SRVCC: Single Radio Voice Call Continuity

Mamizbest   银牌会员    发表于 2018-11-18 23:10:14   最新回复:2018-11-18 23:11:18

SRVcc useful note!

SRVCC Single Radio Voice Call Continuity.

- it is necessary with VoLTE to ensure that calls can be handed over to legacy systems in a seamless manner - SRVCC, Single radio Voice Call Continuity system ensures that this can be achieved.


LTE IntroductionOFDM, OFDMA, SC-FDMALTE MIMOTDD & FDDFrame & subframePhysical logical & transport channelsBands and spectrumUE categoriesSAE architectureLTE SONVoLTESRVCCLTE-MLTE-U / LAASecurity

See also

4G LTE Advanced

SRVCC - Single Radio Voice call Continuity is a level of functionality that is required within VoLTE systems to enable the packet domain calls on LTE to be handed over to legacy circuit switched voice systems like GSM, UMTS and CDMA 1x in a seamless manner.

As LTE systems deploy VoLTE coverage will be limited and it is anticipated that it will be many years before complete LTE coverage will be available.

As a result it is necessary for operators to have a system whereby this complicated handover can be accommodated in a seamless fashion. This scheme needs to be in place as soon as they start to deploy VoLTE.

What is SRVCC?

SRVCC, Single radio Voice Call Continuity, is a scheme that enables Inter Radio Access Technology, Inter RAT handover as well as a handover from packet data to circuit switched data voice calls.

By using SRVCC operators are able to make the handovers while maintaining existing quality of service, QoS and also ensuring that call continuity meets the critical requirements for emergency calls.

Some ideas for handover require that the handset has two active radios to facilitate handover. This is not ideal because it requires additional circuitry to enable the two radios to be active simultaneously and it also adds considerably to battery drain.

The SRVCC requires only a single active radio in the handset and requires some upgrades to the supporting network infrastructure.

SRVCC network architecture

The concept for SRVCC was originally included in the 3GPP specification Release 8. Since then it has evolved to take account of the various issues and changing requirements. As a result GSMA recommends that 3GPP Rel 10 or later is implemented as this ensures a considerably lower level of voice interruption and dropped calls.

The network upgrades required to the cellular network are needed in both the LTE network and that of the legacy network or networks. SRVCC requires that software upgrades are required to the MSS - Mobile SoftSwitch subsystem in the legacy MSC - Mobile Switching Centre, the IMS subsystem and the LTE/EPC subsystem. No upgrades are required for the radio access network of the legacy system, meaning that the majority of the legacy system remains unaffected.

The upgrades required for the MSC are normally relativ.
If You have additional information and updated notes please inform me.
Thanks more.
Mamizbest   银牌会员    发表于 2018-11-18 23:11:18

Good information for me what about you?
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