[ns] PHY - MAC interactions in wireless nodes

[Utente ns2]

Dear all,

I have some doubts concerning the file wireless-phy.cc.
I hope you can help me.

Lets consider the path from channel to MAC.
The physical Layer is just in charge to receive packets from the channel and 
to hand them over the MAC layer.
In order to do this a method sendUp is implemented in which some filter is 
considered with corresponding different actions, namely:

if the Pr < CSThresh_  --> pkt_recvd = 0;
if (CSThresh < Pr < RXThresh_)  --> 2 actions:
1.	hdr->error() = 1
2.	pkt_recvd = 1.
My questions:
A.	Which packets will be actually passed to the MAC layer? Which 
requirements in terms of received power must the packets going to MAC have?
B.	Why we consider a variable pkt_recvd if it is just used in the method 
sendUp? To do what?
C.	In which way do sendUp pass these packets to the MAC? I see no methods 
belonging to MAC invoked by sendUp.

Thank you very much

Pasquale

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