Its been a while I posted something on DAS (a.k.a. Distributed Antenna System). The articles I have posted have been mainly from AT&T and are
here,
here and
here.
Recently I read something interesting from
IDG here:
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.
Complete article is available
here.
This is an interesting point because the Small Cells are still not evolved enough so that a single one can serve multiple operators, etc. Note that I am differentiating the closed residential femtocells from the public access small cells. Maybe a service such as
FaaS or 'Femto as a Service' can help solve this problem. Based on my previous sentences, some of you may say that it should be called Small Cell as a Service (SCaaS) rather than FaaS but unfortunately that term has come to mean something else as can be seen
here.
While initially the in-building solutions were mainly for coverage reasons, this may no longer be the only reason. Capacity is also an issue, especially in-building. Small cells can certainly help in the capacity area much more than DAS. Fortunately as most new phones are coming with inbuilt Wi-Fi chipsets and WiFi is available indoors in plenty, the capacity issue may no longer be a problem indoors. Again this is an area where we can have lots of discussions and each party with a vested interest can argue their case.
Here are couple of interesting videos from youtube that explain DAS:
There is also an interesting presentation by NEC in the Small Cell Americas event, embedded below:
