Bug 1677

Summary:	The annotation of YansWifiPhy needs correction
Product:	ns-3	Reporter:	Junling Bu <linlinjavaer>
Component:	wifi	Assignee:	Nicola Baldo <nicola>
Status:	RESOLVED FIXED
Severity:	normal	CC:	ns-bugs, ruben
Priority:	P5
Version:	ns-3-dev
Hardware:	All
OS:	All
Attachments:	update comments for yans-wifi-phy

Description Junling Bu 2013-05-08 08:39:57 UTC

on src/wifi/model/yans-wifi-phy.h line 74
 * Channel center frequency = Channel starting frequency + 5 MHz * (nch - 1)
but as IEEE 802.11-2007 17.3.8.3.2 defines
Channel center frequency = Channel starting frequency + 5 × nch (MHz)
where nch = 0,1,…200
I don't know why here is nch-1. 

on src/wifi/model/yan-wifi-phy.c line 112
 "Delay between two short frames transmitted on different frequencies. NOTE: Unused now.",
but on line 363
m_state->SwitchToChannelSwitching (m_channelSwitchDelay);
here m_channelSwitchDelay is used actually.

because I think annotation is very important, so I want to correct them.
If I misunderstood here, sorry to report this.

Comment 1 Nicola Baldo 2013-05-25 15:49:37 UTC

Hi Junling,

thanks for your bug report! You're right in both cases: about the formula for the channel frequency, in fact YansWifiPhy::GetChannelFrequencyMhz () implements the formula as you reported. About ChannelSwitchDelay, the comment is clearly obsolete. Would you mind creating a patch updating the attribute descriptions and the comments in the code as needed?

Comment 2 Junling Bu 2013-05-27 07:41:56 UTC

Created attachment 1603 [details]
update comments for yans-wifi-phy

Comment 3 Nicola Baldo 2013-05-27 07:53:42 UTC

Thanks! Just pushed:

changeset:   9818:cfb12f56257a
tag:         tip
user:        Junling Bu <linlinjavaer@gmail.com>
date:        Mon May 27 13:45:39 2013 +0200
summary:     fixed Bug 1677 - The annotation of YansWifiPhy needs correction