Bug 1934 – CCA is interrupted by an incoming packet

Bug 1934 - CCA is interrupted by an incoming packet


Summary:	CCA is interrupted by an incoming packet

Status:	NEW

Product:	ns-3
Classification:	Unclassified
Component:	lr-wpan
Version:	ns-3-dev
Hardware:	All All

Importance:	P5 minor
Assigned To:	Tom Henderson

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Depends on:
Blocks:
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Reported:	2014-06-20 05:07 EDT by Tommaso Pecorella
Modified:	2014-06-20 05:07 EDT (History)
CC List:	1 user (show)

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Description Tommaso Pecorella 2014-06-20 05:07:09 EDT

Tricky bug.

In CCA the radio is in Rx mode, so it can receive a packet. However CCA mode 1 should only assess the CCA according to the energy detection.

With the current code it is impossible to perform CCA Mode 1, as an incoming packet will always block the CCA, and this is equivalent to CCA mode 3.

To have a "real" CCA mode 1, one should disable the packet reception while in CCA mode, unless it's CCA mode 2 or 3.

As a side note, disabling packet reception while in CCA is similar (but not totally equivalent) to disabling packet reception while transmitting a packet (or having a packet in the Tx MAC queue).