参数资料
型号: XRT75VL00D
厂商: Exar Corporation
英文描述: E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCHRONIZER
中文描述: E3/DS3/STS-1线路接口单元与SONET DESYNCHRONIZER
文件页数: 70/92页
文件大小: 836K
代理商: XRT75VL00D
XRT75VL00D
E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCHRONIZER
REV. 1.0.3
67
9.3.4
Why are we talking about Pointer Adjustments?
The overall SONET network consists of numerous "Synchronization Islands". As a consequence, whenever a
SONET signal is being transmitted from one "Synchronization Island" to another; that SONET signal will
undergo a "clock domain" change as it traverses the network. This clock domain change will result in periodic
pointer-adjustments occurring within this SONET signal. Depending upon the direction of this "clock-domain"
shift that the SONET signal experiences, there will either be periodic "incrementing" pointer-adjustment events
or periodic "decrementing" pointer-adjustment events within this SONET signal.
Regardless of whether a given SONET signal is experiencing incrementing or decrementing pointer
adjustment events, each pointer adjustment event will result in an abrupt 8-bit shift in the position of the SPE
within the STS-1 data-stream. If this STS-1 signal is transporting an "asynchronously-mapped" DS3 signal;
then this 8-bit shift in the location of the SPE (within the STS-1 signal) will result in approximately 8UIpp of jitter
within the asynchronously-mapped DS3 signal, as it is de-mapped from SONET. In “Section 9.5, A Review of
we will discuss the "Category I Intrinsic Jitter Requirements (for DS3 Applications) per Telcordia GR-253-
CORE. However, for now we will simply state that this 8UIpp of intrinsic jitter far exceeds these "intrinsic jitter"
requirements.
In summary, pointer-adjustments events are a "fact of life" within the SONET/SDH network. Further, pointer-
adjustment events, within a SONET signal that is transporting an asynchronously-mapped DS3 signal, will
impose a significant impact on the Intrinsic Jitter and Wander within that DS3 signal as it is de-mapped from
SONET.
9.4
Clock Gapping Jitter
In most applications (in which the LIU will be used in a SONET De-Sync Application) the user will typically
interface the LIU to a Mapper Device in the manner as presented below in Figure 47.
In this application, the Mapper IC will have the responsibility of receiving an STS-N signal (from the SONET
Network) and performing all of the following operations on this STS-N signal.
Byte-de-interleaving this incoming STS-N signal into N STS-1 signals
Terminating each of these STS-1 signals
Extracting (or de-mapping) the DS3 signal(s) from the SPEs within each of these terminated STS-1 signals.
In this application, these Mapper devices can be thought of as multi-channel devices. For example, an STS-3
Mapper can be viewed as a 3-Channel DS3/STS-1 to STS-3 Mapper IC. Similarly, an STS-12 Mapper can be
FIGURE 47. ILLUSTRATION OF THE TYPICAL APPLICATIONS FOR THE LIU IN A SONET DE-SYNC APPLICATION
DS3 to STS-N
Mapper/
Demapper
IC
DS3 to STS-N
Mapper/
Demapper
IC
LIU
STS-N Signal
TPDATA_n input pin
TCLK_n input
De-Mapped (Gapped)
DS3 Data and Clock
相关PDF资料
PDF描述
XRT83SL34IV QUAD T1/E1/J1 SH TRANSCEIVER WITH CLOCK RECOVERY AND JITTER ATTENUATOR
XRT83SL34 QUAD T1/E1/J1 SH TRANSCEIVER WITH CLOCK RECOVERY AND JITTER ATTENUATOR
XS2F-A422-90-A 4 CONTACT(S), POLYBUTYLENE TEREPHTHALATE, FEMALE, CIRCULAR CONNECTOR, CLAMP, SOCKET
XS2F-A422-A90-A 4 CONTACT(S), POLYBUTYLENE TEREPHTHALATE, FEMALE, CIRCULAR CONNECTOR, CLAMP, SOCKET
XS2F-A422-AB0-A 4 CONTACT(S), POLYBUTYLENE TEREPHTHALATE, FEMALE, CIRCULAR CONNECTOR, CLAMP, SOCKET
相关代理商/技术参数
参数描述
XRT75VL00D_08 制造商:EXAR 制造商全称:EXAR 功能描述:E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET
XRT75VL00D1V-F 制造商:Exar Corporation 功能描述:
XRT75VL00DES 功能描述:时钟合成器/抖动清除器 1CHT3/E3/STS1LIU+ DESYNC 3.3V DRV VER RoHS:否 制造商:Skyworks Solutions, Inc. 输出端数量: 输出电平: 最大输出频率: 输入电平: 最大输入频率:6.1 GHz 电源电压-最大:3.3 V 电源电压-最小:2.7 V 封装 / 箱体:TSSOP-28 封装:Reel
XRT75VL00DIV 功能描述:时钟合成器/抖动清除器 3.3V 1 CH E3/DS3/STS W/SONET DE-SYNCH RoHS:否 制造商:Skyworks Solutions, Inc. 输出端数量: 输出电平: 最大输出频率: 输入电平: 最大输入频率:6.1 GHz 电源电压-最大:3.3 V 电源电压-最小:2.7 V 封装 / 箱体:TSSOP-28 封装:Reel
XRT75VL00DIV-F 功能描述:时钟合成器/抖动清除器 3.3V 1 CH E3/DS3/STS W/SONET DE-SYNCH RoHS:否 制造商:Skyworks Solutions, Inc. 输出端数量: 输出电平: 最大输出频率: 输入电平: 最大输入频率:6.1 GHz 电源电压-最大:3.3 V 电源电压-最小:2.7 V 封装 / 箱体:TSSOP-28 封装:Reel