Custom Telecom Backplanes

The telecommunications industry is booming. Traditionally, the systems' design was proprietary. However, as the industry has pushed more towards open systems, the CompactPCI market has thrived.

With its PCI heritage and rugged, hot-swappable configuration, it is an excellent form factor for telecom systems. Yet custom telecom backplanes are still in high demand. When considering a custom design, redundant components, high availability components, connectors, and layout issues must be considered.

Most telecom applications require high reliability performance. The designs must have redundancy, which can be achieved several ways. One expensive way is to have 100% redundancy where every board, power supply, and fan has a backup. Another way is to allow hot swappable components. The PICMG 2.13 Redundant System Slot subcommittee is working on redundant CPU issues. Interoperability among manufacturers is not achievable at this point so the system designer must choose a specific CPU for the system. For power supplies, the PICMG 2.11 Power Interface specification defined a 47-pin Positronics connector for pluggable supplies. Power supplies are hot swappable by the OR-ing diodes in the supplies. Power supplies monitor the health of the voltages on the backplane through either third wire or droop current sharing methods. More

PICMG 2.16 CompactPCI Packet Switching Backplane Update
The PICMG 2.16 subcommittee's purpose is to define an IEEE 802.3ab-compliant packet switching backplane (PSB). The PSB uses 10 pins on P3 in node slots and provides an interconnect for every available slot of a 19" chassis backplane. More