The very mention of Internet Protocol Multimedia Subsystem puts a whir in many propeller hats. The whirring is justified to a certain degree, but wireless carriers have approached investment in IMS technology with much caution. To understand their position, it’s essential to first understand just what all the IMS noise is about.
The technology promises to merge the Internet with the cellular world. It uses cellular technologies to provide mobile access and Internet technologies to deliver desirable services. It’s defined as a standardized architecture for telecom operators that want to provide mobile and fixed multimedia services.
It runs over the open-standard IP and uses a Voice over IP implementation based on a Third Generation Partnership Project standardized implementation of Session Initiation Protocol (SIP). And IMS supports both packet-switched and circuit-switched phone systems. So, a multimedia session between two IMS users, between an IMS user and a user on the Internet, and between two users on the Internet is established using exactly the same protocol. Add to that interfaces from service developers, which are also based on IP protocols.
The idea is not only to provide new services, but all the services that the Internet provides. Think of it as a service delivery architecture that allows service providers to tie together all of their network’s applications, offering any value-added service to their subscribers, regardless of which vendor developed the application.
Originally, IMS was defined by the 3GPP as standards were being developed for third-generation systems in UMTS networks. The idea appeared first in 3GPP release 5 of the evolution path from 2G to 3G when SIP-based multimedia was added. Back then, IMS was referred to as IPv4 networks and provided a migration path to IPv6. Eventually, 3GPP releases 6 and 7 added support for WLAN and fixed networks.
Today, IMS allows operators who own different types of networks with varying architectures to offer the same services to all of their customers. Since not a single network operator or service provider has a network with just one vendor’s equipment, carriers can’t rely on one vendor’s service application. IMS allows network operators to buy one application that can be used across its entire network.
Telcordia Technologies Inc.’s Grant Lenahan, vice president of IMS service delivery solutions, compared IMS architecture within a network to Lego blocks, explaining that all the blocks fit together however you want them to, and when you buy new blocks, they fit perfectly with the old blocks.
That’s what access independence is all about. IMS is expected to work with any network eventually, be it fixed, mobile or wireless, with packet-switching functions, such as GPRS, UMTS, CDMA2000, WLAN, WiMAX, DSL and cable. Older circuit-switched systems like GSM are supported through gateways.
So if IMS is all that, why aren’t network operators lining up at the doors of equipment makers to buy IMS solutions?
“The honeymoon is over,” stated Joe McGarvey in a recent IMS advisory report for Current Analysis. “In the past year or so, IMS equipment makers have been able to claim early deployments and industry leadership based solely on the availability of IMS components. To this point, IMS portfolios have not been subjected to any of the traditional scrutiny that marks nearly every other product category in the telecommunications industry. With some exceptions, equipment makers have yet to make available product specification sheets or to disclose basic performance numbers, such as their respective platforms’ abilities to control simultaneous sessions.
“While this is disconcerting to analysts who have been deprived of fundamental information for making head-to-head comparisons, the absence of meaningful discussions concerning scale, reliability and other carrier-class attributes will do nothing but stall the adoption rate of IMS among service providers, most of which are naturally cautious.
“Equipment makers, such as Alcatel (Corp.), (L.M.) Ericsson, Siemens (A.G.) and Lucent (Technologies Inc.), that have already announced deployments or future deployments of portions of their IMS portfolios should not interpret these early successes as evidence that service providers are so anxious to adopt IMS that they will abandon traditional approaches for selecting equipment for their network infrastructures.”
McGarvey also noted that IMS will have a long adoption cycle, perhaps as long as a decade before carriers can claim wholesale adoption of the technology, and service providers likely will engage multiple suppliers with various IMS projects.
“Under the ever-watchful eye of Wall Street, carriers are not likely to again follow the `build it and they will come’ path to financial ruin,” McGarvey said. “Consequently, service providers plan to build out their IMS networks incrementally and largely through revenue delivered by first-generation converged applications. For this reason, equipment makers that can feed customers a steady stream of revenue-generating applications throughout the adoption cycle will have an advantage over competitors.”
McGarvey singled out Lucent’s Service Enhancement Layer, which leverages the Bell Labs brand and technology, as an excellent example for competitors to follow because the equipment maker brings value-added enhancements to their IMS portfolio that delivers capabilities beyond the guidelines specified by the specification.
“IMS represents a near-complete overhaul of the way service providers operate their networks,” McGarvey added.
