CN100539579C

CN100539579C - Local area network transmission control method

Info

Publication number: CN100539579C
Application number: CNB2003101187178A
Authority: CN
Inventors: 陈明群; 朱我辉; 陈宗贤
Original assignee: BenQ Corp
Current assignee: BenQ Corp
Priority date: 2003-12-02
Filing date: 2003-12-02
Publication date: 2009-09-09
Anticipated expiration: 2023-12-02
Also published as: CN1625174A

Abstract

A method for local area network transmission control method, the local area network includes a transmission end and at least a receiving end, the method includes encoding the service quality control signal into the service quality control packet according to RTCP/TCP/IP protocol; encoding the multimedia data stream according to RTP/UDP/IP protocol; transmitting the encoded multimedia data stream from the transmission end to the at least one receiving end; transmitting the QoS control packet from the transmission end to each receiving end without passing through a router; and decoding the QoS control packet to check the transmission status of the multimedia data stream.

Description

The LAN transfer control method

Technical field

The present invention relates to a kind of method of control area net network signal transmission, in particularly a kind of multi-medium data transmission, transmit the method for service quality control package with the RTCP/TCP/IP agreement.

Technical background

Along with the fast development of computer science and technology, the function of computer increases and price descends makes many families have the computer more than two.As long as, just can be used for passing mutually each other data, printer sharing and CD-ROM drive even online each other object for appreciation game on line owing to there are two computers can form a simple LAN.In addition, by LAN, can also share some program.For instance, because hard disc of computer off-capacity or processor speed wait problem too slowly, some programs may only be installed in memory space abundance or processing speed faster on the computer, if LAN is arranged, so just can carry out this one and have memory space abundance or the processing speed program on the computer faster, and needn't two ones all identical program will be installed by an other computer.Especially now several are more than GB easily for multimedia text, and therefore, general family can buy more a computer that has big storage area and store big multimedia text, is sharing these multimedia texts by network at last.

See also Fig. 1, Fig. 1 is the transmission schematic diagram of known LAN 10.LAN 10 comprises a plurality of main frames, and wherein a main frame can be used as transmission ends 12 other main frames then as receiving terminal 14.

Member's desire of supposing one family utilizes LAN 10 to pass on images and sound to carry out the meeting of online family.Since on-line meeting for data packet real-time Transmission such as sound, image require high, therefore in general, transmission ends 12 can be transmitted multimedia data stream and receiving terminal 14 mutual communication such as image and speech data by the RTP/UDP/IP agreement, and this is because the UDP/IP agreement can provide simple but insecure transmission of data packets on the different main frames 11 more than two.Here so-called " unreliable " is to represent not guarantee that the data packet of sending is bound to arrive at purpose, or arrives at correct order.Yet among general LAN, almost can reach 100% the rate of sending of supporting, because the employed package of UDP/IP communication protocol is short and setup parameter is simple and easy, be usually used in the transmission of multi-medium data in addition with the data packet of UDP/IP protocol transmission.Add, UDP/IP can multiple access transmit (multicast) give with other same local network network 10 among receiving terminal 14 given communication port (port).In addition, for package and the multiple access transmission that can handle real-time, and guarantee to use the data packet of UDP/IP protocol transmission can be, so can (Real-Time TransportProtocol, RTP) agreement be wrapped up video-audio data at the collocation RTP in addition in the correct reorganization of receiving terminal 14.Video-audio data package with RTP title (header) provides necessary temporal information (timing information).The RTP title can utilize the information of time and a sequence number (sequence number) so that receiving terminal 14 is known in the process of transmission, whether there is data packet to lose, and the order that receives data packet, and the member's (that is receiving terminal 14 of all addings) who makes all add meetings according to these information audio-visual package that just can recombinate according to this and receive, even estimate at how many audio-visual packet loss.In addition, the RTP title has also comprised the form of data to be differentiated, and allows various data and various compression protocol, for example PCM, ADPCM.Thus, when the huge video-audio data of transmission flows, just can utilize the mode Data transmission of RTP/UDP/IP.Because RTP is known by definition among the IETF RFC 1889 and by being familiar with this technical field person, can consult about the further detailed description of contents of RTP Http:// www.faqs.org/rfcs/rfc1889.html

Before transmission ends 12 is being transmitted data, must obtain a multiple access earlier and broadcast address (multicast address), and a pair of connectivity port (port), one of them port is for the package that receives the realtime transmission protocol RTP agreement (transmitting audio-visual package), another then is the package for RTCP (RTPcontrol protocol) agreement, that is service quality (Quality of Service, QoS) control package.The purpose that transmits QoS control package is can be because of the influence of network bandwidth (bandwidth), delay (delay), shake (jitter), package leakage factors such as (packet loss) in order to ensure communication quality.In general, can be periodically between transmission ends 12 and the receiving terminal 14 send service quality control package and can add a RTCP title, and RTCP can fix and periodically transmits service quality control package at set intervals with RTCP/UDP/IP.In addition, RTCP also can be used for the audio-visual package of synchronization.

