[ns] How can I get the wireless nodes' position information in C++ code.

[mjzrytl]

hello everyone.
   I want to improve DSR routing protocol .I want to define a node's interface 
by the distances from other nodes.
   How can I tell what node code is currently executing on .And how can I get 
the position informantion of all other nodes in the node's  C++ code?
                                                                                
                                        yours 
                                                                                
                                       zhang8677