Emergency Communications is a communication method that can temporarily and maneuverably provide emergency services after emergencies such as combat readiness, emergency rescue and disaster relief, terrorist incidents and communication network failures. Emergency communications must first ensure command communication, usually in wireless mode, which requires the rapid deployment of communication networks to provide communication support. The means of emergency communications mainly include the following:
In emergency situations, there is often a large burst of traffic in local areas and concentrated time periods, and it is the key to maximize the utilization of existing equipment.
(1) GSM wireless opening half rate: the maximum number of users can be accepted under the condition of losing part of the voice quality;
(2) 3G wireless equipment enables multi-carrier frequency: most manufacturers' equipment can now realize multi-carrier on a single board, but only a single carrier is actually turned on because of the procurement problem, and all can be turned on in an emergency;
(3) Expand all hardware capabilities and improve equipment processing capabilities: use spare parts, allocation, etc. to expand the processing capabilities of the existing hardware platform to the maximum (including the Internet, bearer network, local switches, long-distance switches, gateway offices, wireless equipment, etc.);
(4) Close all software license restrictions, or temporarily expand the license: the maximum processing restrictions on the number of users, CE, codewords, etc. should be canceled. In order to ensure that people with mobile phones can make calls, you can consider turning off the verification of the user's balance by the accounting system, or even turning off the user authentication of the mobile network;
(5) Restriction measures: In order to ensure normal communication, for wireless networks, 2G networks can consider turning off the function of data networks and assigning all channels to voice. Try to maximize the efficiency of network usage rather than perception. In addition, it is also extremely important to protect the maximum processing capacity of the equipment, so that the equipment cannot be paralyzed due to overload.
The L-band used by maritime satellites is commonly known as the golden band. Although its digital radio communication costs are expensive and irreplaceable in mobile satellite communications, it is no longer a problem for China, which is developing rapidly. In emergency applications, the ability to maintain moving video images, data communications and voice communications can greatly improve disaster relief.
The emergency communications vehicle is mainly loaded with 2G/3G and antenna equipment in the emergency vehicle, which is used for the widespread gathering of people due to major events (such as the Olympic Games, large-scale outdoor parties, etc.) or the interruption of communication in a certain area due to emergencies (such as mobile antennas in a certain area). tower damage) emergency communications.
There are usually three transmission modes for emergency communication vehicles, namely optical transmission, microwave transmission, and satellite transmission.
The communication equipment in the emergency communication vehicle usually includes several sets of RNC (BSC) and Node-B (BTS) equipment, auxiliary transmission equipment, power security equipment, and an antenna feeder system that can be raised and lowered.
Emergency communication vehicles can usually meet the requirements of communication guarantees such as important conferences, exhibitions, and festivals in various provinces, natural disasters, emergency response and stability maintenance, and combat readiness guarantees.
Ultra-short wave mobile radios (radio station) use a wide range of frequencies, involving 150 MHz, 200 MHz, 350 MHz, 400 MHz, and other frequency bands. Because the public communication network is extremely complex, it is often vulnerable in the face of disasters. The ultra-short-wave radio communication method has a clear voice, strong anti-interference ability, small size and easy to carry, and strong mobile communication ability. It does not rely on wired and optical fibers, especially suitable for disaster relief and emergency use at the scene of the incident.
The characteristics of ultra-short wave communication are basically "line-of-sight transmission", which only has certain diffraction and reflection capabilities. Therefore, if the area to be covered is large, a radio relay station can be appropriately selected for technical support. Usually, it is necessary to select commanding heights such as high mountains and high-rise buildings for "radio relay forwarding".