October 2012
Intermediate to advanced
248 pages
7h 54m
English
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14.6 Voice Evolution
The good quality voice service is the key part of smartphone applications. HSPA evolution enables a number of improvements to voice services in the areas of voice quality, capacity, power consumption and LTE interworking.
14.6.1 Adaptive Multirate Wideband (AMR-WB) Voice Codec
AMR-WB was defined in 3GPP Release 4 for a circuit switched voice. AMR-WB enhances the voice quality by increasing the voice sampling rate from 8 to 16 kHz which makes the audio bandwidth larger. The typical radio data rate is still similar to AMR Narrowband (AMR-NB), so the radio capacity for AMR-WB is similar to AMR-NB. AMR-WB has been activated in tens of networks and many new UEs support AMR-WB.
14.6.2 Voice Over IP (VoIP)
3GPP Release 7 enhancements for HSPA make it possible to run good quality VoIP service with high capacity. HSPA radio brings the benefit that DTX/DRX features can be used also for voice which improves the UE talk time and reduces network interference leading to higher capacity especially in uplink. VoIP may also make it simpler to introduce new packet services.
14.6.3 CS Voice Over HSPA (CSoHSPA)
3GPP Release 8 enables to run CS voice over HSPA radio. This solution is similar to Voice over IP (VoIP) from the radio perspective and similar to CS voice from the core network perspective.
14.6.4 Single Radio Voice Call Continuity (SR-VCC)
SR-VCC enables handover between CS voice and VoIP. SR-VCC from VoIP to CS is defined in Release 8 and from CS to VoIP in Release 11. ...
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