Yet, general home lan network 10 mostly is point-to-point transmission greatly, need router (router) be installed in addition in the family expenses LAN, so in fact being set with the isoparametric service quality control package of jitter and round-trip-time is designed to data packet originally in the UDP/IP agreement and passes through Internet transmission, through routers a large amount of in the internet, so that between router and router, set up flow control mechanism, but data may be without crossing router in LAN, or only pass through limited router, its effect can't take place under this environment transmission, wherein jitter is the time difference that each package of comparison arrives at, and round-trip-time represents that each package transmits the time of required use back and forth.Reason is that the aforementioned UDP/IP of mentioning agreement does not guarantee that the data packet of sending is bound to arrive at purpose, or arrives at correct order.Once when in LAN 10, having a plurality of users to share wireless frequency range simultaneously, in when, easily the problem of network congestion (network congestion) taking place, the package of transmission is just lost easily or is postponed, add because the UDP/IP agreement can't require the package of undelivered to retransfer, so might lose with the service quality control package of UDP/IP transmission; Even if the data arrives in the service quality control package, but because communication environment is a LAN, data packet is not through router or only have 1,2 routers, the defined service quality control parameter of UDP/IP agreement is not sufficient to reflect present network traffic condition, so the parameter of the characteristics such as responsible control package delay in the service quality control package is all nonsensical, the LAN 10 of related feasible use UDP/IP can't suitably be adjusted the quality of Network Transmission video-audio data package between transmission ends 12 and each receiving terminal 14, causes the audio-visual quality of receiving to descend.

Summary of the invention

Therefore the objective of the invention is among a LAN, utilize the RTCP/TCP/IP agreement to transmit service quality (QoS) control package, the service quality control package of the usefulness of can making concessions rtcp protocol is able to make suitably transmission control at parameters such as transmission delays under the environment for use of TCP/IP.

Claim of the present invention provides a kind of method of LAN transfer control method, this LAN comprises a transmission ends and at least one receiving terminal, flow to this at least one receiving terminal by transmission ends transmission service quality control signal and multi-medium data, it is service quality control package according to the RTCP/TCP/IP protocol code that this method includes the service quality control signal; Multimedia data stream is become the multi-medium data package according to the RTP/UDP/IP protocol code; Multi-medium data package and service quality control package are sent at least one receiving terminal by this transmission ends; Transmission ends just the decoding of this service quality control package to obtain of the transmission of this service quality control signal as this multimedia data stream of control.

The accompanying drawing summary

Fig. 1 is the schematic diagram of the transmission of known LAN.

Fig. 2 is the schematic diagram that LAN is used method transmission of the present invention.

Fig. 3 is the flow chart of control area net network signal transmission of the present invention.

The reference numeral explanation

10,20 LAN; 12,22 transmission ends;

14,24 receiving terminals; 26 logical blocks;

Embodiment

See also Fig. 2, Fig. 2 is the schematic diagram of LAN 20 utilizations method transmission of the present invention.LAN 20 comprises a plurality of main frames, and wherein a main frame is as transmission ends 22, and all the other main frames are then as receiving terminal 24.Each main frame all comprises a logical block 26, for convenience of explanation, be transmission ends 22 at this definition main frame wherein, but in fact, every any main frame that is used for sending data person in this local network 20 all may be defined as transmission ends 22, and all the other main frames that receive data then are receiving terminal 24.LAN 20 can be a wireless network (wireless network) or a cable network (wire network).

