US Patent #5,535,212

Implicit Token Media Access Protocol Without Collision Detection

Philip J. Koopman, Jr.

US Patent #5,535,212
Implicit Token Media Access Protocol Without Collision Detection

ABSTRACT

If a transceiver has a message to send during an idle medium condition, it transmits a jam pattern onto the medium for a predetermined time (based on maximum network propagation delay). If a transceiver detects a jamming pattern, it inhibits its own transmissions and waits for the next slot progression. If multiple transceivers begin jamming within a propagation delay of each other (within the network vulnerable time), their jamming transmissions will not destructively interfere with each other. When jamming ceases, all transceivers begin a slot progression. Thus, the end of the jamming period when all transceivers have finished jamming serves as a network-wide synchronization for the start of an implicit token slot progression.

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Phil Koopman --