TABLE OF CONTENTS The analytic methods shown in the previous chapters and in [1] require tedious calculations for call blocking and Erlang capacity, especially when the system supports multiple sectors and multiple FA bands. In this chapter. we propose an approximate analysis method, reducing the exponential complexity of the old method [1]down to the linear complexity. The approximated results also provide a difference of only a few percent from the exact value [1], which makes the proposed method practically useful.
In a CDMA system, call attempts may be blocked due not only to the scarcity of CEs in the BS but also to an excess of the maximum number of concurrent users. The CE is a hardware element that performs the baseband signal processing of the received DS signal for a given channel in the BS and is practically an important system resource. Call blocking, which is caused by insufficient CEs in the BS, is called hard blocking. In addition, the excessive interference due to concurrent users causes call blocking, which is called soft blocking and occurs typically when the number of active users exceeds the maximum number of concurrent users.
At a sectorized CDMA cell, CEs in the BS are pooled and can be assigned to any user regardless of the sector. It would be wasteful to provide CEs per sector based on the per-sector traffic loads, because the trunking efficiency gained by pooling the CEs would be lost. In such case, it is very important for...
