Have a general or technical question about Cel-Fi?

RFI details the most common FAQ on CEL-FI. Find out more below.

Learn more about the complete range of CEL-FI in-building and in-vehicle solutions.

What is CEL-FI?

CEL-FI is Nextivity’s brand of self-configuring, environmentally aware, coverage solutions.

Each CEL-FI system consists of a CEL-FI device along with at least two antennas.

The Donor antenna is placed in the area where the strongest native signal can be received from the carrier network (signal levels as low as -120 dBm are acceptable), typically on a building’s roof or appropriate local for a building or on the Vehicle’s roof or Bull Bar.

The CEL-FI Unit comprises a transmitter and receiver which communicates with the cell tower.

The Coverage Antennas is placed in the area where coverage is required and “lights up” the interior of the house or vehicle with significantly enhanced signal levels, thus enabling better quality calls and greater data throughput. 

What makes CEL-FI so different from other mobile repeaters?

CEL-FI is a smart signal repeater. That means it relies on intelligent, self-organizing algorithms to ensure you benefit from the largest area of coverage without compromising or interfering with your mobile operator’s networks or impeding other subscribers’ signals. CEL-FI does not require any new equipment, any configuring, or any changes to existing network infrastructure or mobile devices. It is also a plug-and-play device, which means that there is no need for professional installation, no drilling, and no cables. In addition, CEL-FI has been recognized for its superior design and effectiveness and is the only consumer repeater authorized for use by the communications commissions in Australia/New Zealand and other Pacific nations. It has specifications that allow very high gain (very high signal gain is necessary to make low-level signals useful in a large coverage area). 

Does the ROAM Connect Pack work with 5G?

The ROAM R41 is capable of repeating the majority of the frequency bands used by the Australian mobile phone operators. Each operator will decide which bands they will use for 4G or 5G and the ROAM R41 currently supports 5G DSS. The Antenna’s provided in the ROAM Connect pack matches the frequency bands provided by the R41 ensuring the best performance in all environments.

Does the ROAM Connect Pack contain an antenna mount?

Due to the large variation of vehicle mounting options, the ROAM Connect pack does not include an antenna mount. RFI has a large range of the antenna mounts that you can carry and sell to the customers to meet their requirements.

Can I switch my ROAM R41 between operators?

The ROAM R41 can be switched between any of the three Australian operators.

Can I use the R41 for in-building applications?

The ROAM R41 is designed to be used in vehicles so it has a low output power when compared to in-building systems. It can, however, be paired with an AC PSU to provide spot coverage in one room or close to end-user devices, like back up modems.

Can the ROAM R41 be installed outdoors?

The ROAM R41 has an IPX0 (also known as IP54) rating, this means that it is not waterproof and can only be installed in a location where it is not exposed to water or excessive dust.

Does the ROAM R41 need to be grounded?

The ROAM R41 is equipped with a grounding point. It is highly recommended to connect this to the vehicle earth in order to protect the unit from any stray currents.

My Vehicle is 24VDC, can I connect my ROAM R41 directly to the vehicle power?

WARNING, the ROAM R41 is designed to operate on 12VDC (with a 11.5-15V range). RFI offers a range of DC-DC converters to take the 24VDC to 12VDC.

Does R41 support B28 (700MHz) for Vodafone/TPG?

The ROAM R41 only supports the lower part of the B28 which means it is not suitable for the Vodafone/TPG network.

What Band 26 is?

Telstra is in the process of winding down their 3G network which operates in B5 (850MHz) with the view to have this completely turned off around 2024. Once this is done, they will be able to re-use the spectrum for 5G with wider channel bandwidths.

Does the CEL-FI require an internet or GPS signal connection?

No. The CEL-FI system only needs to have at least 1 bar of native cellular signal, in at least one spot of your home to be able to cover your whole home or office space. 

What coverage can I expect from a CEL-FI system?

