assign positions to mesh nodes

[Luis Mendes]

Hi,

I'm making a project for the university using ns3, I'm using the example that is provided in src folder called mesh.cc. I want to edit the code, and instead of having a grid position allocator I want to specify a x and y coordinates to wish mesh node. Can anyone help me with that? I know that should be extremely obvious but since I'm new using the ns3 I'm having some difficulties. 

thnks  

[Konstantinos]

In order to do that, you have to use a different Position Allocation class instead of the Grid.

Here is an example:
http://www.nsnam.org/doxygen/classns3_1_1_list_position_allocator.html

  MobilityHelper mobility;
  Ptr<ListPositionAllocator> positionAlloc = CreateObject <ListPositionAllocator>();
  positionAlloc ->Add(Vector(0, 0, 0)); // node0
  positionAlloc ->Add(Vector(1000, 0, 0)); // node1
  positionAlloc ->Add(Vector(450, 0, 0)); // node2
  mobility.SetPositionAllocator(positionAlloc);
  mobility.SetMobilityModel("ns3::ConstantPositionMobilityModel");
  mobility.Install(nodes);

However you can use more than one Allocators in the same script. For example you can use the Grid to place some nodes and the List with exact positions for other nodes.

[Luis Mendes]

thnks!! that was very, very helpful

[Shahrokh Vahabi]

Hi. How can I change position of a node in grid? for instance I want to put sink node in special position in grid.