Method for a simple 802.11e HCF implementation
First Claim
1. A method for controlling channel access by an access point, the access point comprising a Hybrid Coordinator servicing an Enhanced Distributed Coordination Function transmit queue and a strict priority transmit queue, the steps for the Hybrid Coordinator comprising:
- determining whether a sufficient resource is available for an uplink flow, the upstream flow having a periodic service interval;
admitting the upstream flow for a station responsive to determining the sufficient resource is available;
starting a service timer to establish a polling interval for sending a poll transmission to the station to retrieve an uplink frame for the upstream flow, the polling interval corresponding to the periodic service interval for the uplink flow;
inserting the poll transmission into the strict priority transmit queue responsive to the service timer expiring;
gaining control of a channel using a higher priority access than any other wireless device in communication with the access point;
sending the poll transmission from the strict priority transmit queue prior to servicing the Enhanced Distributed Coordination Function transmit queue, wherein the poll transmission comprises data representative of a fixed amount of time for reserving the channel to receive the uplinked frame; and
reclaiming the channel for a portion of the fixed amount of time after sending the poll transmission, wherein reclaiming the channel comprises waiting for a response to the poll for a predefined time period, and sending a frame that cancels the channel reservation for the portion of the time period responsive to not receiving a response to the poll during the predefined time period;
wherein the frame contains data that reduces the channel reservation in other stations.
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Accused Products
Abstract
A Hybrid Coordination Function (HCF) implementation wherein an access point'"'"'s existing (E)DCF transmit queues are augmented by at least one strict priority HCF transmit queue. The HCF queues are only used to schedule downlink data and CF-Poll transmissions are used for admitted downlink flows and for uplink flows. The 802.1D user priority value is used to select the HCF queue for an admitted flow. The strict priority HCF transmit queues are always serviced first, in priority order before any other (E)DCF transmit queue. The channel is considered busy to (E)DCF transmit queues while the strict priority queues are being serviced. An admissions control mechanism is used to control data flows and prevents the strict priority traffic from starving (E)DCF traffic. A single, simple AP scheduler is used for scheduling both polling times and station wakeup times.
33 Citations
46 Claims
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1. A method for controlling channel access by an access point, the access point comprising a Hybrid Coordinator servicing an Enhanced Distributed Coordination Function transmit queue and a strict priority transmit queue, the steps for the Hybrid Coordinator comprising:
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determining whether a sufficient resource is available for an uplink flow, the upstream flow having a periodic service interval; admitting the upstream flow for a station responsive to determining the sufficient resource is available; starting a service timer to establish a polling interval for sending a poll transmission to the station to retrieve an uplink frame for the upstream flow, the polling interval corresponding to the periodic service interval for the uplink flow; inserting the poll transmission into the strict priority transmit queue responsive to the service timer expiring; gaining control of a channel using a higher priority access than any other wireless device in communication with the access point; sending the poll transmission from the strict priority transmit queue prior to servicing the Enhanced Distributed Coordination Function transmit queue, wherein the poll transmission comprises data representative of a fixed amount of time for reserving the channel to receive the uplinked frame; and reclaiming the channel for a portion of the fixed amount of time after sending the poll transmission, wherein reclaiming the channel comprises waiting for a response to the poll for a predefined time period, and sending a frame that cancels the channel reservation for the portion of the time period responsive to not receiving a response to the poll during the predefined time period; wherein the frame contains data that reduces the channel reservation in other stations. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. A method for controlling channel access by an access point, the access point comprising a Hybrid Coordinator servicing an Enhanced Distributed Coordination Function transmit queue and a strict priority transmit queue, the steps for the Hybrid Coordinator comprising:
