[ns] Is it possible to have two nodes with two different MAC layers?
Hello everyone, My question is that is it possible to have two nodes communicating with each other using two different MAC layers. For instance, node A uses 802.11mac and node two uses a modified 802.11mac. Regards, Bahman _ All new Live Search at Live.com http://clk.atdmt.com/UKM/go/msnnkmgl001006ukm/direct/01/
[ns] Two mobilde nodes with different MAC/802_11 attributes?
Hello everyone,I'm simulating a wireless (802.11) ad hoc system with 3 mobile nodes.Is there any way that I could change the attributes (e.g. the MAC) of each of the nodes separately.For example, to increase the timeout value of one node and decrease it on the other one.I appreciate your kind suggestions.Thanks,Bahman _ http://clk.atdmt.com/UKM/go/msnnkmgl001009ukm/direct/01/
[ns] How to create another 802_11 MAC layer?
Hi again, I have another question. How can I create another 802_11/MAC layer, which is exactly the same as the original one, but with a different name. Regards, Bahman. _ http://clk.atdmt.com/UKM/go/msnnkmgl001002ukm/direct/01/
[ns] TCP Transmission between 3 mobile nodes?
Dear all, I have three 802.11b mobile nodes (A.B.C), where A and C are hidden from each other. A sends TCP packets to B (start time = 1 sec) C sends TCP packets to B (start time = 1.5 sec) (end time for both transmissions = 10 sec) Judging by the trace file, I see that only A transmits to B all the way through the simulation (at the beginning C sends some Boradcast packets to B as well, but only 3 or 4 packets, and then it doesn't access the channel afterwards). Does anyone know why this happens? Why there isn't any collisions? This situation doesn't happen in UDP Transmission. I observed there are collisions between packets of stations A and C, (specially, using the Basic Method) which reduces the overall performance. So, UDP works well. Any ideas about the TCP transmission? Thanks, Bahman _ 100’s of Music vouchers to be won with MSN Music https://www.musicmashup.co.uk
[ns] HELP- How to implement 802.11a OFDM PHY?
Ladies Gents, Has anyone implemented the IEEE 802.11a OFDM PHY in NS? Any ideas on how to modify NS or perhaps where the implementation can be found? Couldn't find anything in NS archives... Help please. Thanks, Ben. _ Feel like a local wherever you go. http://www.backofmyhand.com
[ns] Help Error Module in 802.11
Hi,
Does anyone know why the following situation happens. ( Topology: node_(0)
node_(1) node_(2) )
I set the error rate to more than 5%, then all packets heading from node_(0) to
node_(1) get dropped! (packets from node_(1) to node_(2) are fine, and they go
with the defined error rate).
I'm trying to calculate the throughput with 10% error, but in this cases
node_(1)'s throughput with 10% error becomes 0, which can't be correct.
I get the folloiwng .tr and .tcl file (short and simplified versions)
Please help me if you have any suggestions.
