Verizon, others offer IMS extensions: Now comes the hard part for A-IMS

Building consensus around Verizon Wireless proposal will be difficult, observers note

Now that a group of wireless vendors, led by customer Verizon Wireless, have proposed extensions to an evolving industry specification for converging IP-based wireline and wireless services, the hard part will be in garnering further support for their work.

Cisco, Lucent, Motorola, Nortel and Qualcomm have been quietly working with Verizon Wireless over the past year to develop a framework to extend the 3GPP2's Multimedia Domain (MMD) architecture, an offshoot of the 3GPP's IP Multimedia Subsystem (IMS) specification. Among other enhancements, the framework - called Advances to IMS, or A-IMS - is intended to facilitate improved support for non-SIP devices, applications and services, end-to-end security, and wireless VoIP QoS.

The taskforce has completed a 300-page concept and architecture document that it plans to share with the 3GPP, 3GPP2, and other industry standard consortia. Analysts say it may bridge the 3GPP's GSM-focused IMS with the 3GPP2's CDMA-focused MMD.

"A-IMS is actually a way to bring these two standards closer together and 'fix' the issues with both of them," says Andrew Seybold, president of consultancy Outlook 4Mobility.

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Now that a group of wireless vendors, led by customer Verizon Wireless, have proposed extensions to an evolving industry specification for converging IP-based wireline and wireless services, the hard part will be in garnering further support for their work.

Cisco, Lucent, Motorola, Nortel and Qualcomm have been quietly working with Verizon Wireless over the past year to develop a framework to extend the 3GPP2's Multimedia Domain (MMD) architecture, an offshoot of the 3GPP's IP Multimedia Subsystem (IMS) specification. Among other enhancements, the framework - called Advances to IMS, or A-IMS - is intended to facilitate improved support for non-SIP devices, applications and services, end-to-end security, and wireless VoIP QoS.

The taskforce has completed a 300-page concept and architecture document that it plans to share with the 3GPP, 3GPP2, and other industry standard consortia. Analysts say it may bridge the 3GPP's GSM-focused IMS with the 3GPP2's CDMA-focused MMD.

"A-IMS is actually a way to bring these two standards closer together and 'fix' the issues with both of them," says Andrew Seybold, president of consultancy Outlook 4Mobility.

Yet, the A-IMS work is in addition to several efforts underway to arrive at the next-generation converged fixed/mobile infrastructure. The European Telecommunications Standards Institute (ETSI), for example, is developing its TISPAN specification for such an environment, which also includes support for non-SIP network elements and applications.

Also, A-IMS lacks the participation of Verizon Wireless rivals Cingular Wireless and Sprint Nextel, and partner Vodafone. Cingular has tapped Lucent as the IMS supplier for its 3G network, which is based on UMTS/HSDPA, a competing technology to Verizon Wireless' EV-DO.

Vodafone, based in Great Britain, is involved in the recently formed Next Generation Mobile Network Forum, which also includes T-Mobile, Orange, KPN, NTT DoCoMo and China Mobile. Cisco is also involved in this forum, says Jonathan Hindle, senior manager in Cisco's Worldwide Mobile Marketing Organization.

With all of this parallel activity, analysts say it will be difficult to gather consensus around A-IMS.

"Now comes the hard part of this," says Roger Entner of analyst firm Ovum. "It's much harder to turn this from a proprietary proposal to an open standard."

Sprint Nextel applauded Verizon Wireless' effort to improve IMS but stopped short of endorsing it.

"We have to examine the enhancements to see how they apply to Sprint," a spokeswoman says. Sprint claims to have implemented elements of the IMS architecture more than four years ago to support its ReadyLink push-to-talk service and Business Mobility Framework offering.

Cingular, which says it has also implemented aspects of IMS, says A-IMS may be reinventing the wheel.

A-IMS addresses a number of issues already being dealt with in 3GPP, or via specific operator or vendor implementations, a Cingular spokesman says. "The global GSM operator and vendor communities have created these standards with many brilliant minds working to identify and address issues. We are confident in this process and the people behind it, and in the fact that the issues are being addressed."