San Francisco-based Critical Path, best known for its various e-mail and messaging platforms, also has an SMS solution for both wireless carriers and enterprises. Renee Stromberg, Critical Path's product line manager for mobile messaging, said in an interview that the company is using all of its knowledge already gained in the messaging field for its wireless IM system.

"There's a lot of `one-hit wonders' out there as far as instant messaging goes," she said. "The real difference with Critical Path is we're basing this on our platform, and our solid e-mail foundation, and integrating it with our personal address book. So you don't have to worry about synchronizing your buddy list with the same contact list you use for e-mail or SMS. This brings a much-richer end-user experience to the customer."

Critical Path then goes one step farther in combining that experience with standards-based technologies like SIP/SIMPLE (session-initiation protocol/SIP instant messaging and presence leveraging extensions) and Wireless Village. SIP is a signaling protocol for Internet conferencing, telephony, presence, events notification and instant messaging. The protocol initiates call setup, routing, authentication and other feature messages to endpoints within an IP domain. Essentially, the SIP protocol enables real-time messaging, voice, data and video, and is the next-generation of Voice-Over-IP (VOIP) as well.

In the world of IM, Microsoft's Windows XP operating system uses SIP-based IM, and America Online (AOL) has said it will use SIP for its IM services and for interoperability with other services. Other IM client/server systems are slated to use SIP, too.

The SIMPLE protocol deals with the transport of instant messages in SIP.

The Wireless Village initiative, on the other hand, is responsible for defining and promoting the interoperability of mobile instant messaging and presence services (IMPS) among both wireline and wireless users.

Through the use of these and other standards, the Critical Path IM system lets a carrier's end users communicate seamlessly regardless of IM client or device type. Critical Path's solution benefits wireless carriers and service providers by helping to reduce subscriber turnover and drive revenue through increased wireless traffic generated from phones, mobile messaging devices and PCs, company officials also said.

"We've waited on the sidelines until now because we're not very comfortable going with proprietary solutions," Stromberg said. "With SIP/SIMPLE coming out, and everyone rallying around Wireless Village, we felt very comfortable to be able to move into that product offering with those solutions."

Critical Path's new IM solution for wireless carriers and service providers can be integrated with existing SMS and WAP deployments, which lets them leverage their current network infrastructure to extend messaging services without additional infrastructure investment.

The company said a major component of its new IM Solution is its presence capability -- the ability to determine if a person is "available" via his or her PC, PDA or mobile phone. Critical Path's IM solution provides carriers and service providers with the opportunity to leverage presence information throughout multiple Critical Path applications, including personal address book, calendar and Webmail. A subscriber's presence can be updated automatically based on entries in the calendar or when the person picks up the telephone, for example, enabling messages to be routed in an alternative fashion when the person is "unavailable."

The new solution also lets third parties develop applications such as presence-enabled games. Its these kinds of applications that can differentiate carrier service offerings from the competition, the company said.

Critical Path said its IM solution will be generally available late in the third quarter of 2002.

SMS adoption rates in the U.S. are generally lower than in Europe and Asia, where "texting" has taken off like wildfire. Stromberg said wireless IM adoption in the U.S. will likely begin at the end of this year, when IM-capable handsets roll out to the market. "My conviction is that next year we'll see a lot more adoption of the more instantaneous versions of IM," she said. One drawback of SMS is it does not support the same kind of "instant" communication that the wireline services -- AOL Instant Messenger, ICQ, MSN Messenger and Yahoo Messenger -- do.

Bob Woods is the managing editor of InstantMessagingPlanet.