Why Wi-Fi won't solve mobile telcos' data dilemma

If mobile operators rely upon Wi-Fi to relieve themselves of data traffic they are going to need to find some way to get the data home. Right now they're heading for a data bottleneck.

So says Bluwan, which – guess what – has a solution to the problem: its 42GHz point to multi-point backhaul. It sees this as the way Wi-Fi can roll out to its predicted level of one public Wi-Fi hotspot for every 20 people on the planet.

It commissioned a survey from advisory company Real Wireless that came to the conclusion that Wi-Fi was the problem.

The company has 1GHz of spectrum and can support 2.5Gb/sec of data per sector.

Bluwan’s point to multi-point can course be used for backhaul with solutions like streetlights, but the technology is limited in that it is line-of-sight only.

This makes it most suitable for back-hauling to the roof of a building that overlooks and will then communicate with other roofs, running the “carrier grade” Wi-Fi within the target buildings.

Of course, fibre to each of the buildings would be a better solution but Bluwan points out that millimetre wave point-to-multipoint backhaul technology is "pay as you grow", so it can offer operators a quicker and cheaper solution than digging up pavements.

Each site would typically get 150Mbps, but of course this varies on the number of sites in a sector. Bluwan has different antennas to increase and reduce the sector sizes. It is not a replacement for point to point, so you can’t get the full 2.5Gb/sec from a single location.

In its study, “Carrying Carrier Wi-Fi: The Technology Challenges”, Real Wireless identified that data demands through Wi-Fi hotspots will increase dramatically, driven by applications like streamed content, which has high Quality of Service requirements.

Taken globally, these hotspots will need to support a forecast 63 exabytes of Wi-Fi IP traffic per month by 2018.

The mobile industry has always sat a little unhappily with Wi-Fi, not least because it’s hard to work out who is making the call on Wi-Fi (which you need to do if you want to bill them).

It also makes it much easier for people to use VoIP services and cut the operator out of the loop. Technologies such as Unlicensed Mobile Access have so far failed to take off, but Wi-Fi handover is still seen as a solution to bandwidth problems the operators are expecting to face. ®