The radius (half the width) of the coverage bubble is dependent on the building material, input signal level, and antenna isolation. Here are some typical coverage bubble sizes:

Radius = 20 meters for wood-framed walls and less for concrete interior walls. This can easily exceed 65 metres for open commercial spaces.
Is it legal to use a CEL-FI repeater?

CEL-FI meets the newer regulatory requirements that allow a repeater to be used (boosters that do not meet these requirements, which is the vast majority of them, are not legal).  

Australia’s regulator (ACMA) has strict rules around the use of repeaters, for more information click on this link 

Why is the 100dB gain figure so important?

System gain is critical to a repeater’s performance because it tells us how much a signal may be improved and how beneficial the boosted signal can be.  Example: If you have a low-level signal such as -90 dBm per carrier, adding 100 dB of System Gain gives +10 dBm per carrier which can cover a large area.  In contrast, adding only 70 dB of gain would only give -20 dBm of signal per carrier which would only cover a very small space.  Therefore a booster with a gain of 70 dB would need a very strong donor signal to be of much use, regardless of the stated transmit power that likely is going unused. 

In other words, the higher the gain of the repeater, the better it will work, even when far away from a base station. 

Is CEL-FI operator specific?

Yes, and for a good reason!  CEL-FI is controlled by and operates as an extension of an operator’s network.  This is what allows CEL-FI (by the regulatory authority) to boost signals about 1000x more than other solutions, and therefore cover very large areas even if the original network signal is weak.  And it works very well. 

Broad-spectrum boosters can cause interference and damage to networks, so operators have adopted a strict policy against the use of these legacy signal boosters on their own networks. However, CEL-FI (the only smart signal repeater of its kind), is authorized for use by each carrier and allowed to transmit on their licensed spectrum without ruining things for anyone else.

Why doesn’t CEL-FI work with different operators?

Not all cellular operators use the same technologies, and there are various models of CEL-FI devices to suit each operator in Oceania. The CEL-FI systems will support 3G, 4G, and 5G technology of operators that have approved the use of CEL-FI on their network. You can reach out to RFI for more information on what specific model will be best for your needs.

What technologies does CEL-FI support?

CEL-FI system will support 3G, 4G and 5G provided the operator has deployed one of these in a band that is supported by the relevant CEL-FI device. Each CEL-FI system is different. Check your box for a Quick Start Guide or visit the CEL-FI section on the RFI Websiteto choose the right device for your needs.

Once installed, will the CEL-FI require maintenance, or adjustments if changes occur to the native cellular network?

No. CEL-FI does not require any maintenance. The CEL-FI systems will self-adjust and reconfigure automatically to changing cellular network situations.

What is IntelliBoost?

The Nextivity IntelliBoost Baseband Processor is the first core processor designed specifically to optimize the indoor transmission and reception of 3G/4G/5G wireless signals. With advanced filtering, equalization and echo cancellation techniques, Nextivity has developed an embedded architecture that delivers unprecedented in-building data rates and pervasive 3G/4G/5G connectivity. The IntelliBoost processor ensures that CEL-FI products never negatively impact the macro network while providing maximum coverage.

The unit is not lighting up?

When your system does not power up, one of the following things could be happening. You could have a power adapter failure, a hardware failure, or the system could need a simple restart. 

Make sure that your power source is a functional outlet. Test something else, that you know works in the same outlet, or try moving the GO to another outlet that you have confirmed has working power. 

Still Not Working? 

It is possible that you have a bad power supply or malfunction of your GO hardware. Please reach out to your dealer for further instructions.  

My Status Indicator is blinking Green/Yellow but my phone still has a poor signal at the Service Antenna?

A blinking green or yellow status light indicates that your CEL-FI GO is still in the start-up process. Depending on the complexity of your mobile network, this process can take some time. If the unit is still blinking for more than 30 minutes, please attempt a restart. 

Use the CEL-FI WAVE app to check for further information and any error codes.

My Status Indicator is Solid Green/Yellow but my phone still has a poor signal at the Service Antenna?

If your CEL-FI GO has a solid Status Indicator light in either yellow or green, the system is fully functional.

