外文翻譯---寬帶光纖接入網的發(fā)展趨勢

1、<p>　　Wide band optical fiber access network trend of development</p><p>　　Author: Liu Jinhai article source: Computer universal time: 2005-3-8</p><p>　　This article first is brief introduc

2、ed the world broadband access network develops the condition and the main application, next narrated the wide band optical fiber access network merit. With emphasis has once more analyzed the wide band point-to-point act

3、ive Ethernet optical fiber system and the wide band to the passive optical fiber system characteristic and the application. Meets down proposed our country optical fiber access network sends chem. possible to surmount AP

4、ON, BPON and the EPON st</p><p>　　The broadband access network develops condition and main application</p><p>　　In fact, looking from the telecommunication development history, when the network

5、number of users achieves certain scale. Each kind of application meets the nature production; this also is so-called steps the Cuff law might to be at especially. In the history one kind of technology since birth has not

6、 been having a big pile of application, regardless of is the mobile communication or the Internet, on its short note, the browsing, the net chats and so on the key applications all is develops certa</p><p>　

7、　Since has entered for the 21st century, the whole world broadband access network entered the big development phase. To 2004 year's end, the total number of users already achieved 150,000,000, became in the electrici

8、ty reliable historical account to develop one of quickest telecommunication 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

9、 has spent for 5.5 years, but the broadband access service has on</p><p>　　The Asian and Pacific area, specially South Korea's and Japan were the broadband access develop the swiftest most and violent co

10、untry, the South Korean wide band user total already break through 10,000,000, the wide band popular rate occupied the world first, hold family 7 Internet 90%. Japanese Government also vigorously advances the wide band d

11、evelopment through each measure, plans in 2005 to enhance the wide band user total to 30,000,000, in which FTTH achieves 1 10,000.US still is the world </p><p>　　Speaking of the optical fiber access network,

12、 specially the optical fiber to station (FTTP) or optical fiber proficient (FTTH), the whole world already started to enter the unloading phase, only US had 270 FTTP projects, was mostly the local authority, the public c

13、ompany, the property developer and the non-leading telecommunication operation business project. Leading operation business also starts to enter this domain, in which Version plans in 2005 to complete 3,000,000 FTTP; SBC

14、 in the plan pl</p><p>　　Our country broadband access network extremely is also rapid in the near two year development, according to the preliminary statistics, to 2004 year's end our country wide band u

15、ser is 25,000,000, becomes is inferior to US's second big broadband access market, in which leadership technology is only ADSL, probably accounts for about 70%, next is the Ethernet technology, but also has few wide

16、band wireless turning on and electric cable modem turning on, also occupies regarding the FTTH technology </p><p>　　Looking from the wide band application that, according to the American Mai Kenxi Company

17、9;s newest analysis, the initial period wide band application mainly is the high speed surfer, may make the surfer the time to increase approximately 30%.Hereafter, along with the service large-scale development, develop

18、s the power which the new service becomes continues to develop. According to American BHK Corporation demonstrated in 2004 investigation result that, in 2003 the American first five wide band e</p><p>　　Need

19、s to point out that, discusses needs to pay attention to in a basic understanding using the actuation the erroneous zone, namely cannot place hopes in artificially studies beforehand develops 12 items so-called “the Assa

20、ssin's mace application”, promoted application. In fact, looking from the telecommunication development history, when the network number of users achieved certain scale, each kind of application meets the nature prod

21、uction; this also is so-called steps the Cuff law might to b</p><p>　　Wide band optical fiber access network superiority</p><p>　　Along with the optical fiber in the toll network, the metropolit

22、an area network and even the access network branch section massive applications, the logical trend of development will be continues to the access network to match the line segment and to direct the inlet part to extend,

23、the key is advances the speed quickly? This will be decided by many kinds of factors, including the market demand, the competition need, the application stimulation, the technical progress, the cost drop and necessar<

24、/p><p>　　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, b

25、esides 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

26、 the placing installment test technology extremely is also essential. At presen</p><p>　　The point-to-point active Ethernet </p><p>　　Because system the cost, the quality, the management, the se

27、curity and so on many kinds of factors, the Ethernet still had further to improve as the public network turning on way.</p><p>　　The traditional Ethernet belongs to the user in network (cPN).However its appl

28、ication actually in to include the access network other public network domain expansion. In the history, regarding business user application environment, the Ethernet technology always is the most popular method, at pres

