Mobile Network Guide

Product Reviews
 Nextivity Cel-Fi Repeater

Nextivity Cel-Fi Repeater

Was easy to setup, boosted the signal from 2 to 5 bars, increased 3G data speed, great size coverage area

Only available for a single carrier, no GSM or 4G support, currently only for Telstra Next G customers.

Now available for Telstra, Vodafone and Optus (3G & 4G)



UPDATED: Cel-Fi is now available for Telstra, Optus and Vodafone.


If you have ever suffered from poor mobile reception in your home or office, you will understand the frustration of slow internet browsing, poor call quality and moving to a certain spot to get reception.

Nextivity’s Cel-Fi Repeater is a great solution for those wanting to improve indoor 3G coverage for their smart phones or mobile broadband devices. The system works by grabbing the 3G signal from outside or at a window, boosting the signal and then re broadcasting it inside.

Generally you can expect a coverage area of around 600m², enough for the average home or small office. The Cel-Fi system can handle multiple mobile devices, including smart phones and mobile data modems. It will only support a 3G signal, not 2G or 4G

Purchasing and Application Process

The Cel-Fi is available from the distributor Powertec Telecommunications for $767.80 inc GST. Before purchasing there is an application process that requires you to answer a few questions to ensure suitability and enter your installation address. The entire process takes about two minutes to complete and is a mobile carrier requirement.


We set the system up in a 1200sq m open office with several smaller rooms at one end of the building. The open office had one bar of Next G signal and the rooms at the other end of the office had 4 bars. Our aim was to get at least 4 bars throughout the entire office.

Setup was quite easy and the system consists of two boxes, the ‘window unit’ (WU) and the ‘coverage unit’ (CU).

The WU was placed in an area that had the best reception, a window in one of the small rooms. The WU is responsible for communicating with the mobile phone tower. Once installed it indicated full signal strength on the WU.

The other smaller box is the CU, which was placed at the other end of the office about 30m away with two walls in between. The CU disburses the signal throughout the office and connects back to the WU via a wireless link.

The WU and CU units can be up to 30m apart, the further apart they are the more the signal will be amplified and the larger the indoor coverage area will generally be. On the CU you will find an LED indicator with a numbering system from 0-9 representing the output power. Ideally you require an 8 or 9 to ensure maximum indoor coverage. If the CU is close to the WU it will display a 1, as you move it further away the numbers should increase up to 9. At the same time the indoor coverage also increases.

We found that having the WU and CU in line of sight of each other did not create enough separation and having walls in between enabled us to get a 9 on the display.

If you are in an extremely poor signal area the option of connecting an external antenna is available. As a rule the stronger Cel-Fi’s input signal, the larger the coverage area and faster the internet speed should be.


The Next G mobiles in the office went from 1-2 bars, increasing to 5 steady bars. We tested the repeater over a week and only stopped working when a cleaner accidentally turned off the coverage unit.

The Next G data devices in the office also increased to full bars, with data speeds increasing.



The Cel-Fi Repeater does exactly what it is intended to do, boosts your mobile reception. We found it very easy to setup, improved the Next G call quality and data speeds throughout the entire office.

Would recommend the use of this product in offices or houses where you can have at least 20-30m of separation between the two boxes, ideally with a wall in between.

It would have been nice to be able to boost the signal for all mobile carriers. The supplier has advised that in order for the repeater to get approvals and be network friendly it is a requirement to lock the repeater into the carriers frequency bands and network. I understand Optus and Vodafone are currently reviewing the product, so eventually seperate Cel-Fi Repeaters may be available for each carrier.