CN1326273A - Wiring access method of broadband multimedia services - Google Patents
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Abstract
A wiring access method for broadband multimedia services includes processing the active data transmitted from user terminals, transmitting it over coaxal cable, repeating the up signal on physical line, receiving the bit stream of up data at beginning terminal, transmitting the data of beginning terminal over physical line, repeating up and down signals, receiving their bit streams at user terminal, creating link layer connection between beginning and user terminals, transmitting and receiving link layer data of user terminal, and receiving and repeating the link layer data transmitted from user terminal by the beginning terminal. It can provide cheap and convenient broadband multimedia information service to users.
Description
Technical field
The Wiring access method of broadband multimedia services of the present invention belongs to communication technical field.
Technical background
Along with the continuous growth of broadband multimedia services, register one's residence with cheap and practical technology realization broadband, promptly last kilometer problem is the problem that people generally are concerned about.Method by cable TV (CATV) cable (Cable) access band multi-medium data business is enriched, is easy to advantage such as transformation and is subjected to extensive concern because of existing cable television network broad covered area, bandwidth resources.
The bilateral network that present most of wired access network (CATV) is made up of light, coaxial mixing (HFC net, i.e. Hybrid Fiber/Coax Network) can be used for various interactively network multimedia business, as Fig. 1. shown in.Transmission direction from user terminal (T) to coaxial cable head end (H) is called up, and the direction from coaxial cable head end (H) to user terminal (T) is called descending.The about 0-860MHz of the transmission band of cable television network, its low and middle-end frequency is used for up, and high-end frequency is used for the downstream signal transmission.Typical spectrum allocation may mode is shown in table 1, table 2.How to utilize the two-way transmission capabilities of cable television network, transmit the interactive multimedia business efficiently, and employing effective mechanism, cable television network and public network (telephone network, Internet) are combined, for the user provides cheap, wideband multimedia service easily, be that the problem exploring and solve is being done one's utmost on the communication circle.
The existing uplink spectrum of table 1 is distributed
| The area | ????fmin | ????fmax |
| The North America | ????5MHz | ????42MHz |
| Europe | ????5MHz | ????65MHz |
| Japan | ????5MHz | ????55Mhz |
Table 2. has the downstream spectrum method of salary distribution now
| The area | ????fmin | ????fmax |
| The North America | ????88MHz | ????860MHz |
| Europe | ????110MHz | ????862MHz |
| Japan | ????90MHz | ????770Mhz |
The Wiring access method of existing broadband multimedia services is that the user passes through bidirectional lines cable modem (CableModem) transceive data.Subscriber computer can be visited the Internet by Cable Modem and headend (comprising: DVB modulator, burst demodulation device and switch, router etc.), inserts various multimedia services.Cable Modem has two kinds, and a kind of is circumscribed, links to each other with general network interface card on the computer by Ethernet interface; Another kind is a card insert type, can directly be inserted on the internal bus of PC.Cable Modem transporting mechanism is identical with common modulator-demodulator, all is data to be modulated the back transmit in a frequency range, carries out demodulation by receiving terminal.The CableModem of user side modulates the transmission upstream data exactly, the equipment of demodulation, the descending modulation signal of reception.Usually every 8MHz bandwidth is a transmission channel in the cable tv coax transmission, up employing 16QAM (quadrature amplitude modulation), flank speed 20Mbps, descending employing 64QAM or 256QAM.Flank speed can reach 45Mbps.There is following problem in existing cable broadband cut-in method:
1. up employing modulation system is unfavorable for uplink signal transmissions.Reason is:
(1) the uplink band utilance is low.Uplink band is in the low side of Cable frequency.Because 5MHz is subjected to extraneous interference very big to this frequency range of 20MHz, thus in real system up transmission band basically all from 20MHz.Therefore the uplink band peak use rate is no more than 70%.
(2) the funnel noise is difficult to avoid, and the number of users of every coaxial cable support is limited.In wired connecting system, a plurality of user's data are by same coaxial cable transmission, in the signal that each user sends, signal power is arranged, noise power is also arranged, and these signals converge to headend, the noise power addition, and the power of every road signal does not increase, so the signal to noise ratio severe exacerbation.The phenomenon that this noise power is converged, added up at He Luchu just is called the funnel noise.Along with increasing of number of users, the funnel noise of system sharply increases.Owing to when the modulation signal that user terminal sends arrives headend, must satisfy certain signal to noise ratio, the head end demodulator could correct received signal.Therefore, the existence of funnel noise has limited every number of users that coaxial cable can be supported.The number of users representative value of general every coaxial cable support is 200 families.
