Intelligent climate control in outdoor cellular radio bases

An outdoor radio base will enclose a complex set of equipment such as the radio base itself, power supply rectifiers and backup batteries. All of this needs a stable temperature to optimize the function and service life during the very variable external milieu. Also, the network operator usually has a high number of bases over a large area increasing the need for high reliability to keep costs down. There are several problems a climate control system has to handle, all combinations of external temperature and internal load and the rapid change of both can give a very unfair burden on the system. To handle this complex task, a normal thermostat is not sufficient. A microprocessor programmed as an adaptive PID regulator controlling a heater, an air-conditioning unit and fan units is the solution which is described in this paper. If this high reliability equipment is combined with a central management system, fault location will be available. Service personnel will then be able to repair a station with minimum or no down time. Together, the use of a climate controller and supervisory system will save the system operator a significant amount of money.