Tiered contention multiple access (TCMA): a method for priority-based shared channel access
First Claim
1. A method for transmitting a packet, the method comprising:
- determining, at a node having a buffer, an urgency class for the packet according to a schedule, wherein each of a plurality of urgency classes is assigned a plurality of differentiating parameters with values that are different from values of other urgency classes, the plurality of differentiating parameters comprising a backoff window for drawing an initial backoff counter for the packet and a persistence factor, wherein the persistence factor is different for each urgency class of the plurality of urgency classes, and wherein the persistence factor is to derive a subsequent backoff window having a range of values from which a subsequent backoff counter value for the packet is drawn randomly from the range of values upon a transmission retrial of the packet; and
transmitting, by the node, the packet in the urgency class before transmitting another packet of a lower urgency class.
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Accused Products
Abstract
Quality of Service (QoS) support is provided by means of a Tiered Contention Multiple Access (TCMA) distributed medium access protocol that schedules transmission of different types of traffic based on their service quality specifications. In one embodiment, a wireless station is supplied with data from a source having a lower QoS priority QoS(A), such as file transfer data. Another wireless station is supplied with data from a source having a higher QoS priority QoS(B), such as voice and video data. Each wireless station can determine the urgency class of its pending packets according to a scheduling algorithm. For example file transfer data is assigned lower urgency class and voice and video data is assigned higher urgency class. There are several urgency classes which indicate the desired ordering. Pending packets in a given urgency class are transmitted before transmitting packets of a lower urgency class.
139 Citations
20 Claims
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1. A method for transmitting a packet, the method comprising:
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determining, at a node having a buffer, an urgency class for the packet according to a schedule, wherein each of a plurality of urgency classes is assigned a plurality of differentiating parameters with values that are different from values of other urgency classes, the plurality of differentiating parameters comprising a backoff window for drawing an initial backoff counter for the packet and a persistence factor, wherein the persistence factor is different for each urgency class of the plurality of urgency classes, and wherein the persistence factor is to derive a subsequent backoff window having a range of values from which a subsequent backoff counter value for the packet is drawn randomly from the range of values upon a transmission retrial of the packet; and transmitting, by the node, the packet in the urgency class before transmitting another packet of a lower urgency class. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A non-transitory computer-readable medium storing a plurality of instructions which, when executed by a processor of a node having a buffer, cause the processor to perform operations for transmitting a packet, the operations comprising:
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determining an urgency class for the packet according to a schedule, wherein each of a plurality of urgency classes is assigned a plurality of differentiating parameters with values that are different from values of other urgency classes, the plurality of differentiating parameters comprising a backoff window for drawing an initial backoff counter for the packet and a persistence factor, wherein the persistence factor is different for each urgency class of the plurality of urgency classes, and wherein the persistence factor is to derive a subsequent backoff window having a range of values from which a subsequent backoff counter value for the packet is drawn randomly from the range of values upon a transmission retrial of the packet; and transmitting the packet in the urgency class before transmitting another packet of a lower urgency class.
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19. An apparatus for transmitting a packet, the apparatus comprising:
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a processor of a node; and a computer-readable medium storing a plurality of instructions which, when executed by the processor, cause the processor to perform operations, the operations comprising; determining an urgency class for the packet according to a schedule, wherein each of a plurality of urgency classes is assigned a plurality of differentiating parameters with values that are different from values of other urgency classes, the plurality of differentiating parameters comprising a backoff window for drawing an initial backoff counter for the packet and a persistence factor, wherein the persistence factor is different for each urgency class of the plurality of urgency classes, and wherein the persistence factor is to derive a subsequent backoff window having a range of values from which a subsequent backoff counter value for the packet is drawn randomly from the range of values upon a transmission retrial of the packet; and transmitting the packet in the urgency class before transmitting another packet of a lower urgency class. - View Dependent Claims (20)
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Specification