As the existing dispatch communication system was long-used and the limitation of extending capacity of system and part of the function is out of the need of produce, Linxi Mine decided to upgrade the digital dispatch communication system in mining with KTJ7-8000 type to improve its extending capacity of the system, increase security coupling circuit layer and in the use of digital compression to achieve effective speech, etc., effectively improving the reliability and stability of the equipment operation, meeting the needs of the dispatching communication in mine.