PDH Framer and LIU Solutions

Exar has a great reputation for offering innovative T1/E1/J1 as well as T3/E3/STS-1 products with many industry firsts, including the single-chip Jitter Attenuators (JA), integrated LIU with JA and CDR (Clock and Data recovery), and an integrated LIU plus SONET/SDH desynchronizer. The LIU function incorporates the R³ (Relayless, Reconfigurable Redundancy) Technology™ for minimal footprint and cost effective solutions. Exar is well known for outstanding product reliability and design support over a wide range of devices. Used individually or in chipsets, these devices are used in systems for many of the leading networking equipment manufacturers.
Another family of Framer / Mapper products provide flexible mapping of multi-channel T1/E1 clients into SONET/SDH networks. The highest density product in this family provides mapping of 28 independent T1s (or 21 E1s) into an STS-1. It also supports the transparent transfer and regeneration of the independent T1/E1 clocks across the SONET/SDH network and meets all the jitter / wanders specs of the T1/E1 client interfaces.

Exar PDH Technology Advantages

Exar offers many advantages to system designers.  Key among these are features that provide flexibility in design, enable system reliability, reduce cost, and provide standards compliant solutions.

R³ Technology™

R³ Technology™ means Reconfigurable, Relayless Redundancy. Designers can configure or reconfigure a card (board) in software without changing any external components.
• Reduces time-to-market/manufacturing costs
• Allows single Bill-of-Material (BOM) for worldwide applications

Diagnostics

Employing a full suite of loop-backs, Exar devices can quickly identify a fault location, invoke a complete set of alarms, and easily determine the fault type for the network operator. This detection and diagnostic capability is critical to reliable data transmission.  Exar's PDH products have the several client and facility side loop-backs for each function providing designers with a built-in diagnostic solution for the physical layer. A suite of Performance Monitoring (PMON) counters keep track of the integrity of each of section of the links.

Temperature

All of Exar's T/E Carrier and DS3/E3 products are industrial grade with a temperature of -40ºC to +85ºC.

Innovative Features

Redundancy
Internal switches help to implement 1:1 or 1+1 redundancy without the need for any relays, which helps to reduce cost and board space while improving reliability.

Hot Swapping
Exar's LIUs not only support 1:1 or 1+1 redundancy, but also support hot swapping without relays.

Integrated Timing Generators
An on-board timing circuit generates the appropriate system clocks from a single crystal. This again eliminates the need to change any components externally.

Design Flexibility
Choice of Host (software) or Hardware mode for interfacing and control provide design flexibility.

Extensive Diagnostic Capability
System users can quickly isolate a fault location, use alarms, and determine the nature of the fault.

Applications of T1/E1/J1 and T3/E3/STS-1 products

Exar's world-class physical layer solutions are ideal for a wide variety of markets and applications:

• BITS (T1/E1)
• Digital Cross Connects
• Access Concentrators
• Multi-Service Provisioning Platforms (MSPP)
• ATM and Frame Relay Switches
• Routers
• Wireless Base Stations
• DSLAMs