29、ent has become only definitely in the power supply receptacle second big housing and the office public facility connection. Uses the Ethernet is had the huge network foundation and the long-term experie</p><p&

30、gt;　　Regarding the public network housing user application environment, the point-to-point active Ethernet system uses the active service focus point to substitute the passive point-multipoint system the passive componen

31、t, enables the transmitting range to be possible to expand to 1 20 kilometer far. The main merit is special-purpose turning on, the band width has the guarantee, each user may monopolize 100Mb/s and even 1dbs; Bureau end

32、 equipment simple cheap; The transmitting range is long, the serv</p><p>　　Because the cost, the quality, the management, the security and so on many kinds of factors, the Ethernet still had further to impro

33、ve as the public network turning on way. Mainly is the Ethernet technology inherent mechanism does not provide the end-to-end package time delay, the package loss rate, the band width control, supports the real-time serv

34、ice with difficulty the grade of service, lacks the safety mechanism guarantee and so on.</p><p>　　Point-multipoint passive, light network system</p><p>　　Along with IP rising with the developme

35、nt, some people proposed the EPON concept, this thought obtained the positive response in the Ethernet, has already formed the GEPON standard in under the IEEE 802.3ah flag.</p><p>　　1. Passive light network

36、ing</p><p>　　Passive light network (PoN) is one pure medium network, its main characteristic has removed the active equipment in the access network, thus has avoided the electromagnetic interference and the

37、thunder and lightning influence, reduced line and the external instrumentation failure rate, reduced correspondingly has transported the Augur cost. Next, the PON service transparency is good, the band width is wide, sui

38、tably in any service pattern and the speed signal, can support the simulation broadcas</p><p>　　The PON main shortcoming is the disposable investment cost is high, because bureau end light line terminal OLT

39、is very expensive, the optical fiber and the shunt and so on the passive infrastructure must an arriving, when like this the number of users are few or the user distribution surpasses some definition is away from, each u

40、ser'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</p><p>　　2. APON AND BPON</p&g

41、t;<p>　　The early narrow band passive light network is based on TDM, the performance price compared not well, already naturally withers away. An ATM passive light network (APON/BPON) may use ATM the centralism and

42、 the statistics multiplying, the recombination passive shunt to the optical fiber and the light line terminal sharing function, enable the performance price compared to have the important improvement, at present in count

43、ries and so on US and Japan already started commercial.</p><p>　　However, the actual APON/BPON service adaptive provides at present very complex, provision of service ability is limited, the data transmissio

44、n 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 long-term service trend of development that, the APON available band width was s

45、till insufficient. Take FTTC as the example, although the typical branch downward speed may reach 622Mb/s, after but because the by-pass, </p><p>　　3. EPON/GEPON</p><p>　　Along with IP rising wi

46、th the development, some people proposed the EPON concept, namely in with APON and the BPON similar structure and in the O.983 foundation, tries to retain its essence part - physics level PON; But replaces ATM by the Eth

47、ernet to take the link level agreement, constitutes one to be possible to provide a greater band width, the </p><p>　　Low cost and wider professional ability new marriage - EPON. This thought obtained the po

48、sitive response in the Ethernet; in IEEE802.Under the 3ah flag has already formed the GEPON standard. In reality, EPON and the GEPON basic difference is the standardization, the former often </p><p>　　Refers

49、 to the non-sign equipment, the latter refers conforms to IEEE 802.3ah, standard equipment. Moreover, the GEPON transmitting range and the by-pass compare have compared to EPON reduce.</p><p>　　EPON/GEPON an

50、d the traditional point-to-point Ethernet main different place lies in the work in the point-multipoint mailing address. Its downward direction work in the TDM way, the data stream changes the long </p><p>　

51、　Ether frame way to broadcast ONU, each ONU basis ether frame MAC address, decision choices. The upward direction work in the TDMA way, Comes from the different time slot ONU data stream to gather the public optical fibe

52、r facility and OLT. In addition, the traditional Ethernet work in the continual optical transmission pattern, is receiving and dispatching two directions both is the continual bit class, therefore receives the end fixed

53、time easily to realize with the decision. But the EPON/GEPOkI</p><p>　　Looked from the EPON/GEPON structure that, its essential merit </p><p>　　Enormously simplified the traditional multi-layere

