INTRODUCTIONMobile devices are getting smaller and smarterMobile devices are equipped with a limited amount of

battery powerNext-generation wireless standards should provide very

efficient power conservation mechanismsTwo advanced power conservation mechanisms, sleep and

idle modes were proposed and adopted in IEEE 802.16m3GPP LTE adopts a discontinuous reception mechanism for

power conservation in RRC_CONNECTED and RRC_IDLE states

WiMAXWorldwide Interoperability of Microwave Access

WiMAXWiMAX, also known as IEEE 802.16Uses 10-66 GHz frequency bands and provides data rates up

to 70 Mbps & above over distance of 50 kmUses a base station to establish the wireless connection to the

subscriber Communication between two or more WiMAX base stations

could be Point to Point/ Line of Sight & between the base station and the subscriber can be Point to Multi Point/ Non Line of Sight

3GPP LTE Third Generation Partnership Program (3GPP) Long Term

Evolution (LTE)developed to provide higher data rates, lower latencies,

wider spectrumLike other cellular technologies LTE uses OFDM as

multiplexing techniqueLTE uses wider spectrum, up to 20 MHz, to provide

compatibility with existing cellular technologies

POSSIBILITIES FOR POWER SAVING In mobile networks an MS can be in one of the following

states:

State I: Receive or send trafficState II: Do not receive or send traffic while in active

session(s)State III: Not in an active session

POWER MANAGEMENT IN STATE IISleep mode operation of IEEE 802.16m can be divided

into the following stages

Sleep mode initiation

Sleep mode operation

Sleep mode exit

ADVANCED FEATURES TO ACHIEVE HIGHER POWER SAVING

Traffic exchange during sleep operation without sleep mode termination

Predefined sleep cycle settings adaptive to application characteristics

Dynamic adjustment of sleep cycle during sleep operation

LW early terminationVoIP-specific sleep operationMulticarrier sleep operation

SW AND LW OPERATION

Adaptive SW and LW operation makes IEEE 802.16m sleep mode simple and efficient

MSs save power during SWMonitor traffic indication broadcast by BS during LW

VoIP SUPPORT IN SLEEP MODEMS exchanges one set of packets every 20 msDuring its silent periods the MS exchanges a silence

insertion descriptor (SID) every 160 ms

3GPP LTE DRX IN RRC_CONNECTED STATE

Discontinuous reception in RRC_CONNECTED state is used for power saving while user equipment (UE) is in RRC_CONNECTED state

DRX mode can be enabled if there is no traffic longer than DRX inactivity timer or if the UE receives a control signal to enter DRX mode

POWER MANAGEMENT IN STATE IIIIdle mode operation of IEEE 802.16m can be divided into

the following stages

Idle mode initiation

Idle mode operation

Idle mode location update

Idle mode exit

ADVANCED FEATURES TO ACHIEVE HIGHER POWER SAVING

Multiple PGs’ assignment and managementUser mobility considerationElimination of paging and location updateTransfer of short message service without idle mode

terminationPaging overhead reductionMulti-carrier paging

NETWORK MODEL AND MULTIPLE PG OPERATION

MOBILITY-BASED PAGING AREA DESIGN

Determination of paging area size based on speedDetermination of paging area shape based on mobility

trajectory

DCR mode enhancements of idle mode

Multicarrier paging

3GPP LTE DRX IN RRC_IDLE STATEADVANCED FEATURES TO ACHIEVE HIGHER POWER

SAVING

Cell selection optimization during RRC_IDLE State

Mobility-based RRC_IDLE optimization

CONCLUSIONSPower saving is becoming critical in next-generation

wireless systemsNext-generation wireless networks provide advanced

power saving mechanismsEfficient and simple power conservation methodOptimized operation for various applications, traffic

patterns while providing extended battery life