Multipoint packet data communication system using random access and collision detection techniques

Claim 2

In a data communication system having a communication channel for interconnecting a plurality of transceivers, each of said transceivers including means for transmitting a signal having transitions, the improvement comprising: means responsive to the presence and absence of a signal on said communication channel during a transition of a signal transmitted by said transmitting means for providing a collision detected (CD) signal if no signal is detected on said communication channel during a transition of said transmitted signal; and means responsive to said CD signal for terminating said transmitting of said signal.

Claim 3

The improvement according to claim 1 comprising means for checking said channel for the presence of a signal; and means responsive to said checking means for providing a channel is not busy (BUSY) signal when the presence of a signal is not detectable and a channel is busy (BUSY) signal when the presence of a signal is detected.

Claim 4

The improvement according to claim 2 comprising means for providing a request to send (RTS) signal and a request not to send (RTS) signal; means responsive to said RTS and said BUSY signals for providing a clear to send (CTS) signal.

Claim 5

The improvement according to claim 3 wherein said signal transmitting terminating means comprises means responsive to said CD signal for terminating said CTS signal and providing a not clear to send (CTS) signal.

Claim 6

The improvement according to claim 1 comprising: means for providing a clock (LCK) signal having a rate equal to a predetermined multiple of the rate of a transmitted signal received on said channel from a transceiver; and means responsive to said transmitted signal and said LCK signal for providing a clock (RXC) signal having a rate equal to the rate of said transmitted signal and synchronized therewith.

Claim 7

The improvement according to claim 5 comprising: means responsive to said RXC signal and a transmitted signal received from said communication channel for decoding said transmitted signal and providing a decoded data signal (RXD) corresponding thereto.

Claim 8

The improvement according to claim 6 wherein said transmitted signals are non-return zero inverting (NRZI) encoded or non-return one inverting (NROI) encoded and said decoding means comprises means for decoding said transmitted signals.

Claim 9

The improvement according to claim 1 comprising means responsive to said transmitting means for encoding said transmitted signal.

Claim 10

The improvement according to claim 8 wherein said encoding means comprises means for NRZI or NROI encoding said transmitted signal.

Claim 11

The improvement according to claim 8 wherein said transmitted signal comprises a data portion and comprising means coupled between said transmitting means and an input of said encoding means for inserting a binary bit in said data portion of said transmitted signal after every sequence of a predetermined number of the complement of said bit.

Claim 12

The improvement according to claim 4 comprising means for providing a request for access (RFA) signal and wherein said RTS signal providing means comprises: means responsive to said CD signal and said CTS signal or said BUSY, said RFA and said CTS signals for providing a generate random delay (GR) signal; means responsive to said GR signal for generating a clear-to-access (CTA) signal at a random time after receipt of said GR signal; and means responsive to said RFA and said CTA signals for providing said RTS signal.

Claim 13

In a data communication system having a communication channel for interconnecting a plurality of transceivers, each of said transceivers including means for transmitting a signal and first means associated with each of said transceivers for detecting when a plurality of said transceivers is transmitting a signal on said channel simultaneously, the improvement comprising: second means for detecting when said channel is busy prior to a transmission by each of said transceivers; and means responsive to said first and second detecting means for interrupting and delaying said transmitting of each of said transceivers for a geometrically distributed random period of time.

Claim 14

In a data communication system having a communication channel for interconnecting a plurality of transceivers, each of said transceivers including means for transmitting a signal and first means associated with each of said transceivers for detecting when a plurality of said transceivers is transmitting a signal on said channel simultaneously, the improvement comprising: second means for detecting when said channel is busy prior to a transmission by each of said transceivers; and means responsive to said first and second detecting means for interrupting and delaying said transmitting of each of said transceivers for a geometrically distributed random period of time.

Claim 15

In a data communication system having a communication channel for interconnecting a plurality of transceivers, each of said transceivers comprising: means for transmitting a signal; first means for receiving a signal on said communication channel from another of said plurality of transceivers and said transmitting means; means responsive to said first receiving means for providing a busy (BUSY) signal when a signal from any one of said transceivers is received on said communication channel and a not busy (BUSY) signal when no signal is received on said communication channel from any one of said transceivers; second means for receiving a signal transmitted to said communication channel by said transceiver; means responsive to said first and said second receiving means for providing a collision detected (CD) signal when said transmitted signal makes a transition and a signal received by said first means during said transition has a signal value which differs substantially from the value from which said transmitted signal transitioned; means for providing a request for access (RFA) signal; means responsive to said RFA and a clear-to-access (CTA) signal for providing a request to send (RTS) signal; means responsive to said RTS and BUSY signals for providing a clear to send (CTS) signal; means responsive to said CD signal for terminating said CTS signal and providing a not clear-to-send (CTS) signal; means responsive to said CD and CTS signals or said BUSY, RFA and CTS signals for providing a generate random delay (GR) signal; and means responsive to said GR signal for generating said clear-to-access (CTA) signal at a random time after receipt of said GR signal.

Claim 16

In a data communication system having a communication channel for interconnecting a plurality of transceivers, each of said transceivers comprising: means for transmitting a signal; first means for receiving a signal on said communication channel from another of said plurality of transceivers and said transmitting means; means responsive to said first receiving means for providing a busy (BUSY) signal when a signal from any one of said transceivers is received on said communication channel and a not busy (BUSY) signal when no signal is received on said communication channel from any one of said transceivers; second means for receiving a signal transmitted to said communication channel by said transceiver; means responsive to said first and said second receiving means for providing a collision detected (CD) signal when said transmitted signal makes a transition and a signal received by said first means during said transition has a signal value which differs substantially from the value from which said transmitted signal transitioned; means for providing a request for access (RFA) signal; means responsive to said RFA and a clear-to-access (CTA) signal for providing a request to send (RTS) signal; means responsive to said RTS and BUSY signals for providing a clear to send (CTS) signal; means responsive to said CD signal for terminating said CTS signal and providing a not clear-to-send (CTS) signal; means responsive to said CD and CTS signals or said BUSY, RFA and CTS signals for providing a generate random delay (GR) signal; and means responsive to said GR signal for generating said clear-to-access (CTA) signal at a random time after receipt of said GR signal.