The A to Z of wireless

I is for Indoors

With the rise of mobile data carried on 3G networks, indoor mobile coverage has become a thorny issue for operators.

People want to use their phones indoors for data - watching video, browsing the web, and so on - but in-building coverage for data can be patchy.

It's fundamentally a spectrum problem: 3G spectrum tends to occupy high frequency bands which are much worse at penetrating buildings than 2G (GSM) spectrum. (See S is for Spectrum).

Building out mobile networks to ensure high quality 3G coverage indoors would be an expensive business for operators.

However, there are alternatives: common or garden wi-fi has been picking up some of the indoor slack as more smartphones come with an embedded wi-fi radio (see D is for Dual mode). Using wi-fi where available can also be a faster way of consuming data on your mobile and reduces data download costs that can still be extortionate.

Indoor mobile base stations - aka femtocells - are also being looked at by mobile operators as a way of offloading 3G traffic by routing it onto a user's broadband connection - albeit ultimately a DSL line.