Broadband of cable television Cable receives DOCSIS2.0 technology to decode

From;  Author:Stand originally

Cable television cable (Cable) the standard that means broadband receives Internet is DOCSIS (Data Over Cable Service Interface Specification) , this standard upgrades to 2 recently, and Imedia company announced DOCSIS2.0 chip April IM6030 is mixed but instantly the referenced design that batch produces. This means what new-style Cable cat and head carry equipment to appear on the market time can be accelerated greatly, cost also can assure inferior standard, the evolution that this accepts the market to Cable broadband is crucial.

  Improve go up transmission rate

Basically be being improved of new edition DOCSIS was to rise to go up greatly channel rate, can achieve 30Mbps, achieve semmetry basically with rate of be issued to lower levels. And previously 1 with 1.1 version it is to go up rate 10Mbps, 56Mbps of rate of be issued to lower levels (all be peak value) . Improvement share basically is in physical layer, link layer above still is mixed aether net is similar, for IEEE802 LLC. DOCSIS2.0 introduced new S-CDMA (synchronous code divides site) modulation technology, with old A-TDMA (acute time much location) technical photograph is compared, new technology more be helpful for falling to transmit data effectively in abominable noise and interference and low bandwidth environment, support more users, also can support business quality better at the same time. DOCSIS2.0 included S-CDMA and A-TDMA at the same time means of two kinds of modulation, be the same as in order to assure old the compatibility that has establishment.

S-CDMA allows many Cable cat to transmit data at the same time, because this can be obtained,receive rate high. These Cable cats must be in phasic with frequency aspirant travel is synchronous, maintain noninterference of mutual orthogonality, each other in order to make sure each data flow, synchronous clock criterion pretext carries equipment to offer. Be in with TDMA equipment to maintain the compatibility of MAC layer, original time frame still is withheld, turn into by one dimension nevertheless 2 dimension, the frame of S- CDMA became the matrix of time frame, a direction of matrix is time, another direction is a word. Inside a passageway assignable the code word of 128 mutual orthogonality, every time frame uses two codes word, allow so at the same time 64 Cable cat undertakes transmission. S-CDMA still included forward and wrong correction function, can avoid to be passed again on certain level, this is useful in the real time business such as video. In addition, s-CDMA still includes a few optimize parameter, in order to acquire better transmission property.

   3 receive bad of what of technical what actor greatly

Since be a broadband,receive, should be discrepancy it is a broadband, namely be issued to lower levels is a broadband, and going up also is a broadband. With respect to this, ADSL has some of past the appointed time apparently, it is before suiting some year get online browse what wait for asymmetry business with video order programme, and present application increased to go up transmission proportion, be like quits communication, interactive game, and organization user. So, tell from the technology, the first selection that DOCSIS2.0 and aether net should be an user receives kind. In a word, cable receives have the following advantage:
Previous12 Next