Power control method in a wireless communication system
First Claim
1. A method of operating a wireless local area network including a plurality of stations (12) utilizing a common wireless communication channel, said stations communicating through the transmission of information packets (80) having an adjustable transmit power level, said stations employing a CSMA/CA (carrier sense multiple access with collision avoidance) protocol wherein a station desiring access to the transmission medium will first sense the medium to determine whether there is a carrier signal present higher than a predetermined defer threshold value and will defer its transmission until the medium is sensed to be available, said method comprising the steps of:
- providing, in each transmitted information packet (80) a transmit power level value (92) representing the power level at which the packet (80) is transmitted;
measuring a receive power level at which a transmitted information packet (80) is received;
dynamically adjusting the power level of information packets (80) transmitted between any two stations (12), in dependence on the difference between said transmit power level and said receive power level for said two stations; and
dynamically adjusting the defer threshold value for transmissions between said any two stations (12), in dependence on the difference between said transmit power level and said receive power level for said two stations.
5 Assignments
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Accused Products
Abstract
A wireless local area network (10) including a plurality of stations (12) utilizes dynamic transmit power level control such that only the power level needed for reliable transmission to a particular station (12) is utilized. Each transmitted information packet (80) contains a byte (92) representing the power level at which the packet (80) was transmitted. The power level at which the packet (80) is received is measured and a path attenuation value is calculated, averaged over a plurality of packets and utilized, together with a measured interference level also transmitted in the packet (80), to determined a transmit power level for that path. Also determined is an associated defer threshold level. The transmit power levels and associated defer threshold levels are stored in a table (270).
84 Citations
6 Claims
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1. A method of operating a wireless local area network including a plurality of stations (12) utilizing a common wireless communication channel, said stations communicating through the transmission of information packets (80) having an adjustable transmit power level, said stations employing a CSMA/CA (carrier sense multiple access with collision avoidance) protocol wherein a station desiring access to the transmission medium will first sense the medium to determine whether there is a carrier signal present higher than a predetermined defer threshold value and will defer its transmission until the medium is sensed to be available, said method comprising the steps of:
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providing, in each transmitted information packet (80) a transmit power level value (92) representing the power level at which the packet (80) is transmitted; measuring a receive power level at which a transmitted information packet (80) is received; dynamically adjusting the power level of information packets (80) transmitted between any two stations (12), in dependence on the difference between said transmit power level and said receive power level for said two stations; and dynamically adjusting the defer threshold value for transmissions between said any two stations (12), in dependence on the difference between said transmit power level and said receive power level for said two stations.
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2. A method of operating a wireless local area network including a plurality of stations (12) utilizing a common wireless communication channel, said stations communicating through the transmission of information packets (80) having an adjustable transmit power level, said stations employing a CSMA/CA (carrier sense multiple access with collision avoidance) protocol wherein a station desiring access to the transmission medium will first sense the medium to determine whether there is a carrier signal present higher than a predetermined defer threshold value and will defer its transmission until the medium is sensed to be available, said method comprising the step of:
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providing, in each transmitted information packet (80) a transmit power value portion (92) representing the power level at which the packet (80) is transmitted; dynamically adjusting the power level of information packets (80) transmitted over a signal path between any two stations (12), in dependence on the signal path between said stations (12); and dynamically adjusting the defer threshold value for transmissions between said any two stations 12, in dependence on the signal path between said stations (12); and said step of dynamically adjusting the power level of information packets transmitted between any two stations including the steps of; measuring a receive power level at which a transmitted information packet (80) is received; and subtracting said receive power level from the transmit power level contained in said packet to provide an attenuation value for the signal path between said two stations (12). - View Dependent Claims (3, 4, 5, 6)
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Specification