2. lack incorporate, intelligentized headend, solve the wired access of CATV, extension of network and service quality (QoS) assurance problem.
Summary of the invention: the purpose of present technique invention is the method that proposes the wired access of a kind of broadband multimedia services, replace the modulation uplink mode of generally using at present with base band uplink mode, reduce of the influence of funnel noise to uplink signal transmissions, make full use of the two-way transmission capabilities of coaxial cable, for the user inserts high-quality broadband multimedia services.
The Wiring access method of the broadband multimedia services that the present invention proposes comprises following each step:
1. the valid data that user terminal is sent cut, scrambling, Saloman are encoded, interweave, process of convolution, form the fixed length bag, before each fixed length bag, add lead code, the bit stream that the fixed length bag of band lead code is formed carries out code conversion and shaping filter, with the baseband signal after being shaped directly in transmission over coaxial cable.
2. the signal in the coaxial cable is carried out low-pass filtering, takes out the uplink baseband signal that the rate of declining has subtracted, through amplification and Regeneration Treatment after continuation in transmission over coaxial cable.
3. head end is received the uplink baseband signal that user terminal sends, at first carry out low-pass filtering, voltage ratio, reduction, and recover original digital signal by sample circuit, then the digital signal after recovering is deinterleaved, deconvolutes, Saloman decoding, descrambling recover valid data.
4. the valid data that headend is sent cut, scrambling, Saloman are encoded, interweave, process of convolution, form the fixed length bag.Fixed length bag bit stream is carried out chnnel coding, and shaping filter adopts 64QAM or 256QAM (quadrature amplitude modulation) mode to modulate then, and the amplification of the carrier wave after will modulating, and is mixed to specified channel then and sends.
5. with the high pass filter downstream signal that extraction efficiency subtracts from the signal of coaxial cable transmission, carry out signal and amplify, carry out again continuing in transmission over coaxial cable after the high-pass filtering.
6. user terminal is received the descending modulation signal that head end sends, and amplifies, filtering, frequency conversion, demodulation, recovers original digital signal.Then the digital signal after recovering is deinterleaved, deconvolutes, Saloman decoding, descrambling recover valid data.
Head end periodically broadcast registration allow signaling.
8. registration and clock alignment application are sent in start but do not set up the user terminal get in touch with head end as yet and receive after registration allows signaling, during report reception simultaneously right downlink sub-channels (descending reception frequency range).After head end receives the application for registration signaling, give unique logical identifier that takies of online phase of this terminal distribution, confirm simultaneously or distribute two downlink sub-channels, and the side-play amount of sense terminals clock and head end clock.Head end in the signaling that succeeds in registration, is broadcasted down above-mentioned three information package by each downlink sub-channels.The small station receives the one's own signaling that succeeds in registration, adjust local clock according to wherein clock offset and finish clock synchronization with main website, be provided with two and receive frequency range, simultaneously with the pairing signalling path of logical identifier as own signalling path when online, and send registration by this signalling path head-end and finish signaling.
9. after having carried out registration, clock alignment, terminal and head end enter synchronous regime, and can be from two frequency range downlink data receivings.The user is the downlink data packet of two frequency ranges of monitoring constantly, receives the packet that indicates this terminal logic sign, and puts into the reception buffering area.As long as receive the buffering area non-NULL, decode with regard to constantly taking out packet, and recover valid data.If user terminal has data to need to send, then valid data to be sent are deposited and sent buffering area, pass through the signalling path head-end request for data sending time slots of logical identifier correspondence then.Head end is given terminal distribution data sending time slots by down channel.After user terminal is received the time slot allocation instruction, valid data are cut, are encoded into the fixed length bag, in the time slot transmission data of appointment.
10. head end is received the fixed length bag that terminal sends, to its decoding, separate multiple connection, recover valid data, and check the destination address of the valid data that will send, if destination address is inside, sub-district, then from the corresponding address table, search the logical identifier of this destination address correspondence and downlink sub-channels number, data are deposited corresponding downstream send buffering area.According to scheduling strategy, valid data according to priority queueing, at the time slot of appointment, are broken into the descending transmission of fixed length bag then.If destination address is the outside, sub-district, then start routing algorithm, according to the quality requirement of business, select suitable route and speed, and send according to the public network protocol packing.
