Does Carrier Wi-Fi Offload Actually Work?

Mobile service providers are hopeful that deployment of small cells and carrier Wi-Fi will reduce strain on the mobile networks. It seems reasonable that adding Wi-Fi offload, and shifting traffic to localized small cells, will indeed help reduce demand on the macrocell network.

The issue is whether that actually will happen, and in the case of carrier Wi-Fi, under what conditions. The question might seem irrelevant. By some estimates, a majority of mobile data traffic--perhaps 66 percent--already is offloaded to third-party Wi-Fi access. In the future, some predict as much as 80 percent of all mobile data will be offloaded to Wi-Fi.

But there are caveats. In some dense urban areas, carrier Wi-Fi might be much less effective, because of interference issues.

NTT Docomo, for example has found excessive interference in Tokyo limits the effectiveness of carrier Wi-Fi.

Also, new tests by Deutsche Telekom in Hamburg and Rotterdam suggest carrier Wi-Fi networks have little impact on the volume of mobile data network traffic, the very problem carrier Wi-Fi is supposed to help address.

In fact, the test showed very little change in mobile network demand, and in some cases an increase in demand on the mobile data network.

Some might suggest a different outcome might have been obtained if the focus of carrier Wi-Fi had been indoor areas, rather than public outdoor areas.

The reasons require some application of economics principles, namely that behavior (demand) changes when there is a change in supply. It is likely people behaved differently, consuming more data, when they knew Wi-Fi was available, but also did not reduce their mobile usage. More on user behavior and the effect of the consumer on the mobile world can be discovered at the “Personalization for a Mobile and Social World” conference, taking place this week at ITEXPO in Miami, Florida.

Also, it appears applications and devices behaved differently when Wi-Fi was available, conducting app updates, for example, when in the Wi-Fi zones, without affecting mobile network usage.

Deutsche Telekom has partnered with Fon to increase its Wi-Fi coverage in Germany, hoping that will help Deutsche Telekom manage its data infrastructure costs.

Some might say that is the real value of carrier Wi-Fi offload. The cost of delivery of one GB on current LTE networks is about US$3 while the cost of delivery using equivalent carrier-class Wi-Fi networks is about US$1, according to Hetting Consulting.

Cisco  research shows that providers can expect mobile data traffic to increase 18-fold over the five years between 2011 and 2016.