See also Fig. 3, Fig. 3 is the flow chart of control area net network signal transmission of the present invention.Its step is as follows:

Step 100: in LAN, the logical block 26 of transmission ends 22 is service quality control package with service quality (QoS, quality of service) control signal according to the RTCP/TCP/IP protocol code;

Step 102: the multimedia data stream that the logical block 26 of transmission ends 22 is formed image, voice (multi-media data stream) is according to RTP/UDP/IP protocol code multi-medium data package;

Step 104: the multimedia data stream of coding is sent to receiving terminal 24;

Step 106: the QoS package is sent to receiving terminal 24 in the mode via router not; And

Step 108: with the decoding of QoS package, to check the status transmission of 24 of transmission ends 22 and receiving terminals, to adjust the transmission conditions of multimedia data stream between the two.

To illustrate that below method of the present invention adopts TCP (Transmission Control Protocol) to replace the reason that UDP transmits the service quality package.Simply introduce the principle of TCP running at first earlier.Using in the TCP transmission, transmission ends 22 and receiving terminal 24 can be set up one and can provide two-way data are all carried out being connected of error detection.In order to ensure the reliability that data transmit, just guarantee to use the package of ICP/IP protocol transmission to arrive at purpose with being bound to sequence consensus, otherwise be exactly bust this.This is because the title of the package of ICP/IP protocol has two special positions, that is SYN, ACK, in order to coordinate new online generation.When unlatching TCP/IP was online, transmission ends 22 can be sent the package setting the SYN position but do not set the ACK position.24 of receiving terminals are answered with the package of setting ACK position and SYN position simultaneously.Last transmission ends 22 is sent the package setting the ACK position but do not set the SYN position again and is given receiving terminal 24.Whether set via inspecting package ACK position, transmission ends 22 can be recognized the package that requirement is set up online package and set up online answer, so TCP/IP is the host-host protocol that a kind of single access transmits (unicast) characteristic, this is the characteristic that is different from the multiple access transmission (multicast) of UDP/IP agreement.

Though under the situation of network congestion, cause the possibility of service quality control package loss or delay to heighten.But the service quality control package with the TCP/IP transmission can guarantee that but one arrives at receiving terminal 24 surely, because TCP/IP still can transmit once more at the package of losing, and by above-mentioned checking mechanism, till determining that the package that will transmit is sent to receiving terminal 24.Also therefore, in the time of just can avoiding known technology utilization RTCP/UDP/IP, the misgivings that service quality control package may be lost.In addition, also because the arriving at really of service quality control package, it is meaningful that parameters such as jitter that delay changes between responsible control transmission end 22 and the receiving terminal 24 in the RTCP title of service quality control package and round-trip-time become concerning TCP/IP, so transmission ends 22 is able to by come the transmission quality of phase-split network 15 with parameters such as relevant packet transmission delay in the service quality control package of RTCP/TCP/IP transmission, and then the transmission speed of adjustment multimedia data stream, make that the transmission qualities in the LAN 20 are adjusted.

Note that logical block 26 can be a wireless network card or radio access base station (WirelessAccess Point).

Compared to known technology, but method of the present invention utilizes the UDP/IP multiple access to broadcast the characteristic of (Multicast), making needs the multimedia data stream of real-time Transmission to be used the RTP/UDP/IP host-host protocol to transmit, but then transmit with the RTCP/TCP/IP agreement for being used for the service quality control package of control transmission quality, thus, the service quality package just can guarantee to arrive at receiving terminal, and the service quality package is used for the parameter of Control Network transmission environment and is also utilized under the environment of TCP/IP and just brought into play its meaning.

The above only is preferred embodiment of the present invention, and all equalizations of being done according to the present patent application claim change and modify, and all should belong to the covering scope of patent of the present invention.

Claims

1. A local area network transmission control method, the method is used to transmit a service quality control signal and a multimedia data flow, the local area network includes a transmission end and at least one receiving end, the method includes:

Encoding the QoS control signal into a QoS control packet according to the RTCP/TCP/IP protocol;

encoding the multimedia data stream into a multimedia data packet according to the RTP/UDP/IP protocol;

establishing a transmission link between the transmitting end and the at least one receiving end;

transmitting the QoS control packet and the multimedia data packet to the at least one receiving end through the local area network by the transmitting end; and

The at least one receiving end decodes the QoS control packet to obtain the QoS control signal for controlling the transmission of the multimedia data stream.

2. The method of claim 1, wherein the local area network is a wireless network.

3. The method of claim 1, the local area network does not have a router.

4. The method of claim 1, wherein the multimedia data stream includes audio and video data.

5. The method as claimed in claim 1, further comprising: when the at least one receiving end does not receive the QoS control packet, the transmitting end retransmits the QoS control packet using TCP/IP network protocol.