Technical Services for Mine Communications Research. Task B (T.O.1) Applicability of State-of-the-Art Repeaters for Wireless Mine Communication.

摘要

The applicability of state-of-the-art repeaters to wireless communication in U.S. coal mines is investigated. Requirements,the environment,and system design factors are described. Present F1/F1and F1/F2repeater technology and equipment in the MF to UHF bands are reviewed,and system designs based on these are formulated and compared for use in coal mines. F1/F2type radio repeater systems are presently the most practical for U.S. mine applications. F1/F2equipment is commercially available in the HF,VHF,and UHF bands,but not below 25MHz. Although no off-the-shelf repeater equipment presently meets all mine environmental,safety,and user requirements,available UHF (450MHz) equipment,suitably modified,presently offers the most promise for providing wireless communication coverage compatible with the needs of both working sections and haulageways. Repeater systems using radiating coaxial cables offer a practical alternative for radio coverage along haulageways. Recommendations are made for the installation,test and evaluation of a prototype system using modified,commercially available UHF equipment in an operating mine.