Optimal Multi-Objective Capacity Enhancement and Energy Efficient HetNet Planning and Deployment Approach: The Case of Addis Ababa, Ethiopia
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Date
2019-12
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Following growth in infrastructure, number of subscribers and availability of smart devices and
applications, the aggregate cellular data traffic in Addis Ababa city’s cellular network is
increasing exponentially. Moreover, traffic growth follows non-uniform distribution both in space
and time. To accommodate this non-uniformly growing data traffic, ethio telecom, for now, the
sole telecom service provider in the city, deploy single-layer homogeneous macro base stations
(MBSs). Macro-cell densification has been used to increase capacity of the radio access network
(RAN). However, excess densification increases the RAN energy consumption, which is becoming
a concern for cellular network operators like ethio telecom.
Deploying small cells overlaid with macro BSs, named as the heterogeneous network (HetNet), is
an energy-efficient (EE) approach capable of meeting the high capacity demand and also keeps
network deployment costs low. Many studies have analyzed the HetNet planning and deployment
scenario. However, user usage scenarios and their mobility pattern based on realistic data are not
considered for the selection of initial small cell candidate locations. Their results differ from one
another depending on the environment, cell size, data set, and technology, or the methodology on
which the research is made.
This research investigates a genetic algorithm (GA) based multi-objective optimization based on
system capacity and EE maximization to provide a set of optimal solutions for HetNet selection.
In doing so, based on a dataset collected from Addis Ababa cellular network, existing macro BSs
data traffic, user usage scenarios, and spatial data traffic demand distribution are generated to
identify hotspot areas, and are given as input parameters for the GA for optimal small cell
selection. Then, layered planning and deployment is carried out in an interference-limited LongTerm
Evolution
(LTE)
network
based on
the
target
requirement.
Finally,
performance gain
of
the
optimized
layered
approach
is
evaluated
with
system
capacity
and
EE
as
performance
metrics
and
compared
with a uniform topology which is resulted from unplanned small cell deployment
through network simulation tool. The simulation results mainly show that both EE (up to 22%)
and up to 16% capacity gain with cell edge performance gain (52%) of the target area are,
improved by the deployment of optimized small cells, over the uniform (unplanned) deployment.
Description
Keywords
HetNet, energy efficiency, hotspot localization, capacity, deployment scenario, multiobjective optimization, spatial traffic distribution