RF Basestation Antenna System
Objective
Mobile phone basestations have to be located relatively close to their antennas, which results in a large rack of electronics based in every cell and often in an environmentally challenging location. Where the subscriber density is high or there are reception difficulties, both of which occur in urban areas, the cell will be small, and thus there will be a large investment in basestations.
There would be significant commercial advantages for a network provider, if he could use fewer, well-protected, basestations, by allowing each to drive the antennas in adjacent cells as well as its own.
Approach
A major telecommunications supplier wished to add such a system to their portfolio of telecommunications equipment. They asked Cambridge Consultants how they might split their mobile phone basestation so that the transmitter and receiver modules could be located near to the antenna (up to 0.5km) from the basestation. This would allow the basestation to be located in an accessible and safe location, and allow a single basestation to control more than one antenna, each covering a 0.5km cell.
Solution
Cambridge Consultants analysed the existing basestation design and determined the best point to divide the system. The point of least interconnect was not the optimum place to divide the system, as it would have then placed severe response time constraints on the link. We proposed a set of cards linked by a pair of fibre optic links (uplink and downlink), which would meet the required data rate (~50Mbits/s), range (at least 0.5km) and immunity from interference.
Benefit
The resulting basestation offering, developed on time and within budget, has allowed our client to demonstrate their remote antenna head product to gain a leading edge over their competitors.