CN201536410U - UWB access system based on coaxial cable network - Google Patents

A UWB (ultra wide band) access system based on a coaxial cable network comprises head end equipment (11) and a plurality of CPE (customer premise equipment) (12), wherein the head end equipment (11) receives broad band signals from superior network interfaces, distributes and delivers treated broad band signals from a distributor road to each secondary access road and the CPE (12) connected therewith along the tree-shaped coaxial cable network, and sends the treated signals by the CPE (12) to terminal users, so as to fulfill a point-to-multipoint Gbps two-way UWB transmission. By adopting the access scheme provided by the utility model, each user can be provided with an unshared band width above 30Mbps on the same tree-shaped coaxial cable network, so that a fully-covered coaxial cable to-the-home network can be the same as an FTTH (Fiber-To-The-Home) to turn into an ultimate wide band user access network of three networks combination.

Ultra broadband connecting system based on coax network

Technical field the utility model relates to the data switch network, and particularly relating to the via configuration is the Wide Area Network of feature, relates in particular to the ultra broadband connecting system based on coax network.

Three kinds of broadband access schemes of background technology prior art based on coax network, be respectively HomePlug technology, HomePNA (Home Phone-line Network Alliance) access technology and MoCA (Multimedia Over CoaxAlliance), their technical essential is summarized as follows:

One, HomePlug access technology

The HomePlug access technology is based on the transmission technology of power line in the family, it utilizes, and power supply wiring forms network in the existing family room, comprise that terminal equipments such as PC are online by supply socket and internet, and the network savvy that realizes each PC in the family by the indoor power supply distribution network, reduced cost to network provider, the technical essential of HomePlug is:

When the full speed concurrent user was in 10, total throughout was about 90Mbps; During at 32, total throughout is about 60Mbps the full speed concurrent user.

Two, HomePNA (Home Phone-line Network Alliance) access technology

This access technology provides the high-speed data transfer of 1Mbps (HomePNA 1.0 versions) or 10Mbps (HomePNA 2.0 versions) for each user by existing telephone wire, its advantage is to utilize existing telephone circuit transmission broadband digital signal, saved the trouble of rewiring, satisfy the requirement of consumer wideband online, reduced expenses of surfing Internet again, can not influence phone in the time of online and use and fax sending and receiving, the main feature of this technology is as follows:

Three, MoCA (Multimedia Over Coax Alliance) access technology

The MoCA technology can make the quality digital content of multimedia spread all over whole family by the existing coaxial cable transmission, make the domestic consumer can utilize its existing coaxial cable framework as network system, above-mentioned emerging application and advanced feature are spread all in its family, MoCA is adopted by numerous leading U.S. service providers as a main network technology, and its main feature is as follows:

Each broadband access scheme of above-mentioned prior art has the following disadvantages:

1, all adopt semiduplex mode, efficiency of transmission is no more than 50%;

2, HomePlug access technology and HomePNA access technology all adopt the CSMA/CA access-control protocol of TDMA+ priority, and when concurrent user number increased, total throughput descended;

3, the throughput of the single carrier of HomePlug access technology and HomePNA access technology is lower, offer each user to exclusively enjoy bandwidth too low, the demand of discontented foot breadth band business;

4, HomePlug access technology and HomePNA access technology all adopt the baseband OFDM technology, can't improve the total throughput of head end to terminal by the mode that increases carrier wave;

5, the HomePNA access technology adopts QAM modulation-demodulation technique, poor anti jamming capability;

What 6, the MoCA access technology adopted is the high-end frequency of 875-1525MHz, and the transmission attenuation of coaxial cable is big, and transmission range is short; The requirement of frequency response of network is surpassed the register one's residence performance index of cable, connector, branch distributor and subscriber box etc. of network of existing coaxial cable, can't be directly register one's residence and directly move on the net at existing coaxial cable.

Utility model content the technical problems to be solved in the utility model is to avoid above-mentioned the deficiencies in the prior art part and proposes a kind of ultra broadband connecting system and access scheme based on coax network.

The utility model proposes a kind of with the coaxial cable be transmission medium, low-cost high-efficiency a bit to multiple spot Gbps ultra broadband transmitted in both directions technical scheme, adopt this scheme, can surpass 500 meters at an extended distance, cover on 100 left and right sides users' the coaxial cable branch road of tree, for each user provides the bandwidth that exclusively enjoys more than the 30Mbps, net can (FTTH) be the same with Fiber to the home thereby the feasible coaxial cable that has covered has been registered one's residence comprehensively, becomes ultimate broadband user's Access Network of " unification of three nets ".

The utility model solve the technical problem can be by realizing by the following technical solutions: a kind of ultra broadband connecting system based on coax network, comprise headend and many ustomer premises access equipments, described headend is connected with each ustomer premises access equipment by the coax network of tree, and described ustomer premises access equipment is connected with the terminal use by transmission network.

