CN201039192Y

CN201039192Y - Bidirectional transmission system based on optical fiber coaxial mixing network

Info

Publication number: CN201039192Y
Application number: CNU2007201034655U
Authority: CN
Inventors: 林杉
Original assignee: Kaibo Xunjie Technology (beijing) Coltd
Current assignee: Kaibo Xunjie Technology (beijing) Coltd
Priority date: 2007-02-05
Filing date: 2007-02-05
Publication date: 2008-03-19
Anticipated expiration: 2017-02-05

Abstract

The utility model discloses a double-way transmission system on the basis of an optical fiber coaxial mixed network, which comprises a passive light network unit and an interactive mode coaxial network unit. A wired network is connected to the consumer respectively by passing the passive light network unit and the interactive mode coaxial network unit. The coaxial network part of the utility model finishes the modulation of a signal through ICN technology, and is connected to a terminal device of PON network through net twine, and then the transmission of data signal is completed by the PON network, thereby meeting the requirement for the HFC network users to obtain the interaction service.

Description

Bidirectional transmission system based on Hybrid Fiber and Coax Network HFC

Technical field

The utility model relate to a kind of be used for the coaxial hybrid network of existing fiber (English name: HybridFiber-Coax, following abbreviation: the HFC) transmission technology of network, utilize transmission mediums such as optical fiber, coaxial cable, on hfc plant, realize two-way, high-speed channel.

Background technology

Through the construction in more than 20 years and development, China's cable TV network has become the cable TV network of userbase maximum in the world as country important basis for IT application facility and message transmission medium.

Follow the propelling of wired television digitization and networking, deep variation has all taken place from various aspects such as technical system, networking mode and operation management in cable television system, especially in recent years network has proposed to possess the requirements at the higher level of the ability of carrying integrated service towards development two-way, interactive, the Streaming Media application direction to hfc plant.

Therefore, need take all factors into consideration the aspect factor such as topological structure, frequency configuration, program transmission, distribution network design, interaction platform construction, network management of hfc plant, seek suitable technical solution, make it to satisfy the requirement of Digital Television and bidirectional multifunctional.

Cable modem front end system (English name: Cable Modem Termination System is generally adopted in current hfc plant bidirectional rebuilding, hereinafter to be referred as: CMTS) technology, but because the restriction of modulation technique, only can realize basic internet data access service, as: WWW, FTP, EMAIL etc., therefore for the carrying integrated service, also there is certain problem in CMTS, comprising:

1, modulation bandwidth is low, descending 34-41Mbps, up 320Kbps-2Mbps; Can not support the video class service application generally supported, as IPTV, Video Phone etc.;

2, optical fiber and coaxial going up are adopted with a kind of technology, and optical fiber is only made transparent transmission, causes the wasting of resources; Technology relative complex in addition, cost increases.

3, large-scale user covers, and funneling effect is obvious, and influx noise is big, stability decreases, and Single Point of Faliure causes systemic breakdown to influence the large tracts of land user then and uses;

4, agreement complexity, the network design complexity, equipment cost increases, and engineering construction and maintenance issues are many;

5, lack QOS mechanism, the internet data business that is suitable for transmitting as possible can't be supported the real time business of constant rate of speed, variable bit rate.

The utility model content

At the problem of above-mentioned existence, the purpose of this utility model is to provide a kind of bidirectional transmission system based on Hybrid Fiber and Coax Network HFC, and the two-way interaction network of high bandwidth, bi-directional symmetrical, high QOS guarantee, multiple service supporting can be provided for the user.

For achieving the above object, a kind of bidirectional transmission system based on Hybrid Fiber and Coax Network HFC that the utility model provides comprises: EPON (Passive Optical Network, under be called for short PON) unit and interactive coaxial network (Interactive Cable Networks, following abbreviation: ICN) unit, cable network insert the user by described PON unit and ICN unit successively.

Further, described PON unit comprises: optical line terminal (Optical Line Terminal, hereinafter to be referred as: OLT), optical network unit (Optical Line Unit, hereinafter to be referred as: ONU), optical splitter, optical cable, OLT is arranged on the sub-headend of described cable network, described OLT links to each other with optical splitter by optical cable, and this optical splitter links to each other with ONU by optical cable.

Further, described ICN unit comprises: coaxial cable local side apparatus (Ethernet overCable Master, under write a Chinese character in simplified form: ECM) and coaxial cable terminal equipment (Ethernet over CableTerminal, under write a Chinese character in simplified form: ECT), ECM is arranged on described ONU downstream, and ECM links to each other with ECT with the point-to-multipoint networking mode by coaxial cable.

Further, described ECM and ECT are respectively two network interface modes and are provided with.

