VoLTE Interworking Function

Mavenir’s Voice over LTE Interworking Function (IWF) is an overlay solution that helps 4G/LTE mobile operators implement SR-VCC quickly and cost-effectively. This unique approach eliminates the need to upgrade the legacy circuit-switched network with new IP interfaces, thus lowering the cost and complexity to implement this business critical function in the LTE network, and accelerating the time-to-market for Voice over LTE (VoLTE). The IWF acts as a bridge between the operator’s legacy Circuit Switched (CS) core network and the Evolved Packet Core (EPC) without having to upgrade their CS network to support the Sv interface. 

The VoLTE IWF also supports CSFB, which enables the rapid introduction of 4G CSFB-enables devices without having to upgrade the legacy CS core network to support the SGs interface. The CSFB IWF performs all the necessary interworking functions needed to enable SMS service to CSFB devices, as well as trigger fallback to enable voice services from the CS core network. The CSFB application on the VoLTE IWF enables the rapid introduction of CSFB.  Operators looking for CSFB as interim solution can first deploy CSFB IWF and later perform a software upgrade to enable SRVCC IWF functionality, avoiding the need for any MSC upgrades for CSFB or SRVCC.

Mavenir’s VoLTE IWF allows mobile operators to focus investments in next generation technology as they introduce 4G devices and build out VoLTE and RCS enabled IMS networks. The IWF mitigates the need to ongoing investment in CS networks for the sake of deploying 4G devices and services. The IWF solution significantly cuts down on legacy network upgrade process and time, reducing overall network stability period as well. The IWF is a software-based solution that is fully deployed on the operator’s cloud-based infrastructure.

Key Features & Benefits

  • Compliance to SRVCC procedures defined in 3GPP TS 23.237
  • Compliance to CSFB procedures as per 3GPP TS 23.272
  • CSFB IWF Supports SGs/MAP/CAP interface for integration to existing network nodes
  • SRVCC IWF provides Sv/MAP/SIP(Mw/Mg/Mj) interfaces
  • Eliminates costly and time-consuming legacy MSC upgrades
  • TCO reduction and TTM acceleration for CSFB & SR-VCC
  • Fully virtualized software based platform