Carrier Grade Wi-Fi Calling, the Seamless Calling Feature for Enterprise Businesses

wi-fi calling

Wi-Fi calling has become increasingly popular in recent years, allowing users to make phone calls and send texts over a Wi-Fi connection instead of using traditional cellular service. We’ve all been there where our carrier’s cellular coverage could be stronger, and we have no control over where the carriers place their cell towers. Wi-Fi calling lets us connect and make high-quality calls through our local Wi-Fi networks and over the internet. While calling over Wi-Fi is convenient and reliable for personal use, it can also be a game-changer for businesses looking to improve their communication capabilities, especially for areas with poor cellular coverage. Despite all the benefits, Wi-Fi calling relies on connecting to a strong cellular or Wi-Fi connection and struggles when the connected device moves around and is out of coverage.

Enter carrier-grade Wi-Fi calling, a feature that takes the convenience and reliability of Wi-Fi calling to the next level. This new feature allows a set of calling profiles to be loaded onto a WLAN and, using a carrier’s evolved Packet Data Gateway (ePDG), provides carrier-grade calls. This means that businesses and organizations can offer their employees and customers a seamless communication experience, even in areas with limited or no cellular coverage.


One of the significant benefits of carrier-grade Wi-Fi calling is its reliability. Because it can connect to the carrier network in multiple ways, carrier-grade Wi-Fi calling is less prone to dropped calls and other connectivity issues. This makes it an ideal solution for mission-critical communication in hospitals, schools, public safety organizations, and different environments.

In addition to its reliability, carrier-grade Wi-Fi calling offers business cost savings. Because it uses a Wi-Fi connection instead of cellular service, businesses can significantly reduce their phone and text messaging expenses. This can be especially appealing for organizations with large employee populations or industries like hospitality or multi-dwelling units (MDU) where there may be many guests or residents in one network. Employees or guests will benefit from a better experience by connecting to the strongest possible signal – even when moving around on the premises – and prioritizing their calls even in congested situations.

How it works

While VoIP calls on smartphones have been possible for some time over apps like Skype and WhatsApp, carrier-grade Wi-Fi calling is different in how it transparently connects to the mobile operators’ network over the internet.

The mobile operator enables Wi-Fi calling to connect to their networks to support calls over the IP Multimedia Subsystem (IMS) and ePDG, which allows the mobile device to connect to the IMS network via the internet. Regular Wi-Fi calling will look for the strongest network and connect when you make a call, but it can sometimes struggle when you move away from coverage and may occasionally drop calls. With carrier-grade Wi-Fi calling, when a device moves outside a cellular network’s coverage area, but connected to a Wi-Fi network, the device will look up the gateway address, set up a secure IPsec tunnel to the gateway, and register to the IMS network. All this would happen seamlessly, and the call will continue via this new path or vice-versa.

Setting Up on EnGenius Cloud

The EnGenius Cloud offers you the chance to take advantage of carrier-grade Wi-Fi calling, and it makes it simple for you to set up and start taking advantage of all the benefits. The first step is establishing an IPsec (ESP – Encapsulating Security Payload) tunnel between the mobile device and the ePDG server. Next, you will configure each WLAN with one or more profiles to enable the feature for the WLAN.

To enable Wi-Fi calling for a WLAN:

1  Wi-Fi calling function is available on CONFIGURE > General Settings page

2  Select the QoS Priority (DSCP)

3  Click “Add” button to add the ePDG servers of ISP


Overall, carrier-grade wi-fi calling is a powerful tool for businesses looking to improve communication capabilities and reduce costs. As the feature continues to evolve and expand, it will become an increasingly popular choice for organizations of all sizes. EnGenius removes the complexity and makes it simple to take advantage of carrier-grade Wi-Fi calling with our Cloud feature.

Learn more about the other benefits and features of the EnGenius Cloud!