When it comes to keeping users in touch anytime and anywhere, wireless is almost without peer. But as the definition of "in touch" has evolved to include short-message service, e-mail and other enhanced services, subscribers often find that they can't take those services with them when roaming.

A new protocol for GSM networks could change that. Customized application for mobile-enhanced logic (CAMEL) is an IN standard for GSM. CAMEL could help GSM attract the lucrative business-user market because roaming subscribers would have full access to their enhanced services, including virtual private networks (VPNs) and single-number service.

"It will also potentially decrease the long-distance portion of your roaming-related bill because connectivity with the home network exists without any call setup," said Kjell Johansson, Ericsson manager of product configuration, GSM 1,900 local product management. "In the future, CAMEL will offer the home operator a way to reach the subscriber while roaming and without setting up a circuit-switched connection. This will enable development of a whole new group of innovative services (such as) local weather and news."

Other potential benefits include:

*More enhanced services. CAMEL enables a wider range of VPN, personal-number and location-based services, but perhaps the biggest draw is the ability to offer more forms of prepaid, one of wireless' most popular services.

"For example, you can offer a prepaid service where it's prepaid to one number or a selected group of numbers," said David Herndon, BellSouth network director. "You can tailor prepaid services to specific market segments."

*Access to enhanced services while roaming. CAMEL also allows prepaid customers to get service even while roaming. Currently, "prepaid customers are limited to their home network," said Trinh Vu, Siemens senior product manager for wireless IN. "If they go even to the next town, and it happens to be a different service provider, tough luck. Prepaid can be a national service instead of a regional service."

Likewise, VPNs could extend beyond the home network.

"VPN could be expanded to become global VPN," Vu said. "Right now, VPN also is limited to the same network. This will provide global VPN features to allow the subscriber to make calls anywhere (and) anytime."

*Streamlined deployment. CAMEL should help cut deployment costs and speed time to market. VPNs are one example.

"We can do (them) today, but it all depends on switch-based translations, which are very, very difficult and expensive to maintain," Herndon said. "But (with) IN, it's done with what are called 'service building blocks,' where you almost point and click and drag together a featuresuite or a collection of customers."

*Competitive advantage. The cost savings from streamlined deployment could be passed on to subscribers in the form of lower rates. A broad range of enhanced services, tailored to specific market segments or user groups, such as companies, could be a key market differentiator. With a CAMEL VPN, a subscriber could roam in another country and still use 4-digit dialing -- and avoid international long-distance charges.

"The billing piece is wholly separate from the technology piece," Herndon said. "That's going to depend entirely on how the operator structures and prices the service."

*Reduced churn. Customized enhanced services could help increase "stickiness," where subscribers perceive churning as not worth the upheaval.

"The wider usage of customized IN applications will reduce churn because subscribers get used to the look and feel of their home-area services," said Ericsson's Johansson.

*Streamlined multivendor environment.

"CAMEL standardizes the interface between the switches and the SCPs (service control points) and so on, and it provides a good multivendor working environment," Vu said.

"In the past, where you have INAP (intelligent-network application part), it's rather different interfaces, so you have interworking issues. Now, it's standardized and everybody has to support the same thing. It makes the integration of different vendors a lot easier."

*Increased revenues. Roaming revenues, minutes of use and per-subscriber revenues all might increase because subscribers have greater access to enhanced services. Subscribers might be more inclined to sign up for enhanced services if they know that they can use them wherever they go.

"I think (that ability) will definitely drive the popularity of some of these enhanced services because right now there's a lot of frustration," said David Berndt, Yankee Group associate director. "People pay so much for a service, and then they roam into the next market and can't access it."

How CAMEL Works

Implementing CAMEL involves a software upgrade of much of the network.

"CAMEL is a set of standards that basically is a new protocol between the SCP and the SSP (switching service points)," said Siemens' Vu. "That means that all the SCPs and SSPs must be upgraded with the CAMEL protocol. The CAMEL standard provides the operator with a signaling framework to allow the roaming IN subscriber to query the home SCP database for information regarding his or her subscription, known as CAMEL service information (CSI). They would need the CSI information in the HLR to download to the VMSC (visiting-MSC)/SSP when the subscriber is registered to trigger the CAMEL protocol. The VMSC/SSP can initiate a dial-up with the home SCP to provide enhanced IN services just like in the home network."

Because CAMEL facilitates roaming and enhanced services, accurate forecasts are key to ensuring that demand doesn't exceed network capacity. Implementation costs depend on variables such as the size of the network, IN-traffic forecasts and roaming agreements.

"Definitely, there will be a capacity impact on the host network," Vu said. "You have a new group of customers going into your network and using resources. But then again, all operators would like to put additional traffic on their networks because that's how they make their money, and roaming subscribers add a lot of value to their portfolios. So I don't see that as a big concern."

When & Where

CAMEL-ready networks should debut sometime between mid-1999 and early 2000.

"I think the Europeans are also very keen about CAMEL, so I'm not sure who's going to be first," Vu said. "But I think it's a good chance that the United States is going to be in a parallel path because the market in the United States is very competitive."

CAMEL should be attractive to GSM carriers here as a way to compete with the 1-rate plans and nationwide networks of AT&T and Sprint.

"Definitely, they are interested," Vu said. "They see that as a vehicle for them to grow their subscriber base. If they have differentiating services running on their network, their subscribers get the same service everywhere they go. We have a lot of requests for when it's going to be available and how we can help them deploy it."

BellSouth will decide whether to implement CAMEL sometime in the next few months.

"Prepaid has turned out to be the killer application for CAMEL implementation or for any IN implementation," Herndon said. "Some of the carriers have already deployed CAMEL-based prepaid services, and there are others, we believe, that are rapidly following. We may count ourselves among them."