Method and apparatus for use in a network of the ethernet type, to improve fairness by controlling the interpacket gap in the event of channel capture
First Claim
1. For use in a node of a network employing a Carrier Sense Multiple Access with Collision Detection (CSMA/CD) protocol for channel access, a method for improving fairness of access to a channel, comprising the steps of:
- capturing the channel for successive transmissions by this node;
sensing whether this node has captured the channel;
if this node has not captured the channel, observing a prescribed transmit-to-transmit interpacket gap, IPG., after completing a transmission and before any attempt at transmitting or retransmitting a packer andafter sensing capture of the channel, selecting an increased transmit-to-transmit interpacket gap, IPG, interval that must be observed before any attempt at transmitting or retransmitting a packet;
whereby the increased IPG gives a node that has not captured the channel an increased likelihood of transmitting before this node and overcoming capture of the channel.
7 Assignments
0 Petitions
Accused Products
Abstract
A technique for modifying the IEEE 802.3 standard for selecting transmit-to-transmit interpacket gap (IPG) intervals in a Carrier Sense Multiple Access with Collision Detection (CSMA/CD) network, in the event that a node has captured the network communication channel. If there is a small number of active nodes on the network, one node may capture the channel and the standard backoff algorithm makes it increasingly unlikely for another node to transmit. The new technique provides for less aggressive, i.e. longer, interpacket gap (IPG) intervals to be used by a node that has captured the channel, thereby increasing the likelihood that another node will gain access.
-
Citations
10 Claims
-
1. For use in a node of a network employing a Carrier Sense Multiple Access with Collision Detection (CSMA/CD) protocol for channel access, a method for improving fairness of access to a channel, comprising the steps of:
-
capturing the channel for successive transmissions by this node; sensing whether this node has captured the channel; if this node has not captured the channel, observing a prescribed transmit-to-transmit interpacket gap, IPG., after completing a transmission and before any attempt at transmitting or retransmitting a packer and after sensing capture of the channel, selecting an increased transmit-to-transmit interpacket gap, IPG, interval that must be observed before any attempt at transmitting or retransmitting a packet; whereby the increased IPG gives a node that has not captured the channel an increased likelihood of transmitting before this node and overcoming capture of the channel. - View Dependent Claims (2, 3, 4, 5)
-
-
6. For use in a node of a network employing a Carrier Sense Multiple Access with Collision Detection (CSMA/CD) protocol for channel access, apparatus for improving fairness of access to a channel, comprising:
-
means for sensing when this node has captured the channel for successive transmissions by this node; means operative if this node has not captured the channel, for selecting a prescribed transmit-to-transmit interpacket gap, IPG, interval after completing a transmission and before any attempt at transmitting or retransmitting a packet; and means operative after sensing capture of the channel, for selecting an increased transmit-to-transmit interpacket gap, IPG, interval that must be observed before any attempt at transmitting or retransmitting a packet; whereby the increased IPG gives a node that has not captured the channel an increased likelihood of transmitting before this node and overcoming capture of the channel. - View Dependent Claims (7, 8, 9, 10)
-
Specification