Thanks,
Behman
Trace File
---
s 1.109715200 _0_ AGT --- 18 cbr 1518
D 1.109715200 _0_ RTR IFQ 8 cbr 1538 s 1.109715200 _1_ AGT --- 19 cbr 1518 s
1.110929600 _0_ AGT --- 20 cbr 1518 D 1.110929600 _0_ RTR IFQ 10 cbr 1538 s
1.110929600 _1_ AGT --- 21 cbr 1518 s 1.111210182 _1_ MAC --- 9 cbr 1590 s
1.112144000 _0_ AGT --- 23 cbr 1518 D 1.112144000 _0_ RTR IFQ 12 cbr 1538 s
1.112144000 _1_ AGT --- 24 cbr 1518 r 1.112608091 _2_ MAC --- 9 cbr 1538
s 1.112618091 _2_ MAC --- 0 ACK 38 r 1.112633091 _2_ AGT --- 9 cbr 1538 r
1.112989091 _1_ MAC --- 0 ACK 38 s 1.113259091 _1_ MAC --- 11 cbr 1590 s
1.113358400 _0_ AGT --- 25 cbr 1518 D 1.113358400 _0_ RTR IFQ 14 cbr 1538 s
1.113358400 _1_ AGT --- 26 cbr 1518 s 1.114572800 _0_ AGT --- 27 cbr 1518 D
1.114572800 _0_ RTR IFQ 16 cbr 1538 s 1.114572800 _1_ AGT --- 28 cbr 1518 r
1.114657000 _2_ MAC --- 11 cbr 1538 s 1.114667000 _2_ MAC --- 0 ACK 38 r
1.114682000 _2_ AGT --- 11 cbr 1538
TCL FILE
---
set error_rate 0.05;# error rate in percentage
$ns_ node-config -IncomingErrProc UniformErr $error_rate \
#setting up the Error/Loss Module proc UniformErr {} {global error_rate
set err [new ErrorModel]$err unit packet$err set rate_ $error_rate
return $err
#setup UDP connections node_(0) node_(1)Agent/UDP set
packetSize_ 2400 ;# Max UDP packet size without
defragmentationApplication/Traffic/CBR set rate_ 1Kb;# 10Mbps set udp1
[new Agent/UDP] $udp1 set class_ 1 $udp1 set fid_ 1 set null1 [new
Agent/Null] $ns_ attach-agent $node_(0) $udp1 $ns_ attach-agent $node_(1)
$null1 $ns_ connect $udp1 $null1 set cbr1 [new Application/Traffic/CBR]
$cbr1 attach-agent $udp1 $cbr1 set packetSize_ 1518
$ns_ at $opt(cbr1-start) $cbr1 start#setup UDP connections
node_(1) node_(2) set udp2 [new Agent/UDP] $udp2 set class_ 2 $udp2
set fid_ 2 set null2 [new Agent/Null] $ns_ attach-agent $node_(1) $udp2
$ns_ attach-agent $node_(2) $null2 $ns_ connect $udp2 $null2 set cbr2 [new
Application/Traffic/CBR] $cbr2 attach-agent $udp2 $cbr2 set packetSize_ 1518
$ns_ at $opt(cbr2-start) $cbr2 start
_
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[ns] How to change CSThresh_?
Dear all, Does anyone know how I can only change the CS (Carrier Sense) Threshold? I don't want to change the RX (Receiver) Threshold though. I tired to use the threshold.cc file in NS, but it doesn't give me the CSThresh_ value. Looking forward to your replies. Thanks, Bahman _ Feel like a local wherever you go with BackOfMyHand.com http://www.backofmyhand.com
[ns] Error Module in NS
Hi, I'm using a simple Error Model form NS for my ad hoc wireless network. I encounter two problems. 1- packets get dropped with the reason of IFQ. 2- I cann't increase the error rate to more than 4%. Please let me know if you have any ideas please. Thanks, Bahman _ Celeb spotting – Play CelebMashup and win cool prizes https://www.celebmashup.com/index2.html
[ns] Throughput using perl
Hello,A quick and easy question... I'm using a perl script (filterinng tcp, r and node _1_) to get the =throughput of a simple two node 11Mbps BASIC (mode) TCP 802.11b system.When Agent and MAC traces are ON, the throughput is around 8Mbps.When only Agent trace is ON, the throughput is around 4Mbps (max=3D4.45Mbps=).Does this seem to be correct?From other NS emails, I assumed I should get something around 5 - 5.5 Mbps =for a BASIC 11Mbps system?!Please let me know if you know how to calculate the throughput in a bit mor=e detail.Thanks,Bahman _ Feel like a local wherever you go with BackOfMyHand.com http://www.backofmyhand.com
[ns] TCP data and ack packet sizes
Hi, I get the following Trace file (a short version): r 1.115270923 _1_ MAC --- 0 RTS 44 [7a4 1 0 0] s 1.115280923 _1_ MAC --- 0 CTS 38 [66a 0 0 0] r 1.115586923 _0_ MAC --- 0 CTS 38 [66a 0 0 0] s 1.115596923 _0_ MAC --- 4 tcp 1572 [13a 1 0 800] --- [0:0 1:0 32 1] [1 0] 0 0r 1.116916741 _1_ MAC --- 4 tcp 1520 [13a 1 0 800] --- [0:0 1:0 32 1] [1 0] 1 0s 1.116926741 _1_ MAC --- 0 ACK 38 [0 0 0 0] a tcp packet of size 1572 bytes is sent from node 0 to node 1. Is this 1572 byte the MAC payload, or does it include any header? why does node 1 receive 1520 bytes (rather than 1572bytes) ? how could i send a fixed tcp packet size? is there anyway I change the size of ack packet (related to tcp data)? it doesn't seem to be a fixed value! (40, 60 and 80 bytes are in my case) Thanks, Bahman _ 100’s of Music vouchers to be won with MSN Music https://www.musicmashup.co.uk/index.html
