The required technology components are arriving piecemeal, however, so converged mobile nirvana isn't here just yet. As a first step, laptops and handheld devices are gaining embedded connections to both Wi-Fi and mobile WAN networks. This gives a device a higher probability of finding and connecting to a nearby wireless network, effectively extending the user's mobile coverage. Some converged service offerings are already available.
Aggregating Services
Network aggregation services from companies such as iPass Inc. and Fiberlink Communications Corp. represent an early move toward convergence. The wireless and wired network services they bundle and resell from carriers around the world are used with client devices that support connections to multiple networks.
The various services are accessible from a common client software interface provided by the aggregator, so users can access the best available network wherever they are. The aggregator maintains the multicarrier relationships and provides back-end security, billing and settlement services.
The mobile WAN component of these offerings isn't yet globally cohesive, however. "The wireless support of today's providers is not yet mature enough" to consider aggregators for worldwide mobile convergence, says Albert Hitchcock, CIO at Brampton, Ontario-based Nortel Networks Corp. The communications company supports 27,000 global users carrying mobile devices equipped with both Wi-Fi and cellular technology.
IPass and Fiberlink both support access to Wi-Fi hot spots around the world and resell Verizon Wireless' Evolution Data Optimized (EV-DO) services in the U.S. Outside the U.S., however, customers usually must buy mobile WAN services directly from individual providers. The aggregators' connection management client software will allow access to these networks, but managing the global mobile WAN carrier relationships is a key one-stop-shop benefit that isn't yet available internationally.
For seamless internetwork roaming once the desired network connections are in place, mobile client/server VPN software can be installed to let wandering users maintain sessions across network boundaries while retaining authentication credentials. Also, some hardware vendors, such as technology partners Motorola Corp., Proxim Wireless Corp. and Avaya Corp., are starting to offer premises equipment that handles Wi-Fi-to-cellular signal handoffs for voice calls. Carriers are also exploring services-based handoff alternatives.