【正文】 最后 ，考慮采用 PON技術(shù)后比較容易繼續(xù)提供傳統(tǒng)的模擬視頻節(jié)目 ， 因而 ， 多數(shù)美國地方貝爾公司傾向于 PON技術(shù) ， 而不是光以太網(wǎng)技術(shù)。 由于計費、質(zhì)量、管理、安全等多種因素 ， 以太網(wǎng)作為公用網(wǎng)接入方式尚需進一步改進。歷史上 ， 對于企事業(yè)用戶應(yīng)用環(huán)境 ， 以太網(wǎng)技術(shù)一直是最流行的方法 ，目前已成為取 決于供電插口的第二大住宅和辦公室公用設(shè)施接口。 下面將主要從系統(tǒng)技術(shù)的角度來分析幾種主要的寬帶光纖接入技術(shù)的特征、問題和發(fā)展趨勢。 從寬帶應(yīng)用看 ， 按照美國麥肯錫公司的最新分析 ， 初期的寬帶應(yīng)用主要是高速上網(wǎng) ， 可以使上網(wǎng)的時間增加約 30%。美國依然是世界最大的寬帶接入市場 ，總用戶數(shù)超過 3000 萬。各種應(yīng)用會自然產(chǎn)生 ， 這也是所謂的邁特卡夫定律的威力所在。 Has the very high transmission efficiency to each kind of service, even if regarding the TDM service also can the nimble highly effective low expenses transmission. May help the operation business to plete from the traditional TDM pronunciation electric circuit to the entire IP work smooth transition, its shorting is still retains has the plex ATM level function, the cost is high. Because three kind of PON capital expenditures (70% all are approximately) the light connections, thus its hardware cost should differ not much, but because in the realization technology difference, the GEPON difficulty is at present smallest, the cost is lowest. But speaking of the transmission efficiency, then GPON regardless of is harassing the code efficiency, the transmission gathering plate efficiency, the load bearing agreement efficiency and the service adaptive efficiency aspect all is highest, therefore its overall effectiveness index is highest. For example the supposition TDM service accounts for 10%, but the data service accounts for 90%, then the GPON overall effectiveness index is 94%, but APON and GEPON respectively are 72% and 49%. GPON and EPON/GEPON face the together challenge includes: How can have nine load bearing TDM service on Ethemet/GFP and can provide the telemunication level the grade of service。 The downward service speed reaches as high as 1Gb/s, the permission support multiuser, each user39。 this also is socalled steps the Cuff law might to be at especially. In the history one kind of technology since birth has not been having a big pile of application, regardless of is the mobile munication or the Inter, on its short note, the browsing, the chats and so on the key applications all is develops certain degree after the user scale to produce naturally, but is not sedulously designs beforehand plans. Wide band optical fiber access work superiority Along with the optical fiber in the toll work, the metropolitan area work and even the access work branch section massive applications, the logical trend of development will be continues to the access work to match the line segment and to direct the inlet part to extend, the key is advances the speed quickly? This will be decided by many kinds of factors, including the market demand, the petition need, the application stimulation, the technical progress, the cost drop and necessary will transport Augur system development and so on. Our country in 2020 will hold the Olympic Games and in 2020 holds world expo these two big events to a certain extent to be able to advance the wide band optical fiber access work the development Below mainly will analyze several kind of main wide band optical fiber turning on technology from the system technology angle the characteristic, the question and the trend of development. Certainly, besides the system technology, affects its application the factor to be very many, mainly is the service and the application as well as the control policy. In addition, each kind of necessary primary device technology and the placing installment test technology extremely is also essential. At present the low cost photo source hopefully has realized, 850nm VCSEL only several US dollars, 1310nm VOSEL had the breakthrough, the speed reaches 10Gb/ PLC mix integration technology, the high density low cost optical cable and the correlation technology, uses the optical fiber to the curving insensitive room in, the low cost passive ponent, work the technology, the automatic light operation test system and so on also all is affects the light access work promotion application the key aspect, needs to have the properly solution. The pointtopoint active Ether Because system the cost, the quality, the management, the security and so on many kinds of factors, the Ether still had further to improve as the public work turning on way. The traditional Ether belongs to the user in work (cPN).However its application actually in to include the access work other public work domain expansion. In the history, regarding business user application environment, the Ether technology always is the most popular method, at present has bee only definitely in the power supply receptacle second big housing and the office public facility connection. Uses the Ether is had the huge work foundation and the longterm experience knowledge, at present all popular operating system and the application as the business user turning on method primary cause also all is with the Ether patible, the performance price pared to good, the extendibility, easy to install the clear as well as redundant reliable and so on. Regarding the public work housing user application environment, the pointtopoint active Ether system uses the active service focus point to substitute the passive pointmultipoint system the passive ponent, enables the transmitting range to be possible to expand to 1 20 kilometer far. The main merit is specialpurpose turning on, the band width has the guarantee, each user may monopolize 100Mb/s and even 1dbs。 this also is socalled steps the Cuff law might to be at especially. In the history one kind of technology since birth has not been having a big pile of application, regardless of is the mobile munication or the Inter, on its short note, the browsing, the chats and so on the key applications all is develops certain degree after the user scale to produce naturally, but is not sedulously designs beforehand plans. Since has entered for the 21st century, th