also computing devices, such as a combination of DSPs and microprocessors, multiple microprocessors, one or more microprocessors with DSP cores, and any other such configuration. It may be realized as a combination of.

0042The steps of the methods or algorithms described in connection with the exemplary embodiments disclosed herein may be embodied directly in hardware, in software modules executed by a processor, or in combination of both. Good. Software modules include random access memory (RAM), flash memory, read-only memory (ROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disks, removable disks, and CDs. -May be present in ROM, or some other form of storage medium known technically. The exemplary storage medium may be coupled to the processor so that the processor can read information from the storage medium and write the information to the storage medium. In alternative embodiments, the storage medium may be integrated with the processor. The processor and storage medium may reside in the ASIC. The ASIC may exist on the user terminal. In an alternative embodiment, the processor and storage medium may be present at the user terminal as a disk rate component.

0043In one or more exemplary embodiments, the described functionality may be implemented in hardware, software, firmware, or any combination of these. When implemented in software, a function may be stored on a computer-readable medium as one or more instructions or codes, or transmitted as one or more instructions or codes on a computer-readable medium. You may. Computer-readable media include both computer storage media and communication media, including some medium that facilitates the transfer of computer programs from one location to another. The storage medium may be any available medium accessible by the computer. By way of example, but not limited to, such computer readable media are accessed by RAM, ROM, EEPROM, CD-ROM or other optical disc storage, magnetic disk storage or other magnetic storage device, or computer. It can include any other medium that can be used to transmit or store the desired program code in the form of instructions or data structures. Also, any connection is appropriately referred to as a computer-readable medium. For example, software can use coaxial cables, fiber optic cables, twisted pairs, digital subscriber lines (DSL), or wireless technologies such as infrared, wireless, and microwave to create websites, servers, etc. Alternatively, when transmitted from other remote sources, coaxial cables, fiber optic cables, twisted pairs, DSLs, or wireless technologies such as infrared, wireless, and microwave are included in the definition of medium. Discs (disk and disc) as used herein include compact discs (CDs), laser discs, optical discs, digital general purpose discs (DVDs), floppy (registered trademark) discs, and Blu-ray discs (registered trademarks). In general, disks play data magnetically, while discs dis. In c), the data is optically reproduced by a laser. A combination of the above should also be included within the scope of computer readable media.

0044Previous descriptions of the disclosed exemplary embodiments have been provided to allow those skilled in the art to make or use the present invention. Various improvements to these embodiments will be readily apparent to those of skill in the art, and the general principles defined herein apply to other exemplary embodiments without departing from the spirit or scope of the invention. May be good. Therefore, the present invention is not intended to be limited to the exemplary embodiments presented herein, but should be consistent with the broadest scope consistent with the principles and new features disclosed herein. is there.<u style="single">Hereinafter, the inventions described in the claims at the time of filing the application of the present application will be added.</u><u style="single">[1] In a way to improve the efficiency of data packet transmission between multimedia sessions.</u><u style="single">Including sending information from the interworking node to the packet switching terminal</u><u style="single">A method in which the information includes parameters related to the maximum packet size negotiated with another termination of the multimedia session.</u><u style="single">[2] The method according to [1], wherein the multimedia session is a multimedia telephone session.</u><u style="single">[3] The method according to [1], wherein the information further includes an indication of whether or not another termination of the telephone session is a circuit-switched terminal.</u><u style="single">[4] The method described in [1], wherein another termination of the multimedia session comprises a circuit-switched terminal, the parameter associated with the maximum packet size includes a maximum negotiated service unit of data (SDU) size.</u><u style="single">[5] The method described in [1], wherein the information further includes an SDU reception interval.</u><u style="single">[6] In a way to improve the efficiency of data packet transmission between multimedia sessions.</u><u style="single">Including receiving information from interworking nodes at packet switching terminals</u><u style="single">A method in which the information includes parameters related to the maximum packet size negotiated with another termination of the multimedia session.</u><u style="single">[7] The method according to [6], wherein the multimedia session is a multimedia telephone session.</u><u style="single">[8] The method according to [6], wherein the information further includes an indication of whether or not another termination of the multimedia session is a circuit-switched terminal.</u><u style="single">[9] The method according to [8], wherein another termination of the multimedia session comprises a circuit-switched terminal, the parameter associated with the maximum packet size includes a maximum negotiated service unit of data (SDU) size.</u><u style="single">[10] The method according to [9], wherein the information further includes an SDU reception interval.</u><u style="single">[11] The method according to [6], wherein the packet switching terminal is a PSVT.</u><u style="single">[12] Further includes adjusting the processing in the packet switching (PS) terminal so that the generated packet does not become larger than the negotiated maximum packet size in response to the reception of the information [6]. the method of.</u><u style="single">[13] The method according to [8], further comprising selecting a picture loss display (PLI) mode of feedback in response to receiving an indication that the telephone session is a circuit-switched terminal.</u><u style="single">[14] In packet switching devices that communicate during multimedia sessions</u><u style="single">With a receiver configured to receive information containing parameters related to the maximum packet size negotiated with another end of the multimedia session.</u><u style="single">A device comprising a transmitter configured to generate a packet that is not greater than the maximum negotiated packet size in response to the received information.</u><u style="single">[15] The device according to [14], wherein the multimedia session is a multimedia telephone session.</u><u style="single">[16] The device according to [14], wherein the information further includes an indication of whether or not another termination of the multimedia session is a circuit-switched terminal.</u><u style="single">[17] The device according to [16], wherein the device is configured to select a picture loss display (PLI) mode of feedback in response to receiving an indication that the telephone session is a circuit-switched terminal.</u><u style="single">[18] The device according to [16], wherein another termination of the multimedia session comprises a circuit-switched terminal, the parameter associated with the maximum packet size includes a maximum negotiated service unit of data (SDU) size.</u><u style="single">[19] The device according to [17], wherein the information further includes an SDU reception interval.</u><u style="single">[20] In packet switching devices that communicate during multimedia sessions</u><u style="single">Equipped with a means to receive information from the interworking node,</u><u style="single">The information includes parameters related to the maximum packet size negotiated with another termination of the multimedia session.</u><u style="single">[21] The device according to [20], further comprising means for generating packets that are not greater than the maximum negotiated packet size during the multimedia session.</u><u style="single">[22] In computer program products to improve the efficiency of data packet transmission during multimedia sessions.</u><u style="single">The product is</u><u style="single">The code that causes the computer to receive information, including parameters related to the maximum packet size negotiated with another end of the multimedia session.</u><u style="single">A computer program product comprising a computer-readable medium comprising a code for causing a computer to generate a packet that is not greater than the maximum negotiated packet size in response to the received information.</u>