Tuesday, April 23, 2013

Voice over LTE Training - VoLTE Training Course

Voice over LTE Training Course, VoLTE Training Course

Learn about Voice over LTE Implementation alternatives including concepts behind Circuit Switched Fallback (CSFB), Single Radio Voice Call Continuity (SR-VCC) and Voice over IMS, all-IP network, voice and video over IP and rich communication services (RCS) and interoperability across network access methods and operators (LTE, 3G/HSPA, WiFi and legacy telephony domains.


Circuit Switched FallBack (CSFB) is a technology whereby voice and SMS services are delivered to LTE devices through the use of GSM/UMTS or another circuit-switched network.

Circuit Switched FallBack is needed because LTE is a packet-based all-IP network that cannot support circuit-switched calls. When an LTE device is used to make or receive a voice call or SMS, the device "falls back" to the 3G or 2G network to complete the call or to deliver the SMS text message.


Despite the fact that LTE was originally designed as a data network, its quality of service (QoS) and capacity gains also provide subscribers and operators with significant additional benefits for voice services, such as HD voice, enhanced video capabilities, and rich communication offerings.

in CSFB:
  • Device is registered for both CS and PS services via LTE
  • CS voice pages are delivered over LTE
  • Device remains on LTE except for voice calls
  • SMS can be received over LTE
  • For voice calls, UE falls back to UMTS/GSM/C2K

SRVCC applies to the scenario that LTE  coverage is not continual SRVCC applies to multi-mode single radio UE. SRVCC is essentially a handover procedure,  including transport level handover and session  level handover. Considering the impacts to the networks  introduced, SRVCC is not recommended until  LTE becomes middle level coverages. SRVCC requires deployment of IMS network.



To learn more, visit us at LTE Training Page.

Monday, April 22, 2013

VoLTE Single Radio Voice Call Continuity (SRVCC)

What is Single Radio Voice Call Continuity (SRVCC)?


SRVCC is an LTE functionality that allows a VoIP/IMS call in the LTE packet domain to be moved to a legacy voice domain (GSM/UMTS or CDMA 1x).



Consider a case where a new LTE network operator wants to move voice services to VoIP over IMS in conjunction with the deployment of an LTE access network. In the absence of other options, this operator would need to provide ubiquitous LTE coverage on day 1 to have a competitive VoIP service. However SRVCC enabled LTE may not require complete LTE coverage. 

Learn more LTE Training 

 

Friday, April 12, 2013

VoLTE Training Course

VoLTE as the Technology of Choice for LTE Voice Transmission and SMS


 GSM Association IR.92 specifications highlight specific standards to deliver voice and SMS services over an LTE network with IMS (IP Multimedia Sub-systems).  WiFi as an “offload” is also an interesting concepts for many operators. VoLTE is essentially VoIP over 4G/LTE using IMS architecture.
VoLTE Training Course
In order for LTE UE to establish a voice call over IMS, the following steps are essential:
    • UE RRC Connection Request to EPC & IMS
    • PDN Connectivity Request 
    • Protocol Configuration Options IE 
    • P-CSCF address
    • EPS Attach & P-CSCF Discovery
    • UE initial IMS registration

    KEY TECHNICAL REQUIREMENTS FOR VoLTE ARE:

    • PCC rule authorization and QoS rule generation
    • Multiple Bearers (Default, Dedicated)
    • QoS Class Identifiers (QCIs)  
    • Semi-Persistent Scheduling
    • Transmission Time Interval (TTI) Bundling
    • Discontinuous Reception (DRX)
    • Robust Header Compression (RoHC)

    COMMON RTP PAYLOAD TYPES FOR VOLTE ARE:
    • Audio AMR 8000
    • Audio AMR-WB 16000
    • Text T140 1000
    • Video H.263 90000
    • Audio EVRCB 8000
    • Audio EVRCWB
    • Video H.263-2000 90000
    • Video H.263-2000 90000
    • Video H.264
    • Video MP4V-ES 90000