The FCC Plan for a Public Safety Broadband Wireless Network

Wireless broadband functionality could revolutionize the way public safety responds to emergencies by bringing capabilities to first responders they have never before had access to. By also providing public safety users with roaming access to commercial networks, on a priority basis, it is possible to increase the aggregate capacity, geographic coverage, and service reliability available to these users far beyond what would be possible with networks dedicated to public safety users alone. The benefits of roaming depend in part on how this priority access is structured. This paper studies the technical and operational issues associated with providing public safety users with priority roaming access. Results are applicable in any nation where public safety users have access to both public safety and commercial networks that are based on the Long Term Evolution (LTE) technology standard. First, the paper shows that the LTE standard offers a wide range of priority-related capabilities that could be important for making roaming valuable to public safety users. These include the ability to differentiate traffic streams based on a number of factors that reflect their relative importance, to manage traffic such that objectives with respect to data rate and quality of service (QoS) can be met for the important streams, and to make more resources available for more important streams during times of heavy utilization by either blocking, dropping, or lowering the QoS of streams that have been identified as less important. Second, this paper addresses some of the issues associated with potential agreements among the many public safety agencies and commercial operators. Such agreements may prove important in ensuring that the needs and expectations of all parties are met. This paper describes how guidelines that promote commonality can reduce transaction costs, but shows how such agreements should also consider and accommodate some forms of technical diversity that can emerge across implementations, even when they all comply with the LTE standard. Third, this paper discusses issues associated with making a given standard such as LTE useful for public safety purposes even as both the standard and the needs of public safety evolve over time. Finally, this paper shows that LTE supports a wide range of operational policies and arrangements, allowing policy makers to consider important non-technical factors when choosing among these arrangements. One option is an automated system, in which decisions that affect priority are made based on factors that the network knows a priori (e.g. user identity) or that can be detected by the network automatically (e.g. roaming status). Alternatively, the system might allow real-time human intervention so that priority-related decisions can be based in part on situational information that the system cannot detect on its own, such as the intention of users. This paper shows that the LTE standard could support a range of technical implementations, in which different degrees of responsibility for these real-time interventions can be assigned to individual first responders, to more centralized representatives of public safety, or to operators of commercial networks. ** Please note that the opinions stated in this paper reflect those of the authors not the institutions they represent.