WiFi Roaming: The Technical Considerations
The vision for WiFi 2.0 or next-generation hotspots (NGH), as outlined by the Wireless Broadband Alliance (WBA) and noted in previous blog entries, is for WiFi roaming to become truly interoperable, whereby end users can seamlessly roam between WiFi networks and providers. (See Commercial Opportunities in the 'Internet Anywhere' Space and WiFi 2.0: Roaming Holds the Key.)
For this to happen, "there needs to be standardisation across all elements involved -- from mobile device, to access point, to service provider," the WBA points out. "In order for Wi-Fi roaming to become a truly disruptive innovation, there needs to be very little fragmentation in deployments. Wi-Fi service providers, mobile service providers and hardware manufacturers must all work to the same guidelines and standards."
However, the reality is that ubiquity is still a long way off. There are multiple providers, multiple standards, and a mix of legacy and NGH infrastructure. Support for the 802.1x/EAP standard is growing, but it's still limited, given that infrastructure rip-and-replace projects are costly and happen slowly.
Market success for this vision requires a solution that will span multiple generations of WiFi networks and can leverage the world's current supply.
To facilitate global WiFi roaming today, legacy infrastructure needs to work like NGH infrastructure, and NGH needs to work like legacy. Both must be accessible in a common format. This means that interim solutions are now critical to bridge the gap and provide customers with a WiFi 2.0-like experience today and into the foreseeable future.
What kinds of things does a bridging solution need to consider? In order to roam between networks and providers (WiFi and cellular), operators need to achieve three crucial transactions seamlessly -- authentication, authorization, and accounting (AAA). It is crucial for operators to be able to manage subscribers effectively by seamlessly authenticating and authorizing them every time they log on to a network. However, mobile network operators (MNOs) traditionally have not been able to authenticate WiFi access at the device level. The majority of WiFi networks support only WISPr v1.0, and this requires authentication to be performed using remote authentication dial-in user service.
Device-based AAA (DBA) solutions (as used by iPass) provide an EAP-SIM experience over today's WISPr network by translating WiFi credentials from subscribed devices into a device identity within the network services fabric. By automating access and authentication and securely relating the data session to the mobile subscriber's cellular identity, a DBA solution frees MNOs from entering cumbersome usernames and passwords. These solutions are interoperable with GSM, CDMA, or LTE operational and business support systems. They emulate an international mobile subscriber identity for GMA networks and a mobile identification number for CDMA networks. This means that a mobile device identifier, not a person or user, is the common element to provisioning, authorizing, and charging for services across different networks.
This kind of bridging technology is a game changer bringing the legacy and NGH WiFi worlds together for users while we wait for WiFi 2.0. With this technology, subscribers can effectively experience the concept of 2.0 earlier than the infrastructure is forecast to allow. Operators should be keenly tuned into this opportunity to protect their subscriber base from seeking competitive offerings from players that can bundle all device types (including WiFi-only ones) on to a single roaming plan.
— Steve Livingston, Senior VP, Open Mobile Exchange, iPass