Bug 1918 – RandomWalk2dMobilityModel is stuck in the corner

Bug 1918 - RandomWalk2dMobilityModel is stuck in the corner


Summary:	RandomWalk2dMobilityModel is stuck in the corner

Status:	NEW

Product:	ns-3
Classification:	Unclassified
Component:	mobility models
Version:	ns-3-dev
Hardware:	All All

Importance:	P5 normal
Assigned To:	ns-bugs

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Reported:	2014-05-21 15:10 UTC by Tommaso Pecorella
Modified:	2014-05-21 15:10 UTC (History)
CC List:	0 users

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Description Tommaso Pecorella 2014-05-21 15:10:56 UTC

If the node reaches the corner (or it starts from a corner) the mobility model gets stuck.

The reason is in RandomWalk2dMobilityModel::Rebound (Time delayLeft)
The function checks what's the "closest" side of the bounds and changes the speed accordingly.
If there are TWO equally close sides (as in a corner), only the horizontal speed is changed, and the vertical one is left as it is, leading to a loop.

I suspect that a similar things happens in all the mobility models with bounds, as the Rectangle::GetClosestSide() function only returns a side and not a corner.