Radio resource management (RRM) is the system level management of

co-channel interference Co-channel interference or CCI is crosstalk from two different radio transmitters using the same channel. Co-channel interference can be caused by many factors from weather conditions to administrative and design issues. Co-channel interference ...

, radio resources, and other radio transmission characteristics in

wireless communication Wireless communication (or just wireless, when the context allows) is the transfer of information between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most ...

systems, for example

cellular network 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 ...

wireless local area network A wireless LAN (WLAN) is a wireless computer network that links two or more devices using wireless communication to form a local area network (LAN) within a limited area such as a home, school, computer laboratory, campus, or office buildi ...

s, wireless sensor systems, and radio

broadcasting network A terrestrial network (or broadcast network in the United States) is a group of radio stations, television stations, or other electronic media outlets, that form an agreement to air, or broadcast, content from a centralized source. For example, ...

s. RRM involves strategies and algorithms for controlling parameters such as transmit power, user allocation, beamforming, data rates, handover criteria, modulation scheme, error coding scheme, etc. The objective is to utilize the limited radio-frequency spectrum resources and radio network infrastructure as efficiently as possible. RRM concerns multi-user and multi-cell network capacity issues, rather than the point-to-point channel capacity. Traditional telecommunications research and education often dwell on

channel coding In computing, telecommunication, information theory, and coding theory, an error correction code, sometimes error correcting code, (ECC) is used for controlling errors in data over unreliable or noisy communication channels. The central idea is ...

and

source coding In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compression ...

with a single user in mind, but when several users and adjacent base stations share the same frequency channel it may not be possible to achieve the maximum channel capacity. Efficient dynamic RRM schemes may increase the system spectral efficiency by an

order of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...

, which often is considerably more than what is possible by introducing advanced channel coding and source coding schemes. RRM is especially important in systems limited by co-channel interference rather than by noise, for example cellular systems and

broadcast network A terrestrial network (or broadcast network in the United States) is a group of radio stations, television stations, or other electronic media outlets, that form an agreement to air, or broadcast, content from a centralized source. For example, ...

s homogeneously covering large areas, and

wireless 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 business installations avoid the costly process of introducing c ...

s consisting of many adjacent access points that may

reuse Reuse is the action or practice of using an item, whether for its original purpose (conventional reuse) or to fulfill a different function ( creative reuse or repurposing). It should be distinguished from recycling, which is the breaking down of u ...

the same channel frequencies. The cost for deploying a wireless network is normally dominated by base station sites (real estate costs, planning, maintenance, distribution network, energy, etc.) and sometimes also by frequency license fees. So, the objective of radio resource management is typically to maximize the system spectral efficiency in ''bit/s/Hz/area unit'' or ''Erlang/MHz/site'', under some kind of user fairness constraint, for example, that the

grade of service In telecommunication engineering, and in particular teletraffic engineering, the quality of voice service is specified by two measures: the grade of service (GoS) and the quality of service (QoS). Grade of service is the probability of a call in a ...

should be above a certain level. The latter involves covering a certain area and avoiding outage due to

noise Noise is unwanted sound considered unpleasant, loud or disruptive to hearing. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrations through a medium, such as air or water. The difference arise ...

, attenuation caused by path losses,

fading In wireless communications, fading is variation of the attenuation of a signal with various variables. These variables include time, geographical position, and radio frequency. Fading is often modeled as a random process. A fading channel is a ...

caused by shadowing and multipath,

Doppler shift The Doppler effect or Doppler shift (or simply Doppler, when in context) is the change in frequency of a wave in relation to an observer who is moving relative to the wave source. It is named after the Austrian physicist Christian Doppler, who d ...

and other forms of

distortion In signal processing, distortion is the alteration of the original shape (or other characteristic) of a signal. In communications and electronics it means the alteration of the waveform of an information-bearing signal, such as an audio signal ...

. The grade of service is also affected by blocking due to

admission control Admission control is a validation process in communication systems where a check is performed before a connection is established to see if current resources are sufficient for the proposed connection. Applications For some applications, dedicated ...

scheduling starvation A schedule or a timetable, as a basic time-management tool, consists of a list of times at which possible tasks, events, or actions are intended to take place, or of a sequence of events in the chronological order in which such things are i ...

or inability to guarantee

quality of service Quality of service (QoS) is the description or measurement of the overall performance of a service, such as a telephony or computer network, or a cloud computing service, particularly the performance seen by the users of the network. To quantitat ...

that is requested by the users. While classical radio resource managements primarily considered the allocation of time and frequency resources (with fixed spatial reuse patterns), recent multi-user MIMO techniques enables adaptive resource management also in the spatial domain. In cellular networks, this means that the fractional frequency reuse in the

GSM The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...

standard has been replaced by a universal frequency reuse in LTE standard.

Static radio resource management

Static RRM involves manual as well as computer-aided fixed

cell planning Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...

radio network planning Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitt ...

