manual.txt

These mobility generator tools are used to generate a rich set of mobility scenarios used to evalua

USER MANUAL for "IMPORTANT" MOBILITY GENERATORS in ns-2 simulator 



Version: important-1.0-beta



Author: 

Fan Bai, Narayanan Sadagopan, Ahmed Helmy

agroup@Univ. of Southern California



Release Date: Feb.1, 2004



Relevant Website:

http://nile.usc.edu/important/

(backup site) http://www-scf.usc.edu/~fbai/important/



Disclamer: The copyright of this mobility tool is owned by ProTest Lab, Univ. of Southern California. 

This research is part of the MARMALADeS Research Project under the supervision of Prof. Ahmed Helmy 

at EE dept, USC. This work and the corresponding tools are made possible by a grant from NSF Career 

Award 0134650.



Please contact with authors ([e-mail] or [e-mail]) for further questions.



 

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I. Overview



These mobility generator tools are used to generate a rich set of mobility scenarios used to evaluate 

the protocol performance in Mobile Ad Hoc Network. The tools include the Reference 

Point Group Mobility(RPGM) model, Freeway Mobility Model and Manhattan Mobility Model. 



The trace files generated by these tools are compatible with the format required 

by ns-2. Thus, the user could directly input the trace files generated

by this generator into the ns-2 simulator and run the simulations. 



After modification of appropriate parameters, this set of mobility generators are able to create 

various mobility scenarios with different moblity characteristics, as stated in details in the following

sections. 





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II. Mobility Models



2.1 Random Waypoint (RW) Model: 

The Random Waypoint model is most commonly used mobility model in research community. In the current network 

simulator (ns-2) distribution, the implementation of this mobility model is as follows: at every 

instant, a node randomly chooses a destination and moves towards it with a velocity chosen uniformly

 randomly from [0,V_max], where V_max is the maximum allowable velocity for every mobile node. 

After reaching the destination, the node stops for a duration defined by the 'pause time' parameter. 

After this duration, it again chooses a random destination and repeats the whole process again until 

the simulation ends. In our framework, the RW model acts as the 'baseline' mobility model to 

evaluate the protocols in Ad Hoc Network. 



The Random Waypoint model is provided by the setdest tool in the standard ns-2 distribution, thus

we do not provide it in our release. 





2.2 RPGM Model:

Group mobility can be used in military battlefield communication. Here, each group has a logical 

center (group leader) that determines the group's motion behavior. Initially, each member of the 

group is uniformly distributed in the neighborhood of the group leader. Subsequently, at each 

instant, every node has a speed and direction that is derived by randomly deviating from that of the

 group leader. 



Important Characteristics:

 Each node deviates its velocity (both speed and direction) randomly from that of the leader. 

The movement in group mobility can be characterized as follows:

(1) V_{member}(t)  = V_{leader}(t)  + random() * SDR * max_speed 

(2) theta_{member}(t) = theta_{leader}(t) + random() * ADR * max_angle 



where 0 <= SDR,ADR <= 1. SDR is the Speed Deviation Ratio and ADR is the Angle Deviation Ratio. 

SDR and ADR are used to control the deviation of the velocity (magnitude and direction) of group 

members from that of the leader. Since the group leader mainly decides the mobility of group members,

group mobility pattern is expected to have high spatial dependence for small values of SDR and ADR.





2.3 Freeway Mobility (FW) Model: 

This model emulates the motion behavior of mobile nodes on a freeway. It can be 

used in exchanging traffic status or tracking a vehicle on a freeway.



Important Characteristics: 

In this model we use maps. There are several freeways on the map and each freeway has lanes 

in  both directions. The differences between Random Waypoint and Freeway are the following: 

(1) Each mobile node is restricted to its lane on the freeway.

(2) The velocity of mobile node is temporally dependent on its previous velocity. Formally, 

vec{V_{i}}(t+1)  = vec{V_{i}}(t)  + random() * vec{a_{i}}(t) 

(3) If two mobile nodes on the same freeway lane are within the Safety Distance (SD), the velocity 

of the following node cannot exceed the velocity of preceding node. Formally, 

for all {i}, for all {j},for all{t} 

if D_{i,j}(t) < Safety_Distance, then vec{V_{i}}(t) < vec{V_{j}}(t), if j is ahead of i in its lane.



