Fast channel switching scheme for IEEE 802.11 WLANs

A method for switching at least two wireless nodes of a plurality of wireless nodes, located within the coverage area of a basic-service set (BSS1) or infrastructure-basic-service set (IBSS), in a wireless-local-area network (WLAN) from a first communication channel to a second communication channel, the method comprising the steps of:

• (a) determining whether said second communication channel to be used by said at least two wireless nodes is needed;
• (b) broadcasting, by a source node, a first management frame including a channel switch announcement element (CSAE) to said at least two wireless nodes when it is determined in step (a) that said second communication channel is needed, said first management frame including said CSAE including a channel-switch time and a second communication channel identifier;
• (c) upon receiving said broadcasted first management frame including said CSAE at said at least two wireless nodes, halting all further frame exchanges in said first communication channel to quiet said first communication channel during the duration of the channel-switch time;
• (d) determining, in a second node of said at least two wireless nodes, that said first management frame including said CSAE was not received by a first node of said at least two wireless nodes;
• and
• (e) re-transmitting, in response to said determination, said first management frame including said CSAE from said second node of said at least two wireless nodes that received said first management frame including said CSAE.

A system for switching at least two wireless nodes of a plurality of wireless nodes located within the coverage area of a basic-service set (BSS1) or infrastructure-basic-service set (IBSS) in a wireless-local-area network (WLAN) from a first communication channel to a second communication channel, the system comprising:

• means for determining whether said second communication channel to be used by said at least two wireless nodes is needed;
• means for broadcasting, by a source node, a management frame including a channel switch announcement element (CSAE) to said at least two wireless nodes when it is determined that said second communication channel is needed, said management frame including said CSAE including a channel-switch time and a second communication channel identifier;
• means for switching, at each of said at least two wireless nodes receiving said management frame including said CSAE, from said first communication channel to said second communication channel at the expiration of a countdown time corresponding to said channel-switch time, wherein said channel-switch time is independent of the beacon interval;
• means for determining, at a second node of said at least two wireless nodes, that said management frame including said CSAE was not received by a first node of said at least two wireless nodes;
• and
• means for re-transmitting said management frame including said CSAE from the second node of said at least two wireless nodes that received said management frame including said CSAE.

A system for switching at least two wireless nodes of a plurality of wireless nodes located within the coverage area of a basic-service set (BSS) or infrastructure-basic-service set (IBSS) in a wireless-local-area network (WLAN) from a first communication channel to a second communication channel, the system comprising:

• means for determining whether said second communication channel to be used by said at least two wireless nodes is needed;
• means for broadcasting, by a source node, a first management frame including a channel switch announcement element (CSAE) to said at least two wireless nodes when it is determined that said second communication channel is needed, said CSAE including a channel-switch time and a second communication channel identifier;
• means for halting all further frame exchanges in said first communication channel to quiet said first communication channel upon receiving said broadcasted first management frame including said CSAE at said at least two wireless nodes;
• means for determining, at a second of node of said at least two wireless nodes, that said first management frame including said CSAE was not received by a first node of said at least two wireless nodes;
• and
• means for re-transmitting said first management frame including said CSAE from the second node of said at least two wireless nodes that received said first management frame including said CSAE.