Carrier sense multiple access with collision avoidance utilizing rotating time staggered access windows

Claim 2

In a communications system wherein a plurality of stations each transmit at different times to one another over a shared communications medium, each said station including detection means for detecting the presence or absence of a transmission on said communications medium, a method of controlling access by each station to said communications medium, said method comprising the steps of: reserving an arbitration period of time commencing from the termination of each transmission on said medium,; dividing said arbitration period into a plurality of access windows; assigning unique arbitration addresses to stations sharing said medium; generating, at each station desiring access to said medium, an access control number independent of the address of said each station to be transmitted to said medium as part of its communication; receiving said access control number at each other station desiring access to said medium and combining said received access control number with the respective assigned address of said each other station to determine one of said plurality of access windows assigned to said each other station during the next arbitration period; detecting at each station the termination of a transmission transmitted over said medium; generating at each station a new access control number calculated from the current access control number; and transmitting said new access control number from any station desiring access to said medium, during its respective access window if no other station has transmitted during a previous access window in the same arbitration period.

Claim 3

The method of claim 1 wherein the incremental value added by each terminal is a predetermined constant.

Claim 4

The method of claim 2, wherein said predetermined constant is a value greater than 1.

Claim 5

The method of claim 1 wherein the incremental value is a variable derived by random number generation.

Claim 6

The method of claim 1, wherein at least some of the transmissions are from a transmitting station to a destination station, said stations maintaining the same access window assignments in the next arbitration period if a transmitting station does not receive a response from a receiving station.

Claim 7

The method of claim 1, wherein each station includes means for detecting whether the access control number received with a transmission is invalid, and wherein a station uses the old control number if the access control number received with the last transmission is determined to be invalid.

Claim 8

In a communications system wherein a plurality of stations each transmit at different times to one another over a shared communications medium, each said station including detection means for detecting the presence or absence of a transmission on said communications medium, a method of controlling access by each station to said communications medium, said method comprising the steps of: reserving an arbitration period of time commencing from the termination of each transmission on said medium,; dividing said arbitration period into a plurality of access windows; establishing unique arbitration addresses for stations sharing said medium by assigning node addresses to stations in a numerical sequence and developing arbitration addresses from said node addresses by reversing the order of bits in the node addresses, whereby the times allotted to access windows within each arbitration period are spread out in accordance with the number of stations then actually using the medium; generating, at each station desiring access to said medium, an access control number to be transmitted to said medium as part of its communication; receiving said access control number at each other station desiring access to said medium and combining said received access control number with the respective assigned address of said each other station to determine one of said plurality of access windows assigned to said each other station during the next arbitration period; detecting at each station the termination of a transmission transmitted over said medium; generating at each station a new access control number calculated from the current access control number; and transmitting said new access control number from any station desiring access to said medium, during its respective access window if no other station has transmitted during a previous access window in the same arbitration period.

Claim 9

In a communications system wherein a plurality of stations each transmit at different times to one another over a shared communications medium, each said station including detection means for detecting the presence or absence of a transmission on said communications medium, a method of controlling access by each station to said communications medium, said method comprising the steps of: reserving an arbitration period of time commencing from the termination of each transmission on said medium,; dividing said arbitration period into a plurality of access windows; establishing unique arbitration addresses for stations sharing said medium by assigning node addresses to stations in a numerical sequence and developing arbitration addresses from said node addresses by reversing the order of bits in the node addresses, whereby the times allotted to access windows within each arbitration period are spread out in accordance with the number of stations then actually using the medium; generating, at each station desiring access to said medium, an access control number to be transmitted to said medium as part of its communication; receiving said access control number at each other station desiring access to said medium and combining said received access control number with the respective assigned address of said each other station to determine one of said plurality of access windows assigned to said each other station during the next arbitration period; detecting at each station the termination of a transmission transmitted over said medium; generating at each station a new access control number calculated from the current access control number; and transmitting said new access control number from any station desiring access to said medium, during its respective access window if no other station has transmitted during a previous access window in the same arbitration period.

