Optimisation of transmission parameters of access points in wireless networks
First Claim
1. A method of optimising radio frequency field strength in a radio communications network, the network comprising a wireless access point arranged to transmit a signal at a configurable power level, the radio frequency field strength being dependent on the transmitted signal power level, and the network further comprising a plurality of sensors, each sensor having a defined location with respect to a designated zone of wireless coverage, the method comprising:
- receiving at each sensor the signal transmitted from the wireless access point;
measuring the power of said received signal at each sensor, the received signal power being dependent on the radio frequency field strength at the location of the sensor; and
controlling transmitted power from the wireless access point in dependence on a difference between said power measured at each sensor and an expected level of power at each sensor, said expected level of power at each sensor being a function of the location of each sensor with respect to said designated zone of wireless coverage;
controlling the transmitted power from the wireless access point in dependence on minimizing an objective function, in which the objective function comprises contributions from two or more sensors selected from a group comprising;
a first sensor at the edge of the designated zone of coverage, the contribution of the first sensor having a characteristic that that increases with increasing as deviation from a target received signal power;
a second sensor, the second sensor being within the designated zone of coverage, the contribution of the second sensor having a characteristic that decreases with increasing received signal power up to the target received signal power and that is substantially constant when the signal power is above the target signal power; and
a third sensor, the third sensor being outside the designated zone of coverage, the contribution of the third sensor having a characteristic that increases with increasing received signal power above to a threshold of received signal power and that is substantially constant when the signal power is below the threshold, the threshold being lower than the target received power,in which at least one of said sensors is located at the edge of or outside the designated zone of wireless coverage.
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Accused Products
Abstract
In a wireless network comprising access points deployed within a designated zone of coverage, the radio frequency field strength resulting from radiation from the access points is optimised as a function of location by means of control of the transmission power and/or radiation pattern of the access points in response to measurements from sensors at defined locations that measure received signal power, the received power being related to radio frequency field strength. Sensors may be deployed within the designated zone of coverage, at the edge of the zone and/or outside the zone and optimization of the transmission parameters of the access points in terms of transmission power and/or radiation pattern is carried out taking into account the location of the sensors in addition to the received power at the sensors.
11 Citations
16 Claims
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1. A method of optimising radio frequency field strength in a radio communications network, the network comprising a wireless access point arranged to transmit a signal at a configurable power level, the radio frequency field strength being dependent on the transmitted signal power level, and the network further comprising a plurality of sensors, each sensor having a defined location with respect to a designated zone of wireless coverage, the method comprising:
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receiving at each sensor the signal transmitted from the wireless access point; measuring the power of said received signal at each sensor, the received signal power being dependent on the radio frequency field strength at the location of the sensor; and controlling transmitted power from the wireless access point in dependence on a difference between said power measured at each sensor and an expected level of power at each sensor, said expected level of power at each sensor being a function of the location of each sensor with respect to said designated zone of wireless coverage; controlling the transmitted power from the wireless access point in dependence on minimizing an objective function, in which the objective function comprises contributions from two or more sensors selected from a group comprising; a first sensor at the edge of the designated zone of coverage, the contribution of the first sensor having a characteristic that that increases with increasing as deviation from a target received signal power; a second sensor, the second sensor being within the designated zone of coverage, the contribution of the second sensor having a characteristic that decreases with increasing received signal power up to the target received signal power and that is substantially constant when the signal power is above the target signal power; and a third sensor, the third sensor being outside the designated zone of coverage, the contribution of the third sensor having a characteristic that increases with increasing received signal power above to a threshold of received signal power and that is substantially constant when the signal power is below the threshold, the threshold being lower than the target received power, in which at least one of said sensors is located at the edge of or outside the designated zone of wireless coverage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A radio communications network comprising a wireless access point transmitting a signal and a plurality of sensors, each sensor having a defined location with respect to a designated zone of wireless coverage, the network further comprising:
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a receiver at each sensor for receiving the signal transmitted from the wireless access point; a detector at each sensor for measuring the power of said received signal, the received signal power being dependent on the radio frequency field strength at the location of the sensor; and a radio network controller for controlling transmitted power from the wireless access point in dependence on a difference between said power measured at each sensor and an expected level of power at each sensor, said expected level of power at each sensor being a function of the location of each sensor with respect to a designated zone of coverage, wherein the radio network controller further controls the transmitted power from the wireless access point in dependence on minimizing an objective function, in which the objective function comprises contributions from two or more sensors selected from a group comprising; a first sensor at the edge of the designated zone of coverage, the contribution of the first sensor having a characteristic that that increases with increasing as deviation from a target received signal power. a second sensor, the second sensor being within the designated zone of coverage, the contribution of the second sensor having a characteristic that decreases with increasing received signal power up to the target received signal power and that is substantially constant when the signal power is above the target signal power; and a third sensor, the third sensor being outside the designated zone of coverage, the contribution of the third sensor having a characteristic that increases with increasing received signal power above to a threshold of received signal power and that is substantially constant when the signal power is below the threshold, the threshold being lower than the target received power, wherein at least one of said sensors is located at the edge of or outside the designated zone of wireless coverage, whereby to optimise radio frequency field strength. - View Dependent Claims (14, 15, 16)
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Specification