The characteristics of the method for wired access band multimedia service that the present invention proposes are:
1. be transmission medium with the bidirectional coaxial cable, guarantee full-duplex communication.
2. replace the modulation uplink mode that generally adopts at present in base band uplink mode, make full use of the power of regeneration of digital signal, reduce in wired connecting system the funnel noise to the influence of signal transmission quality, increased the every number of users that coaxial cable is supported.
3. design is based on the baseband transmission equipment of coaxial cable.Comprise the trunking that uses in the physical layer transceiver equipment that uses in head end and the terminal equipment and the transmission.Problems such as the amplitude fading that the solution baseband signal occurs in the Cable transmission, the distortion of sign indicating number shape, phase jitter.
4. the data link layer protocol of independent design has solved a series of problems such as clock synchronization in the uplink baseband transmission, range finding, signaling transmission, transfer of data.For network route and exchange agreement are submitted necessary information.The data link layer protocol of native system special use is supported the IP agreement comprehensively.
5. rational time slot allocation scheme improves upstream channel utilization.The transmission cycle of up channel is set, and it is divided into signalling time slot and data slot two large divisions.Signalling time slot is adopted the fixed allocation mode, and head end distributes a fixing signalling time slot for each online user, and all signalings that this user sends are all passed through this fixedly upwards transmission of time slot, have avoided the signaling collision.Data slot is controlled by head end, distributes according to need according to kind, the priority level of customer service.Downlink data is transferred to the user with the forms of broadcasting, and the user has selection or has authority ground to receive data.Head end is the descending receive channel of online user's dynamic assignment.
6. headend supports many coaxial cables to insert, and ATM, Fast Ethernet interface are arranged, and has both supported also to support the exchanges data between coaxial cable user and the public network user with user's data exchange on bar coaxial cable, the different bar coaxial cable.
7. head end inserts many coaxial cables simultaneously, and number of users that every coaxial cable connects is fixed.When number of users increased, head end was by increasing the coaxial cable quantity extending user quantity that connects.This way can make the headend functions modularization, only needs during expansion peripheral module is duplicated, and does not need to change nucleus module.
8. special-purpose route and exchcange core module are arranged in the headend, load kernel scheduling and routing algorithm, for the user provides high speed, high quality-of-service (QoS), access service cheaply, utilize existing band resource, support multiple services such as high-quality phone, video conference, video request program, the Internet.
9. user terminal is provided with the double reception frequency range, can receive data simultaneously from the two-way downlink sub-channels, has improved the flexibility of channel allocation greatly.
10. subscriber terminal equipment adopts computer based multifunctional all platform.Support TV, phone and business of networking simultaneously.
Native system up channel frequency range is 0～75MHz, directly baseband level transmission, and transmission rate can reach 120Mbps; The down channel frequency range is 120-860MHz, adopts the frequency division multiplexing mode, and each downstream channel bandwidth is 8MHz.If adopt 256QAM (quadrature amplitude modulation), the transmission rate of each down channel can reach 45Mbps.Consider protection and loss, the descending transmission rate of a coaxial cable can reach the gigabit magnitude.The disposal ability of a headend can reach 4 Jis.Only need head end and the terminal equipment that less input, just can make full use of the channel resource of cable television network (CATV), for the user provide cheapness, wideband multimedia information service easily.
Description of drawings:
Fig. 1. wired access multimedia application system schematic diagram, H represents headend among the figure, and T represents subscriber terminal equipment, and S represents database, and 1,2,3 represent different sub-districts respectively.Chain-dotted line is represented metropolitan area network, the coaxial cable that on behalf of the sub-district cable television network, fine line use, and heavy line is represented the minizone, and the high speed fibre between sub-district and public network.
Fig. 2. wired access uplink signal transmissions flow chart, RS among the figure (Reed Solomon), expression Saloman coding.
Fig. 3. wired access downstream signal transfer process figure, RS among the figure (Reed Solomon), expression Saloman coding.
