| 摘要 |
<p>A contention mechanism is disclosed for a communication network that provides perfect scheduling to avoid collisions between packets from a cluster (10) of M circuit boards (11) connected to a communications bus (20,23). The contention mechanism (19) includes a 2-phase contention procedure comprising a first phase priority contention phase (50), where boards with a highest priority and a real data packet to transmit proceed into a second contention phase (51), where a pointer is used to declare one of the remaining priority phase circuit boards as the overall winner to transmit its packet during a subsequent packet period. When no circuit board has a packet to transmit, all M circuit boards are declared as winners of the first priority phase, and a board is declared the winner on a distributed basis to transmit a "dead-space" packet over the bus (20). The real and dead-space packets can also be encoded and/or include a parity bit (56) to ensure signal transitions sufficient to maintain a duty cycle required by A-C coupled devices connected in the network and also provide fault isolation.</p> |
