Wireless Network Design: Optimization Models and Solution ...

280 Marina Aguado, Jasone Astorga, Nerea Toledo and Jon Matias
12.4 Survey of Simulation for Wireless Network Design
One common use of simulation techniques is network planning. In this sense, the
authors in [26] make use of simulation for CDMA network planning. More precisely,
they propose simulation for offline coverage and load evaluation in order to
determine a candidate network’s efficiency in the physical layer when the overall
service demand exceeds the capacity of the network. Such an evaluation is essential
to determine prior to deployment if a potential network configuration can provide
adequate physical performance for different numbers of users, located in different
points over time. Similarly, in [11] the OPNET simulation tool is used to perform a
simulation of the network-traffic characteristics that a mobile WiMAX network to
be deployed in a near future will have to face. Additionally, a demand estimation
and a VoIP performance assessment is also carried out. The obtained results are crucial
for the successful cell and network-capacity planning of any operator interested
in deploying a WiMAX mobile network.
Regarding network planning, the use of simulation is not restricted to communications
networks or applications; it can be used in other research fields. For example,
for efficient power system expansion planning, it is essential to evaluate and
minimize the total cost of the grid expansion including the construction costs associated
with investing in new transmission lines, the operation costs of generators,
and the stand-by costs which are the auxiliary service costs for reliable energy supply.
Therefore, the authors in [6] propose a new cost simulation methodology which
allows for efficient and reliable cost evaluation.
Another important application field for which simulation is essential is the evaluation
of novel and emerging approaches or technologies which have not been implemented
yet in the real world. Following this approach, the authors in [3] use the
ns2 simulation tool 2 to prove the effectiveness of a novel protocol designed for efficient
power management in wireless sensor networks designed for periodic data
acquisition. Although sensor networks have a great potential and can be used for
countless applications, they must still surmount a key challenge before their massive
deployment becomes a reality: effective energy management. Most sensors operate
on non-rechargeable batteries, and thus the lifetime of the sensor network is
bounded by the duration of the sensor batteries. The authors confirm the reliability
of the results obtained by simulation by an experimental evaluation in a real testbed.
Another example is given by [18], where the authors propose a novel architecture
for interworking the emerging WiMAX mobile technology with the already
deployed 3G cellular networks built around technologies such as UMTS and
CDMA2000 using IP Multimedia Subsystem (IMS). As they argue, such an architecture
is essential to make the initial deployment of WiMAX networks easier and
thus make the real world exploitation of this technology more feasible. In order to
validate the performance of the proposed architecture, the authors present an analytical
evaluation of crucial parameters such as handover delay, packet loss, jitter,
2 The ns2 tool is available for free online at http://nsnam.isi.edu/nsnam/index.php/User Information.