A distributed dynamic resource allocation for a hybrid TDMA/CDMA system

A distributed dynamic resource allocation (DDRA) strategy for a hierarchical cellular structure (HCS) is proposed. In the DDRA, resources are shared not only between cells of the same hierarchy, but between layers. The proposed DDRA strategy is evaluated using the hybrid time-division multiple-access/code-division multiple-access (TDMA/CDMA) proposal made in the future radio wide-band multiple-access system (FRAMES) Project Mode I (FMI) as a case study. A mixed environment is suggested for the evaluation of the DDRA, which consists of Manhattan-like microcells covered by hexagonal-shaped umbrella cells (macrocells). Users are classified according to their speed as slow- and fast-moving users and are attended to by the most suitable layer of the hierarchy according to their speeds. Two types of real-time circuit-switched services are considered in the evaluation: speech and data at different rates. The DDRA is compared with the fixed resource allocation (FRA) strategy with overflow and with FRA with overflow, handdown, and channel reallocations (FRANR).