From one earthquake to another, from one hurricane to another, and from one terrorist attack to another, the world has seen again and again, the destruction of communication infrastructure caused by natural and man-made disasters and their impact on human lives. In each and every situation, the story repeated itself – communication systems and networks get choked, bringing emergency services to a complete halt. The solution to this problem is the development of rapidly deployable and interoperable communication systems. Despite the efforts from the federal government, academic, and telecommunication industry, the progress has been rather slow. This article makes a case for the need for standards in rapidly deployable communication systems and the engineered ecosystem around them with capabilities to augment first-responder activities during disaster relief operations. The grand vision is availability of a portable and interoperable communication system, the size of a backpack that fits in a fire engine at every fire department in every town in near future. The system should be readily and rapidly deployable in minutes to establish communications to the citizens and first responders. This article describes what has been done so far and what needs to be done to make this vision a reality!
Emergency situations arise without notice. It could be a plane crash, an earthquake, or a tornado which can cause significant destruction in minutes. It doesn’t matter how much we are prepared and planned to deal with them, we may still not be ready when they occur. Power and communications infrastructure, the two most important resources needed for human survival are the first things that get destroyed during these major disasters. As recent as 2017, in Puerto Rico, we witnessed the impact of hurricane Maria on the communication infrastructure and how it brought down the entire cellular network to its heels. It is time to quickly build portable and interoperable communication systems that can be carried in a fire-truck and can be deployed on the ground, on roof-tops, or in the air, to facilitate disaster-relief operations. How far are we in achieving this goal? What are the barriers and how can we circumvent them? Let us take a stock!
As of today, first responders still rely on thousands of separate, incompatible, and often proprietary radio networks to communicate with each other during emergencies . Lack of interoperable radio networks leads to bottlenecks for information sharing among the first responders. If first responders are not connected on one network, it becomes hard, and at times impossible, for emergency responders from different jurisdictions or agencies to communicate and work together to save lives .
The First Responder Network Authority (FirstNet), an independent division within the U.S. Department of Commerce, was established to build the first nationwide public safety broadband network (NPSBN) to provide first responders with the ability to communicate across jurisdictions and agencies. FirstNet signed a partnership with AT&T to build NPSBN based on industry standards, nationwide spectrum, and device interoperability. On March 17th, 2018, AT&T announced the launch of the dedicated, robust, highly available and redundant distributed core infrastructure. NPSBN separates public safety traffic from commercial traffic and supports functions like Quality of Service (QoS), priority and preemption. It will also support future mission-critical services to be offered by FirstNet, like mission critical push-to-talk and location based services .
FirstNet addressed the central problem of interoperability of disparate radio networks through a common core network. However, there are several other significant barriers to enabling effective emergency communications, and for bridging the gaps in communication infrastructure caused by disasters. Imagine a scenario in which you are pinned down under a concrete slab due to an earthquake and your cell phone is not getting any signal because the nearest cell tower is destroyed due to the same earthquake. In this situation, you are doomed unless someone finds you under the rubble. The solution to this problem is a rapidly deployable communication systems that can provide the connectivity to your cell phone before the battery dies. A portable LTE node (or a 5G cell), for example, can be airlifted to the location to substitute for the dysfunctional cell tower and bridge the gap created by the disaster . Such an aerial deployment of portable LTE node is illustrated in Fig. 1.
Fig.1: Illustration of a Rapidly Deployable Communication Systems (Image Courtesy: Mutualink Inc. and Virtual Network Communications, Inc.)
An LTE node includes eNodeB and Evolved Packed Core (EPC) shown on the right. Such a system can provide cellular coverage for an area determined by the transmit power of the LTE node and altitude of the deployment. A portable LTE node with a virtualized EPC from Virtual Network Communications Inc., implemented on a System-on-Chip is shown on the right. Such an LTE node with its smallest form factor weighs about three to four pounds, making it easier to airlift in many ways – using a balloon, small Unmanned Aircraft System (sUAS) or an aerostat.
Rapidly deployable communication systems would have been of great use immediately after hurricane Maria in Puerto Rico. At present, however, only prototypes of such deployable systems are available at universities (for example, [5, 6, 7, 10]) and Federal Laboratories such as National Institutes of Standards and Technology (NIST). Although, AT&T deployed what it calls “Cells on Wings” in Puerto Rico several weeks after hurricane Maria, it is a one-time effort. There is an immediate need for developing fundamental engineering processes, standards and best practices to be able to deploy rapidly deployable systems immediately after a disaster. Such a standardization process has recently been initiated by the National Public Safety Telecommunications Council (NPSTC).
NPSTC’s Deployable Systems Working Group (DSWG) developed use cases and the desired operational capabilities of deployable systems . A set of metrics—such as quality of communications, time to deploy, duration of operation in the air, interoperability with existing terrestrial cellular networks, among others—are under development.
