Small cells may be all the rage at this year's Mobile World Congress, with Informa Telecons & Media predicting that the installed base of small cells will grow from 11 million units today to 92 million units in 2016, but one company claims that small cells are not always the best answer to indoor coverage problems.

According to Rob Bruce, Chief Operating Officer at distributed antenna system (DAS) vendor Axell Networks, a building is an asset, and that asset wants to deliver all the services it can in the simplest and most economical way. 

“You wouldn't put five separate lighting systems into a building because there are five separate tenants in that building. You would put one in, and it becomes a utility for that building,” Bruce told Techworld.

“Our view of life is it's the same for cellular coverage. You put one system in which covers the building. That is then a utility for the building, and operators can then connect into that infrastructure – that's how a DAS system works.”

Bruce said that small cells are very good for single operator environments, when a single operator wants to add some capability into a particular area. But if they want to put multiple technologies into that environment then they have to put in multiple small cells.

So if a company in the UK wants to put GSM, UMTS and LTE into an office block, it has to install three small cells. If it wants to make that truly operator agnostic, it will probably have to put in 12 units, because each of the four operators uses at least three spectrum bands.

Axell Wireless recently installed a multi-operator DAS in The Shard in London, using 20 remote units to cover the whole building. Bruce claimed that, if the same thing had been done using small cells, it would involve over 100 units.

“So the building owner is saying I've got 100 lumps of intelligent electronics gadgetry that is scattered all over my building, and there's 4 different operators wanting access to all those different things in private flats, hotels and offices – it's just an operational nightmare,” said Bruce.

“What we've got is one common system that's run and delivered by the building owner and the building management company. It all leads down into a room in the basement where the operators put all of their equipment, so if there are any problems the operator goes to that room. They don't have to crawl all over the building.”

Axell Wireless announced today that it is integrating WiFi into its Optical Master Unit II based DAS, meaning that organisations only need one backhaul cabling infrastructure. Building owners can plug a WiFi access point directly into the DAS and WiFi traffic is then carried over the DAS fibre connections. 

“What we've done is say, why put lots of different systems into a building when you could combine things? So what we're arguing is, we've got to put our cellular system in, let's hang WiFi off that infrastructure, so then it's all on one common distribution environment.”

Bruce said that the idea for integrating WiFi came when Axell was installing its DAS technology at the Olympic Park, ahead of the London 2012 Olympic Games.

“We were running around the Olympic park, working with al the different parties to roll out this huge infrastructure – this big DAS – and we were sitting there looking at Cisco doing exactly the same thing using WiFi, which was going in exactly the same place and you've got fibre optic cables being duplicated right left and centre,” he said. 

“We do get quite a lot of people that are asking us whether we can provide some kind of solution that integrates the WiFi with the cellular DAS system.”