MWC 2013 Telefonica, owner of the O2 brand in the UK, has been showing off technology to integrate mobile phone networks with Wi-Fi.
The idea is to let handsets, tablets, and anything else, use Wi-Fi hotspots just like cellular base stations, with all the security, reliability, and billing which that involves.
The problem is that wireless Ethernet is a bodge job of the highest order - a wired protocol stuffed into the airwaves - but that's changing as the standard evolves and operators find ways to make it work, such as that being demonstrated by O2 at Mobile World Congress in Barcelona.
Seamlessly roaming from cellular to Wi-Fi presents two key problems: convincing the handset to give up a Wi-Fi connection when cellular is a better option, and identifying the subscriber when they drop back onto wireless, so addressing them requires two solutions.
Identifying the subscriber is part of the Hotspot 2 initiative, championed by the Wireless Broadband Alliance and it is in testing around the world. A load of manufacturers are already building Hotspot 2 technology into access points, ready for final ratification of the standard later this year.
Devices connecting to a Hotspot 2 point can authenticate themselves using the SIM card, and traffic can then be tunnelled through the network operator to apply usage policies (such as blocking porn or counting data packets) and, critically, to resume existing data connections making the handoff seamless.
Once connected to a Wi-Fi network, devices are generally very reluctant to let go, hanging on to the connectivity until the signal completely disappears rather than switch to cellular as it degrades.
Humans can override that, but it's a pain, and handsets aren't going to do it themselves for fear of incurring costs - so small-cell specialist biz ip.access has created Wi-Fi access points that identify devices capable of switching to cellular and then kick them off the wireless network when the service degrades to the point where they'd be better off using high-speed mobile broadband 4G LTE.
That's not necessarily when the signal degrades; ip.access is keen to point out that degradation can be down to having too many users, and that new users joining the hotspot knock down the quality for all, at least until its technology kicks some users off, forcing them onto LTE instead, to the benefit of all.
All this needs network integration, of course, so both Wi-Fi and LTE networks need to come from the same operator, but it does allow a device to roam between both technologies without interrupting the data stream and, ideally, with the user being entirely unaware that it's happening.
Whether Wi-Fi hotspots will remain free when operators can control it so effectively, or how they'll let customers know when they're being charged, remains to be seen, but that's a matter of business models that are often more complicated than the technology behind them.
Combining Hotspot 2 with technology such as that from ip.access can turn a Wi-Fi access point into a cellular base station, so now the technical problems have been solved the business discussions can start. ®