Gsm Frequency Reuse

This paper researches the application of 1×3 tighten frequency reuse technique deeply, which is used to enlarge the radio network capacity, in details and with the practical project "Kuerle China Unicom GSM900 Network Planning". The objective of the subject is to plan out a practically needed network which can enlarge the network capacity with good voice quality.The paper starts with 4×3 reuse pattern, which is one of the ordinary frequency reuse techniques, introduces the principles and various patterns of frequency reuse, the frequency reuse density and the requirement of carrier-to-interference ratio. With the practical project, the paper involves the technical analysis and implementing comparison. Via theoretical analysis and on-field test, the influence of the tighten reuse to the network quality and that of the engineering parameters to the 1×3 reuse are described. As the network capacity increases, the interference becomes more serious. Aiming at this situation, a solution is discussed which is the concentric cell technique.Practice tells us, using 1×3 tighten reuse pattern under 6MHz bandwidth, massive and continuous S3/3/3 sites can be supported. Each S3/3/3 site can contain up to 2104 subscribers which is more than that of an S2/2/2 plus an S1/1/1 in ordinary reuse pattern by 433. The network capacity is enhanced by 26% without obvious decrement of the overall network quality.