ns-3 testbed programs exist in the ~/gits/ns3_testbed/ns3_programs directory. Currently, ns3_mobility and ns3_csma are available.

Configuration

ns-3 testbed programs take the following parameters:

• Count: The number of robots to simulate.
• Length: The mobility box edge length, in meters, within which mobility robots will move.
• Setup file: A setup file for describing more configuration parameters. Currently, only mobility settings are available.

Here is the provided default ns3_defaults.csv setup file, which defines positions for five stationary robots:

mobility,,,
Node,X,Y,Walks
R1,0,0,false
R2,1,0,false
R3,0,1,false
R4,-1,0,false
R5,0,-1,false

where:

• Mobility starts the section for defining node mobility.
• Column Node identifies the robot node name, starting with R, and one of R1, R2, R3, etc. The number of R* nodes is set using the count parameter you provide when running setup scripts. Note that you may provide an inclusive range for robots, for example R2-R29 for 28 robots from R2 to R29.
• Columns X and Y define robot antenna positions, in meters.
• Column Walks sets whether the robot is stationary or uses ns-3's random walk mobility model.

ns3_mobility

The ns3_mobility program models a Wifi ad hoc network: https://www.nsnam.org/docs/models/html/wifi.html. Here is the Wifi section of code in ns3_mobility.cpp:

// Wifi settings
ns3::WifiHelper wifi;
wifi.SetStandard(ns3::WIFI_PHY_STANDARD_80211a);
wifi.SetRemoteStationManager("ns3::ConstantRateWifiManager",
                        "DataMode", ns3::StringValue("OfdmRate54Mbps"));

// physical layer
ns3::YansWifiChannelHelper wifiChannel(ns3::YansWifiChannelHelper::Default());
ns3::YansWifiPhyHelper wifiPhy(ns3::YansWifiPhyHelper::Default());
wifiPhy.SetChannel(wifiChannel.Create());

// ad-hoc Wifi network
ns3::WifiMacHelper wifiMac;
wifiMac.SetType("ns3::AdhocWifiMac");

This sets the following:

• 802.11 physical layer model to 802.11a.
• Data mode to OfdmRate54Mbps.
• Physical layer implementation to YansWifi with default power values.
• Network mode to AdhocWifiMac.

Configuration by Changing Code

Wifi settings may be changed by changing code. For alternate Wifi settings, we recommend that you start withns3_mobility.cpp, copy it to, for example, ns3_my_wifi.cpp, change it, set up CMakeLists.txt to build it, then build it using cmake amd make.

ns3_csma

This program uses default CSMA settings for a wired instead of wireless setup:

// install the CSMA devices onto our ns3_nodes
ns3::CsmaHelper csma;
ns3::NetDeviceContainer devices = csma.Install(ns3_nodes);