Coaxial network of the present utility model is partly finished the modulation of signal by the ICN technology, by the terminal equipment of ethernet line access PON network, finished the transmission of data-signal again by the PON network, satisfies the demand that the hfc plant user obtains interactive service.Have following advantage specifically:

1, combining of PON and ICN technology made full use of the fiber resource of hfc plant and huge access frequency (frequency range) resource, can be the user bandwidth up to 128Mbps is provided;

2, system supports TV, speech and data service simultaneously, is integration of three networks network truly.Not only can provide wideband data at a high speed to insert, also promote traditional One-to-All Broadcast type TV service, can support live broadcast service, demand (telecommunication) service, time-shift service, information service etc. simultaneously, also can support high bandwidth interactive service based on high definition;

3, agreement is simple, has dwindled the coverage with shaft portion, reduces the interference between the user, the IP link that provides symmetrical rate, full duplex, high bandwidth, high QOS to guarantee;

4, network is simple, need not to change existing network infrastructure, need not existing network equipment is done a large amount of transformations, is easy to dispose and build, and the fault point is few, saves related resources such as machine room, operation maintenance;

5, equipment cost is cheap, and improvement cost descends, and can realize extensive, wide covering, high concurrent network design; Business development with invest into linear dependence, be an effective attainable system;

6, the technological development direction that meets following FTTH realizes Fiber-To-The-Building, and that Fiber to the home is ready for smooth evolution, is more suitable for the high-quality business of high bandwidth, is suitable for carrying out of following new business.

Description of drawings

Fig. 1 is the utility model structural representation.

Embodiment

The utility model mainly is the IP-based PON technology that adopts in optical networking, transmits the up-downgoing data by PON equipment.As shown in Figure 1, the bidirectional transmission system that the present invention is based on Hybrid Fiber and Coax Network HFC comprises: passive optical network unit 1 and interactive coaxial network unit 2, the key ring of cable TV 3 (being cable network) are inserted the user by PON unit 1 and ICN unit 2 successively.Concrete set-up mode is as follows:

PON unit 1 comprises: OLT11, ONU15, optical splitter 13,

optical cable

12,16, OLT11 is arranged on the sub-headend 4 of the key ring 3 of cable TV, OLT11 links to each other with optical splitter 13 (optical splitter 13 can be arranged on original cable network optical node 14 places) by optical cable 12, this optical splitter 13 links to each other with ONU15 by optical cable 16, and optical cable 16 extends in the building from optical splitter 13.OLT11 can provide multichannel up-downgoing gigabit light mouth, and each gigabit downlink port connects a plurality of ONU15 by passive optical splitters 13, can realize the transmitted in both directions on the fiber optic network.

ICN unit 2 comprises: ECM21 and ECT22, ECM21 are arranged on the ONU15 downstream, and ECM21 links to each other with ECT22 with the point-to-multipoint networking mode by coaxial cable 23 (Ethernet).Adopt frequency multiplexing technique in coaxial, transmit broadcasting and data message simultaneously, the mixing of signal is finished by ECM21 equipment, and Signal Separation is finished by ECT22 equipment.

The ICN technology is realized by local side ECM21 and terminal ECT22 two parts, ECM21 is deployed under the ONU15, equipment connects by ethernet line, ECM21 finishes mixing of CATV signal (comprising simulated television and Digital Television) and data-signal, ECT22 is placed in the user family, be used to insert user's PC6 or TV5, ECM21 and ECT22 realize the transmitted in both directions of data message at coaxial distribution network by the QAM modulation technique.

ECT22 adopts two network interface modes to design, and concrete set-up mode is: ECT22 adds the label of representing different priorities to the different pieces of information information that is entered by two network interfaces, again time and the channel resource that comes distribute data to transmit according to label priority by ECM21.The two network interface design indicates of ECT22 are in the differentiation to type of service, and promptly the user can use a plurality of different domestic. applications terminals and unaffected each other simultaneously.

ICN unit 2 is in actual deployment, change to coax network and subscriber household network includes but not limited to following dual mode: first, to family's mounting strap bandpass filter of non-installation ECT22 equipment, to user's non-ECT22 line attachment mounting strap bandpass filter is installed; The second, the coaxial cable of the indoor installation ECT22 of user equipment is to adopting the Building F connected mode.

Claims

1. the bidirectional transmission system based on Hybrid Fiber and Coax Network HFC is characterized in that, comprising: passive optical network unit and interactive coaxial network unit, cable network insert the user by described passive optical network unit and interactive coaxial network unit successively.

2. the bidirectional transmission system based on Hybrid Fiber and Coax Network HFC according to claim 1, it is characterized in that, described passive optical network unit comprises: optical line terminal, optical network unit, optical splitter, optical cable, optical line terminal is arranged on the sub-headend of described cable network, described optical line terminal links to each other with optical splitter by optical cable, and this optical splitter links to each other with optical network unit by optical cable.

3. the bidirectional transmission system based on Hybrid Fiber and Coax Network HFC according to claim 2, it is characterized in that, described interactive coaxial network unit comprises: coaxial cable local side apparatus and coaxial cable terminal equipment, the coaxial cable local side apparatus is arranged on described optical network unit downstream, and the coaxial cable local side apparatus links to each other with the coaxial cable terminal equipment with the point-to-multipoint networking mode by coaxial cable

4. the bidirectional transmission system based on Hybrid Fiber and Coax Network HFC according to claim 3, it is characterized in that, described coaxial cable terminal equipment possesses two network interfaces, and this pair network interface is used to enter different pieces of information information and sends this data message to this coaxial cable terminal equipment.