Claim 10

In a communications system wherein a plurality of stations each transmit at different times to one another over a shared communications medium, each said station including detection means for detecting the presence or absence of a transmission on said communications medium, a method of controlling access by each station to said communications medium, said method comprising the steps of: reserving an arbitration period of time commencing from the termination of each transmission on said medium,; dividing said arbitration period into a plurality of access windows; assigning unique arbitration addresses to stations sharing said medium; generating, at each station desiring access to said medium, an access control number to be transmitted to said medium as part of its communication; receiving said access control number at each other station desiring access to said medium and combining said received access control number with the respective assigned address of said each other station to determine one of said plurality of access windows assigned to said each other station during the next arbitration period; detecting at each station the termination of a transmission transmitted over said medium; generating at each station a new access control number calculated from the current access control number; transmitting said new access control number from any station desiring access to said medium, during its respective access window if no other station has transmitted during a previous access window in the same arbitration period; if no station has commenced transmission during said arbitration period, sending no transmissions onto said medium and allowing network arbitration to lapse until a particular station desires access to said medium; and when said particular station desires access to said medium, transmitting a synchronization signal from said particular station for a predetermined period of time, an arbitration period commencing at the termination of said synchronization commencement signal.

Claim 11

In a communications system wherein a plurality of stations each transmit at different times to one another over a shared communications medium, each said station including detection means for detecting the presence or absence of a transmission on said communications medium, a method of controlling access by each station to said communications medium, said method comprising the steps of: reserving an arbitration period of time commencing from the termination of each transmission on said medium,; dividing said arbitration period into a plurality of access windows; assigning unique arbitration addresses to stations sharing said medium; generating, at each station desiring access to said medium, an access control number to be transmitted to said medium as part of its communication; receiving said access control number at each other station desiring access to said medium and combining said received access control number with the respective assigned address of said each other station to determine one of said plurality of access windows assigned to said each other station during the next arbitration period; detecting at each station the termination of a transmission transmitted over said medium; generating at each station a new access control number calculated from the current access control number; transmitting said new access control number from any station desiring access to said medium, during its respective access window if no other station has transmitted during a previous access window in the same arbitration period; if no station has commenced transmission during said arbitration period, sending no transmissions onto said medium and allowing network arbitration to lapse until a particular station desires access to said medium; and when said particular station desires access to said medium, transmitting a synchronization signal from said particular station for a predetermined period of time, an arbitration period commencing at the termination of said synchronization commencement signal.

Claim 12

In a communications system wherein a plurality of active stations each transmit at different times to one another over a shared communications medium, each said station including detection means for detecting the presence or absence of a transmission on said communications medium, a method of controlling access by each station to said communications medium, said method comprising the steps of: reserving an arbitration period of time commencing from the termination of each transmission on said medium,; dividing said arbitration period into a plurality of access windows; assigning unique arbitration addresses to stations sharing said medium; generating, at each station desiring access to said medium, an access control number to be transmitted to said medium as part of its communication; receiving said access control number at each other station desiring access to said medium and combining said received access control number with the respective assigned address of said each other station to determine one of said plurality of access windows assigned to said each other station during the next arbitration period; detecting at each station the termination of a transmission transmitted over said medium; generating at each station a new access control number calculated from the current access control number; transmitting said new access control number from any station desiring access to said medium, during its respective access window if no other station has transmitted during a previous access window in the same arbitration period; and upon a station first becoming active, requiring said newly active station to wait for the expiration of two complete network arbitration periods before transmitting in its assigned access window.

Claim 13

In a communications system wherein a plurality of active stations each transmit at different times to one another over a shared communications medium, each said station including detection means for detecting the presence or absence of a transmission on said communications medium, a method of controlling access by each station to said communications medium, said method comprising the steps of: reserving an arbitration period of time commencing from the termination of each transmission on said medium,; dividing said arbitration period into a plurality of access windows; assigning unique arbitration addresses to stations sharing said medium; generating, at each station desiring access to said medium, an access control number to be transmitted to said medium as part of its communication; receiving said access control number at each other station desiring access to said medium and combining said received access control number with the respective assigned address of said each other station to determine one of said plurality of access windows assigned to said each other station during the next arbitration period; detecting at each station the termination of a transmission transmitted over said medium; generating at each station a new access control number calculated from the current access control number; transmitting said new access control number from any station desiring access to said medium, during its respective access window if no other station has transmitted during a previous access window in the same arbitration period; and upon a station first becoming active, requiring said newly active station to wait for the expiration of two complete network arbitration periods before transmitting in its assigned access window.