For years, the critical communications industry has relied on narrowband LMR (Land Mobile Radio) networks for mission critical voice and basic data services. Due to the bandwidth limitations of these LMR networks, public safety agencies and other users within the critical communications industry are keen to leverage commercial cellular network technologies to support growing demands for mobile broadband services such as video transmission and bandwidth-intensive field applications.

Considering its thriving ecosystem, spectrum flexibility and performance metrics, LTE has emerged as the leading candidate for critical communications broadband networks. In addition, with the recent approval of the MCPTT (Mission Critical Push to Talk) voice standard as part of 3GPP Release 13, LTE has also become an attractive substitute for providing LMR-like voice services.