Described headend comprises medium access controller, network bridging unit, at least one send channel, receive channel, microprocessor unit and radiofrequency signal blender;

Described radiofrequency signal blender is connected with each ustomer premises access equipment of coax network, and described receive channel one end and radiofrequency signal blender are electrically connected, and the described receive channel other end and network bridging unit are electrically connected; Described network bridging unit and medium access controller are electrically connected;

Described radiofrequency signal blender is connected with each ustomer premises access equipment of coax network, and described send channel one end and radiofrequency signal blender are electrically connected, and the described send channel other end and network bridging unit are electrically connected; Described network bridging unit and medium access controller are electrically connected;

Described ustomer premises access equipment comprises medium access controller, network bridging unit, send channel, receive channel, microprocessor unit and radiofrequency signal blender;

Described radiofrequency signal blender and headend are electrically connected; Described receive channel one end and radiofrequency signal blender are electrically connected, and the described receive channel other end and network bridging unit are electrically connected; Described network bridging unit and medium access controller are electrically connected;

Described radiofrequency signal blender and headend are electrically connected; Described send channel one end and radiofrequency signal blender are electrically connected, and the described send channel other end and network bridging unit are electrically connected; Described network bridging unit and medium access controller are electrically connected.

Described send channel comprises interface unit, quadrature OFDM send channel unit, digital to analog converter and quad upconverter, and described network bridging unit and interface unit are electrically connected; Described interface unit is electrically connected with quadrature OFDM send channel unit again; Described quadrature OFDM send channel unit and analog to digital converter are electrically connected; Described analog to digital converter and then be electrically connected with quad upconverter;

Described send channel comprises interface unit, quadrature OFDM send channel unit, digital to analog converter and quad upconverter, and described network bridging unit and interface unit are electrically connected; Described interface unit and quadrature OFDM send channel unit are electrically connected; Described quadrature OFDM send channel unit is electrically connected with analog to digital converter again; Described analog to digital converter is electrically connected with quad upconverter again.

Described receive channel comprises interface unit, quadrature OFDM receive channel unit, analog to digital converter and quadrature down converter, and described radiofrequency signal blender and quadrature down converter are electrically connected; Described quadrature down converter and analog to digital converter are electrically connected; Described analog to digital converter is electrically connected with quadrature OFDM receive channel unit again; Described quadrature OFDM receive channel unit and then be electrically connected with interface unit;

Described receive channel comprises interface unit, quadrature OFDM receive channel unit, analog to digital converter and quadrature down converter, and described radiofrequency signal blender and quadrature down converter are electrically connected; Described quadrature down converter and analog to digital converter are electrically connected; Described analog to digital converter is electrically connected with quadrature OFDM receive channel unit again; Described quadrature OFDM receive channel unit is electrically connected and then is electrically connected with interface unit.

Described quadrature OFDM send channel unit comprises AES encrypting module, FEC coding module and IFFT﹠amp; The DSP processing module.

Quadrature OFDM receive channel unit comprises AES deciphering module, fec decoder module and FFT﹠amp; The DSP resume module.

Described headend comprises a send channel at least.

Compare with prior art, the beneficial effect of the technique scheme that the utility model adopted is:

1, descending (head end is to user side) adopts different carrier communications simultaneously with up (user side is to head end), realizes full-duplex mode, and communication efficiency doubles;

2, headend can improve total throughput of whole system by a plurality of descending carriers of configuration (send channel);

3, head end and adopt BoD (the Band on Demand) access-control protocol not have collision and competition with the communication between the end is in order to improve the efficient of communicating by letter.

Description of drawings Fig. 1 is the access schematic diagram that the utility model is realized the access scheme that ultra-wide band network inserts;

Fig. 2 is the headend theory diagram that the utility model is realized the connecting system that ultra-wide band network inserts;

Fig. 3 is the ustomer premises access equipment theory diagram that the utility model is realized the connecting system that ultra-wide band network inserts;

Fig. 4 is the schematic block circuit diagram of the quadrature OFDM send channel unit of described headend/ustomer premises access equipment;

Fig. 5 is the schematic block circuit diagram of the quadrature OFDM receive channel unit of described headend/ustomer premises access equipment;

Fig. 6 ustomer premises access equipment send channel frequency conversion theory diagram;

Fig. 7 headend receive channel frequency conversion theory diagram.

Embodiment is described in further detail below in conjunction with the preferred embodiment shown in each accompanying drawing.

A kind of connecting system of realizing that ultra-wide band network inserts of the utility model as shown in Figure 1, comprises headend 11 and ustomer premises access equipment 12.

The broadband signal that described headend 11 is accepted from higher level's network interface, provide and deliver along the coax network of tree after treatment, from the cadre to each branch road, arrive the ustomer premises access equipment 12 of each minute branch road connection again, signal after institute's ustomer premises access equipment 12 is handled is delivered to the terminal use, realizes a bit multiple spot Gbps ultra broadband transmitted in both directions.

Same principle, on headend 11, the high-speed AD converter that can use the 200MHz clock is realized the quadrature frequency conversion of upward signal then to the upward signal Direct Sampling with digital method, its theory diagram is as shown in Figure 7.

Descending and uply adopt different carrier frequencies to communicate by letter simultaneously, realize full-duplex mode.

The BOD access-control protocol that does not have collision and competition is adopted in communication between headend 11 and the ustomer premises access equipment 12.

Above content be in conjunction with concrete optimal technical scheme to further describing that the utility model is done, can not assert that concrete enforcement of the present utility model is confined to these explanations.For the utility model person of an ordinary skill in the technical field, under the prerequisite that does not break away from the utility model design, can also make some simple deduction or replace, all should be considered as belonging to protection range of the present utility model.