54、d overlapping network </p><p>　　Structure, the main characteristic included:</p><p>　　- - Eliminated ATM and the SDH level, thus reduced the initial cost and the movement cost; </p><p

55、>　　- - The downward service speed reaches as high as 1Gb/s, the permission support multi-user, each user's band width may be higher, and can provide video frequency professional ability and good QOS</p><

56、;p>　　- - The hardware is simple, does not need outdoor electronic installation, and enables the installment deployment work to simplify;</p><p>　　- - May use the Ethernet technology mature chip massively,

57、 the realization is simple, the cost low</p><p>　　- - improved the electric circuit to refer to the coordination service nimbly provision with the reshuffle ability.</p><p>　　IEEE 802.3ah the st

58、andard GEPON technology standards is good, on the downward wave length is 1310 and 1490nm, on the downward speed is 1.25Gb/s, the transmitting range is 10/20km, the by-pass compared to is 16, the primary service is the d

59、ata and the sound of talking, </p><p>　　after increases a 1550nm visual broadcast wave length, becomes the sound of talking, the data and the television method of three-in-one “triple-play” the wide band ser

60、vice colligation service, but this will be the future family service “the Assassin's mace application”.</p><p>　　The EPON/GEPON main shortcoming is the efficiency low and supports outside the Ethernet wi

61、th difficulty the service. The former is because uses 8B/10B the line code, introduces 20% band width loss, in addition other expenses, available load only about 50%, but APON and GPON </p><p>　　all use NRZ

62、to harass the code are the line codes, does not have the band width loss.</p><p>　　In addition reasons and so on load bearing plate efficiency, transmission gathering plate efficiency, service adaptive effic

63、iency, cause the EPON/GEPON total transmission efficiency to be very low, probably only is GPON half.</p><p><b>　　4. GPON</b></p><p>　　In 2001, formulated EPON standard positively wh

64、ile IEEE, the FSAN organization starts to initiate the formulation speed to surpass 1Gb/s PON network standard 1,000,000,000,000,000 Ethernet passive light network (GPON), afterwards, ITU-T also involved this new standar

65、d formulation work and 1 Dan (speed enhances in 2003 through two related GPON new standard G.984.1 and G.984.2 to 2.5Gb/s). According to this newest standard stipulation, GPON may provide 1.244 and the 2.488Gb/s downward

66、 speed and th</p><p>　　Seals the existing SDH network each kind of data signal the general standard signal adaptive mapping technology, may adapt any subscriber signal form and any transmission network servi

67、ce 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 comprehensively to the

68、 provision of service nimble request, but APON/BPON and EPON/GEPON all need to provide the speci</p><p>　　From the technical angle, GPON is the BPON inheritance and the development, GPON has inherited BPON v

69、ery 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

70、used some newest technology achievement, besides most important GFP seal, but also includes the forward-acting error correction and so on the new technology.</p><p>　　From the service which provides looked,

71、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. T

72、otal 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

73、 reach 2.4Gb/s; Has </p><p>　　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 t

74、echnology 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 pla

75、te efficiency, the load bearing agreement efficiency and the service adaptive efficiency aspect all is </p><p>　　GPON and EPON/GEPON face the together challenge includes: How can have nine load bearing TDM s

76、ervice on Ethemet/GFP and can provide the telecommunication level the grade of service; Next, because GPON and EPON/GEPON are select to the multi-spot star type or the shape of tree network, will need 1+1 and passes thro

77、ugh the different route light network through one to realize the telecommunication level protection to restore the request, the network cost extremely is high; Third, at present GPON and</p><p>　　Recently so

78、me people to optical fiber communications development scene, somewhat puzzled. First, in 2000 the IT profession froth, caused the optical fiber communications the scale of production investment oversized, the overproduct

79、ion, in the IT profession many small companies went out of business. Specially the optical fiber, overseas dumps to China. Second, some people thought that, Optical fiber communications through-put capacity already achie

80、ved 10Tbps, could not use up nearly, moreover the</p><p>　　The author will believe that, optical fiber communications technology still have the very big development space, will be able to have the very big d

81、emand and the market from now on. Mainly is: The optical fiber to family FTTH, the light exchange and the integrated photoelectron component aspect can have the big development. Mainly discusses the optical fiber communi

82、cations in this the trend of development and the market..</p><p>　　Generally speaking, the optical fiber access network has represented the broadband access network long-term development direction, each kind

