Claims
- 1. A communication system comprising:a) a plurality of peripheral access shelves each comprising a plurality of interconnected universal card slots; b) a plurality of intershelf links for interconnecting said peripheral access shelves; c) a plurality of common equipment cards including a plurality of interface cards insertable into any one of said plurality of universal card slots for receiving incoming ATM cells containing data, a first predetermined one of said interface cards being provided for generating a reference clock signal (ESYNC), and a predetermined one of said common equipment cards for generating an extracted timing signal (ETOS) derived from said reference clock signal (ESYNC); d) a system timing unit (SSU) insertable into any one of said plurality of universal card slots for receiving said extracted timing signal (ETOS) and in response generating a system timing signal (STOS); e) means within each of said peripheral shelves for transmitting and receiving supercells via said intershelf links, each of said supercells comprising a Start of Supercell (SOS) Ordered Set and a predetermined number of said outgoing ATM cells; and f) means within each of said peripheral shelves for transmitting and receiving Ordered Sets, wherein each of said Ordered Sets comprises a first data byte in the form of a symbol character for identifying each of said Ordered Sets and three further data bytes, at least one of said further data bytes including predetermined bits for encoding a start of supercell indicator, for encoding said extracted timing signal (ETOS) derived from said reference clock signal (ESYNC) and for encoding said system timing signal (STOS), and wherein each of said Ordered Sets is insertable into any location within said supercells, independent of ATM cell boundaries.
- 2. The communication system of claim 1, wherein said symbol character comprises a K28.5 character byte in 8B/10B encoding.
- 3. The communication system of claim 1, wherein one of said further data bytes comprises a Drive & Scan byte for effecting out-of-band communication between said peripheral shelves.
- 4. The communication system of claim 1, wherein said reference clock signal (ESYNC) is transmitted to said predetermined one of said common equipment cards along a common backplane bus.
- 5. The communication system of claim 4, wherein said predetermined one of said common equipment cards transmits said extracted timing signal (ETOS) along a drop bus of said communication system.
- 6. The communication system of claim 1, wherein said predetermined one of said common equipment cards further comprises a hub card.
Parent Case Info
This is a divisional of copending application Ser. No. 08/727,535 filed Oct. 24, 1996, which is incorporated herein by reference.
US Referenced Citations (10)