. Examples: *

Frequency allocation Frequency allocation (or spectrum allocation or spectrum management) is the allocation and regulation of the electromagnetic spectrum into radio frequency bands, normally done by governments in most countries. Because radio propagation does no ...

band plan A frequency plan, bandplan, band plan or wavelength plan is a plan for using a particular band of radio frequencies, that are a portion of the electromagnetic spectrum. Each frequency plan defines the frequency range to be included, how channels a ...

s decided by standardization bodies, by national frequency authorities and in frequency resource auctions. * Deployment of base station sites (or broadcasting transmitter site) * Antenna heights * Channel frequency plans * Sector antenna directions * Selection of

modulation In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the ''carrier signal'', with a separate signal called the ''modulation signal'' that typically contains informatio ...

and

parameters * Base station antenna

space diversity Antenna diversity, also known as space diversity or spatial diversity, is any one of several wireless diversity schemes that uses two or more antennas to improve the quality and reliability of a wireless link. Often, especially in urban and ind ...

, for example ** Receiver

micro diversity Micro may refer to: Measurement * micro- (μ), a metric prefix denoting a factor of 10−6 Places * Micro, North Carolina, town in U.S. People * DJ Micro, (born Michael Marsicano) an American trance DJ and producer *Chii Tomiya (都宮ちい ...

using antenna combining ** Transmitter macro diversity such as OFDM single frequency networks (SFN) Static RRM schemes are used in many traditional wireless systems, for example 1G and 2G cellular systems, in today's wireless local area networks and in non-cellular systems, for example broadcasting systems. Examples of static RRM schemes are: * Circuit mode communication using

FDMA Frequency-division multiple access (FDMA) is a channel access method used in some multiple-access protocols. FDMA allows multiple users to send data through a single communication channel, such as a coaxial cable or microwave beam, by dividing ...

and TDMA. *

Fixed channel allocation Fixed may refer to: * ''Fixed'' (EP), EP by Nine Inch Nails * ''Fixed'', an upcoming 2D adult animated film directed by Genndy Tartakovsky * Fixed (typeface), a collection of monospace bitmap fonts that is distributed with the X Window System * ...

(FCA) * Static

handover In cellular telecommunications, handover, or handoff, is the process of transferring an ongoing call or data session from one channel connected to the core network to another channel. In satellite communications it is the process of transfe ...

criteria

Dynamic radio resource management

Dynamic RRM schemes adaptively adjust the radio network parameters to the traffic load, user positions, user mobility, quality of service requirements, base station density, etc. Dynamic RRM schemes are considered in the design of wireless systems, in view to minimize expensive manual cell planning and achieve "tighter"

frequency reuse 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 ...

patterns, resulting in improved system spectral efficiency. Some schemes are centralized, where several base stations and access points are controlled by a

Radio Network Controller The Radio Network Controller (RNC) is a governing element in the UMTS radio access network (UTRAN) and is responsible for controlling the Node Bs that are connected to it. The RNC carries out radio resource management, some of the mobility managem ...

(RNC). Others are distributed, either autonomous algorithms in

mobile station A mobile station (MS) comprises all user equipment and computer software, software needed for communication with a Cellular network, mobile network. The term refers to the global system connected to the mobile network, i.e. a mobile phone or mob ...

s, base stations or wireless access points, or coordinated by exchanging information among these stations. Examples of dynamic RRM schemes are: *

Power control Power control, broadly speaking, is the intelligent selection of transmitter power output in a communication system to achieve good performance within the system.Guowang Miao, Jens Zander, Ki Won Sung, and Ben Slimane, Fundamentals of Mobile Data ...

algorithms *

Precoding Precoding is a generalization of beamforming to support multi-stream (or multi-layer) transmission in multi-antenna wireless communications. In conventional single-stream beamforming, the same signal is emitted from each of the transmit antennas ...

algorithms *

Link adaptation Link adaptation, comprising adaptive coding and modulation (ACM) and others (such as Power Control), is a term used in wireless communications to denote the matching of the modulation, coding and other signal and protocol parameters to the condit ...

algorithms *

Dynamic Channel Allocation In radio resource management for wireless and cellular networks, channel allocation schemes allocate bandwidth and communication channels to base stations, access points and terminal equipment. The objective is to achieve maximum system spectral ef ...

(DCA) or Dynamic Frequency Selection (DFS) algorithms, allowing "cell breathing" * Traffic adaptive

criteria, allowing " cell breathing" * Re-use partitioning *

Adaptive filter An adaptive filter is a system with a linear filter that has a transfer function controlled by variable parameters and a means to adjust those parameters according to an optimization algorithm. Because of the complexity of the optimization algorit ...

ing ** Single Antenna Interference Cancellation (SAIC) * Dynamic

diversity scheme In telecommunications, a diversity scheme refers to a method for improving the reliability of a message signal by using two or more Channel (communications), communication channels with different characteristics. Diversity is mainly used in radio ...

s, for example ** Soft handover **

Dynamic single-frequency networks {{Unreferenced, date=January 2008 Dynamic Single Frequency Networks (DSFN) is a transmitter macrodiversity technique for OFDM based cellular networks. DSFN is based on the idea of single frequency networks (SFN), which is a group of radio transmi ...

