Be Wary of Using Commercial Broadband Networks for Public Safety Voice
Posted on January 8, 2021 by Scott Neal
More than ever, broadband communications networks are essential to the public safety and justice communities. Such networks easily transmit highly bandwidth-intensive files, e.g., video and building floor plans, that would choke a narrowband network. Such files enhance situational awareness for incident commanders and other officials—as well as emergency responders and jail/prison officers—by orders of magnitude, which in turn helps them do their jobs better.
But there’s a flip side to broadband communications networks of which the public safety community needs to take seriously. Such networks typically are owned and operated by commercial entities, and because of this public safety agencies that contract for broadband services typically do not receive the performance guarantees and—even more importantly—the visibility into these networks that they’re used to receiving from the networks that they own and operate, for example, their land mobile radio (LMR) systems.
Consequently, public safety agencies should proceed carefully when they consider whether to contract with any commercial entity for broadband services.Right now, agencies thinking about broadband are doing so to leverage huge amounts of data that are not available to them via narrowband networks. Long-Term Evolution (LTE) was created for this purpose. The commercial networks were the driving force behind LTE’s creation, because they needed a way to transmit enormous amounts of data, mostly video, to smartphone and tablet computer users, and the data volume was beginning to choke their networks. Indeed, in the beginning LTE was never contemplated to perform any function other than transmitting enormous amounts of data at incredibly fast speeds.
But then LTE began to evolve, as technologies always do. A voice component was added to the standard and then a so-called mission-critical voice capability emerged. Regarding the latter, it is suitable for government officials—think the mayor or police chief of a large city—who do not need to carry an LMR device, but do need to communicate with public safety officials during a major emergency. It is important to understand that the mission-critical push-to-talk (MCPTT) function that enables officials to use their smartphones as de facto walkie-talkies, does not meet public safety’s definition of mission-critical, i.e., that the network is available wherever and whenever it is needed, regardless of the circumstances.
Nevertheless, many agencies today are wondering whether they can transition their mission-critical voice capabilities to a commercial broadband network. Typically this question stems from a desire to avoid funding operation and/or maintenance of two networks, one for data (LTE) and one for voice (LMR). Often it also is driven by the fact that the legacy public safety radio network has aged significantly, and upgrading or replacing it represents a significant financial investment that the agency will be dealing with for decades.
Key Mission-Critical Voice and Commercial Broadband Considerations
As agencies mull whether to place their mission-critical voice eggs entirely into the commercial broadband basket, they need to contemplate the following:
Consideration 1: Redundancy and Resiliency
Commercial networks are not architected with the redundancy and resiliency that public safety LMR networks typically provide. The latter offer:
- Robust backup power (generators and/or batteries) at each tower site.
- Resilient network designs that enable the immediate rerouting of traffic if a pathway because compromised.
- No single points of failure—usually LMR tower coverage overlaps to such a degree that if a tower were to become inoperable, most if not all of the affected area still would be able to leverage coverage provided by the other network towers.
- Geographically diverse network cores, which are vitally important when a natural or manmade event renders a facility inoperable, e.g., a tornado, wildfire or terrorist bombing, as occurred recently in Nashville. The Pennsylvania State Police, for example, have multiple network cores for its statewide radio network which are located in different areas of the commonwealth, and are separated by significant distances—therefore, an event that affected one of these areas almost certainly would not affect another, and traffic simply would be rerouted through an unaffected core.
Commercial broadband networks provide none of these protections. Consequently, when a commercial network goes down, it can take hours, even days, for service to be restored—and no public safety agency can afford to have its mission-critical voice network down for minutes, much less days. It wouldn’t be good for an agency to have its data network down for that amount of time either, but as important as data has become, voice is still king in the public safety realm.
Consideration 2: Service Level Agreements or Performance Benchmarks
Commercial broadband network providers typically do not provide, and will not agree to, service level agreements or network performance benchmarks to ensure that they are providing a public safety-grade level of service.
Consideration 3: Network Visibility
Commercial broadband network providers provide limited visibility into their networks, which is a big problem for public safety agencies, which need such visibility to optimize network performance and to troubleshoot and—better still—prevent service-affecting issues. This is especially true as it relates to cybersecurity. But commercial entities, when asked about such visibility, claim that it cannot be provided for competitive reason, and tell the agency, “trust us.” When it comes to public safety communications networks, especially mission-critical voice networks, that’s not good enough—seeing is believing. Moreover, commercial subscribers have little control over network coverage. Let’s use the recent siege on the U.S. Capitol as an example. LMR system users could ensure that adequate coverage exists in the building, but would be at the mercy of the commercial provider if they were using an LTE system for voice. Maybe the coverage would be adequate, maybe it wouldn’t—which is completely unacceptable in a situation where lives are at risk, as they were during the siege.
Eventually the day will come when public safety agencies will be able to transition their mission-critical voice capabilities to a commercial broadband network—remember, technology always evolves—but that day has not arrived and it likely won’t for many years. We can provide sound guidance on what your agency should do in the meantime—please reach out.