If your system has a solid (non-red) status light but your phone is not picking up a stronger mobile signal you might need to check the Service Antenna. 

Make sure that your Service Antenna is fully functional. You might try swapping out your Service Antenna with another device. 

To find out more, please contact your dealer or see FAQ "I’ve installed my CEL-FI but I don’t see more bars on my phone”.

My Status Indicator is Flashing Red?

There are several reasons why your status light would be flashing red.   

Use the CEL-FI WAVE app to check for error codes, see below for error code descriptions. 

My Status Indicator is Solid Red?

There are several reasons why your status light would be solid red.   

Use the CEL-FI WAVE app to check for error codes, see below for error code descriptions. 

I’ve installed my CEL-FI, but I don’t see more bars on my phone?

There could be several reasons for this: 

First, you can try rebooting your phone near the Coverage Unit, so it takes a fresh look at the available channels. Also, verify that your phone is compatible with the channels that your CEL-FI model is boosting. iPhones can also show fewer “bars” of signal if the network is heavily loaded.

How do I register my CEL-FI device?

Download the CEL-FI Wave app from Google Play or Apple App Store and ensure Bluetooth is enabled on your device. Open the Wave App close to your CEL-FI device, connect to the device, and follow the prompts.

Why do I have to register my CEL-FI?

Mobile systems are protected assets of the Operators that own them.  Illegal boosters in the market cause problems for those networks (which means all of us using the networks too).  

In Australia/New Zealand the ACMA/RSM and mobile network operators require users to register their CEL-FI repeaters. 

The information collected during registration includes user contact information, the address where the booster is used, booster make, model, and serial number. This information will enable the carrier to contact users or locate the repeater in the event of network issues. Any information collected through this program will be used as described above and is subject the CEL-FI’s Privacy Policy. 

 If you received an “(Error 5) Registration Required”, or “(Error 9) Location Lock – Registration Required” you are required to register your device before you can continue boosting. 

Error messages: 

(Error 5) Registration Required 
Before use, you must register this device and have your provider’s consent. You must operate this device with approved cables as specific by the manufacturer. Systems can be registered via the WAVE application. 

(Error 9) Location Lock – Registration Required 
Your system has been moved from its original address. Please move the system back to its original location or register your new address with your wireless provider. Systems can be registered via the WAVE application.

No bars are showing?

If you have no bars, your Unit may still be trying to find the incoming mobile network signal. Your Unit may display a blinking power indicator light. This can sometimes take more than a few minutes. 

If you have bars of service on your phone in the location of your GO, and after 60 minutes you are still unable to receive bars of service on your Unit try a simple restart. To restart your Unit simply unplug for a moment and then plug back in. If the restart does not solve the issue please reach out to your point of sale for support. 

Can CEL-FI boost the signal of multiple mobile networks at once?

CEL-FI signal repeaters are Operator specific and will only boost one Operator’s channels at a time. Being Operator specific is one of the main reasons that we are network safe and can provide 100 dB of signal gain, and why we are the only signal booster approved by a growing number of Operators.

The WAVE app is stuck on the synch/gathering information page?

If you have launched the CEL-FI WAVE app but it continues to sync… 

Please verify the following: 

  • Make sure your CEL-FI Repeater is powered on and in relay mode (see the product support pages for your CEL-FI repeater). 
  • Ensure you have the latest version of the WAVE app installed. 
  • Make sure that your mobile device is compatible. The app requires Bluetooth 4.1, Android 5 or newer, and iOS 8 or newer. 

If the problem persists, force the app to close (see the iOS or Android instructions) reboot your CEL-FI system and re-launch the CEL-FI WAVE app next to your Coverage Unit. 


Why do I need internet access to register my device?

The WAVE app requires an internet connection to successfully register a system. This is more of an issue when installing CEL-FI devices where there might be a poor network signal and no Wi-Fi available. If there is no data coverage available, you cannot register the product. Unfortunately, the first time connecting (and registering) requires a data connection. Once this has been accomplished, you may be able to operate with our coverage as the app can work in an ‘off-line mode. 

