1. ITU Workshop on “Voice and Video over LTE” Geneva, Switzerland, 1 December 2015 VoLTE at Swisscom Dr. Marcus Brunner Head of Standardization Swisscom marcus.brunner@swisscom.com

2. Current Deployments First European Carrier with commercial VoLTE/WiFi calling offer – Large Amount of UEs are VoLTE/WiFi calling enabled (>20% of LTE capable devices) Migration to All-IP for fixed line ongoing First interconnection projects started(national and international) – Very early since most of our peers are in the introduction of VoLTE

3. Interoperability Challanges VoLTE – Roaming für VoLTE (several approaches, to be seen which one will be used) – QoS-enables IP interconnection as a basis for VoLTE and other IP-based services interconnections Service interoperability – It is not only about calling, but also other services (e.g. RCS) which make interoperability more difficult Devices lagging – Video on many devices not supported – WiFi calling has a lot of implementation challenges on the devices – Advanced calling with RCS limited availability on devices Most deployment problems are implementation issues – Time will solve those

4. Open Issues NGN was meant to be access network agnostic – Localization requirements must be access network agnostic as well Short term solutions possible with access network, but his is not a solution long term, specifically with the higher and higher number of different access network technologies UE-based localization possible (most UEs have GPS and location-based services implemented) Device support for various functions missing – Mostly an implementation issue – When more and more service providers agree on deploying VoLTE time will fix that Interconnection – business aspects unclear, requires more discussions – most of our peers are not ready to discuss that in depth

5. Summary Swisscom has VoLTE/VoIP/WiFi calling deployed Challenges are in the detailed implementation and regulation Interconnection open No standardization challenges – probably even too many standards available