U.S. operator Verizon Wireless expects VoLTE interoperability with AT&T Mobility to become commercially available this year, according to Verizon’s vice president of network planning and technology, Adam Koeppe. Speaking at a FierceWireless panel called “The Path to 5G” at the Mobile World Congress in Barcelona, Koeppe said that trials of the service with AT&T were progressing well. The companies said in November 2014 that they expected to offer VoLTE calling between the two networks by the end of 2015. In December AT&T said that it had achieved the first VoLTE exchange between its customers and Verizon customers in select areas. Currently, customers of each operator who have VoLTE-enabled phones can only call other VoLTE phones on the same network.
VoLTE technology has the potential to revivify an aspect of mobile service that has been suffering lately—voice telephony. The rise of data, including OTT messaging, has caused voice to recede in terms of proportion of use. VoLTE, due to its higher quality, promises to deliver greater customer satisfaction and therefore to boost the use of voice calling. Increased traffic over operators’ LTE networks due to VoLTE stands to increase revenue and also maximize capacity on those networks. However, VoLTE will not be appealing to customers if it remains only within one network. The average customer has too many friends and contacts who use the services of different operators to make it worth their while to buy a new, VoLTE-enabled device for on-net use only. Furthermore, full off-net calling is needed to fully utilize network capacity. Therefore, interoperability is essential if VoLTE is to be viable and live up to its promise.
The recent trials show that AT&T and Verizon, the two biggest operators in the U.S., have established interoperability as a practical possibility; all that remains is for them to implement it across their national footprints. Finally, uptake of VoLTE-enabled smartphones will be driven only by wide availability of VoLTE across operator networks, so device manufacturers will be watching AT&T and Verizon’s progress with interest. Fully-realized VoLTE has been a long time coming in the U.S. Now it seems be arriving at last. We expect that T-Mobile and Sprint will be working hard to connect their own VoLTE services with those of the two market leaders.