Mitel Semiconductor has introduced the world’s highest density AAL2 segmentation and re-assembly (SAR) device which simultaneously processes 1023 CIDs and 1023 VC connections - more than any device available on the market. Called the MT90502, it offers manufacturers a high-bandwidth solution for combined voice and data services in multiservice switching platforms, 3G mobile system equipment, carrier-class gateways, Next Generation Digital Loop Carriers (NGDLC), and ATM edge switches. The MT90502 AAL2 SAR receives constant bit rate (CBR) and variable bit rate (VBR) traffic from a TDM stream, and maps it to cells for transmission over ATM networks.

For Voice over Digital Subscriber Line (VoDSL) applications, the MT90502 directly accepts Pulse Code Modulation (PCM) and Adaptive Differential Pulse Code Modulation (ADPCM) traffic for packetisation.

The device also implements silence suppression and comfort noise generation for G.711 and G.726 data formats.

Supporting 1023 active CIDs and 1023 active VC connections, the device easily accommodates scalability and bandwidth requirements.

When two MT90502 devices are cascaded, over 2000 phone call terminations can be processed.

This is equivalent to three T3 links, or a full Sonet link at 155Mbit/s.

The ability to achieve SONET density with only two SAR devices yields a substantial reduction in cost, power consumption and board space compared to other currently available solutions.

The MT90502 AAL2 SAR supports both compressed and uncompressed voice.

The device connects to commercially available DSPs through synchronous ports.

Most other solutions consist of interfacing a SAR to a DSP through an asynchronous port.

This requires interrupt service routines or polling mechanisms to establish transfers of information from the DSP to the AAL2 SAR, which loads the CPU.

The MT90502 eliminates the load on the CPU by using a serial interface to the DSP that supports CBR and VBR traffic using HDLC encapsulation.

The device can route ATM cells to any one of the three Utopia interfaces, the microprocessor or the SAR engine.

The ability to route traffic is optimal for SONET equipment, since it allows instantaneous redundancy support.

The multiple UTOPIA interfaces also allow for cascading of multiple SAR devices, to increase AAL2 density, or to support AAL1 and AAL5 traffic.

The MT90502 is currently sampling, supplied in a 456-pin BGA package.