Fault Finding

This could be down to a number of things, but here are some checks you can perform before contacting our technical team:

• If the unit is calling a mobile phone, make sure the receiver of the call has WiFi calling disabled.
• If the network in the area is down or having issues, this could cause the DTMF tones to stop working. To check if this is the case, try another SIM on a different network in the unit.
• On landline units, if the line it is connected to has audible interference, the unit may not be able to hear the DTMF tones clearly. If this is the case, you will need to contact the line provider and ask them to perform a test on the line.

Please note: Our systems are experiencing a non-compatibility issue with most digital lines where DTMF tones are not available.

If your customer is using a digital line in their household, it is recommended that they have their mobile phone connected as a point of contact rather than the landline phone which is using the digital line.
Regarding digital line issues, you can refer to the following link: https://www.voipmechanic.com/dtmf-issues.htm

If the above checks have been done and you are still experiencing issues, please contact our technical team.

You can check the status of your network’s signal on their website. You can find links to O2, Vodafone and EE’s websites below.

Mobile phones have priority access to network masts and can switch between masts to maintain a signal while roaming. This allows them to consistently find the best signal available in any given location.

Intercoms, on the other hand, are stationary and cannot move between network masts. As a result, they are assigned a lower priority than mobile phones, which can lead to weaker or less reliable signals.

To address this issue, we recommend performing a signal test with an analyser to determine the best network in your area before the intercom is installed. If your intercom is already installed, you can connect its antenna to a signal analyser to identify the most suitable network for optimal performance.

Advancements in technology have led to the shutdown of 3G to enable redistribution of bandwidth and frequency to later generations. This has driven the major networks to begin the evolution of 4G LTE to VoLTE.

VoLTE means Voice over LTE (Long-Term Evolution) and can be used to make and receive phone calls when 2G/3G is not present.

Previously, 4G was limited to internet browsing, and your device would automatically switch to 3G or 2G to make or receive phone calls.

Commtel products use the network to make a phone call via 2G/3G/4G LTE. The 3G bandwidth is predominantly the generation impacted by the network changes, however, 4G LTE, which runs on a similar bandwidth to 3G, is also evolving to a later generation – VoLTE. This will only affect limited areas where a 2G or 3G/4G LTE signal is insufficient.

The major networks are rolling out the renovations UK wide. Currently major networks are not legislated or required to pre-publish areas they will be working on. We do continue to monitor communications to establish the expected durations of the works.

The changes are being gradually rolled out across the UK between 2024 and 2033.

The major networks are reporting that changes to 2G will not be made until the 2030’s. 3G renovations are already underway in small pockets of the UK, accelerating the evolution of 4G LTE to VoLTE.

If there is no 2G or 3G/4G LTE coverage in the area where the unit is installed, then yes, a new PCB with the latest firmware and a VoLTE enabled SIM will be required.

Through rigorous testing and supplier expert inputs, we strongly recommend that the SIM cards used in our products are also VoLTE enabled, to allow for optimised performance and compatibility. We have taken steps to on-board a new SIM supplier, ensuring that the SIM cards we are supplying are also VoLTE ready.

The SIM cards we supply are VoLTE enabled. Additionally, we have a list of recommended SIM cards, should customers wish to purchase their own. Retail SIMs are also VoLTE enabled, for example, purchasing SIMs via the major phone stores or supermarkets.

Yes, as of October 2023, Commtel products requiring a SIM card are VoLTE enabled.

Any units within warranty, either the original 2-year warranty, or an extended product warranty, will be covered for product issues relating to VoLTE.

To safeguard our ability to provide safe, secure, reliable solutions we will be offering a PCB exchange to customers who are affected. This is via the installation company who installed the intercom.

Upgrading to VoLTE requires a replacement PCB. If the SIM card is not VoLTE enabled, you will also need to replace the SIM. Please contact your installer who will walk you through the process.

We are continuing to work with our component source manufacturers, updating the firmware profiles to align with the ever-changing network requirements.

Please rest assured that we are diligently working to ensure our products continue to meet and exceed expectations in this dynamic landscape. Our efforts are focused on understanding and overcoming network technological developments whilst responding in an agile manner.