TETRA  |   LTE  |   P25  |  2013-12-17

How LMR and LTE Work Together for Public Safety?

Source: MCCResources | John Kedzierski - Motorola Solutions Director of Product & Solutions Marketing

What seems to be on the minds of everyone in the industry is convergence. When will an LTE network and LTE device provide not only data but also Mission Critical Push-To-Talk (PTT) Voice, replacing an LMR system and LMR device?

One network and one device that meet all your mission critical communications needs is a simple and elegant concept, so it’s easy to see why so many are enamored by the concept of convergence.  The simple truth is that delivering mission critical voice over LTE the same way it is done over LMR is a lot harder than just Voice over LTE (VoLTE).  There is still much work to be done by the industry to add mission critical PTT to the 3GPP standards and bring solutions to market.

While the 3GPP standards for mission critical voice are being developed and we work to overcome technical hurdles, it is critical that government agencies are able to take advantage of the benefits of LTE as soon as possible.  To us, that means integrating LTE into existing P25 systems.  We see it as the first step in the convergence evolution:  A multi-network environment where LTE and LMR networks work together and allow users – whether in the command center or on the front lines – to efficiently communicate.  If you look at the end-to-end picture, you quickly realize that first responders will continue to have a device in their hand and a dispatcher will still use a dispatch application.  As a result, you come to the conclusion that the current LMR to LTE debate is just over the wireless interface – between the communications tower and the end-user device, be it P25 or LTE.  It’s like debating copper vs. PVC pipes in your house.  At Motorola Solutions, we are focused on building that entire house, which in the case of a public safety communications system includes public safety grade devices, mission critical networks, common interfaces, and applications.

Our view is simply you will have both LMR and LTE for some time, and possibly forever. Government agencies have invested millions of dollars in robust, redundant, interoperable, mission critical P25 systems built to be always available during any incident.  LTE technology will not replace that capability overnight, even when the technology hurdles of mission critical PTT voice are solved.  We simply have to look at the fact that despite the 15+ year availability of digital trunked radio technology like P25,  the majority of agencies still use analog radio in some form, be it for voice dispatch, tactical communications such as the fireground, or paging, to know that agencies will maintain multiple networks for a long time.  With the VALR mission critical architecture, we are enabling agencies to add LTE into their current or future P25 systems, creating a multi-network environment that leverages existing investments, coverage and interoperability. LMR and LTE technologies can and do complement each other, providing public safety with the most robust set of communication tools available today and for years to come.