US wireless carrier Verizon Wireless, backed by its leading suppliers, including Lucent, Cisco, Motorola, Nortel and Qualcomm, has developed a new advanced "flavor" of IMS technology dubbed A-IMS. According to Ed Salas, network planning vice president for Verizon Wireless, the hope is that enhancements included in A-IMS will make it easier to implement next-generation services in existing wireless networks around the world.
The A-IMS architecture developed by the multi-vendor team provides solutions to implement next-generation services in current networks, as well as creates a foundation for the rollout of SIP-based and non-SIP-based services in future networks. The architecture is based on EVDO, although it embraces other technologies as well, according to Salas.
Salas said the effort started more than a year ago when Verizon wanted to seamlessly integrate VoIP applications across platforms "and saw the limitations in IMS, which doesn't address end-to-end security very well or easily co-exist with non-SIP applications." Verizon took the lead role in driving the architectural direction and defining the functional components in the new architecture. There are inherent shortcomings in IMS that needed to be addressed, Salas noted.
One goal was to simplify IMS implementation and integrate SIP and non-SIP architectures. "We pulled our supplier set into a room, added the best-and-brightest R&D minds, and discussed how we might approach the requests we received (for new applications) with the (existing IMS) architecture. We did not want to obviate anything within IMS. We wanted to build on the existing IMS structure," Salas says.
The result is A-IMS, touted as a more flexible and secure version of existing IMS for wireless carriers. Salas says A-IMS will enable more rapid deployment of IP-based applications to mobile subscribers; seamlessly support both SIP and non-SIP applications; provide better network management for service providers; and optimize network performance and quality-of-service.
Verizon has put together with its suppliers a strong base of support. What is being introduced is an architecture document that an industry task force will now make available to other industry leaders and submit for standards review. The idea is to broadly distribute the work so that engineers can evaluate it. Proponents contend that with the A-IMS architecture, a Skype and a Vonage user, for example, would be able to seamlessly and securely communicate with each other using wireless devices.