T-Mobile has kickstarted the roll out of Voice over LTE network in Seattle area and will soon deliver the emerging technology to more cities with support for more devices.

T-Mobile, the fastest growing wireless carrier in the US, is bringing the Voice over LTE (VoLTE) technology to its customers in Seattle area to deploy faster call setup and LTE data speeds simultaneously. The carrier has not only started offering VoLTE, they also have three compatible devices able to handle the emerging technology. The emphasis on the VoLTE deployment is because T-Mobile is placing both data and voice on the same radio layer.

In an official blog post, Thursday, T-Mo's chief technology officer, Neville Ray, highlighted the technicalities of the VoLTE service. The new technology uses the LTE network instead of a circuit-switched path on 4G HSPA+ network. With this, T-Mobile is able to use the fast LTE network to set up a call, which it claims to be twice as fast as the non-VoLTE call setup and superfast LTE data while on a call. The carrier also noted that a call made using VoLTE does not drop in case the user goes out of LTE coverage, but it switches to 4G HSPA+ or even 2G for uninterrupted connection.

"T-Mobile's Voice over LTE is just one of the many ways our customers are benefiting from our ongoing multi-billion dollar network modernization - along with ever-faster data speeds on America's fastest nationwide 4G LTE network, and truly unlimited talk, text and data on our wide-open nationwide network," Ray wrote in the blog.

The carrier plans to launch VoLTE in additional cities with more compatible devices under its bracket. T-Mobile also wants to expand the possibilities of the new technology around Wi-Fi calling over the coming months.

Ray claimed in the blog that MetroPCS was the first to launch VoLTE in the United States back in 2012.

T-Mobile customers in Seattle area can take advantage of VoLTE with existing LG G Flex, Galaxy Note 3 and Galaxy Light smartphones. All they have to do is update the handsets with the latest software update under Settings > General > About Device.