802.11u is a little-known protocol extension (soon to be standard) that stands to have a BIG impact on the user experience of emerging mobile Wi-Fi networks being built by operators. The key for widespread adoption of 802.11u ultimately rests in the hands of the Wi-Fi Alliance and its industry certification process.
Requiring changes to both clients as well as infrastructure devices, 802.11u was developed to effectively automate (make simpler) how Wi-Fi devices connect to available Wi-Fi networks. The MAC-layer enhancement assists the advertising and connection to remote services by providing information to clients about the external networks available prior to association. 802.11u enables Wi-Fi hotspots to advertise themselves and devices to connect to them using, for example, SIM-based authentication rather than requiring the end user to select an SSID number.
From a user perspective, the aim is to improve the experience of a traveling user who turns on a laptop in a hotel many miles from home. Instead of being presented with a long list of largely meaningless SSIDs the user could be presented with a list of networks, the services they provide, and the conditions under which the user could access them including indications that a selected network that is being advertised has valid roaming agreements in place with the user’s home network provider.
Typically, when a Wi-Fi device scans the RF environment it can find tens or even hundreds of Wi-Fi networks. How should it select the right one? If the client doesn’t recognize a given SSID, it doesn’t know whether it has the right security credentials to connect, whether it has a service plan that applies, or even whether the Wi-Fi network being advertised provides Internet access at all. So devices don’t know whether or not to attempt an association. Meanwhile the battery on the mobile devices is being drained.
With 802.11u clients can selectively scan for the desired network type. Bits are set in probe requests that alert APs to the type of Wi-Fi network the client is looking for. Conversely, special bits can be set in the AP beaconing mechanism to advertise the different network services available to clients.
With 802.11u running, a Wi-Fi client can request a list of all the mobile operators’ names that are allowed to automatically connect to the Wi-Fi hotspot. If your operator’s name is on the list, your device will automatically authenticate and offload.
No doubt 802.11u will be a huge help in delivering a seamless subscriber experience, eliminating the need for users to fiddle with configuring their mobile devices. I’m anti-fiddling – so stay tuned.