(DSFN) **

Phased array antenna In antenna theory, a phased array usually means an electronically scanned array, a computer-controlled array of antennas which creates a beam of radio waves that can be electronically steered to point in different directions without moving th ...

with ***

beamforming Beamforming or spatial filtering is a signal processing technique used in sensor arrays for directional signal transmission or reception. This is achieved by combining elements in an antenna array in such a way that signals at particular angles e ...

***

Multiple-input multiple-output communications In radio, multiple-input and multiple-output, or MIMO (), is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. MIMO has become an essential element of wi ...

(MIMO) ***

Space-time coding In physics, spacetime is a mathematical model that combines the three dimensions of space and one dimension of time into a single four-dimensional manifold. Spacetime diagrams can be used to visualize relativistic effects, such as why diffe ...

Admission control Admission control is a validation process in communication systems where a check is performed before a connection is established to see if current resources are sufficient for the proposed connection. Applications For some applications, dedicated ...

Dynamic bandwidth allocation Dynamic bandwidth allocation is a technique by which traffic bandwidth in a shared telecommunications medium can be allocated on demand and fairly between different users of that bandwidth. This is a form of bandwidth management, and is essentiall ...

using resource reservation

multiple access In telecommunications and computer networks, a channel access method or multiple access method allows more than two terminals connected to the same transmission medium to transmit over it and to share its capacity. Examples of shared physical med ...

schemes or

statistical multiplexing Statistical multiplexing is a type of communication link sharing, very similar to dynamic bandwidth allocation (DBA). In statistical multiplexing, a communication channel is divided into an arbitrary number of variable bitrate digital channels or ...

, for example

Spread spectrum In telecommunication and radio communication, spread-spectrum techniques are methods by which a signal (e.g., an electrical, electromagnetic, or acoustic signal) generated with a particular bandwidth is deliberately spread in the frequency dom ...

and/or

packet radio In digital radio, packet radio is the application of packet switching techniques to digital radio communications. Packet radio uses a packet switching protocol as opposed to circuit switching or message switching protocols to transmit digital dat ...

* Channel-dependent scheduling, for instance **

Max-min fair scheduling In communication networks, multiplexing and the division of scarce resources, max-min fairness is said to be achieved by an allocation if and only if the allocation is feasible and an attempt to increase the allocation of any participant necessari ...

using for example fair queuing ** Proportionally fair scheduling using for example

weighted fair queuing Weighted fair queueing (WFQ) is a network scheduling algorithm. WFQ is both a packet-based implementation of the generalized processor sharing (GPS) policy, and a natural extension of fair queuing (FQ). Whereas FQ shares the link's capacity in ...

Maximum throughput scheduling {{Short description, Procedure for scheduling data packets in a packet switched best-effort network Maximum throughput scheduling is a procedure for scheduling data packets in a packet-switched best-effort network, typically a wireless network, in ...

(gives low

due to starvation) ** Dynamic packet assignment (DPA) ** Packet and Resource Plan Scheduling (PARPS) schemes *

Mobile ad hoc network A wireless ad hoc network (WANET) or mobile ad hoc network (MANET) is a decentralized type of wireless network. The network is ad hoc because it does not rely on a pre-existing infrastructure, such as routers in wired networks or access points ...

s using multihop communication *

Cognitive radio A cognitive radio (CR) is a radio that can be programmed and configured dynamically to use the best wireless channels in its vicinity to avoid user interference and congestion. Such a radio automatically detects available channels in wireless spec ...

Green communication Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 Nanometre, nm. In subtractive color systems, used in painting and color printing, it is created by ...

* QoS-aware RRM *

Femtocells In telecommunications, a femtocell is a small, low-power cellular base station, typically designed for use in a home or small business. A broader term which is more widespread in the industry is ''small cell'', with ''femtocell'' as a subset. It c ...

Inter-cell radio resource management

Future networks like the LTE standard (defined by 3GPP) are designed for a frequency reuse of one. In such networks, neighboring cells use the same frequency spectrum. Such standards exploit Space Division Multiple Access (SDMA) and can thus be highly efficient in terms of spectrum, but required close coordination between cells to avoid excessive inter-cell interference. Like in most cellular system deployments, the overall system spectral efficiency is not range limited or noise limited, but interference limited. Inter-cell radio resource management coordinates resource allocation between different cell sites by using multi-user MIMO techniques. There are various means of

inter-cell interference coordination In mobile telecommunications, inter-cell interference coordination (ICIC) techniques apply restrictions to the radio resource management (RRM) block, improving favorable channel conditions across subsets of users that are severely impacted by the ...

(ICIC) already defined in the standard.

, coordinated scheduling, multi-site MIMO or joint multi-cell precoding are other examples for inter-cell radio resource management.

References

{{DEFAULTSORT:Radio Resource Management Radio technology

Static radio resource management

Dynamic radio resource management

Inter-cell radio resource management

See also

References