BT Mobile prepares dignified death for its Signal Assist femtocells

Sometimes old technology does die, and it's not anyone's fault.

Cisco USC 3331

Cisco USC 3331BT is about to stop service to tens of thousands of 3G femtocells that provide its Signal Assist service to BT Mobile customers.

Signal Assist is a service from BT Mobile that lets customers get mobile access in indoor coverage blackspots. BT will close the service by the end of June. It says it is about to start contacting its customers.

The wider picture is that BT is preparing a 3G spectrum shutdown that is due to take full effect in 2024, so any remaining 3G femtocell users would have faced the end of the service by then, anyway. This impending end of June service shutdown just pulls things forward a little.

Aside from the spectrum shut-off, which of course really will put the end on things, it seems that, reading between the lines, platform support for the femtocells is likely to run out before the spectrum does. Perhaps that’s not surprising as the femto units that BT used for the service are Cisco Universal Small Cells 3331, which were in fact end-of-lifed by Cisco back in 2017, at the same time as Cisco announced it was putting an end to its small cell programme.

So is there likely to be an impact on customers? Well, over the years BT said that it has shipped hundreds of thousands of the units (who knew?), and added there are still “low tens of thousands” of users of Signal Assist in its network.

Signal Assist are sent to customers who have problems with mobile coverage in their home or area. It is possible that once service is shutdown, these users will not have mobile voice connectivity. However, BT thinks that there may be mitigation.  BT’s main proposed path for retaining voice service is to point users towards WiFi calling. (The Signal Assist unit is connected to a customer’s existing WiFi router, meaning that all Signal Assist customers should also have WiFi available. They’ll need a phone that is compatible with WiFi calling too, which should be OK unless they have a pretty old phone.) It is also possible that users may be able to access 4G voice services.

In any case, if you are a Signal Assist user that relies on it to be able to make mobile calls, then things are about to change in some way for you. Look out for comms from BT on this. Here is EE’s web page on the closure of its Signal Box, including its advice on what to do next

EE has already communicated with its femto users that service will be closed at the end of June. EE’s similar service is called Signal Box. Signal Assist is BT Mobile’s version of the same solution.