Scheme for reducing transmission delay following collision of transmissions in communication networks
First Claim
1. Method of handling interfering communications in a communication network comprising a communication medium and a plurality of stations connected to the medium for communication, each station having intrastation propagation delay of B and the medium having maximum interstation propagation delay of A, comprising the steps of:
- detecting interfering communications;
monitoring the medium to detect when the medium becomes quiescent following detection of the interfering communications;
determining a backoff time period as a function of a time slot S wherein
space="preserve" listing-type="equation">B+2A≦
S<
2B+2A;
waiting for expiration of the backoff time period following the medium becoming quiescent; and
communicating following the expiration of the backoff time period.
1 Assignment
0 Petitions
Accused Products
Abstract
In a contention type of communication network, the collision backoff time period during which retransmission of collided messages may not be attempted is computed as a multiple of a time slot S such that B+2A≦S<2B+2A, where A is the maximum interstation propagation delay of the communication medium and B is the intrastation propagation delay of the network stations. The collision backoff time period is timed from the point at which the medium becomes quiescent following collision and transmission of the jam signal.
40 Citations
20 Claims
-
1. Method of handling interfering communications in a communication network comprising a communication medium and a plurality of stations connected to the medium for communication, each station having intrastation propagation delay of B and the medium having maximum interstation propagation delay of A, comprising the steps of:
-
detecting interfering communications; monitoring the medium to detect when the medium becomes quiescent following detection of the interfering communications; determining a backoff time period as a function of a time slot S wherein
space="preserve" listing-type="equation">B+2A≦
S<
2B+2A;waiting for expiration of the backoff time period following the medium becoming quiescent; and communicating following the expiration of the backoff time period. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. Method of handling at a station a collision of signal transmissions of a plurality of stations in a communication network having a communication medium and a plurality of stations connected to the medium for communication, the stations contending with each other for signal transmission access to the medium, the medium having maximum interstation propagation delay of A and each station having intrastation propagation delay of B, comprising the steps of:
-
detecting a collision; transmitting on the medium a collision enforcing signal in response to the detection of the collision; monitoring the medium to detect when the medium becomes quiescent following transmission of the collision enforcing signal; determining a backoff time period as a multiple R of a time slot S wherein
space="preserve" listing-type="equation">B+2A≦
S<
2B+2A,and wherein R is a number selected from a group of numbers the difference between any two of which is at least one; waiting for expiration of the backoff time period upon the detection of the medium being quiescent; and retransmitting signals involved in the collision following expiration of the backoff time period. - View Dependent Claims (8, 9)
-
-
10. Apparatus for handling interfering communications in a communication network comprising a communication medium and a plurality of stations connected to the medium for communication, each station having intrastation propagation delay of B and the medium having maximum interstation propagation delay of A, comprising:
-
means for detecting interference of communications; means for determining a backoff time period as a function of a time slot S wherein
space="preserve" listing-type="equation">B+2A≦
S<
2B+2A;means responsive to the detecting means for monitoring the medium to detect when the medium becomes quiescent following detection of the interference of communications; means responsive to the determining means and to the monitoring means for timing the backoff time period following the medium becoming quiescent and for indicating expiration of the backoff time period; and means responsive to the timing and indicating means for communicating following the indication of expiration of the backoff time period. - View Dependent Claims (11, 12, 13, 14)
-
-
15. Apparatus for handling interfering communications in a station of a communication network comprising a communication medium and a plurality of stations connected to the medium for communication, each station having intrastation propagation delay of B and the medium having maximum interstation propagation delay of A, the apparatus comprising:
-
means for detecting interference with a communication of the station; means for determining a backoff time period as a function of a time slot S wherein
space="preserve" listing-type="equation">B+2A≦
S<
2B+2A;means responsive to the detecting means for monitoring the medium to detect when the medium becomes quiescent following detection of the interference with the communication; means responsive to the determining means and to the monitoring means for timing the backoff time period following the medium becoming quiescent and for indication expiration of the backoff time period; and means responsive to the timing and indicating means for repeating the communication following the indication of expiration of the backoff time period.
-
-
16. Apparatus for handling a collision of signal transmissions of a plurality of stations, for use in a station of a communication network having a communication medium and a plurality of stations connected to the medium for communication, the stations contending with each other for access to the medium, the medium having maximum interstation propagation delay of A and each station having intrastation propagation delay of B, the apparatus comprising:
-
means for detecting a collision; means responsive to the collision detecting means for transmitting on the medium a collision-enforcing signal in response to the detection of the collision; means for determining a backoff time period as a multiple R of a time slot S wherein
space="preserve" listing-type="equation">B+2A≦
S<
2B+2A,and wherein R is a number selected from a group of numbers the difference between any two of which is at least one; means responsive to the transmitting means for monitoring the medium to detect when the medium becomes quiescent following transmission of the collision enforcing signals; means responsive to the monitoring means and to the determining means for timing the backoff time period following the medium becoming quiescent and for indicating expiration of the backoff time period; and means responsive to the timing and indicating means for retransmitting signals involved in the collision following expiration of the backoff time period. - View Dependent Claims (17)
-
-
18. Apparatus for interfacing a device for communications to a communication medium for use in a station of a communication network comprising the communication medium and a plurality of stations connected to the medium for communication, the medium having maximum interstation propagation delay of A and each station having intrastation propagation delay of B, comprising:
-
means for transmitting signals to the medium; means cooperative with the transmitting means for indicating collision of the transmitted signals with signals of another station; means for determining a backoff time period as a multiple R of a time slot S wherein
space="preserve" listing-type="equation">B+2A≦
S<
2B+2A,and wherein R is a number selected from a group of numbers the difference between any two of which is at least one; means for indicating that the medium is quiescent; and means responsive to the quiescence indicating means, the collision indicating means, and the determining means, for preventing the signal transmitting means from retransmitting the collided transmitted signals for the duration of the backoff time period from indication of the medium becoming quiescent following indication of collision. - View Dependent Claims (19, 20)
-
Specification