We start by understanding your building, the networks affected and where the signal problems occur. From there, we can recommend the most suitable solution and, where needed, arrange a survey before finalising the design and installation approach.

Yes. We only recommend network-safe, Ofcom-compliant solutions designed for legal use in the UK. We’ll also advise whether your site needs a straightforward installation or a more tailored design.

Yes. We can advise on solutions for the major UK mobile networks, and depending on the product and site, we can support either single-network or multi-network coverage.

For smaller, single-network projects in relatively small buildings, an on-site survey may not always be required. For larger or more complex installations, a survey helps us design the most suitable solution.

Even if you have no mobile signal indoors, a signal booster can usually improve reception as long as there is a mobile signal available outside or at roof level.

Find out more about our three-stage process.

Once we understand the site and the signal issue, we can usually advise on the next step quickly. For suitable projects, the process can move fast from survey through to installation, testing and support.

CEL-FI is Nextivity's range of intelligent mobile signal enhancement systems, designed to improve mobile voice and data coverage inside buildings.

The systems receive an existing mobile network signal, typically from outside or at roof level, enhance it and distribute it to the areas requiring improved coverage.

CEL-FI solutions are available for different building sizes and mobile network requirements, from smaller premises to large commercial installations.

Learn more about how mobile signal boosters work.

A mobile signal repeater receives and amplifies existing mobile network signals to improve coverage inside buildings.

Yes, suitable mobile signal repeaters can legally be used in the UK without an individual Ofcom licence, provided they meet the applicable technical and operating requirements.

Frequency Signal Solutions specialises in compliant CEL-FI systems for commercial buildings and can advise on the most suitable solution for your requirements.

Learn more in our Ofcom compliance guide.

CEL-FI mobile signal boosters use the available mobile network signal to improve indoor coverage, rather than relying on a broadband connection to carry mobile calls or data.

Internet, GPS, setup and monitoring requirements can vary depending on the CEL-FI system selected. We can advise on the requirements for your installation.

Wi-Fi (wireless fidelity) is a wireless networking technology used to connect your laptop, mobile phone, tablet or other internet-enabled device to your broadband/internet provider. Wi-Fi signal repeaters (or boosters) are devices that increase the reach of your Wi-Fi network to improve connectivity in areas where the signal is weak. A booster amplifies a weak signal to eliminate Wi-Fi blackspots and give fast connectivity all over the home.

Mobile signal connects your phone or device to a mobile network carrier. Mobile signal repeaters (or boosters) improve the mobile signal received from mobile networks in indoor areas. They focus specifically on improving voice clarity and reduce dropped calls for mobiles in areas with poor network coverage, as well as increasing download speeds and improving streaming and internet browsing on mobile broadband enabled devices.

CEL-FI can turn one bar of mobile signal into up to 5 bars and can retransmit the amplified 3G / 4G / 5G signal to other areas that have little or no coverage. Unlike Wi-Fi boosters, CEL-FI does not require a broadband connection.

Different CEL-FI systems support different mobile technologies, frequencies and networks.

Frequency Signal Solutions can help identify the right solution for the mobile networks and coverage requirements of your building.

Certain building materials can affect the coverage area of CEL-FI units. Older buildings tend to use more materials and have thicker walls, therefore reducing the radius coverage. Modern construction materials such as foil-backed insulation and thermally-reflective glass can have a similar effect. If you would like to discuss a particular material in further detail with one of our advisors, please contact us.

Every product in the current CEL-FI range can be connected to an external antenna. An external antenna is required when there is inadequate signal strength available within the property.

If you have an older system which is failing to detect a signal in a new property or on a new network etc. you can check the model number on the label, which will have an '_EXA' suffix (e.g. D32-1/3_EXA) if an external antenna can be used. Another way to determine external antenna compatibility is by looking at the Network (window) Unit; if there is a gold threaded fitting on the back then an external antenna can be attached.

CEL-FI systems are designed to operate within applicable radio equipment safety standards.

Radio-frequency power levels depend on the specific CEL-FI model and antenna configuration, so there is no single figure that applies to every installation.

