Disaster and emergency communications – satellites are key communication providers that provide a critical path for relief in emergency and disaster situations. Communication helps connect and move logistical, rescue, and first responder resources in any region of the world facing or recovering from natural or manmade disasters.
Deploying wireless communications is typically among the first priorities in any emergency response, rescue, or relief situation. However, terrestrial wireless equipment is useful only when communication towers and other fixed equipment are in place to connect wireless equipment to the local and global communications backbone. In the majority of emergency situations, this infrastructure has either been destroyed by the disaster or was not available before the disaster. This reality makes it critical for local government and emergency workers to have access to a wireless communications network that is not dependent on terrestrial infrastructure.
Satellites are the only wireless communications infrastructure not susceptible to damage from disasters, because the main repeaters sending and receiving signals are located outside the earth’s atmosphere. In recent years, the cost of satellite bandwidth has dropped so dramatically it is competitive with both DSL and cable solutions. Users today have two kinds of satellite communications networks available: geostationary satellite systems (GEO) and low earth orbit satellites (LEO).
GEO satellites are located 36,000 km above the earth in a fixed position and provide service to a country or a region covering up to one-third of the globe. They are capable of providing a full range of communications services, including voice, video, and broadband data. These satellites operate with ground equipment ranging from very large fixed gateway antennae down to mobile terminals the size of a cellular phone. There are currently almost 300 commercial GEO satellites in orbit operated by global, regional, and national satellite carriers. Even before disasters strike, these networks are used in many countries to provide seismic and flood-sensing data to government agencies to enable early warning of an impending situation. Also, they broadcast disaster-warning notices and facilitate general communication and information flow between government agencies, relief organizations, and the public.
LEO satellites operate in orbits between 780 km and 1500 km and provide voice and low-speed data communications. These satellites can operate with handheld units about the size of a large cellular phone. The highly portable nature of LEO-based units makes them another valuable satellite solution for first responders in the field. In order to most effectively utilize the capabilities of these systems, government agencies, relief organizations, and other first responders must define as far in advance as possible what kind of terminals they will need to have in the field before and after an emergency.
Satellite technology can provide narrowband and broadband IP communications with speeds starting at 64 Kbps from handheld terminals up to 4 Mbps bidirectional from portable VSAT antennae. Fixed installation can bring the bandwidth up to 40 Mbps.
Solutions using this topology can be used for both advanced disaster mitigation services and to support relief and recovery efforts under three general categories. Handheld mobile satellite communications – once a disaster has occurred, local infrastructure is often knocked out. In the immediate aftermath, there is one reliable form of communication, which is the use of handheld satellite telephone systems provided by mobile satellite service providers; portable and transportable mobile satellite communications – mobile satellite systems, or terminals used for communications on the move include equipment that can be transported and operated from inside a car, truck, or maritime vessel, as well as in helicopters and other aircraft, including commercial airplanes. This kind of terminal is useful where data-intensive, high-speed connections are needed on an expedited basis for damage assessment, medical evaluation, or other applications for voice, video, and data; and fixed satellite communications – terminals would typically be installed in cases where the equipment is required for longer than one week, including pre-disaster applications – for example, environmental monitoring, communications redundancy – as well as post-disaster recovery operations. Such systems can be configured to provide everything from low-speed data transmissions up to very broad bandwidth data and full broadcast-quality video to replace local and national telecommunications infrastructure.