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determining whether a sufficient resource is available for an uplink flow, the upstream flow having a periodic service interval; admitting the upstream flow for a station responsive to determining the sufficient resource is available; starting a service timer to establish a polling interval for sending a poll transmission to the station to retrieve an uplink frame for the upstream flow, the polling interval corresponding to the periodic service interval for the uplink flow; inserting the poll transmission into the strict priority transmit queue responsive to the service timer expiring; gaining control of a channel using a higher priority access than any other wireless device in communication with the access point; sending the poll transmission from the strict priority transmit queue prior to servicing the Enhanced Distributed Coordination Function transmit queue, wherein the poll transmission comprises data representative of a fixed amount of time for reserving the channel to receive the uplinked frame; and reclaiming the channel for a portion of the fixed amount of time after sending the poll transmission, wherein reclaiming the channel comprises receiving data from the station indicating that sending of the uplink frame is completed while the channel is still reserved for receiving uplinked frame, and sending a frame that cancels the channel reservation for the portion of the time period responsive to not receiving a response to the poll during the predefined time period. - View Dependent Claims (35, 36, 37)
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38. An access point, comprising:
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a Hybrid Coordinator servicing an Enhanced Distributed Coordination Function transmit queue and a strict priority transmit queue; wherein the Hybrid Coordinator is configured to determine whether a sufficient resource is available for an uplink flow, the upstream flow having a periodic service interval; wherein the Hybrid Coordinator is configured to admit the upstream flow for a station responsive to determining the sufficient resource is available; wherein the Hybrid Coordinator is configured to start a service timer to establish a polling interval for sending a poll transmission to the station to retrieve an uplink frame for the upstream flow, the polling interval corresponding to the periodic service interval for the uplink flow; wherein the Hybrid Coordinator is configured to insert the poll transmission into the strict priority transmit queue responsive to the service timer expiring; wherein the Hybrid Coordinator is configured to gain control of a channel using a higher priority access than any other wireless device in communication with the access point; wherein the Hybrid Coordinator is configured to send the poll transmission from the strict priority transmit queue prior to servicing the Enhanced Distributed Coordination Function transmit queue, wherein the poll transmission comprises data representative of a fixed amount of time for reserving the channel to receive the uplinked frame; wherein the Hybrid Coordinator is configured to reclaim the channel for a portion of the fixed amount of time after sending the poll transmission, wherein reclaiming the channel comprises waiting for a response to the poll for a predefined time period, and sending a frame that cancels the channel reservation for the portion of the time period responsive to not receiving a response to the poll during the predefined time period; and wherein the frame contains data that reduces the channel reservation in other stations. - View Dependent Claims (39, 40, 41, 42)
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43. An access point, the access point, comprising:
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a Hybrid Coordinator servicing an Enhanced Distributed Coordination Function transmit queue and a strict priority transmit queue; wherein the Hybrid Coordinator is configured to determine whether a sufficient resource is available for an uplink flow, the upstream flow having a periodic service interval; wherein the Hybrid Coordinator is configured to admit the upstream flow for a station responsive to determining the sufficient resource is available; wherein the Hybrid Coordinator is configured to start a service timer to establish a polling interval for sending a poll transmission to the station to retrieve an uplink frame for the upstream flow, the polling interval corresponding to the periodic service interval for the uplink flow; wherein the Hybrid Coordinator is configured to insert the poll transmission into the strict priority transmit queue responsive to the service timer expiring; wherein the Hybrid Coordinator is configured to gain control of a channel using a higher priority access than any other wireless device in communication with the access point; wherein the Hybrid Coordinator is configured to send the poll transmission from the strict priority transmit queue prior to servicing the Enhanced Distributed Coordination Function transmit queue, wherein the poll transmission comprises data representative of a fixed amount of time for reserving the channel to receive the uplinked frame; wherein the Hybrid Coordinator is configured to reclaiming the channel for a portion of the fixed amount of time after sending the poll transmission, wherein reclaiming the channel comprises receiving data from the station indicating that sending of the uplink frame is completed while the channel is still reserved for receiving uplinked frame, and sending a frame that cancels the channel reservation for the portion of the time period responsive to not receiving a response to the poll during the predefined time period. - View Dependent Claims (44, 45, 46)
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Specification