Passpoint WiFi tech promises cellphone-like handoff between hotspots

>Nice to see things happening but the main problem to solve is >not the end user equipment this article talks about, but >rather operator systems (systems that could handle this and >scale for the increased traffic is not something many >operators have).

Overall, Passpoint can help decrease cellular traffic and redirect it over fixed lines via Wi-Fi. So IMHO it might be attractive to operators.

Without going too deep into the technical details:

An ESS network is most often under a single organization (say, the IT department of a large Hotel). The Wi-Fi credential combination required by a user to roam across the different Access Points in the ESS is the same.

But what about when you leave hotel premises and go to the airport? Manual intervention is often required by you, especially if you are going to that airport for the first time and have not yet purchased a plan there. With Passpoint, the hotels in the city, the airport etc could all be participating in a common program. Sign up once, use anywhere. With passpoint software, your device has a _standardized_ way to avail of such facilities.

The ESS architecture does not handle such possibilities - it operates at a much lower level. Higher level handshaking is required to enable this, and in a standards defined manner so that it works everywhere.

If you mean handoff between access points then yes, that's been a part of the IEEE 802.11 standard since forever. The only new thing with Passpoint / 802.11u is that they've added a beacon field that indicates to the STA (mobile device) that it cannot expect Layer2 connectivity between access points. The device will then purge ARP cache, request new DHCP lease, etc during handover. This is slower than good old 802.11 but makes it easier for the operator to build hotspot networks.