Fig. 4. wired access repeat circuit schematic diagram
Fig. 5. wired access head end structure chart
Fig. 6. wired structure chart that accesses terminal
Fig. 7. wired access head end exchange and routing function block diagram, among the figure, 1,2,3,4 is wired uplink baseband signal, 6,7,8,9 is wired descending modulation signal.5,10 signals for home server turnover head end.11,12,13,14 is outside public network signal.
Fig. 8. wired access signal transmission hierarchy chart, MAC refers to Media Access Control among the figure, media interviews control, Cable refers to the coaxial cable of cable television network.
Embodiment:
Below in conjunction with a embodiment, introduce content of the present invention in detail based on wired access band multimedia system of the inventive method.
Fig. 1. be to adopt method of the present invention that the representative instance figure of broadband multimedia services is provided for the resident of city intellectual communityintellectualized village.Among the figure, the intellectual communityintellectualized village in city is net distribution, and is middle continuous by high-capacity optical fiber.Cable television network in the sub-district is tree-like distributed architecture, uses coaxial cable to be connected to every family.By so two-way optical fiber, coaxial hybrid network, can insert multimedia service at a high speed for the terminal use.
The sub-district is inserted part and is made up of user terminal (T), bidirectional coaxial cable, head end access device (H) and cell data base (B).User terminal is serially connected on the coaxial cable with bus form.About 1 kilometer of the coverage of every bidirectional coaxial cable.Consider present community, about 5 unit, every building, each 15 family, unit other, building have 75 families other.20 buildings are arranged in 1 kilometer range, and then the number of users of every bidirectional coaxial cable access is 1500.Because adopt the base band uplink, the number of users of every coaxial cable support depends primarily on the requirement of user to channel resource, rather than the funnel The noise.1500 just individual representative values.In order to improve access rate, can suitably reduce the number of users that every cable connects.Each sub-district Access Network can interconnect composition metropolitan area network (WAN) by the external interface of head end or directly link to each other with public network.
In this programme, consider use cost and convenience, user terminal adopts two-way Cable card and PC.The up employing of two-way Cable card baseband transmission mode provided by the invention, descending employing 64 or 256QAM modulation system are with general DVB-C standard (digital video broadcasting) compatibility.In native system, consider the diversity of family information service, require each Cable card can receive the data of two downlink sub-channels simultaneously.Typical user terminal structure as shown in Figure 6.Among the figure, signal receiving module is used to receive the wired descending modulation signal of two-way, comprises matched filtering and demodulation etc.Signal transmitting module is used to send wired uplink baseband signal.The processing data packets module is used for coding, decoding, protocol processes, interface processing of signal etc.Two-way Cable cartoon is crossed the total interface of PCI and is inserted on the PC, and TV and telephony interface are provided simultaneously.
Head end is the core hinge of exchanges data between the user outside user and the sub-district in the sub-district between the user, in the sub-district.Headend will have powerful routing and switching function, multi-protocol interface and good autgmentability.The head end structure that should use as shown in Figure 5.Among the figure, signal receiving module is used for the sampling and the recovery of wired base band upward signal.Signal transmitting module is used for filtering, modulation and the transmission of wired downstream signal.Data processing module is used for coding, decoding, input, analysis and protocol processes, interface processing of signal etc.Exchange and routing module are used to exchange control, Route Selection and QoS quality assurance.System management module is used for system parameters configuration, condition monitoring, user management etc.
The exchange of head end and routing function are as shown in Figure 7.In this example, head end has 4 wired access ports, can connect 4 coaxial cables.Support 6000 users.1 cell server interface.Community user can carry out VOD program request etc. by the database of wired network access server.4 outer network interfaces.Can support the access of gigabit Ethernet, ATM, E1, T1.
