COSC6397 Homework Assignment 4
October 4, 2004
Due date: Oct. 20, 2004; Maximum group size = 2
In this project, we use ns-2 to study the impact of mobility models on
the performance of routing protocols.
Mobility models: Download the mobility generator from IMPORTANT
web site http://nile.usc.edu/important/. Construct simulation scenarios
for random way point model (RWP), random point group mobility model
(RPGM) and Manhattan mobility model (MH) using the parameters listed
in Table 1. Compute the following statistics from the resulting scenario file:
•Average speed among all users over time.
•Spatial distribution (if applicable). In a 2-D plane, at time tcompute
the density of nodes for each 50mx50m square. Vary t(e.g., t = 0, t
= 100s) and compare if the spatial distribution changes over time.
•Distribution of link holding time defined as the total time that a link
exists. Draw histogram of the link hold time for each mobile scenario
(e.g., use Matlab) and compute the mean and variance. Explain why
the shapes for different mobility models are different.
•(Bonus) Correlation of link breakage events. Consider two links A-B
and C-D, record the time that the link is established and broken. Find
out if there is correlation between them in particular when the links
share common nodes.
[Hint: you can either instrument the mobility generator to get these statistics
or write your own program using the output scenario files from the genera-
tor.]
Assume the wireless transmission range is 250m, i.e., if two nodes are
separated by no more than 250m, there exists a bi-directional link between
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