WLAN scheduler
A system comprises a plurality of wireless stations for exchanging data over a wireless network and a coordinator station such an access point. The coordinator station receives a request for a traffic specification from one of the wireless stations. The traffic request comprises a traffic parameter ( 202 ) representative of the traffic specification. The coordinator station runs an acceptance algorithm ( 226 ) to determine if the request can be met based on the parameter and a current traffic schedule based on other previously granted traffic requests ( 228 ). If the new request can be accommodated, a traffic scheduler thereafter generates a new traffic schedule ( 232, 234 ) using the Cyclic Executive Model ( 230 ).
1. A method for scheduling traffic in a wireless local area network (WLAN) comprising a coordinator station and a plurality of wireless stations, the method comprising:
receiving, by the coordinator station, from one of the wireless stations on the WLAN, a new traffic request including traffic specification parameters;
running a traffic request acceptance algorithm based on the traffic specification parameters and other previously received traffic requests;
if the new traffic request is accepted, using a Cyclic Executive Model to generate a new periodic traffic schedule table with a minor cycle time and a major cycle time to reflect the new traffic request, wherein:
the traffic schedule table comprises a plurality of entries corresponding to accepted traffic requests, each entry comprising an address of a polled station that will be granted a transmission opportunity and a time slot comprising a poll starting time and a variable duration, and
at least two entries in the traffic schedule table correspond to the same traffic request.
2. The method of claim 1 , further comprising:
polling a station during a contention-free period as indicated in the new traffic schedule table by granting the station a transmission opportunity.
3. The method of claim 1 , wherein the entry of the new traffic schedule table comprises a duration of a contention-free period or a duration of a contention period.
4. The method of claim 1 , wherein the new traffic schedule table is determined from a current traffic schedule table derived from the other traffic requests previously received from other stations; and splitting, a particular traffic request into at least two entries.
5. A wireless local area network (WLAN) scheduler comprising:
a receiver for receiving a traffic request for a traffic specification over a wireless local area network (WLAN) from a wireless station in the network, the traffic request comprising traffic parameters representative of the traffic specification;
an acceptance control module configured to determine if the request can be accommodated based on the parameters and a previously determined traffic schedule table;
a traffic scheduler configured for generating a new periodic traffic schedule table with a minor cycle time and a major cycle time from the parameters and the previously determined traffic schedule table using a Cyclic Executive Model, wherein:
the traffic schedule table comprises a plurality of entries corresponding to accepted traffic requests, each entry comprising an address of a polled station that will be granted a transmission opportunity and a time slot comprising a poll starting time and a variable duration, and
at least two entries in the traffic schedule table correspond to the same traffic request.
6. A system comprising:
a plurality of wireless stations for exchanging data over a wireless local area network (WLAN);
a coordinator station comprising:
a receiver for receiving a request for a traffic specification from one of the wireless stations, the request comprising a traffic parameter representative of the traffic specification;
an acceptance control module configured to determine if the request can be accommodated based on the parameter and a previously determined traffic schedule;
a traffic scheduler configured to generate a new periodic traffic schedule with a minor cycle time and a major cycle time from the parameters and the previously determined traffic schedule using a Cyclic Executive Model, wherein:
the traffic schedule table comprises a plurality of entries corresponding to accepted traffic requests, each entry comprising an address of a polled station that will be granted a transmission opportunity and a time slot comprising a poll starting time and a variable duration, and
at least two entries in the traffic schedule table correspond to the same traffic request.
7. The method according to claim 1 , wherein said at least two entries that correspond to the same traffic request comprise two entries of different duration.
8. The method according to claim 7 wherein the two entries of different duration are adjacent each other.
9. The method according to claim 1 , further comprising deleting an entry for a particular wireless station if no data is transmitted after no transmission occurs for a predetermined number of transmission opportunities (TXOP).
10. The method according to claim 1 , wherein the traffic schedule table further comprises an entry associated with the coordinator station.
11. The method according to claim 1 , wherein the new traffic request corresponds to at least two entries.
12. The method according to claim 1 , wherein a previous traffic request corresponds to at least two entries.
13. The method according to claim 1 , wherein each entry further comprises remarks indicating an action to be taken by the coordinator station.