You may have to take the repeater and register it elsewhere and then bring it back to the site. 

Why do I need to allow location access for the WAVE app?

This is an optional step and is only asked the first time you open the WAVE app. This latitude/longitude data is used by the mobile network operators to help locate the repeater in the event of network issues.


Who is the WAVE app for?

The CEL-FI WAVE App is designed for end users and installers. The app is available on iOS and Android smartphones and tablets. It connects via Bluetooth to the CEL-FI GO, GOX, Solo, and GO G41. 

Do I need to keep the wave app open to use the CEL-FI?

No, the WAVE is only required for the initial registration of the device. Once the device has been registered any mobile that is on the same mobile operator that the CEL-FI device is boosting can use the signal from the device.  

The WAVE app is then only needed to make configuration changes or to do troubleshooting. 


Does the CEL-FI provide Wi-Fi?

No, the CEL-FI devices boost the mobile signal from your chosen operator. It merely relays the signal from the nearest mobile phone tower, and you need a mobile device with a SIM card to use the signal. You can use your mobile device to create a Wi-Fi hotspot or use a dedicated Wi-Fi hotspot product to provide Wi-Fi to local users.


What is antenna separation?

Antenna separation is a measure of how much signal one antenna will pick up from the signal that the other antenna transmits. It is critical to get the separation between the antennas as high as possible, this will allow the CEL-FI to operate at a higher gain level which will equate to better service from the unit and a larger coverage bubble. There are two ways to improve antenna separation: 

  • The first is the distance between the antennas and note that Vertical separation generally provides better isolation. 
  • The second is physical isolation via a barrier of some type, ie. a structure or wall in the case of a building, and in a vehicle the roof, or other metal parts. 

In a vehicle is not really possible to get any meaningful distance between the antennas and as such it is best to try to utilise as much of the vehicle as possible. Generally, we recommend mounting the antenna on a bull bar or as far forward as possible with the internal antenna under the dash by the driver's knees. This put the car’s bonnet, engine, and dash structure between the two antennas. Alternatively, the external antenna is mounted on the roof of the vehicle so that the metal roof can provide a barrier.

What is signal strength?

Signal strength is a measure of the amount of signal that the device is receiving from the Mobile Phone Tower. The phone measures this in dB (Decibel) and it is sued in conjunction with a few other parameters to calculate the number of bars to display. Note that each mobile phone vendor has their own formula for this calculation which means that different brands of phones might display different bars in the same area.  


What is signal quality?

Signal Quality is a measure of how “clean” the signal is. The mobile phone not only receives the signal from the tower that it is connected to, but it also receives signals from all the other towers in the area. The other signals can be seen in the mobile phone as interference and the higher this interference the lower the signal quality. Poor signal quality can lead to lower download speeds as well as poor voice quality and even call dropouts. 


I have full 4G service but I cannot make a call.

Please ensure that your handset supports VoLTE calls and that this feature is active. Also confirm that this feature is available on your subscription, some MVNO SIM card also does not have the VoLTE capability. Follow this link for a guide on how to activate VoLTE on your handset: https://www.telstra.com.au/support/mobiles-devices/enable-volte-mobile-phone 

What is an MVNO?

Mobile virtual network operator (MVNOs) are companies that rely on the Telstra, Vodafone or Optus networks to deliver services to their customers. Please see the following site for up to date information on the MVNO market in Australia: https://www.finder.com.au/mvno 

Will my MVNO SIM card work with a CEL-FI device?
Your CEL-FI device will work on a Network that your MVNO SIM card is tied to but there may be limited coverage and services compared to an operator SIM card. The two main issues are generally VoLTE support as well as a limited coverage footprint. The following site can be used to see the difference between the coverage using a Telstra SIM card versus a MVNO SIM card: https://www.whistleout.com.au/MobilePhones/Guides/Telstra-network-coverage-vs-ALDI-Woolworths-Belong-Boost