83、 of wide band optical fiber access network all has its best use situation and the opportunity, the wide band point-to-point active Ethernet optical fiber system suits in the low density user dispersible area application,

84、 the wide band point-multipoint passive optical fiber system most suits newly built or the reconstruction crowded user area should. Our coun</p><p>　　寬帶光纖接入網的發(fā)展趨勢</p><p>　　作者：劉金海 文章出處：計算機世界 時間：

85、2005-3-8</p><p>　　本文首先簡要介紹世界寬帶接入網發(fā)展的狀況和主要應用；其次講述了寬帶光纖接入網的優(yōu)點；再次重點分析了寬帶點到點有源以太網光纖系統和寬帶點到多無源光纖系統的特點和應用。接下來提出我國光纖接入網的發(fā)展可能跨越</p><p>　　APON、BPON和EPON階段，從寬帶點到點以太網光纖系統和GEPON開始，乃至最終過渡到GPON階段的初步設想。最后從各個角度

86、剖析了光纖通信技術的發(fā)展趨勢。</p><p>　　寬帶接入網發(fā)展的狀況和主要應用</p><p>　　事實上,從電信發(fā)展歷史看，當網絡用戶數達到一定規(guī)模。各種應用會自然產生，這也是所謂的邁特卡夫定律的威力所在。歷史上沒有一種技術生來就帶著一大堆應用的，無論是移動通信還是互聯網，其短信、瀏覽、網上聊天等關鍵應用都是在用戶規(guī)模發(fā)展到一定程度后自然產生的，而不是事先刻意設計策劃出來的。<

87、/p><p>　　進入21世紀以來，全球寬帶接入網進入了大發(fā)展階段。到2004年底,總用戶數已經達到1.5億，成為電信史上發(fā)展最快的電信業(yè)務之一，甚至比移動業(yè)務還快。例如全球移動業(yè)務從1000萬發(fā)展到1億花了5.5年，而寬帶接入業(yè)務僅用了3.5年。按照IDC的預測，2007年全球寬帶總用戶可以達到2.09億，其中9.9，即大約2000萬用戶為光纖接入網。 </p><p>　　亞太地區(qū)，特別是

88、韓國和日本是寬帶接入發(fā)展最迅猛的國家，韓國寬帶用戶總數已經突破1000萬，寬帶普及率居世界第一，占據家庭的7互聯網的90%。日本政府也通過各種措施大力推進寬帶發(fā)展，計劃2005年將寬帶用戶總數提高到3000萬，其中FTTH達到1000萬。美國依然是世界最大的寬帶接入市場，總用戶數超過3000萬。美國FOC將寬帶業(yè)務定位為2003—2008年的六大目標之一，事實上寬帶接入正成為美國普遍服務的下一個目標。美國寬帶接入是以電纜電視和ADSL為

89、主發(fā)展的，由于電信管制政策鼓勵采用新技術建設網絡(例如FCC規(guī)定運營商建設光纖接入網可以不受限于本地環(huán)路的非捆綁政策)以及競爭和業(yè)務增長的壓力，近來主導運營商對光纖到駐地(FTTP)的發(fā)展十分積極。</p><p>　　就光纖接入網，特別是光纖到駐地(FTTP)或光纖到家(FTTH)而言，全球已經開始進入啟動階段，僅美國就有270個FTTP項目，多半是地方政府、公共公司、房地產開發(fā)商和非主導電信運營商的項目。主導

90、運營商也開始進入該領域，其中Version計劃2005年完成300萬FTTP，SBC在其龐大的“光速”計劃中計劃2007年達1800萬FTTN，每戶具備速率20-39Mb/s，提供端到端的三重業(yè)務捆綁(trite play)業(yè)務。日本是世界上推進FTTH最激進的國家，2004年其光纖就已經通達1800萬多戶家庭，但是用戶發(fā)展滯后，大約為200萬，2005年計劃發(fā)展1000萬。歐洲比較穩(wěn)健保守，到2004年FTTH總共敷設了50萬，有16

91、7個小項目或試驗項目在進行。</p><p>　　我國寬帶接入網在近兩年發(fā)展也十分迅速，據初步統計，到2004年底我國寬帶用戶為2500萬，成為僅次于美國的第二大寬帶接入市場，其中主導技術是ADSL，大約占70%左右，其次是以太網技術，還有少量寬帶無線接入和電纜調制解調器接入，對于FTTH技術還處在跟蹤階段，少數發(fā)達城市也已經在開始考慮和試驗各種FTTHI技術。</p><p>　　從寬帶

