Ofcom would like to legitimise the use of consumer-installed cellular repeaters in the UK – provided it can find a way of ensuring that only good quality equipment that does not cause interference is sold to consumers.
Ofcom is taking a view that as consumers and some businesses are already installing cellular repeaters of dubious quality – it reckons some 3,000 were sold in the UK in 2014 – it would be better if it could somehow legitimise the use of approved-quality repeaters and in so doing clean up interference issues.
Given the potential benefits that consumer installed repeaters can provide to consumers, Ofcom would like to enable their legitimate use in the UK, if this can be achieved without being likely to cause undue interference to, or otherwise adversely affect the technical quality of service for, other spectrum users.
Right now, Ofcom says, repeaters can often cause interference, damaging the experience of other users. Since 2009 Ofcom has investigated 494 complaints where repeaters were likely to have been causing adverse effects. A study found that if a repeater operating with no interference avoidance measures is located within 400m of a 2G 900MHz base station, then call drop rates at that base station would exceed 1%. For 3G at 900MHz that distance drops to 290 metres.
But Ofcom doesn’t think it would be so hard to build features into repeaters that would lessen the negative impact on users around them. Mitigation would include features such as only amplifying the channel used and not other channels, automatically switching the repeater of when not in use, and adapting transmit power to the minimum required.
Ofcom says that, in fact, many repeaters currently sold already advertise these features although design quality and build varies. So the question is one of implementation. How can Ofcom get to a situation where it can be sure that repeaters being sold are of good enough quality?
Its proposal is that “relevant stakeholders” submit to Ofcom the specifications of repeaters they would like to put on the market: “This would allow Ofcom to identify the characteristics, and any conditions of installation and use, required for repeaters of particular descriptions to be authorised for use in the UK on a licence exempt basis.”
There may also be additional requirements, such as logging the location of the repeater.
The benefits of repeaters, as seen by Ofcom, are that unlike small cells they don’t require a dedicated backhaul connection and they can be multi-network, and they are cheaper than DAS. Note that repeaters are a coverage extension solution – good for getting indoors, inside trains, and extending coverage in some rural areas – and are not a capacity solution.
Note that Ofcom says there is a good deal of detail still to work out, in terms of specifications. It would also like those specifications to be internationally harmonised – say via ETSI standards – bringing about economies of scale and lower prices.
In summary: it may be that consumer-installed repeaters, installed legally without the need for a license, will become a coverage extension option in the UK, but not for a while.