Introduction to Unified Critical Communications
What is the Future of LTE?
Commercial Public LTE vs Private LTE vs Public Safety Mobile Broadband
Mission critical users who want to take advantage of mobile broadband have several choices. In this topic, we’ll discuss the top 3.
Commercial Public LTE
Commercial cellular providers offer the vast majority of LTE services currently available to the public and businesses.
In the US, Verizon Wireless, AT&T, T-Mobile, Sprint and U.S. Cellular are the only providers that operate their own networks. Economies of scale permit them to take on the heavy cost of building and maintaining these networks to deliver nationwide coverage and a platform for mobile data services and applications to a vast market of subscribers on domestic and business plans.
Cell phones are relatively inexpensive (compared to LMR radios), pocket-friendly, and generally high quality with user interfaces that look good and are easy to use. It’s no wonder that businesses and even several critical communications users have had second thoughts about the cost and effort of operating their own communications systems.
For some it may be the right move to jump onto a commercial system. To others, however, this move entails giving up too much control. The logic is simple: if you don’t own the system, you can’t control it, and if you can’t control it, you can’t absolutely rely on it. To give some examples of where issues could arise:
- Coverage, for instance, is determined by where cellular companies see it worthwhile to provide. A public safety entity in a rural area has different priorities and may require coverage in regions that have little economic potential. Call dropouts and loss of service can be expected.
- Users of commercial systems share resources with everyone else. If the network is overloaded with rush hour, video-sharing, an emergency or a hacking attack, everyone suffers the performance hit, including business and organizational users. A public network carries a lot of public traffic and applications irrelevant to business or critical users, who nevertheless have little control over the prioritization of traffic when things get heavy.
- Maintenance and upgrades are performed according to schedules determined by the cellular provider, not its customers. However accountable the provider may be and however worthy the service level agreements, in the end the maintenance schedule belongs to the provider rather than the customer.
- When a cellular network crashes, or a key site loses power, or the systems becomes otherwise unavailable, all communications stop for all until normal service is restored. There is no backup service to kick in until then.
Private LTE, as the name implies, is a dedicated LTE network that serves a specific enterprise business, government agency or educational outfit, who can own and operate the system or who may instead outsource to a commercial mobile operator or third-party network provider. The system is entirely separate from public commercial networks. Private LTE enables an organization to have the benefits of LTE without losing so much control. Outsourcing removes the need for total ownership or assuming full responsibility for operating the system.
Since a private LTE system runs on its own dedicated equipment, its coverage, performance, and security are independent of public LTE services. Large mining companies in Australia are investing in private LTE systems that are optimized for mining traffic and applications. Backup communications, whether using LTE or another technology will be part of their system design.
A major constraint on private LTE is the availability of suitable radio spectrum. In many countries existing licensed spectrum is already congested. Depending on where you are, this can mean either that you need to wait until new LTE frequencies are allocated, or you need to pay a premium to buy into an existing block of spectrum, or you will need to wait until someone else gives up their frequencies. Alternatives include using unlicensed spectrum, such as 5GHz, with an LTE-based technology such as MulteFire. Or, using shared spectrum e.g. through the Citizen’s Broadband Radio Service (CBRS) in the U.S., or through the Licensed Shared Access (LSA) model being tested in Europe.
Public Safety Mobile Broadband networks
Public Safety Mobile Broadband networks are a specific type of private LTE network – one dedicated to public safety and first responders. They are not available to other types of critical communications users and are generally government-funded. Examples include FirstNet in the U.S., Emergency Service Network (ESN) in the United Kingdom, and SafeNet in South Korea. Australia is also in the early planning stages for a Public Safety Mobile Broadband (PSMB) network. The aim of such systems is to provide public safety agencies something they did not get out of LMR namely, secure, nationwide, interoperable communications with voice and broadband data.
In the U.S. FirstNet is an independent authority within the National Telecommunications and Information Administration (NTIA), an agency of the U.S. Department of Commerce. The FirstNet Authority contracted private mobile operator AT&T to build and operate the LTE network for the lifetime of its contract. Public safety agencies such as state patrols, fire department, and federal departments sign up as subscribers to use the FirstNet system.
What happens to existing public safety communications systems? If they are LTE networks, such as Los Angeles’ LA-RICS LTE system, the equipment will be transferred into FirstNet (or its non-US equivalent). If the existing network is not LTE, such as the TETRA system used by the UK Police, it will be de-commissioned and officers will need to work with a whole new technology.