92、應用看，按照美國麥肯錫公司的最新分析，初期的寬帶應用主要是高速上網，可以使上網的時間增加約30%。此后，隨著業(yè)務的大規(guī)模拓展，開發(fā)新的業(yè)務成為繼續(xù)發(fā)展的動力。據美國BHK公司在2004年的調查結果顯示，</p><p>　　2003年美國前五名的寬帶消費是網上賭博、成人節(jié)目、游戲、音樂下載和點播電視，具有明顯的向消費類傾斜的趨勢。</p><p>　　需要指出，討論應用驅動需要注意一個基本

93、認識上的誤區(qū)，即不能寄希望于人為事先研究開發(fā)出一二項所謂“殺手锏應用”、推廣應用。事實上，從電信發(fā)展歷史看，當網絡用戶數達到一定規(guī)模，各種應用會自然產生，這也是所謂的邁特卡夫定律的威力所在。歷史上沒有一種技術生來就帶著一大堆應用的，無論是移動通信還是互聯網，其短信、瀏覽、網上聊天等關鍵應用都是在用戶規(guī)模發(fā)展到一定程度后自然產生的，而不是事先刻意設計策劃出來的。</p><p>　　寬帶光纖接入網的優(yōu)勢</p

94、><p>　　隨著光纖在長途網、城域網乃至接入網主干段的大量應用，邏輯的發(fā)展趨勢將是繼續(xù)向接入網的配線段和引入線部分延伸，關鍵是推進速度有多快，這將取決于多種因素，包括市場的需求、競爭的需要、應用的刺激、技術的進步、成本的下降和配套運行系統的開發(fā)等等。我國2008年舉辦奧運會和2010年舉辦世界博覽會這兩大事件將會在一定程度上推進寬帶光纖接入網的發(fā)展。</p><p>　　下面將主要從系統技術

95、的角度來分析幾種主要的寬帶光纖接入技術的特征、問題和發(fā)展趨勢。當然，除了系統技術外，影響其應用的因素很多，主要是業(yè)務和應用以及管制政策。此外，各種配套元器件技術和敷設安裝測試技術也十分關鍵。目前低成本光源已有望實現，850nm的VCSEL僅需幾美元,1310nm的VOSEL已有突破，速率達10Gb/s。PLC混合集成技術高密度低成本光纜及相關技術，對彎曲不敏感的室內用光纖，低成本無源器件，施工安裝技術，自動光操作測試系統等也都是影響光接

96、入網推廣應用的關鍵因素，需要有妥善的解決方案。 點到點有源以太網系統 </p><p>　　由于計費、質量、管理、安全等多種因素，以太網作為公用網接入方式尚需進一步改進。</p><p>　　傳統以太網屬于用戶駐地網(cPN)。然而其應用卻在向包括接入網在內的其他公用網領域擴展。歷史上，對于企事業(yè)用戶應用環(huán)境，以太網技術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

97、公用設施接口。采用以太網作為企事業(yè)用戶接入手段的主要原因是已有巨大的網絡基礎和長期的經驗知識。目前所有流行的操作系統和應用也都是與以太網兼容的、性能價格比好、可擴展性、容易安裝與開通以及高可靠性等。</p><p>　　對于公用網住宅用戶應用環(huán)境，點到點有源以太網系統采用有源業(yè)務集中點來替代無源點到點系統的無源器件，使傳輸距離可以擴展到120公里之遠。主要優(yōu)點是專用接入帶寬有保證；每個用戶可以獨享100Mb/s乃

98、至1dbs；局端設備簡單便宜；傳輸距離長，服務區(qū)域大；成本隨用戶數的實際增長而線性增加，無需規(guī)劃，投資風險低，因而在低密度用戶分散地區(qū)成本較低。缺點是兩端設備和光纖設施專用，用戶不能共享局域端設備和光纖，當需求快速增長且用戶很密集時，光纖和兩端設備數量及其成本以及空間需求也隨之迅速增加，因而不太適合高密集用戶區(qū)域。影響選擇以太網技術的另一個因素是傳統視頻業(yè)務的提供方式，例如美國地方貝爾公司都承諾提供傳統模擬RF視頻節(jié)目，而以太網和模擬視