In Building Cellular Networks Icon

In-Building Mobile Signal Boosting Solutions.

Watch Video to Learn More

Solve poor mobile coverage problems with Nextivity's Ofcom-approved intelligent mobile signal boosting solutions.

Simpli-Fi provides solutions for small offices to large enterprise buildings across the Education, Care, Leisure and Commercial sectors, all fully compliant with Ofcom’s UK Interface requirement.

We deliver the most advanced technology solutions for improving indoor mobile coverage. We design, supply, install and support next-generation mobile signal booster systems that reliably deliver high-speed voice and data services for every aspect of your in-building business communications.

All our inbuilding coverage systems are based on the Nextivity CEL-FI cellular coverage solutions, which are license-exempt and fully compliant with Ofcom’s legislation regarding usage. With the award-winning Intelliboost chipset at their core, Nextivity mobile signal boosters are self-configuring according to network coverage conditions, unconditionally network safe and automatically power down if there is a network conflict.

We provide an In-building mobile signal-boosting proof of concept (POC) so you can see the difference it can make to your business.


Request your design survey.


In-Building Mobile

What is an in-building mobile network signal booster?

An in-building mobile signal booster takes the external mobile signal, amplifies it and rebroadcasts it in the building areas where it is required. Boosting mobile signal in the way Nextivity solutions operate, apart from reduced dropped calls, also means improved voice clarity and streaming, as well as faster downloads and improved battery life for the devices benefiting from the service.

Once installed, Simpli-Fi provides bespoke ongoing managed services and digital performance monitoring and applies automatic updates to support continual network changes in your area.

Core Benefits

What are the core benefits of the Nextivity intelligent mobile signal; boosting solution, delivered through Simpli-Fi?

Cost effective

Our solution is the lowest TCO (total cost of ownership), delivering the highest gain at the industry’s lowest cost per m2.

Best performance

Nextivity solutions provide reliable cellular coverage with 3x the coverage footprint of comparable systems.

Super fast data retrieval

We provide lightning-fast data rates so that the data you need is with you in seconds.

No dropped calls

We boost your signal so you can receive crystal clear, reliable voice connections.

Rapidly installed, set up and configured

It can be configured across multiple floors or across campuses, and no operator approval is required, enabling rapid deployment.


CEL-FI systems are fully compliant with Ofcom requirements. It is rapidly installed, set up and configured by Nextivity certified installers.

Remote management through CEL-FI Wave

Wave is the software platform used to remotely manage, activate and optimise CEL-FI systems.

3G 4G 5G and LTE networks

Nextivity solutions are approved by over 200 carriers and are unconditionally network safe.

Mobile network operator consultancy

Simpli-Fi provides Mobile Network Operator (MNO) consultancy and advice for when choosing or changing providers.

New ESN ready

Public safety communications in preparation for new emergency services network (ESN) – covering lone working and basement working.

End To End Support From Simpli-Fi


Our expert project managers and telecommunication engineers will consult with your team, survey your premises and recommend the best solution for your business.


Our specialists will then work with surveyors' recommendations to design a mobile phone signal booster solution to optimise connectivity, whether you are centrally or remotely located.


From installation to on-going support, our team of engineers offers UK-wide coverage, ensuring we will reach you whatever the site location and delivering expert, reliable service to keep you connected.


Once installed, we provide bespoke, ongoing managed services and digital performance monitoring and apply automatic updates to support continual network changes in your area.

Request a FREE design Survey

Find out how we can help you improve your business communication through mobile signal boosting.

Our Partners and Vendors

We have been working with trusted vendors for decades. These valued partnerships allow us to exchange views and support innovation, ensuring our clients always receive the right solution at the best price.