Due to the above relationships, the Freeway mobility pattern is expected to have spatial 

dependence and high temporal dependence. It also imposes strict geographic restrictions on 

the node movement by not allowing a node to change its lane. 





2.4 Manhattan Mobility (MH) Model:

We introduce the Manhattan model to emulate the movement pattern of mobile nodes on streets defined 

by maps. It can be useful in modeling movement in an urban area where a pervasive computing service 

between portable devices is provided.



Important Characteristics: Maps are used in this model too. However, the map is composed of a 

number of horizontal and vertical streets. The mobile node is allowed to move along the grid of 

horizontal and vertical streets on the map. At an intersection of a horizontal and a vertical 

street, the mobile node can turn left, right or go straight with certain probability. Except 

the above difference, the inter-node and intra-node relationships involved in the Manhattan model 

are very similar to the Freeway model.



Thus, the Manhattan mobility model is also expected to have high spatial dependence and high 

temporal dependence. It too imposes geographic restrictions on node mobility. However, it differs 

from the Freeway model in giving a node some freedom to change its direction. 





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III. Usage and Desciption of Mobility Generators





3.1 RPGM Model (in the directory /rpgm)



Once the program is run, the users will be asked for the value of several key parameters. 

(1) Firstly, the user will be asked about the 'number of groups' used in the mobility scenarios. 

Here, if user is going to use single group mobility model, please input 1; otherwise, please input

the desired number, e.g., 4 for our INFOCOM2003 paper.  

(2) Then, parameter 'the number of nodes in each group' will be asked.

(3) Later, the values of Speed Deviation and Angle Deviation will be asked.

(4) To work appropriately, the RPGM model needs the trace file (we call it as 'checkpoint file') 

of the group leaders of each group. The file names will be asked. If single group model is used, 

only one checkpoint file for group leader is needed; if multiple group model (e.g., 4 groups) is 

used, then four checkpoint files for the group leaders of each group are required. Please just 

input the filename as following the instruction. 

    The 'checkpoint file' is needed to be created by users. It represents the movement trace of the 

group leader. It could be manually created by the users according to the predefined trace of 

movement trace, or easily converted from the random waypoint model. The format of this 'checkpoint 

file' is described in Appendix A.

    In sub-directory /rpgm/checkpoint1 and sub-directory /rpgm/checkpoint2, we provide two sets of 

the checkpoint files for single group mobility model and multiple group mobility model respectively.

(5) Finally, the user needs to input the file name of the generated trace file.

    If the users would like to generate more rich mobility scenarios, please refer the source code and 

change it appropriately.







3.2 Freeway Model (in the directory /fwy)



    Once the program is run, the users will be asked for similar questions as in RPGM model. 

    In FW model, a map file is also needed for the Freeway mobility generator to work appropriately. When 

the user is asked, the file name of this map file should be typed. The format for the map file is 

described in Appendix B. In the sub-directory /fwy/mapset1 and /fwy/mapset2, two sets of maps used for

freeway model are provided.



    The users are also asked for the value of acceleration speed. By changing this parameter, the users

are able to adjust the mobility behavior. In our INFOCOM2003 paper, we use the following setting:

Acceleration_speed = 10% * MAX_VELOCITY.





3.3 Manhattan Model (in the directory /man)



Once the program is run, the users will be asked for similar questions as in RPGM model. 

(1) First, the overall number of mobile nodes in the simulation field is asked.     

(2) Second, The Max and Min allowed velocity of mobile nodes are asked respectively. The users can 

input their desired values. 

(3) Then, the users are also asked for the value of acceleration speed. By changing this parameter, the users

are able to adjust the mobility behavior. In our INFOCOM2003 paper, we use the following setting:

Acceleration_speed = 10% * MAX_VELOCITY.

(4) In MH model, a map file is also needed for the Manhattan mobility generator to work appropriately. When 

the user is asked, the file name of this map file should be typed. The format for the map file is 

described in Appendix C. In the sub-directory /man/mapset1 and /man/mapset2, two sets of maps used for

manhattan model are provided.

(5) Finally, the filename of output trace files are asked.