[ns] GPSR - Perimeter mode

[mmul at itu.dk]

Hi,

I have looked into GPSR and I seem to have missed a point
in the perimeter mode forwarding:

I understand it the following way:
When a packet enters perimeter mode at node x, destined to node d,
its starts to forward by the right hand rule. GPSR determines
whether the edge to the next hop n intersects the line from x to d,
and if so, the packet is forwarded along the next edge bordering the
point that is intersected by line x to d.
As soon as it reaches a node closer to destination d than x, it goes
back to the greedy mode.

My problem is:
If a packet in perimeter mode reached a node, which borders an edge
that intersects line x to d, it would return to greedy mode since
the node is bound to be closer to d than x is.
Thus the whole idea of checking if the edge intersects line x to d
makes no sence.
It is assumed that all nodes have the same transmission range, which
I believe is necessary for GPSR perimeter mode to function properly.

Regards

Mark Mullertz