[ns] Disabling the NAV of 802.11
Hi, How can I disable the NAV in 802.11. Thanks, Bahman _ Try Live.com - your fast, personalised homepage with all the things you care about in one place. http://www.live.com/?mkt=en-gb
[ns] Scheduler error in 802.11
Hi, I'm simulating a simple wireless (802.11b Basic Mode) experiment. At the end of the simulation, I get this error: Scheduler: Event UID not valid! I understand that the message is being initiated from /ns/common/scheduler.cc file line 93 only because the UID of an event is positive. In other words, an event with positive UID cannot be scheduled again. Now, I'm using a timer to introduce a fixed delay for each packet -either control or data packet- passing through the interface layer. When I introduce 1 to 39us of delay to my system, the simulation works perfectly and as expected (i.e. there is a fixed delay for the transmission of each packet reflected into my trace file). However, when I increase this delay to 40us and above, then run the simulation I get the above error. I have adjusted the timeouts in the ns/mac/mac-802_11.cc as well so that my packets are not all dropped. Please let me know if you have any ideas or thoughts about this. Where do you think I should look at first? What could the problem be? Thanks, Bahman _ Txt a lot? Get Messenger FREE on your mobile. https://livemessenger.mobile.uk.msn.com/
[ns] How to bind to phy.cc
Hi, Could anyone please help me. I managed to bind a variable (extra_delay_ ) to wireless-phy.cc and mac-802_11.cc files, but don't know how to bind it to phy.cc file. Any ideas on how to do this please? Thanks, Bahman. _ MSN Hotmail is evolving check out the new Windows Live Mail http://ideas.live.com
[ns] Trace File Generation
Hi, Firstly, thank you for your kind suggestions. Unfortunately, I didn't get any answer to my question as it wasn't a clear one. So, I am wirting my question one more time in a bit more detail. What I need to know is that how the trace file is constructed. I mean, for example, is the line (Event, Time, From Node, To Node, Packet Type, Packet Size, etc.) generated from a C++ file or a TCL file. In other words, is it the output of a C++ file or a TCL file? If so, where can I find this file (that generates each line of the trace file). I need to check, for instance, where the trace file gets its timing, packet type, etc. from. Thanks, Bahman. _ MSN Hotmail is evolving check out the new Windows Live Mail http://ideas.live.com
[ns] Binding a variable to Phy.cc
Dear all, I need to add an additional delay into the network interface of the 802.11 standard. I managed to bind this delay into wireless-phy.cc and mac-802_11.cc. I need to put this delay into the recv() function of phy.cc as well, but I dont know how to bind in phy.cc Any ideas on how to do this please? Thanks, Bahman. _ Click Here To Find Your Perfect Match This Valentines! http://msnuk.match.com/
[ns] Trace file generation
Dear all, Does anyone know how and where the Trace file (*.tr) is generated from? Bahman. _ Get Hotmail, News, Sport and Entertainment from MSN on your mobile. http://www.msn.txt4content.com/
[ns] Insering a Delay module in NetIF
Hi, Does anyone know how I can insert a delay module inside the NetIF layer so that all the packets being received from the channel, and being sent to the channel go through this fix delay (of e.g. 20us). Thanks, Bahman. _ Get Hotmail, News, Sport and Entertainment from MSN on your mobile. http://www.msn.txt4content.com/
[ns] wireless-phy.cc/h description