According to the definition of OSI/RM hierarchical structure, the transmission level of wired connecting system internal data as shown in Figure 8.The exchange and the routing section of native system belong to network layer, adopt the IP agreement of standard.For realizing wired base band uplink, MAC layer and physical layer have adopted some special signal processing means.As Fig. 2, Fig. 3, shown in Figure 4.The signals transmission of each layer is:
1. physical layer signal transmission:
(1) uplink signal transmissions
User terminal to the upper strata valid data cut, scrambling, RS encodes, interweaves, convolution, forms the fixed length bag, increases lead code again before each fixed length bag.The base band code stream that the fixed length bag of being with lead code is constituted forms filtering then, and the baseband signal after being shaped is directly transmitted on head-end on the coaxial cable.Baseband signal is transmitted in coaxial cable certain loss, therefore will carry out a relaying at a certain distance and amplify.At first the upward signal to decay carries out low-pass filtering, and voltage ratio makes a yard shape reduction then, and the base band upward signal after the reduction is carried out low-pass filtering and continue on the next stage cable sending.Signal arrives head end through relaying repeatedly.Head end is received the uplink baseband signal that terminal sends, at first carry out low-pass filtering, voltage ratio, reduction, and recover original digital signal by sample circuit.Then the digital signal after recovering is deinterleaved, deconvolutes, RS decoding, descrambling.Recover valid data.
(2) downstream signal transmission
Head end to send valid data cutting, scrambling, Saloman coding and interweave, process of convolution and base band shaping filtering, adopt the carrier wave after 64QAM or 256QAM mode are modulated and will modulate to amplify then, be mixed to the specified channel transmission then.Descending modulation signal transmits in coaxial cable, and along with distance increases, shunting point increases, level also can constantly reduce.In case be lower than the working range of user terminal demodulator, will can not receive data, therefore also to amplify descending modulation signal relaying.Method is at first to select downstream signal by high pass filter, after the amplification, carries out a high-pass filtering again, continues transmission.Terminal is received the descending modulation signal that head end sends, and amplifies, filtering, frequency conversion, demodulation, recovers original digital signal.Then the digital signal after recovering is deinterleaved, deconvolutes, RS decoding, descrambling.Recover active data.
2. link layer signal transmission
The link layer signal is shared transmission medium with time division multiplexing mode.But the user terminal that coaxial cable connects is different apart from the distance of head end, so the signal transmission delay is also different.In addition, the clock of each terminal also is independently.In order to guarantee the reliable transmission of time multiplexing signal, must adjust the clock of terminal, overcome transmission delay and clock jitter, make all terminal clock all with the head end clock synchronization.Method is:
User terminal powers up at every turn, and all head-end equipment sends application for registration, applies for clock alignment simultaneously.After head end receives the application for registration signaling, according to current channel operating position, give downlink sub-channels of this terminal distribution, distribute an online unique logical identifier (LogicID simultaneously,), and the clock offset of detection application for registration signaling packet, above-mentioned three information package in the signaling that succeeds in registration, are broadcasted down by each downlink sub-channels.The small station receives the one's own signaling that succeeds in registration, and adjusts local clock, finishes the clock synchronization with main website, receives data and sends registration in the up signalling path head-end of logical identifier (LogicID) appointment in the downlink sub-channels of appointment and finish signaling.
If do not receive the one's own signaling that succeeds in registration in the certain hour of small station after sending the application for registration signaling, carry out the another registration of taking turns after then waiting a period of time, until succeeding in registration; Do not finish signaling if receive the registration of returning in the certain hour of head end after signaling is succeeded in registration in transmission, then resend the signaling that succeeds in registration, reply until receiving.All do not reply if repeatedly retransmit, think that then the user shuts down, send the registration failure signaling.
After after having carried out registration and clock alignment, terminal and head end enter synchronous regime, can carry out real-time process of data communication.At first, terminal obtains effective data packets from network layer, deposits buffering area, then the signalling path head-end request for data sending time slots by taking.The size of the data volume of head end basis and local network conditions are given the terminal distribution data slot.Terminal breaks into the fixed length bag with packet after receiving the time slot allocation instruction, in the time slot transmission data of appointment.Head end is received the fixed length bag, to its decoding, multiple connection, recovers the effective data packets bag.
The downlink data transmission process is: head end obtains effective data packets from network layer, according to the destination address in the packet, inquires about the logical identifier (LogicID) and the current downlink sub-channels of the terminal of this address correspondence.Packet is put into the corresponding downstream channel send buffering area, in the descending time slot that scheduling strategy distributes, packet is broken into the fixed length bag transmit downwards.If broadcast message is then in all subchannel broadcast transmissions.Terminal is received the fixed length bag of head end, by logical identifier (LogicID), selects one's own fixed length bag, to its decode, multiple connection, be reduced into valid data.
