Consensus around Verizon Wireless-led proposal could be challenge given competing efforts.
Vendors push new way to build converged IP networks.
Now that a group of wireless technology 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.
Cisco, Lucent, Motorola, Nortel and Qualcomm have been working quietly 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. Last week the companies made the plan public.
Among other enhancements, the framework – called Advances to IMS, or A-IMS – is intended to facilitate improved support for non-Session Initiation Protocol (SIP) devices, applications and services, end-to-end security and wireless VoIP QoS.
“Once we identified these issues that we wanted to address, we decided the best way to be a catalyst here was to work with a group of vendors that we had a good relationship with,” says Bill Stone, executive director of network strategy for Verizon Wireless, which he says assembled the “best and brightest” engineers and strategists for the effort.
“In no way is this intended to be a closed solution,” Stone asserts. “Our intent is to bring it forward, to make it public and to ask others to take a look at what we’ve done and think of ways to improve upon it . . . and standardize it.”
The effort, however, presents yet another activity to define an architecture for next-generation, converged fixed/mobile IP networks and services. These multiple developments could fragment the industry, further delaying delivery of advanced services to businesses and consumers, observers note.
“[The industry’s] done a good job of keeping the different efforts coordinated,” says Joe McGarvey, an analyst at Current Analysis. “But now there’s another proposal. When you add another cook to the works, it definitely introduces delay.”
Conceived by the 3rd Generation Partnership Project (3GPP), IMS is an architecture that essentially takes the place of the control infrastructure in the traditional circuit-switched telephone network, separating services from the underlying networks that carry them. It uses SIP as its signaling method for setting up calls and handling data sessions, and enables services such as text messaging, voice mail and file sharing to reside on application servers anywhere and be delivered by multiple wired and wireless service providers.
IMS is generally accepted by the industry as a core component of virtually all next-generation, IP-based communications networks for SIP-based applications. It is designed to assure standardization of multimedia services across all interconnected wireless and wireline networks.
Yet Verizon Wireless noted shortcomings in the MMD/IMS architecture two years ago, Stone says, most notably in legacy non-SIP elements, security and wireless VoIP. The task force has completed a 300-page concept and architecture document that it plans to share with the 3GPP, 3GPP2 and other industry standard consortia.
Stone says A-IMS also is intended to simplify the complex IMS standard. Analysts say it may bridge the 3GPP’s GSM-focused IMS with the 3GPP2’s Code Division Multiple Access-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.
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 Universal Mobile Telecommunications System/High-speed Downlink Packet Access, 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 includes T-Mobile, Orange, KPN, NTT DoCoMo and China Mobile. Cisco also is 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 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 says it 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 also has implemented aspects of IMS, says A-IMS may be reinventing the wheel.
“A-IMS . . . addresses a number of issues, none of which are not either being dealt with in 3GPP or via implementation of specific actions,” 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.”
Nonetheless, Cingular plans to have conversations with Verizon and the vendors involved to “better understand their positions and thought processes,” the spokesman says.
A spokesman for ETSI and 3GPP says the A-IMS proposal will receive “serious consideration.”
Stone and Hindle downplayed the potential for industry fragmentation of IMS.
“We’re bringing forward solutions that we hope will be considered based on technical merit, not where they originated from,” Stone says.
Adds Hindle: “There’s still a negative reaction from other people who feel they’ve not been included. I think there’s also a level of pragmatism that’s enabled the cellular industry to cooperate where it makes business sense.”
Consultant Seybold says the wireless industry should coalesce around A-IMS. “If the industry is smart they will see that A-IMS is really a way to bring IMS back to being what it started out to be: A completely open architecture,” he says. n
Senior Editor Denise Pappalardo contributed to this story.
