Civil Defence Emergency Command shortwave multimedia system

Date:2013/8/26 17:13:12　Hits:7685

Product description:

With the rise of China and the global shortage of resources, the world's political, economic and military pattern is re-shuffle, the international situation and China's neighboring geopolitical increasingly subtle and serious, civil status and growing importance of emergency means of communication and command and guarantee efficiency has become a key part.

    In addition to conventional means of public communication, the present, China has established a civil defense system HF communication systems, are new or improved ultrashort wave communication system in which short-wave communications Invulnerability strongest single station the most extensive coverage, the strongest independent communication is All means of communication are not the only constraint network hub and active repeater remote communication methods. But usually only guarantee analog SSB radio calls and low-speed data reported, the existing data modem (MODEM) product and the actual rate of a misnomer. Recognizing the importance of data services, civil defense began to try to rely on mobile base stations, telecom cable, maritime satellite, radio and television public network to establish the emergency multimedia display terminal, but in addition to outside of confidentiality, is still a large extent limited by carrier commercial considerations, limiting their unified deployment, independent scheduling, self-contained and the economy's ability to operate.

    In order to achieve analog shortwave radio digitization of the team in 2008 that with the Nanjing Military communication equipment and technology Battalion cooperation "analog radio digital transformation" project, the use of coded orthogonal frequency division multiplexing (COFDM) system and virtual radio technology, done through software programming information sampling, quantization, voice coding / decoding (CODEC, while achieving the ITU-T G.723.1, G.722.2, G.729, MPEG-4AAC and other international standards and the US 2.4kbps vocoder standard), data multiplexing / demultiplexing, modulation / demodulation, and all other processes via the computer sound card directly with a bandwidth of 300-3000Hz SSB shortwave radio interface is connected to an analog telephone channel, built a software-only voice-band shortwave 3kHz MODEM (as shown below).

    The product is working at 300Hz-10kHz bandwidth chosen arbitrarily, can be directly adapted shortwave single / double-sideband radio channel analog audio port transmission 3-24kbps net bit rate, support for digital voice, image, text messaging, fax and other multimedia mixed data formats, achieve compatibility with existing analog equipment digital transformation. Test simulation software, hardware channel simulator testing and field trials shortwave communication, indicating that the transmission performance over the existing data transmission with short product specifications.

    This software product to shortwave radio as a platform for wide-area information dissemination to civil defense emergency command center for the sources of information support to the province each receiving terminal (both in the short wavelength coverage) to receive and broadcast information platform, a complete set of the self into system of the "civil defense emergency command multimedia system" application platform, so usually occupied, emergencies emergencies; mainly social, economic, supplemented; peacetime and wartime, with a combination of training and improve the skills of civil defense emergency communications command tactical level and the operational level personnel, to ensure integrity of equipment and readily available.

Previous:Ship far out at sea and Monitoring Command System Information Services