Capture-division packet access for wireless personal communications

This paper presents a new architecture for the third-generation mobile systems, capture-division packetized access (CDPA), that overcomes most of the limitations of present cellular systems. It addresses the three main issues of radio access, namely the channel reuse, the multiple access, and the handover problems, in complete adherence to packet-switching principles. The CDPA channel reuse mechanism is a completely new alternative with respect to time-division, frequency-division, or code-division multiple-access (TDMA, FDMA, and CDMA, respectively), which achieve communication parallelism by subdividing the bandwidth a priori among cells. In CDPA, a single frequency channel is used and parallel transmissions are achieved through the “capture” capability of receivers. The hybrid reservation-polling multiple access mechanism used in CDPA is able to integrate any kind of traffic and guarantees almost immediate retransmission of packets that are not captured, thus assuring their correct reception. Finally, the packet-switching approach allows connectionless communications with any base station (BS), and eliminates the need for extra radio traffic in managing handovers. This turns out to be very effective in local area systems where the required high bandwidth is obtained by using a pico-cell structure. We present the CDPA architecture, discuss some implementation issues, and evaluate its performance under a variety of system parameters and operating conditions, using analytical and simulation methods