Power control, broadly speaking, is the intelligent selection of

transmitter power output In radio transmission, transmitter power output (TPO) is the actual amount of power (in watts) of radio frequency (RF) energy that a transmitter produces at its output. This is not the amount of power that a radio station reports as its power, as i ...

in a

communication system A communications system or communication system is a collection of individual telecommunications networks, transmission systems, relay stations, tributary stations, and terminal equipment usually capable of interconnection and interoperati ...

to achieve good performance within the system.

Guowang Miao Guowang Miao is an associate professor at KTH Royal Institute of Technology, Sweden, working on design and optimization of wireless communications and networking and the author of ''Fundamentals of Mobile Data Networks'' and ''Energy and Spectrum ...

, Jens Zander, Ki Won Sung, and Ben Slimane, Fundamentals of Mobile Data Networks, Cambridge University Press, , 2016. The notion of "good performance" can depend on context and may include optimizing metrics such as link data rate, network capacity, outage probability, geographic

coverage Coverage may refer to: Filmmaking * Coverage (lens), the size of the image a lens can produce * Camera coverage, the amount of footage shot and different camera setups used in filming a scene * Script coverage, a short summary of a script, wri ...

and range, and life of the network and network devices. Power control algorithms are used in many contexts, including

cellular networks A cellular network or mobile network is a communication network where the link to and from end nodes is wireless. The network is distributed over land areas called "cells", each served by at least one fixed-location transceiver (typically thre ...

sensor networks Wireless sensor networks (WSNs) refer to networks of spatially dispersed and dedicated sensors that monitor and record the physical conditions of the environment and forward the collected data to a central location. WSNs can measure environmental c ...

wireless LAN A wireless LAN (WLAN) is a wireless computer network A wireless network is a computer network that uses wireless data connections between network nodes. Wireless networking is a method by which homes, telecommunications networks and bus ...

s, and

DSL Digital subscriber line (DSL; originally digital subscriber loop) is a family of technologies that are used to transmit digital data over telephone lines. In telecommunications marketing, the term DSL is widely understood to mean asymmetric dig ...

modems.

Transmit power control

Transmit power control is a technical mechanism used within some networking devices in order to prevent too much unwanted interference between different

wireless networks A wireless network is a computer network that uses wireless data connections between network nodes. Wireless networking is a method by which homes, telecommunications networks and business installations avoid the costly process of introducing c ...

(e.g. the owner's network and the neighbour's network). It is also essential component in case of cognitive radio networks deployed in a distributed fashion, aka distributed power control.F. Foukalas and T. Khatta
Distributed Power Control for Carrier Aggregation in Cognitive Heterogeneous 5G Cellular Networks
" CrownCom 2015: Cognitive Radio Oriented Wireless Networks, Oct.2015, pp 681-695 The network devices supporting this feature include

IEEE 802.11h IEEE 802.11h-2003, or simply 802.11h, refers to a 2003 amendment added to the IEEE 802.11 standard for Spectrum and Transmit Power Management Extensions. It addresses problems like interference with satellites and radar using the same 5 GHz ...

Wireless LAN A wireless LAN (WLAN) is a wireless computer network A wireless network is a computer network that uses wireless data connections between network nodes. Wireless networking is a method by which homes, telecommunications networks and bus ...

devices in the 5 GHz band compliant to the

IEEE 802.11a IEEE 802.11a-1999 or 802.11a was an amendment to the IEEE 802.11 wireless local network specifications that defined requirements for an orthogonal frequency-division multiplexing (OFDM) communication system. It was originally designed to support ...

. The idea of the mechanism is to automatically reduce the used transmission output power when other networks are within range. Reduced power means reduced interference problems and increased battery capacity. The power level of a single device can be reduced by 6 dB, which should result in an accumulated power level reduction (the sum of radiated power of all devices currently transmitting) of at least 3 dB (half of the power).

UMTS

Because of the interference in the WCDMA system, power control plays a very important role in the quality control for the different services in the UMTS system. Power control is executed 1500 times per second, whereas in the GSM system it is ~2 times per second.{{citation needed, date=March 2015

References

Radio resource management IEEE 802.11

Transmit power control

UMTS

See also

References