Growth in the deployment of in-building wireless systems has accelerated to nearly 26 per cent, and more than 500,000 buildings will use such a system by 2013, according to new research.

The systems provide indoor cellular coverage and capacity when the macro network cannot effectively penetrate buildings.

ABI Research said that the systems fall into four broad categories: passive distributed antenna, active distributed antenna, distributed repeater and distributed radio.

Dan Shey, principal analyst at ABI, said: "Buildings are the last great frontier for cellular coverage for vast portions of the population.

"With the majority of mobile voice and data network traffic originating inside buildings, operators need a strong in-building wireless service in an increasingly competitive environment if they expect to keep customers."

Drivers for in-building system growth are region-dependent, according to the analyst, and include frequency spectrum band distribution, network air interface protocol, data services adoption forecasts, customer revenue spend and margin, building height and materials construction.

However, operators and building owners will influence this market as a result of their propensity to deploy in-building wireless networks.

Equipment used for such systems includes the individual components of active and passive distributed antenna systems, repeaters, cabling, picocells and femtocells, ABI said.

"But in-building wireless systems will also change the marketplace for serving business customers," said Shey.

"In-building wireless systems establish a footprint for the delivery of information and services.

"Successful mobile providers will leverage these networks to fundamentally change the way data and communications are delivered to mobile customers."