Hi eveyone, Does any of you know where I can find the description of the functions/variables/classes etc. of the /ns/mac/wireless-phy.cc(and h) files? Any documents, powerpoints, pdf files I could look into? Thanks, Bahman _ MSN Hotmail is evolving check out the new Windows Live Mail http://ideas.live.com
[ns] Inserting a Delay Module in MAC
Hi everyone, I would like to insert a timer in the NetIF of my node so that every packet going up towards the MAC and down towards the channel is held for a certain delay_ time. This is to simulate an 802.11 network and analyse the RTS,CTS,ACK frames. In other words, making sure that all these packets go through this delay. Where should I start and what should I do? Thanks, Bahman. _ Windows Live Messenger has arrived. Click here to download it for free! http://imagine-msn.com/messenger/launch80/?locale=en-gb
[ns] Implementing a DELAY in sendDown ( Packet * p )
Hi, How could I implement the function --sendDown ( Packet *p ) -- with some delay? Thanks, Bahman
[ns] Inserting a delay module in 802.11 Node
Hi, How can I implement a delay to the packets that are left or received at a node? Thanks, Bahman
[ns] Modifying 802.11 wireless Channel Propagation Delay
Hi, Does anyone know how I can change the wireless channel propagation delay. I have two mobile nodes, use FTP over TCP, with RTS-CTS mechanism. I want to increase the delay, so that every packet (including the control packets) passing the channel goes though this delay. Then I want to increase this delay, until there wouldn't be any throughput because the CTS_Timeout expires and the transmitter keeps retransmitting the RTS packet until it stops. Any ideas, please let me know. Regards, Bahman
[ns] MAC_802_11 sendup and senddown Delay
Dear all, I want to add an additional delay (suppose: a variable called delay2_ ) to the NefIF of my node, so that all the packets sent from/to the WirelssPhy are scheduled to go through this delay. I want to investigate the MAC performance (throughtput) of the system when this delay is increased from zero to the point where the system's throughput becomes zero again. I have been advised to check wireless-phy.cc/h, phy.cc/h (sendup and senddown function) and add some codes there. But don't know where and what to add. I have studied most of the c++ codes of the related files (including: mac-802_11, Phy, wireless-phy,mac-timers, scheduler) and have a fair amount of understanding there. The other point given was that I have to create a 'timer' so that all the packets are scheduled by this timer i.e.s.schedule(delay_handler_, p, delay2_). How do I do this? (do I write a new class in the mac-timers.cc/h ? ) Just to let you know that I have never carried out any changes in the c++ files of NS-2. After I did this, what should I do in order that NS-2 works with these new codes? Looking forward to your suggestions, Many thanks Ben PhD Researcher Department of EE @ UCL.
[ns] MAC_802_11 Sendup and Senddown delay
Dear all, I want to add an additional delay (suppose: a variable called delay2_ ) to the NefIF of my node, so that all the packets sent from/to the WirelssPhy are scheduled to go through this delay. I want to investigate the MAC performance (throughtput) of the system when this delay is increased from zero to the point where the system's throughput becomes zero again. I have been advised to check wireless-phy.cc/h, phy.cc/h (sendup and senddown function) and add some codes there. But don't know where and what to add. I have studied most of the c++ codes of the related files (including: mac-802_11, Phy, wireless-phy,mac-timers, scheduler) and have a fair amount of understanding there. The other point given was that I have to create a 'timer' so that all the packets are scheduled by this timer i.e.s.schedule(delay_handler_, p, delay2_). How do I do this? (do I write a new class in the mac-timers.cc/h ? ) Just to let you know that I have never carried out any changes in the c++ files of NS-2. After I did this, what should I do in order that NS-2 works with these new codes? Looking forward to your suggestions, Many thanks Ben PhD Researcher Department of EE @ UCL.
