[ns] backoff timer implementation in 802.11

[sasan zhalehpour]

hi,
thank u for ur reply
If the medium is busy the station defer the access to the medium , and when
the
medium is idle for the DIFS , begins a backoff contention window to try
avoid
the collisions so if the medium wasn't idle the backofftimer wouldn't start.
i want to ask when backofftimer works (during idle time of medium, busy time
of medium or both of them)
as i know backoff timer just works  in idle time of medium and after
expiration of defer timer

On Fri, Jul 4, 2008 at 7:03 PM, Anastasios Daniilidis <
anastasios.daniilidis at gmail.com> wrote:

> If the backoff timer didn't start in case the medium was not idle, a
> collision would certainly occur. But what you say is also correct.
>
> 2008/7/4 sasan zhalehpour <sasan175571 at gmail.com>:
>
>
>> ---------- Forwarded message ----------
>> From: sasan zhalehpour <sasan175571 at gmail.com>
>> Date: Sun, Jun 29, 2008 at 3:46 AM
>> Subject: backoff timer 802.11
>> To: ns-users at isi.edu
>>
>>
>> hi,
>> i read in ns2.33 in MAC802_11.cc in
>
>
      " Incoming Packet Routines
       void

> MAC802_11:: send(...) class
>> ...
>> /*
>> if the medium is not IDLE, then we start the backoff timer  */
>> ....
>> "
>>  but as i know backoff timer starts when the channel is idle after
>> expiration of defer timer.
>> please tell if i made a mistake!!!
>> best regards
>> sasan.
>>
>
>