Title :
A channel borrowing scheme for TDMA cellular communication systems
Author :
Jiang, Hua ; Rappaport, Stephen S.
Author_Institution :
Syst. Eng., BNR Inc., Richardson, TX, USA
Abstract :
The use of real time channel borrowing in digital cellular TDMA systems is considered. Some systems (such as IS-54) are asynchronous in the sense that time slots in different cells are not aligned. CBWL (channel borrowing without locking) techniques can be applied but (without cell-to-cell synchronization) borrowing individual time slots from adjacent cells would violate co-channel interference constraints. Instead, frequency carriers can be borrowed. But(for example) in IS-54, a carrier supports three channels. So if only one channel is needed in the borrowing cell, two channels are unnecessarily transferred. We devised an appropriate carrier borrowing scheme and an analytical model to determine the traffic performance of TDMA/CBWL. Fast carrier returning is used to increase channel utilization by returning borrowed carriers as soon as possible. An efficient computational method that uses macro-states, decomposition, combinatorial analysis and the convolution algorithm is devised to find blocking probabilities. The results show that in comparison with FCA, the new CBWL scheme can significantly improve system performance of asynchronous TDMA cellular systems that use FDMA/TDMA multiplexes
Keywords :
cellular radio; digital radio; frequency allocation; land mobile radio; radio spectrum management; telecommunication channels; telecommunication traffic; time division multiple access; CBWL; IS-54; TDMA; asynchronous systems; blocking probabilities; cellular communication systems; channel assignment; channel borrowing scheme; channel borrowing without locking; channel utilization; co-channel interference constraints; combinatorial analysis; convolution algorithm; decomposition; digital cellular radio; efficient computational method; fast carrier returning; macro-states; traffic performance; Algorithm design and analysis; Analytical models; Convolution; Frequency synchronization; Interchannel interference; Interference constraints; Real time systems; System performance; Time division multiple access; Traffic control;
Conference_Titel :
Vehicular Technology Conference, 1995 IEEE 45th
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-2742-X
DOI :
10.1109/VETEC.1995.504837