ATCA: An Evolution in Open Standards

Interoperable hardware standards are by no means a new concept. Open standards enabling the use of Commercial-Off-The-Shelf (COTS) components in the telecom infrastructure have certainly been around for the better part of a decade. For instance, since the development of CompactPCI (News - Alert) in the 1990s, telecom equipment manufacturers have been using building blocks to speed deployment and hold down costs. Unfortunately, just as CompactPCI was picking up steam, the bubble burst and the telecom sector fell into a deep chasm.

In the midst of the recession, the PCI Industrial Computer Manufacturers Group (PICMG (News - Alert)) began work on improvements to CompactPCI. By 2003, the Advanced Telecom Computing Architecture (AdvancedTCA (News - Alert) or ATCA) specification was born. CompactPCI is still prevalent today. But even if you look at the ATCA spec in its original form back when it was initially approved in December 2002, many facets of the predecessors are already obsolete.



The basic elements of PICMG 3.0 form factor consist of Front Boards, Backplanes, the Subrack, and the Shelf. The Front Boards, which define power connection and Shelf management, Data Transport Interface and user-defined Input/Output (I/O) interconnect, are capable of utilizing a maximum of four Advanced Mezzanine Cards (AMCs). The Backplanes, which are designed to accommodate anywhere from 2 to 16 Front Board Slots, distributes power and manages metallic test bus, ring generator bus and low-level Shelf Management signals. The PICMG 3.0 spec dictates that systems are capable of dissipating as much as 200 Watts per single-Slot Board and further defines everything from airflow cooling to shelf management. The shelves comply with NEBS and are rack-mountable to ETSI specifications.

The new architecture has resulted in a high-speed switched fabric with peak throughput of 10 Gigabits per second (Gbps), 10 times higher than the peak throughput of CompactPCI. The ATCA fabric supports full-mesh interconnect and is also protocol-agnostic, capable of supporting Ethernet, InfiniBand, PCI Express and/or RapidIO. As such, ATCA provides reliable standardized platform architecture for carrier-grade communications functionality without sacrificing the high availability (99.999%) and manageability (Hot-Swap) that is associated with costly proprietary hardware. In addition, a vast ecosystem of vendors has formed over the last few years to support the ATCA initiative further reducing costs and time-to-market for potential customers.

Robert Liu is Executive Editor at TMCnet.