Dependent on the nature of a disaster, there are usually many personnel requiring communications and because of the urgent nature of most communications, a good Grade of Service (GoS) is required. These factors mean that a significant amount of network capacity needs to be available throughout the disaster and affected areas to support effective Public Protection and Disaster Relief (PPDR) communications.
Also, because of the nature of most disasters, mobile communications is the main requirement. At the very early response stages voice communications are very important, after which non-voice communications can become an important requirement (narrowband, wideband and broadband data applications), dependent on the nature of the disaster. However, the need for voice communications will always be a major requirement.
As most mobile telecommunications networks located in a disaster area have been designed to support normal traffic loads, they will not have the required capacity to provide effective PPDR communications. Therefore, mobile communication networks will need to be rapidly deployed to provide additional capacity.
Because disasters require effective co-ordination, support and communication between all agencies involved, it would be ideal if one communication solution could be provided to meet all needs. However, each agency will need to retain autonomy of communications within their own organisation but have the ability to fully interoperate with other agencies when required. This autonomy of operation is particularly important for agencies involved in Public Protection (PP) where secure communications are often an important requirement.
PPDR in Europe
In Europe, the radio communications networks used by public safety and the emergency services will normally be used to provide Public Protection. When required, most public safety organisations have the capability to rapidly deploy mobile communications network elements to provide additional capacity and/or maintain communications if the main network fails.
As the trend in some parts of Europe is to allow non-public safety organisations that could be involved in major emergencies and disasters (for example transportation, utilities, military, etc.) to operate on the same networks as used by public safety organisations, it is logical that provision could be made on these networks (issue of terminals) to other agencies providing Disaster Relief (DR). If the nature of the disaster is such as to require aid from other European nations, the frequency band 380-385/390-395 MHz has been harmonised throughout Europe for public safety and emergency services applications.
On a global perspective, the European 380-385/390-395 MHz frequency band is not widely available outside Europe. Similarly, most of the frequency bands designated for PPDR applications in ITU Regions 2 & 3 by WRC03 are not available in Europe. Also, across the globe public safety organisations already use different wireless communications technologies, which are incompatible at the air interface. However, outside public safety specific communications, the technology and frequency bands for public cellular networks are harmonized, thus enabling this technology to be used globally for some PPDR applications.
Within the public safety 380-385/390-395 MHz radio frequency band TETRA is becoming the preferred technology of choice. Although the TETRA market covers traditional PMR and PAMR users, the public safety market is the largest and most significant. Also, as the trend is for shared national public safety networks for increased interoperability between different emergency services organisations, as well as the economics of sharing, it is recognised that other non-public safety organisations, such as transportation, utilities and the military, could be involved in emergencies.
Understanding this, provision has been made on some national shared public safety TETRA networks for these non-public safety organisations, thereby enabling interoperability when emergencies dictate mutual assistance, co-ordination and co-operation.
When a disaster occurs, the operators of these shared TETRA public safety networks are able to rapidly deploy network elements to provide additional capacity throughout the affected disaster area. In addition, operators of these networks are able to issue a number of terminals to other organisations involved in disaster relief activities. Currently, TETRA provides a comprehensive portfolio of voice and narrowband data services and facilities. Also, the TETRA standard will support wideband data with the advent of the TETRA Enhanced Data Service (TEDS), which is part of the new Release 2 standard completed at the end of 2005.