英语翻译The G-PON network architecture supports atwo-wavelength WDM scheme for downstreamand upstream digital services .Additionally,another downstream wavelength is allocatedfor distribution of analog video service.The networksupports up to 60 k

英语翻译The G-PON network architecture supports atwo-wavelength WDM scheme for downstreamand upstream digital services .Additionally,another downstream wavelength is allocatedfor distribution of analog video service.The networksupports up to 60 k
英语翻译
The G-PON network architecture supports a
two-wavelength WDM scheme for downstream
and upstream digital services .Additionally,
another downstream wavelength is allocated
for distribution of analog video service.The network
supports up to 60 km reach,with 20 km
differential reach between optical network units
(ONUs).The split ratio supported by the standard
is up to 128.Practical deployments typically
would have lower reach and split ratio,limited
by the optical budget.
ITU-T G.984.2 specifies the PMD layer for
G-PON,covering the range of G-PON upstream
and downstream bit rates,and the optical parameters
for the various rate combinations.
As network operators requirements evolved,
the preferred G-PON bit rate was selected to be
2.488 Gb/s downstream,1.244 Gb/s upstream.
This focus has then allowed the definition of
best practice optical parameters for G-PON,
which was documented as an amendment to
G.984.2.The parameters,known as Class B+,
apply to a network with or without a video overlay
and to ONUs based on either APD or PIN
technology.

英语翻译The G-PON network architecture supports atwo-wavelength WDM scheme for downstreamand upstream digital services .Additionally,another downstream wavelength is allocatedfor distribution of analog video service.The networksupports up to 60 k
该g-pon网络架构支持
双波长波分复用方案的下游
与上游数字服务.此外,
另一个下游波长分配
分布模拟视频服务.网络
支持多达60公里到20公里,
微分及光网络单元
（责任）.分流比的标准
高达128.通常实际部署
将有较低的到达和分流比,有限公司
由光学预算.
g.984.2指定ITU - T的偏振模色散层
g-pon,覆盖范围的g-pon上游
下游比特率,和光学参数
对各种速率组合.
作为网络运营商要求的演变,
首选的g-pon比特率被选为
2.488/1.244/上游下游.
这一重点,然后允许定义
最佳实践g-pon光学参数,
这是记载的一个修正案
g.984.2.参数,称为乙类+,
适用于网络或无视频覆盖
和责任基础上要么雪崩光电二极管或针
技术.