Conference Proceeding

A study on hierarchical cellular structures with inter-layer reuse in an enhanced GSM radio network

Tech. Univ. Dresden
02/1999; DOI:10.1109/MOMUC.1999.819497 ISBN: 0-7803-5904-6 In proceeding of: Mobile Multimedia Communications, 1999. (MoMuC '99) 1999 IEEE International Workshop on
Source: IEEE Xplore

ABSTRACT In today's cellular networks it becomes harder to provide the
resources for the increasing and fluctuating traffic demand exactly in
the place and at the time where and when they are needed. Moreover,
frequency planning for a hierarchical cellular network, especially to
cover indoor areas and hot-spots is a complicated and expensive task.
Therefore, we study the ability of hierarchical cellular structures with
inter-layer reuse to increase the capacity of a GSM (Global System for
Mobile Communications) radio network by applying total frequency hopping
(T-FH) and adaptive frequency allocation (AFA) as a strategy to reuse
the macro- and microcell resources without frequency planning in indoor
picocells. The presented interference analysis indicates a considerable
interference reduction gain by T-FH in conjunction with AFA, which can
be used for carrying an additional indoor traffic of more than 300
Erlang/km2, i.e. increasing the spectral efficiency by over
50%, namely 33 Erlang/km2/MHz. From these results we draw a
number of general conclusions for the design of hierarchical cellular
structures in future mobile radio networks. For example, we may conclude
that they require reuse strategies that not only adapt to the current
local interference situation, but additionally distribute the remaining
interference to as many resources as possible. For a hierarchical GSM
network this requirement is fulfilled by the T-FH/AFA technique very

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