Status of UK Mobile Signal Boosters from O2, Three, Vodafone and EE

The spread of Wi-Fi Calling across the UK’s major operators, which uses your home or other WiFi (broadband) service to run mobile calls and text (SMS) messages, has resulted in the gradual phasing-out of indoor femtocell signal boosters. But some people still want these, so we set out to find which operators will support them.

Until recently all of the major UK mobile operators offered Mobile Signal Booster devices – Three UK (Home Signal), EE (Signal Box), O2 (BoostBox) and Vodafone (Sure Signal). Crucially, these aren’t the same as indoor signal repeaters that merely boost an existing signal, instead these devices were often sold to consumers in areas (e.g. rural locations) where no 3G signal existed at all, or where the signal was too weak to be reliable.

The idea is simple enough. The device is plugged into a fixed line broadband ISP network, which enables it to harness your home or office internet connection in order to create its own indoor 3G mobile signal (microcell / femtocell) over a specific band (e.g. 2100MHz). A minimum download speed of between 0.5Mbps to 1Mbps was often required for this to work, as well as about half that in upload performance.

However, the advent of WiFi Calling (VoWiFi), which enables consumers with supporting Smartphones to harness a nearby wireless network in order to make mobile voice calls or send text messages, has gradually been reducing the need for such boosters. As has the ever-expanding coverage of 4G services, not least through the new Shared Rural Network (SRN) project (latest progress).

In response, many mobile operators have been gradually withdrawing their signal boosting devices from sale and Vodafone aim to completely shut the service down in September 2021 (here).

The Future

The biggest problem with WiFi Calling, perhaps not unlike the signal boosting solutions before it, is that it’s not yet a perfect service. Support for WiFi Calling remains a bit of a mixed bag and is partly dependent upon the capability of your Smartphone (note: many people still use basic mobiles). Likewise, some operators support voice calls but struggle with texts, while in other cases you won’t be able to get either on certain plans.

Equally, WiFi Calling may struggle to work if the wireless signal is weak or congested with a lot of users. On top of that, the feature is mainly designed to kick in around areas of weak mobile signal, but some have found issues with call stability when moving between rooms in areas where the difference between WiFi and Mobile signal strength can be highly variable (i.e. the transition should be seamless, but that’s not always the case).

Suffice to say that some consumers have opted to continue using Femtocell Mobile Signal Boosters instead, but many are concerned about the future of these devices. In response, we’ve attempted to find out the current state of play as best we can from each operator.

Vodafone (Sure Signal)

As above, Vodafone stopped selling their Sure Signal (v3) devices last April 2020 and they aim to completely withdraw the service by September 2021.

Three UK (Home Signal)

Three also stopped selling their Home Signal devices last year, although they are currently still supporting existing users. We did ask Three what their plans were for future support or retirement, and they promised us a response, but after several days of waiting – and two nudges to respond – no reply came.

EE (Signal Box)

We know from past comments that EE have officially “phased signal boxes out in favour of WiFi calling.” At the time of writing, we are aware of several people with working units, although EE remain vague about how long their support for existing customers will last. A spokesperson told ISPreview.co.uk: “EE customers can now keep connected in even more places with WiFi Calling, offering a superior experience and so the EE Signal Box is no longer available to buy from our website. We continue to support existing EE Signal Box customers and our contact centre colleagues are always on hand to answer any questions customers may have.”

O2 (BoostBox)

At present, O2 (VMO2) are the only mobile operator still able to supply their BoostBox to new customers (here), albeit only business customers. A spokesperson for the operator told ISPreview.co.uk: “The service is still available for customers to buy, and any existing or new O2 Business or Enterprise Customer can order a Boostbox. The service for consumers is still WiFi calling. We have no plans to withdraw the service at this time.”

Like it or not, these devices are a relic of the past, and those that still exist probably won’t be around for much longer. The fact that most of them are based off 3G bands and technology is another inevitable nail in the coffin, since most operators are currently preparing to sunset related bands in favour of 4G and 5G services in the near future. The exception would be O2’s BoostBox, which works with both 4G and 3G.