I understand that later this year, when Orange and T-Mobile have fully harmonised their networks, a new version of the firmware will be available for the booster that will allow it to make use of both the Orange and T-Mobile networks simultaneously. Will it be possible to upgrade to this firmware and whether there will be a charge for this?


The updated software still only boosts one network (either Orange or T-Mobile) but it’s just that the new version automatically picks the best one.  The issue is more that there are network changes required by Everything Everywhere before we can release the software update. (It actually happened in May, 2012 & there’s no additional charge for that.)

The units supplied by Frequency Telecom (purchased on this website) can be manually reconfigured so there is less of a requirement for this ‘pick the better network’ capability in the software as you can always swap the micro-SD cards around in the Window Unit.

What is the difference between RS1 and RS2?


The RS1 has lower capacity than the RS2, in terms of the number of radio channels it supports. The RS1 was deployed to a limited extent by T-Mobile UK and in tiny amounts by O2 UK. It is no longer being supplied in the UK.

The RS2 has 3x the radio capacity of the RS1 and is deployed in the UK with a configuration that allows the mobile operator whose network it is configured for to turn it off by setting particular parameters in the network.

In all other respects the RS1 and RS2 are the same, they are locked to a particular network, only boost that network’s radio frequencies and implement hardware and software algorithms that completely protect the network from the harmful effects usually associated with repeater products.

What frequencies does Cel-Fi support?


The main 3G band is known as ‘UMTS Band 1’ and it operates in a range of frequencies around 2100 MHz. Each mobile operator in the UK has 2 or 3 frequencies within this band which is supported by Cel-Fi.

What is the range and capacity of the system?


Range from the base station is determined by the uplink power of the Window Unit – this is a maximum of 24.7 dBm EIRP across all 3 carriers (basically range from the base station is similar to a phone).

Footprint of coverage inside the building provided by Cel-Fi depends on building construction; we quote 20-metre radius as typical, but it can be smaller or bigger depending on:

• the building construction
• strength of the signal at the Window Unit and
• physical separation of the Window Unit and Coverage unit (more separation = more boost).

There is not limit of the number of devices that can be attached to the network via Cel-Fi. Capacity in terms of number of calls at the same time depends on how far away the Cel-Fi is from the serving base station; If the Cel-Fi is far away (1 or 2 bars on the WU) then it might only support 4-6 calls. If the Cel-Fi is closer to the serving base station (say, 4 or 5 bars) it can support around 20 calls.

Are there any problems with multi users on one unit? That is if our neighbours in adjacent offices on the same network use it?


Within the footprint of the unit any devices on that particular network will use it (so yes, neighbours might see benefit).  There is a limit to the number of users; this is because all of the uplink traffic from the users within its coverage is funnelled through the uplink radio of the Cel-Fi unit and it has a finite maximum power.

The number of calls the unit can support depends on how far away it is from the serving base station (shown by the number of coverage bars on the display of the Cel-Fi Window Unit). Where the coverage is weak (1 or 2 bars on the Cel-Fi Window Unit) the unit may support as little as 3-6 calls.  Where the coverage is good (4 or 5 bars on the Cel-Fi Window Unit) of the order of 20 calls can be supported.