28 channel T1/E1 LIU/Framer with VT/TU Mapper and M13 Multiplexer for Optical Transport Applications

2006-01-16

New from Exar is the “Voyager”, the industry’s first integrated 28 channel T1/E1 LIU/framer with VT/TU Mapper/DeMapper and the M13 multiplexer. The XRT86SH328 is optimized for the tributary aggregation applications such as multi-service provisioning platforms, optical transport systems, routers and wireless transport systems.

The Voyager integrates 28 T1/E1 LIU’s and framers along with a SONET/SDH framer, VT/VC mappers, M13 Multiplexer and DS3/E3 framer. This allows the customers to deploy a single line card that supports the simultaneous mapping and transport of both T1 and E1. Each channel of the LIU can be selected to operate independently in T1 or E1 mode. Each T1 and E1 channel offers a user programmable arbitrary pulse generator as well as an integrated clock synthesizer that supports a wide range of input clock frequencies.

The device incorporates DS1/E1 framers for performance monitoring in both egress and ingress directions. Each of the 28 T1 or E1 uses an internal de-synchronizer with a pointer leak algorithm to remove the jitter due to mapping and pointer adjustments.

The device provides mapping of up to 28 T1/21 E1 streams asynchronous into VT/STS-1 or TU/STM-1. Each of 28 T1/E1 channels includes a PRBS generator and detector. On the system side, Voyager supports either a telecom bus or clock and data interface.

The device provides significant board space savings due to an unprecedented level of LIU/Framer/Mapper integration. When three XRT86SH328s are combined on one line card, the device’s unique innovative architecture delivers a complete OC-3/STM-1 solution that supports up to 84 T1 or 63 E1 port aggregation applications. The XRT86SH328 includes all the SONET/SDH framing functionality to provide an OC-3/STM-1 compliant interface. Also, the XRT86SH328 (Voyager) can be used as a chipset with Exar’s XRT91L30 transceiver providing a SONET/SDH compliant serial interface at 155 Mbits/sec that can be directly connected to an optical module. In addition, the device utilizes Exar’s proprietary R3 TechnologyTM (Reconfigurable, Relayless Redundancy) delivering key benefits to customers designing T1/E1/J1 interface cards.

Instead of using separate LIU and framer modules, system designers now have the option of using a single module for both LIU and framer functionality, saving significant systems cost and board space.

Each LIU channel on the XRT86SH328 supports Exar’s R3 Technology - introduced in 2002. Devices using R3 Technology are reconfigurable with integrated termination supporting all common T1/E1/J1 line impedances enabling customers to build a simple board and eliminate the need for external relays for 1:1 and 1+1 redundancy applications. This feature allows final device configuration to be made just prior to line-card installation.

Voyager’s architecture supports SONET/SDH compliant T1/E1 de-synchronizers in the drop direction in addition to the jitter attenuator functionality in the add direction. This architecture addresses different types of rigorous network jitter requirements, which in the past required very expensive multi-chip solutions. Voyager also provides unique DS3 capabilities, which includes M13 functionality, by multiplexing 28/21 T1/E1’s onto a DS3 signal for sending either on a serial DS3 interface or by mapping onto an STS-1. In addition, DS1’s or E1’s received from a DS3 signal can be mapped into SONET/SDH through VT/TU mapping (trans-muxing).

Another unique advantage of the XRT86SH328 is the capability to mix T1’s or E1’s on any one of the LIU interfaces without requiring additional timing devices to support this mixed mode capability. In the past system designers were limited to the feature set of individual LIU and Framer devices for supporting this mixed mode solution which required very expensive timing components on their board design. The XRT86SH328 in a 568 PBGA operates at 3.3V/1.8V with 3.3V tolerant I/O’s over the industrial temperature range. Full back up is available from DT Electronics’ technical and FAE teams.