Frequency Signal Solutions can provide the manufacturer's technical and compliance information for the equipment recommended for your building.

No.

CEL-FI signal boosters are compatible with all four of the UK mobile operators: EE, O2, Three or Vodafone. However, within these networks there are also Mobile Virtual Network Operators (MVNOs). Please check our Networks page for list of the most common MVNOs and the operator they use.

Please note that MVNOs may occasionally change their host network. If this happens, please contact us about reconfiguring your CEL-FI unit. Please also note that network operators have the right to shut down your system at any time, without notice.

Signalboosters only sell CEL-FI signal boosters configured to UK based networks which comply with the Ofcom (IR2102) (UK) and ComReg S.I.No.283 of 2018 (Ireland) regulatory requirements.

However, CEL-FI is authorised by almost 200 mobile operators worldwide and can be reconfigured to other networks using the Wave app. Signalboosters claim no responsibility for product performance in other countries which may have different regulatory requirements.

Yes. In the UK all CEL-FI units must be registered using the Wave^™ mobile app available for Apple/iOS and Android mobile devices. Other networks may or may not require registration.

Yes. Each CEL-FI system is configured to work on an individual operator network or selection of operator networks.

Yes. If they were supplied by signalboosters.co.uk CEL-FI units can be re-configured to other networks using the Wave^™ mobile app if you change your mobile network. Units supllied directly through the UK mobile networks cannot be reconfigured to other networks.

CEL-FI systems can automatically adjust to changing mobile network conditions, helping maintain indoor coverage with minimal day-to-day attention.

For commercial installations, optional remote monitoring, system updates and maintenance services are also available where required. These can be quoted individually as part of your project.

Learn more about remote system monitoring.

Yes.

Yes. All iPad and iPhone versions are supported by CEL-FI systems sold on this web site.

CEL-FI units are set to particular frequencies and locked to the network identity (referred to as the 'PLMN-ID'). Therefore CEL-FI devices typically only work for the particular country and network they are sold to. Only the manufacturer, Nextivity, can create the configuration for any given network.

CEL-FI offer various configurations for a range of EU networks. Please contact us to find out if we can support you.

Please view our Resources page for installation videos, quick start guides and data sheets for CEL-FI products.

IntelliBoost is Nextivity's proprietary signal-processing technology used in CEL-FI systems.

It intelligently adjusts the way mobile signals are amplified, using techniques such as filtering and automatic gain control to help deliver reliable indoor coverage while protecting the surrounding mobile network.

Yes. CEL-FI systems are mobile signal repeaters that use intelligent signal processing and automatic controls to improve indoor mobile reception.

Selected CEL-FI models meet Ofcom's technical requirements for licence-exempt use in the UK when installed and operated in accordance with the applicable conditions.

Gain describes how much a system can amplify the mobile signal it receives.

Selected CEL-FI systems can provide up to 100dB of gain, helping improve indoor reception even where the available outdoor signal is relatively weak.

High gain is an important advantage, but the best results also depend on factors such as the available signal, antenna positioning, building layout and system design.

Frequency Signal Solutions can recommend the right equipment and antenna arrangement to deliver the coverage your building requires.

No. CEL-FI is designed to improve indoor coverage while protecting the surrounding mobile network.

Nextivity's IntelliBoost technology uses intelligent signal processing, automatic gain control and filtering to adjust to network conditions and manage interference.

This allows CEL-FI systems to deliver improved indoor reception while operating within the applicable technical requirements.

CEL-FI combines Nextivity's proprietary IntelliBoost technology with intelligent signal management and high-performance amplification to deliver reliable indoor mobile coverage.

The CEL-FI range includes solutions for different building sizes and network requirements, from smaller single-network installations to larger commercial systems supporting multiple networks.

Frequency Signal Solutions can help specify the appropriate CEL-FI equipment and system design for your building.

Try running the “CEL-FI Wave” mobile app on your Apple or Android mobile device and connect to the CEL-FI Coverage Unit using Bluetooth. The mobile app will prompt you, if required, to enter registration information and offer trouble-shooting tips.

If the issue is still not resolved after carrying out the instructions on the troubleshooting guide, please contact a member of our customer service team.