Communications links are almost always disabled and disrupted during the first hours of a major disaster. When disaster relief workers arrive on the scene, there is an urgency to establish effective and comprehensive communication links between the affected area and national disaster response facilities, and with the larger international community.

Access to information is paramount. Relief agencies need know how many people have been injured or are dead; how many need medical help or transportation to medical facilities; where people may be trapped in damaged buildings; and where search and rescue teams are most needed. Workers rely heavily on telecommunications equipment to transmit this kind of information to central facilities in order to coordinate the complicated logistics of rescue operations.

Humanitarian organizations classify disasters as either natural disasters, sudden on-set disasters or complex emergencies (such as sudden or long-running civil conflicts).

These organizations are more concerned about how they will fulfill their mandate to bring relief and save lives. The cause of a disaster is of lesser importance – an outbreak of civil strife such as the one which occurred in Rwanda in 1994 can be as sudden as a volcanic eruption, or an industrial disaster such as Chernobyl in 1986.

Sudden onset disasters create very specific telecommunications needs. Existing infrastructures may have been destroyed and relief managers will need to obtain rapid and up-to-date information from workers in the field. In complex emergencies, existing national telecommunications are used wherever possible; however, if a conflict affects a widespread rural area in a developing country, some telecommunications equipment such as mobile phones may not be able to be used due to a lack of relay stations, or congestion caused by a sudden large volume of calls.

Existing public networks are used whenever possible in disaster relief operations if they are intact. However, with the centralization of modern networks and the increasing use of new types of technology such as satellite links for international telecommunications, damage to a single piece of equipment may mean total breakdown of communications and a loss of all connection to the outside world. Emergency telecommunications then become the lifeline for thousands of people.