3. network layer
Head end adopts IP-based routing and switching function in network layer.Among Fig. 7, wired upstream data, outer net data enter head end through wired access interface (1,2,3,4) and outer net access interface (11,12,13,14), revert to the IP packet at head end.Head end is checked the destination address of IP packet, if destination address is inside, sub-district, then from the corresponding address table, search the logical identifier (LogicID) of this address correspondence and downlink sub-channels number, through the inner exchanging module, data are transferred to corresponding downstream send buffering area, according to priority,, break into the descending transmission of fixed length bag at the time slot of appointment.If destination address is the outside, sub-district, then through the route module,, select the public network output port for data according to the requirement and the destination address of business to service quality, send according to the public network protocol packing.
Claims (1)
1, a kind of Wiring access method of broadband multimedia services is characterized in that this method comprises following each step:
(1) valid data that user terminal is sent cut, scrambling, Saloman are encoded, interweave, process of convolution, form the fixed length bag, before each fixed length bag, add lead code, the bit stream that the fixed length bag of band lead code is formed carries out code conversion and shaping filter, with the baseband signal after being shaped directly in transmission over coaxial cable;
(2) signal in the coaxial cable is carried out low-pass filtering, takes out the uplink baseband signal that the rate of declining has subtracted, through amplification and Regeneration Treatment after continuation in transmission over coaxial cable;
(3) head end is received the uplink baseband signal that user terminal sends, at first carry out low-pass filtering, voltage ratio, reduction, and recover original digital signal by sampling, then the digital signal after recovering is deinterleaved, deconvolutes, Saloman decoding, descrambling recover valid data;
(4) valid data that headend is sent cut, scrambling, Saloman are encoded, interweave, process of convolution, form the fixed length bag, fixed length bag bit stream is carried out chnnel coding, shaping filter, adopt 64QAM or 256QAM quadrature amplitude modulation mode to modulate then, and the amplification of the carrier wave after will modulating, be mixed to specified channel then and send;
(5) by the high-pass filtering downstream signal that extraction efficiency subtracts from the signal of coaxial cable transmission, carry out signal and amplify, carry out again continuing in transmission over coaxial cable after the high-pass filtering;
(6) user terminal is received the above-mentioned descending modulation signal that head end sends, amplify, filtering, frequency conversion, demodulation, recover original digital signal, then the digital signal after recovering is deinterleaved, deconvolutes, Saloman decoding, descrambling recover valid data;
(7) head end periodically broadcast registration allow signaling;
(8) start but do not set up the user terminal get in touch as yet and receive after registration allows signaling with head end, send registration and clock alignment application, when report receives simultaneously right downlink sub-channels, it is descending reception frequency range, after head end receives the application for registration signaling, give unique logical identifier that takies of online phase of this terminal distribution, confirm simultaneously or distribute two downlink sub-channels, and the side-play amount of sense terminals clock and head end clock, head end with above-mentioned three information package in the signaling that succeeds in registration, broadcast down by each downlink sub-channels, the small station receives the one's own signaling that succeeds in registration, adjust local clock according to clock offset wherein, finish clock synchronization with main website, be provided with two and receive frequency ranges, send to register simultaneously with the signalling path of the pairing signalling path of logical identifier when own online, and by this signalling path head-end and finish signaling;
(9) registering, after the clock alignment, terminal and head end enter synchronous regime, and from two frequency range downlink data receivings, the user is the downlink data packet of two frequency ranges of monitoring constantly, reception indicates the packet of this terminal logic sign, and put into the reception buffering area, if receive the buffering area non-NULL, decode with regard to constantly taking out packet, and recover valid data, if user terminal has data to need to send, then valid data to be sent are deposited and sent buffering area, pass through the signalling path head-end request for data sending time slots of logical identifier correspondence then, head end is given terminal distribution data sending time slots by down channel, user terminal after receiving the time slot allocation instruction cuts valid data, be encoded into the fixed length bag, in the time slot transmission data of appointment;
(10) head end is received the fixed length bag that terminal sends, to its decoding, separate multiple connection, recover valid data, and check the destination address of the valid data that will send, if from marking the address is inside, sub-district, then from the corresponding address table, search the logical identifier of this destination address correspondence and downlink sub-channels number, data are deposited corresponding downstream send buffering area, then according to scheduling strategy, with valid data according to priority queueing, at the time slot of appointment, break into the descending transmission of fixed length bag, if destination address is the outside, sub-district, then start routing algorithm, according to the quality requirement of business, select suitable route and speed, and send according to the public network protocol packing.