Fig. 2: An Engineering Ecosystem for Emergency Preparedness
In addition to aerial communications, the ecosystem for emergency preparedness includes a component for information acquisition and sharing through Internet of Things (IoT) and a decision-support system based on public safety analytics.
Information Acquisition and Sharing through Internet of Things: Typically, information sharing is achieved through collaboration and situational assessment strategies. The Department of Homeland Security (DHS) Science and Technology (S&T) Directorate’s vision of Next Generation First Responder , includes the development of Internet of Things (IoT) that will help assess an emergency situation accurately. There is a need to identify the types of sensors that are necessary for situational assessment during disaster-relief and efficient strategies for data acquisition and information sharing between the first responders and decision-makers. The need for real-time information sharing among the participants engaged in emergency response is as important as the need for communications. These participants include first responders, volunteers and support staff, decision makers and news media [8, 9]. Information sharing enhances situational awareness capabilities of the first responders, and resource allocation capabilities of decision makers. Decision makers, such as the incident commander, should be able to view the situation as it evolves and call for resources when and where they are most needed. DHS S&T launched the Incident Management Information Sharing (IMIS) pilot to harness the capabilities of IoT to improve first responders’ situational awareness during emergencies .
Decision-support System based on Public Safety Analytics: The focus in this dimension is the real-time analysis of data including voice, images and video collected from different sources—and most notably, the aerial platform. NIST identified public safety analytics as an important capability and created an R&D roadmap . Data Analytics will result in actionable information for decision makers during emergencies and disaster recovery operations. Data collected by means of remote sensing systems, environmental sensors, and wearable devices integrated into first responders’ personal protective equipment, may be overwhelming to process and analyze in real-time . However, if successfully processed to the level of information, such data will allow the incident commander to generate actions with greater efficiency, to allocate resources and assets with greater precision, and to manage relief operations with greater efficacy.
Fig. 3: Networking of two communication systems requires a microwave backhaul link (ABS: Aerial base Station, DU: Downlink User, D2D: Device-to-Device link, RABS: Radius of ABS)
Size and power constraints limit the coverage area for a deployable communication system placed on an aerial platform. The solution for expanding the coverage area is by networking several small systems together. This requires a backhaul solution such as a microwave or in-band communication links among the deployable systems. A microwave link between two deployable communication systems requires a line-of-sight between them, which is difficult to maintain when the aerial platforms are not stationary. There is a need to investigate this topic further and develop solutions for connecting communication systems deployed through aerial platforms including drones, balloons, and aerostats. Alternative strategies include running a fiber-optic wire from the aerial node to the ground.
Integration with the nationwide public safety broadband network is another important challenge. A deployable system provides coverage to an isolated bubble unless it is connected to the terrestrial network through wired or wireless communication links. Fig. 4 shows a possible deployment where the aerial node placed on a tethered aerial platform is connected to the terrestrial network through a satellite service.
Fig. 4: A aerial node connected to the terrestrial broadband network through a tethered backhaul and satellite service. (Image Courtesy: Mutualink Inc.)
Summary: Rapidly deployable communication systems are the need of the hour during disaster-relief operations. Standards for deployment, scaling, and integrating with terrestrial networks are required to speed up the development process. Further studies include 5G based deployable system design and integration, air-to-air, and air-to-ground channel modeling with 5G systems.
Acknowledgements: This article is based on the research work carried out under a National Science Foundation grant titled “NSF 1622978: Networked Aerial Base Stations for Enabling Emergency Communications during Disaster Recovery”.
Kamesh Namuduri is a Professor of Electrical Engineering at the University of North Texas. He received his B.S. degree in Electronics and Communication Engineering from Osmania University, India, in 1984, M.S. degree in Computer Science from University of Hyderabad in 1986, and Ph.D. degree in Computer Science and Engineering from University of South Florida in 1992. Over the past eight years, his research is focused on aerial networking and communications. He co-organized a series of workshops on “Airborne Networking and Communications” in conjunction with AIAA, AUVSI, and ACM Conferences. He is serving as the chair for the IEEE Standards Working Group (IEEE 1920.1: Aerial Communications and Networking Standards). He is a co-editor for the book titled “Unmanned Aerial Vehicle Networks” published by the Cambridge University Press in 2017. He published over one hundred research articles. He is leading the Smart and Connected Community project on “Deployable Communication Systems” in collaboration with the government, public, and private organizations. This living laboratory project was demonstrated thrice during the Global City Teams Challenge hosted jointly by the National Institute of Standards and Technology and US Ignite in 2015, 2016, and 2017. He contributed to the development of research agenda, requirements and blueprints highly deployable communications systems led by the National Institute of Standards and Technology and National Public Safety Telecommunications Council.