Voice over LTE via Generic Access (VoLGA)

Voice over LTE via Generic Access (VoLGA) is an initiative by T-Mobile Germany and several equipment vendors (Cisco, Kineto, Motorola, Ericsson, and Alcatel-Lucent and others) to support voice over LTE networks. The solution will enable transparent delivery of traditional circuit switched services such as voice, SMS and VMS over LTE without IMS deployment. The overall objective is to enable GSM/UMTS operators to re-use existing equipment to deliver circuit based services over LTE and reduce costs.

 

The proposed architecture will require a client on the devices and gateway deployed in the LTE network. Circuit based services like voice, SMS, and VMS will be encapsulated in packets to traverse the LTE network.

 

The advantage of the proposed solution is that it will minimize the number of elements required to deploy VoIP over LTE. The architecture will also enable handoff of circuit based services between GSM/UMTS and LTE networks. This will enable operators with legacy networks to migrate portions of their network to LTE while still supporting legacy services in rural and suburban areas. It will also enable roaming between LTE and GSM/UMTS networks.

This initiative will help some operators who wish to leverage their existing circuit based architecture but it seems to defeat the purpose of migrating to an all IP network. If the vendor is still required to deploy a new gateway to support this solution why not leverage IMS instead of creating two competing solutions which will prevent ubiquitous service coverage across different operators’ networks. Rich Communication Suite (RCS) Release 1 is completed. RCS provides the device component needed for end-to-end IMS services.

 

Verizon Wireless is taking the IMS approach to delivering services over LTE. Since VZW is a CDMA operator, this will set the precedence for other CDMA operators migrating to LTE. VoLGA is initially aimed at operators with GSM/UMTS based networks.  While it is good to set a standard for delivering voice over LTE, organizers should focus on developing solutions to ensure interoperability across all LTE networks.