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Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100353761C (en) * | 2003-07-18 | 2007-12-05 | 华为技术有限公司 | Method for transmitting multiple digital subscriber line services by using coaxial cable, and equipment therefor |
| CN100442725C (en) * | 2005-12-27 | 2008-12-10 | 华为技术有限公司 | Method for carrying out sampling on device transmission signal |
| CN100444589C (en) * | 2003-10-02 | 2008-12-17 | 香港应用科技研究院有限公司 | System and method for providing multimedia wireless messages across a broad range and diversity of networks and user terminal display equipment |
| CN100493179C (en) * | 2003-12-03 | 2009-05-27 | 北京泰美世纪科技有限公司 | Transmission method for raio multimedic broadcast system and its system |
| CN101009547B (en) * | 2006-01-25 | 2010-06-09 | 普诚科技股份有限公司 | Searching method for packet front synchronization signals and its device |
| CN101208977B (en) * | 2005-06-29 | 2012-01-11 | 艾利森电话股份有限公司 | Evaluation of random access lead code |
| CN102571508A (en) * | 2010-12-20 | 2012-07-11 | 上海大亚科技有限公司 | Ethernet interconnection system based on coaxial cable technology and data transmission control method |
| CN102595091A (en) * | 2012-03-20 | 2012-07-18 | 深圳市鼎盛威电子有限公司 | Transmission system and transmission method for serial digital interface (SDI) high-definition video signals |
| CN102938743A (en) * | 2012-10-23 | 2013-02-20 | 国家广播电影电视总局广播科学研究院 | Data transmission method and device |
| CN102282843B (en) * | 2009-01-15 | 2014-08-20 | Lg电子株式会社 | Apparatus for transmitting and receiving a signal and method of transmitting and receiving a signal |
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2001
- 2001-07-13 CN CN 01120427 patent/CN1131603C/en not_active Expired - Fee Related
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| CN100353761C (en) * | 2003-07-18 | 2007-12-05 | 华为技术有限公司 | Method for transmitting multiple digital subscriber line services by using coaxial cable, and equipment therefor |
| CN100444589C (en) * | 2003-10-02 | 2008-12-17 | 香港应用科技研究院有限公司 | System and method for providing multimedia wireless messages across a broad range and diversity of networks and user terminal display equipment |
| CN100493179C (en) * | 2003-12-03 | 2009-05-27 | 北京泰美世纪科技有限公司 | Transmission method for raio multimedic broadcast system and its system |
| CN101208977B (en) * | 2005-06-29 | 2012-01-11 | 艾利森电话股份有限公司 | Evaluation of random access lead code |
| CN100442725C (en) * | 2005-12-27 | 2008-12-10 | 华为技术有限公司 | Method for carrying out sampling on device transmission signal |
| CN101009547B (en) * | 2006-01-25 | 2010-06-09 | 普诚科技股份有限公司 | Searching method for packet front synchronization signals and its device |
| CN102282843B (en) * | 2009-01-15 | 2014-08-20 | Lg电子株式会社 | Apparatus for transmitting and receiving a signal and method of transmitting and receiving a signal |
| CN102571508A (en) * | 2010-12-20 | 2012-07-11 | 上海大亚科技有限公司 | Ethernet interconnection system based on coaxial cable technology and data transmission control method |
| CN102595091A (en) * | 2012-03-20 | 2012-07-18 | 深圳市鼎盛威电子有限公司 | Transmission system and transmission method for serial digital interface (SDI) high-definition video signals |
| CN102938743A (en) * | 2012-10-23 | 2013-02-20 | 国家广播电影电视总局广播科学研究院 | Data transmission method and device |
| CN102938743B (en) * | 2012-10-23 | 2016-06-15 | 国家广播电影电视总局广播科学研究院 | Data transmission method and device |
| CN110521202A (en) * | 2017-07-24 | 2019-11-29 | 优普利兹通讯技术公司 | The videoconference server and its method of multi-screen video conference can be provided using multiple video conference terminals |
| CN110521202B (en) * | 2017-07-24 | 2021-02-02 | 优普利兹通讯技术公司 | Video conference server capable of providing multi-screen video conference by using a plurality of video conference terminals and method thereof |
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