Fixed Channel Assignment in Cellular
Mobile Telecommunication Systems - Using packed patterns to reduce the search space
Pedro Castro Borges, and Rene Victor Valqui Vidal
Abstract
The problem of fixed channel assignment in cellular communication
systems with nonuniform traffic distribution is addressed. The criterion
for channel allocation is minimising the average blocking probability.
Methods for finding a good allocation can be to different extents based on
first building a number of sets of cochannel cells or allocation patterns
and then assigning them to channels. This usually implies that only a
subset of the feasible region is attainable. The approach suggested in this
paper uses the concept of packed pattern, since all patterns in an optimal
solution will be of that kind. With a constructive method, the entire set
of packed patterns is built and used in the optimisation process.
The complexity (large-scale and nonlinearity) of the resulting problem
suggests the use of general search procedures (local search, tabu search,
simulated annealing, etc) which have the further advantage of flexibility
when dealing with extensions to the problem. A neighbouring structure is
used, that facilitated the calculations while still allowing for the search
in the entire solution space. A summary of extensive numerical experiments
is presented. The outcome is an improvement over previous results.
Keywords: mobile communication systems, search methods, channel allocation.
IMM Technical Report 25/96
Last modified February 4, 1997
For further information, please contact, Finn Kuno
Christensen, IMM, Bldg. 321, DTU Phone: (+45) 4588 1433. Fax: (+45) 4588
2673, E-mail: fkc@imm.dtu.dk
