2.6 Summary

In WCMTS, CASs play an important role in increasing spectrum efficiency. For a given spectrum and a specific technology, the traffic-carrying capacity of a cellular system depends on how the radio channels are managed.

There are several classifications of CASs according to different comparison bases, but in the most widely accepted classifications they can be classified as FCA, DCA, and FICA. Here, they are classified according to the way in which the cochannel sets are separated. Conventionally, FCA is used where each cell is assigned a set of fixed nominal channels. If a new call arrival finds all the nominal channels busy, then the call is blocked from the system. In contrast, in DCA, there is no relationship between the channels and the cells in the system. Channels are given to the cells on demand only for the duration of the calls; as soon as they are finished, the channels are returned to a central pool that manages the resources. Any cell can use any channel as long as the reuse distance is fulfilled. An important feature of DCA strategies is their adaptability to varying traffic conditions. They can adapt to both time and space variations of traffic.

In the third category of this classification, the total available channels are divided into two subsets: one set of channels is assigned to each cell on a nominal basis and the others are kept in a central pool for dynamic use.

As the demand for WCMTS grows, the deployment of...