SIM-plify Wi-Fi Roaming and Authentication
By Eric Lin, Mon Jun 07 05:00:00 GMT 2004

Using mobile phone technology could ease authentication and roaming on Wi-Fi networks. This could simplify paid Wi-Fi for users and operators alike.


A state-funded consultancy in Germany has proposed applying aspects of mobile phone technology to Wi-Fi. WIK suggests that Wi-Fi needs a SIM-card type system to handle authentication and billing/roaming. SIM chips in GSM phones take care of authenticating users as a valid member of a specific network, and then allows the networks to bill the user according to where he is calling from, whether it be his home network or another.

Hotspots are quite the opposite. At paid hotspots, users must manually authenticate themselves with a name and password. Most hotspot operators do not have roaming agreement with other Wi-Fi networks, and if they do, it is usually quite difficult to login on the other networks. There are aggregators, like iPass or Boingo who have negotiated access for users on a number of networks, but they don't work with every network and users still run into the problem of logging into roaming networks.

A SIM chip system would provide the back end data that hotspot providers need in order to bill for roaming, thus encouraging operators to forge roaming agreements, creating a more complete network. It would also provide a transparent, hassle-free authentication system for users, even on their home network, which could encourage them to venture out and use Wi-Fi more often.

Although Wi-Fi cards with SIM slots are available, many laptops and PDAs have built-in Wi-Fi radios that can't be retrofitted for SIM use. While a SIM does provide authentication and a means for back end accounting systems to reconcile users, it is not a technological silver bullet. Since retrofitting thousands of computers and PDAs is not an option, operators need an alternative that acts like a SIM chip for authentication and back end systems, but isn't actually a SIM chip- that is if they would like to get more users by having a larger, easier to use network. Now all we need is an enterprising developer to deliver a virtual SIM or some similar Wi-Fi based authentication.