Case studies

Pain-Free Home Calling Process

Using VoLTE VHE to help roaming subscribers dial home as if they’d never left.

About the client

Under NDA.

Regions served

North America

Provided solutions


The customer needed to improve the quality of service for handling VoLTE outbound roaming, i.e. calls being made back home. Particularly, given the fact that voice services are home routed and delivered differently in a VoLTE roaming scenario from traditional Circuit Switch voice, the challenges of using the right international dialing prefixes and calling home short numbers meant that many roamers could easily get frustrated. More specifically, if the user dials a short number without the international dial code, the customer would not know if the destination number is located in Canada or the visited country. Imagine a roamer being able to call a taxi on a 3G network by dialing the local number, but not being able to do the same on a 4G network. Calls being wrongly connected or dropped could create the perception of a poor-quality VoLTE roaming service from the customer.

Furthermore, with the imminent 2G/3G network shutdowns in the USA, this issue is particularly relevant to the customer, since Canada accounts for the second-highest volume of international travelers to America (12.3 million in 2021).



TOMIA’s Virtual Home Environment (VHE) is designed to eliminate the complexities and uncertainties of dialing in roaming scenarios. It uses an extensive knowledge base built from our data on dialing error patterns, global numbering and short codes, along with a feature-rich translation process and intelligent call-connection algorithms, to check and correct dialed numbers in real time. The service supports the correction and completion of all domestic (calls to Canada) and geo-local (calls in the visited country) VoLTE calls. As a result, roaming customers can dial the same numbers and short codes as they would at home, and get a reliable connection seamlessly, even to value-added or emergency services. The customer was already using our VHE product for older network technologies, so VoLTE VHE was a natural choice for delivering the same, high service quality to its VoLTE roaming customers when dialing home.

The solution was built around one of our standard products, but the main value lies in customizing it to integrate with the customer’ IP multimedia subsystem (IMS) architecture from Ericsson.

The initial rollout was in Germany, which was chosen as a VoLTE-enabled test country with relatively few roamers dialing out of the country. This allowed the customer to run and monitor a live VoLTE VHE service to assess its suitability and performance. The service was extended to other countries, especially the United States.



The primary benefit was that VoLTE VHE would provide roamers with a reliable and worry-free connection process when calling home, by maximizing the number of dialed calls that successfully reach their destination. The seamless quality of service they were expecting didn’t suddenly degrade when using VoLTE networks, and so mitigated the risk of a poor user experience, leading to churn.

A secondary benefit of VoLTE VHE was related to revenue. Failed calls have no value, and wrongly connected ones are short, but calls which go straight through to the intended destination last longer, and are more likely to be made, more often.

From our client

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Maison John

Chief Technology Officer
Our customers

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