【正文】 是以太網(wǎng)技術(shù)的固有機(jī)制不提供端到端的包延時(shí)、包丟失率、帶寬控制 ， 難以支持實(shí)時(shí)業(yè)務(wù)的服務(wù)質(zhì)量 ， 缺乏安全機(jī)制保證等。采用以太網(wǎng)作為企 事業(yè)用戶接入手段的主要原因是已有巨大的網(wǎng)絡(luò)基礎(chǔ)和長(zhǎng)期的經(jīng)驗(yàn)知識(shí)。當(dāng)然 ， 除了系統(tǒng)技術(shù)外 ， 影響其應(yīng)用的因素很多 ， 主要是業(yè)務(wù)和應(yīng)用以及管制政策。此后 ， 隨著業(yè)務(wù)的大規(guī)模拓展 ， 開發(fā)新的業(yè)務(wù)成為繼續(xù)發(fā)展的動(dòng)力。美國(guó) FOC 將寬帶業(yè)務(wù)定位為 2020— 2020 年的六大目標(biāo)之一 ， 事實(shí)上寬帶接入正成為美國(guó)普遍服務(wù)的下一個(gè)目標(biāo)。歷史上沒有一種技術(shù)生來就帶著一大堆應(yīng)用的 ， 無論是移動(dòng)通信還是互聯(lián)網(wǎng) ， 其短信、瀏覽、網(wǎng)上聊天等關(guān)鍵應(yīng)用都 是在用戶規(guī)模發(fā)展到一定程度后自然產(chǎn)生的 ， 而不是事先刻意設(shè)計(jì)策劃出來的。 Next, because GPON and EPON/GEPON are select to the multispot star type or the shape of tree work, will need 1+1 and passes through the different route light work through one to realize the telemunication level protection to restore the request, the work cost extremely is high。s band width may be higher, and can provide video frequency professional ability and good QOS The hardware is simple, does not need outdoor electronic installation, and enables the installment deployment work to simplify。 Bureau end equipment simple cheap。s end, the total number of users already achieved 150,000,000, became in the electricity reliable historical account to develop one of quickest telemunication services, and even was also quicker than the mobile service. For example the whole world mobile service from 10,000,000 developed to 100,000,000 has spent for years, but the broadband access service has only used for years. According to the IDC forecast, in 2020 the global wide band total user may achieve 209,000,000, in which , namely about 20,000,000 users for optical fiber access work. The Asian and Pacific area, specially South Korea39。s end our country wide band user is 25,000,000, bees is inferior to US39。s cost is very high. Moreover, its tree branch topology caused the user not to have the protection function or the protection function cost is high, has affected the largescale development. 2. APON AND BPON The early narrow band passive light work is based on TDM, the performance price pared not well, already naturally withers away. An ATM passive light work (APON/BPON) may use ATM the centralism and the statistics multiplying, the rebination passive shunt to the optical fiber and the light line terminal sharing function, enable the performance price pared to have the important improvement, at present in countries and so on US and Japan already started mercial. However, the actual APON/BPON service adaptive provides at present very plex, provision of service ability is limited, the data transmission rate and the efficiency are not high, the cost is high, but its market prospect as a result of ATM decline dim. Finally, looking from the longterm service trend of development that, the APON available band width was still insufficient. Take FTTC as the example, although the typical branch downward speed may reach 622Mb/s, after but because the bypass, actual as separable greatly will reduce as each user39。 