Two months ago, Congress passed legislation that reallocated the 700-MHz D-Block spectrum to public safety and provided $7 billion in grant money for the creation of a nationwide broadband network for first responders. As with any transformational process, the build-out of this system has many stages to pass through and it will take several years before it’s fully functional.
That means public safety’s migration to LTE will occur in increments. Change won’t take place all at once or across-the-board in all places, and it also won’t abandon other technologies that have proved their worth in certain areas.
Land mobile radio (LMR) provides one example. LMR remains the standard for mission-critical voice communications and it has made many new improvements in the last decade. It’s gone from analog to digital, and has been available as an IP network-based service for several years now. APCO P25 has also enabled much-improved interoperability between different LMR systems, provided enhanced functionality and ensured competition through open standards.
Push-to-talk LMR will continue to play a role as we evolve toward LTE because at this point, a public safety broadband network wouldn’t be able to support voice capabilities. A recent Government Accountability Office (GAO) report estimates it could take 10 years or more before LTE will be able to accommodate voice. For now, VoIP remains a reliable alternative.
On the technical side of choosing the right model for this nationwide network, we have lots of choices--some in keeping with the times, others less so. The fallback position of using legacy, closed, proprietary approaches is still favored by a few, although it’s an antiquated notion for mission-critical communications.
The right model must be one that parallels the current and future direction of technology development. That means a model based on the following principles: non-proprietary, open architecture, standards-based, customer-owned (and with customer input on design), and above all, interoperable.
It’s generally agreed that interoperability will be among the greatest challenges in the evolution toward LTE. LMR, P25, LTE and, most likely, different flavors of each will all be in use at the same time. Such diversity will continue because there’s no single technology that fits everybody’s needs. In firefighting, analog is preferred for building penetration while law enforcement pushes for digital trunking.
This doesn’t mean we won’t have a mobile broadband public safety network that’s truly national in scope. It does mean that we’ll need a layered architecture that accommodates everyone, is built to mission-critical specs--without fail and whatever the conditions--and is interoperable from one location and technology to the next.