The transmitting range amounts to 20 kilometers at least, has the high speed highly effective transmission characteristic. Moreover, GPON has selected two seal methods, besides traditional ATM, but also has used one brandnew in the transmission gathering level based on sDH standard general group frame procedure GFP, this is one kind may transparently highly effective Seals the existing SDH work each kind of data signal the general standard signal adaptive mapping technology, may adapt any subscriber signal form and any transmission work service pattern, namely may according to the inherent form transmission pronunciation, the data and the video signal, does not need to attach ATM or the P seal level, has manifested the service provider prehensively to the provision of service nimble request, but APON/BPON and EPON/GEPON all need to provide the specific adaptive method to each kind of specific service. Because uses the GFP mapping, the GPON transmission gathering level essentially is a synchronization, enables GPON to be possible to support endtoend fixed time and other orbit service, specially may the direct high quality support the TDM service nimbly. From the technical angle, GPON is the BPON inheritance and the development, GPON has inherited BPON very many essential features, for example both all use the same OLT nucleus, the heart technology, and uses the similar physical optical fiber facility and the luminous power budget and so on. On the other hand, GPON has used some newest technology achievement, besides most important GFP seal, but also includes the forwardacting error correction and so on the new technology. From the service which provides looked, not only GPON may provide 10/100Mb/s,1Gb/s the service, moreover may provide the VLAN service and the pronunciation service, in fact might adapt any view to have the service and the future new service adaptive request. Total looking at, GPON is not the manufacturer actuation technical standard, but is one kind of operation business actuation standard, therefore has the thoroughbred operation benefit to consider, the speed is higher, may reach 。s trend of development possibly will surmount APON, BPON and the EPON stage, will start from the wide band pointtopoint Ether optical fiber system and GEPON, and even will transit quickly to the GPON stage. 寬帶光纖接入網(wǎng)的發(fā)展趨勢(shì) 作者：劉金海 文章出處：計(jì)算機(jī)世界 時(shí)間： 202038 本文首先簡(jiǎn)要介紹世界寬帶接入網(wǎng)發(fā)展的狀況和主要應(yīng)用 ；其次講述了寬帶光纖接入網(wǎng)的優(yōu)點(diǎn)； 再次重點(diǎn)分析 了寬帶點(diǎn)到點(diǎn)有源以太網(wǎng)光纖系統(tǒng)和寬帶點(diǎn)到多無源光纖系統(tǒng)的特點(diǎn)和應(yīng)用。例如全球移動(dòng)業(yè)務(wù)從 1000 萬發(fā)展到 1 億花了 年 ， 而寬帶接入業(yè)務(wù)僅用了 年。主導(dǎo)運(yùn)營(yíng)商也開始進(jìn)入該領(lǐng)域 ，其中 Version計(jì)劃 2020 年完成 300 萬 FTTP， SBC 在其龐大的“光速”計(jì)劃中計(jì)劃 2020 年達(dá) 1800 萬 FTTN， 每戶具備速率 2039Mb/s， 提供端到端的三重業(yè)務(wù)捆綁 (trite play)業(yè)務(wù)。事實(shí)上 ， 從電信發(fā)展歷史看 ， 當(dāng)網(wǎng)絡(luò)用戶數(shù)達(dá)到一定規(guī)模 ， 各種應(yīng)用會(huì)自然產(chǎn) 生 ， 這也是所謂的邁特卡夫定律的威力所在。 PLC 混合集成技術(shù)高密度低成本光纜及相關(guān)技術(shù) ， 對(duì)彎曲不敏感的室內(nèi)用光纖 ， 低成本無源器件 ， 施工安裝技術(shù) ， 自動(dòng)光操作測(cè)試系統(tǒng)等 也都是影響光接入網(wǎng)推廣應(yīng)用的關(guān)鍵因素 ， 需要有妥善的解決方案。主要優(yōu)點(diǎn)是專用接入帶寬有保證 ； 每 個(gè) 用戶可以獨(dú)享 100Mb/s 乃至 1dbs； 局端設(shè)備簡(jiǎn)單便宜 ； 傳輸距離長(zhǎng) ， 服務(wù)區(qū)域大 ； 成本隨用戶數(shù)的實(shí)際增長(zhǎng)而線性增加 ，無需規(guī)劃 ， 投資風(fēng)險(xiǎn)低 ， 因而在低密度用戶分散地區(qū)成本較低。其次 ， PON 的業(yè)務(wù)透明性較好 ， 帶寬寬 ，可適用于任何形式和速率的信號(hào) ， 能比較經(jīng)濟(jì)地支持模擬廣播電視業(yè)務(wù) ， 具備三重業(yè)務(wù)功能 (triple— play)