Re: [ns] Large ad hoc simulation using FreeSpace propagation model is way too slow
Hi Ricardo, the obvious answer - the number of events to process is very different. But why? First of all, the different propagation models result in different transmission ranges. And greater transmission range results in a larger number of nodes receiving an event and hence more processing time required. You can check this by counting the number of events in the event trace. Second, when you start your simulation it should print a line containing distCST_ = 550.0. This is the maximum range one node can affect another one (carrier sense). If it is unknown you will see a really huge number. This value is used to optimize the propagation computation because nodes further away do not need to be considered during the transmission of a packet. So, larger values will increase computation time. Third, even if you set the transmission range of different models to the same value you will get different event counts. The reason is that all models produce different carrier sense to transmission range ratios. That means, equal transmission ranges will result in different carrier sense ranges that obviousely results in a different behavior of your simulation. Daniel. Ricardo Ulisses schrieb: Hi all, I've been doing research on large mobile ad hoc network simulation, so far using Two-Ray Ground radio wave propagation model. I suppose I was achieving a reasonable amount of time to fully complete a simulation run with 10k nodes with 3k connections between them during 300 seconds of simulation time (about 2 days and a half). Now I've switched to the FreeSpace propagation model and I've noticed that the time to process the simulation largely increased. Let me show some small scale network examples: 1) Simulating 10 nodes, 3 connections between them, 300s simulation time: FreeSpace..1m3.232s TwoRayGround0m0.500s 2) Simulating 100 nodes, 30 connections between them, 300s simulation time: FreeSpace..more than 30 minutes TwoRayGround1m11.207s I've also made some simulations using the Shadowing model and the time spent was very close to the ones obtained when using the TwoRayGround model. I am really surprised with the high time consumption of the simulation run using FreeSpace model as it is a much less complex model than TwoRayGround and Shadowing. Does anyone have any clue about the reason why this is happening? Yes, I've read the FAQ, ns-problems page, and manual and I couldn't find the answer there neither in any other document or website. Please, ask me if more information about how the simulation is configured is needed. Thanks in advance. Ricardo J. Ulisses Filho = Departamento de Sistemas e Computacão - DSC Universidade de Pernambuco - UPE Recife - Pernambuco - Brazil [EMAIL PROTECTED] [EMAIL PROTECTED]
Re: [ns] Vectors in NS
Hi, vector.erase(...) works only on iterators. Look here for more information: http://www.cplusplus.com/reference/stl/vector/erase.html Daniel. SS Mukaka schrieb: Dear All How do you define and manipulate vectors in C++ code. I have written my own protocol but I'm having problems with the vectors Here is how I defined my vector: vector int MyVector and this is how I manipulate it MyVector.erase(index) MyVector. push_back(DataItem) This is the error that I get when I try to compile my code (using make) error: no matching function for call to 'std::vectorint, std::allocatorint ::erase(int)' /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/vector.tcc:110: note: candidates are: typename std::vector_Tp, _Alloc::iterator std::vector_Tp, _Alloc::erase(__gnu_cxx::__normal_iteratortypename std::_Vector_base_Tp, _Alloc::_Tp_alloc_type::pointer, std::vector_Tp, _Alloc ) [with _Tp = int, _Alloc = std::allocatorint] /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/vector.tcc:122: note: typename std::vector_Tp, _Alloc::iterator std::vector_Tp, _Alloc::erase(__gnu_cxx::__normal_iteratortypename std::_Vector_base_Tp, _Alloc::_Tp_alloc_type::pointer, std::vector_Tp, _Alloc , __gnu_cxx::__normal_iteratortypename std::_Vector_base_Tp, _Alloc::_Tp_alloc_type::pointer, std::vector_Tp, _Alloc ) [with _Tp = int, _Alloc = std::allocatorint] Regards SS Mukaka
Re: [ns] About wireless cards specifications simulation
Hi, Gabrial Monty schrieb: You have said that : To answer your question: NO, it is absolutely not realistic to deduce from a result of 150m transmission range to be in an indoor scenario. Do you mean that I cannot assume an indoor range to be 150m, or I cannot assume that an infrastructured network is working in an indoor environment? What I tried so say is: If your transmission range is 150m, you cannot assume to be in an indoor environment. For your question: a) you cannot assume that the transmission range will be 150m in an indoor environment. Usually, when someone gives a transmission range, he means that the transmission range can be _up to_ this value. You can never assume a minimum range (s. the elevator example). b) An infrastructured network is known to work in an indoor environment. The point that I want to get to, is that in the standard it is specified that the maximum transmit power for 802.11a cards in the range 5.725-5.825 GHz can reach 800 mW, following this can I assume a range of 150m (for example) for a card using 600 mW as its transmit power, apart from the propagation model or lets say I am working with TwoRayGround model, can I assume this or one can argue that my simulation settings are not real? In a general environment (one you have no specific knowledge about) you cannot assume anything (s. the elevator). If you define some properties of the environment as prerequisits (e.g. we are in an open park area with clear line-of-sight and no obstacles within the first fresnel zone) you can assume a transmission range with high confidence (e.g. 150m +/- 20m). In an indoor environment this is quite difficult because the variation is extremly high - something linke 50m +/- 50m does not help you much. Furthermore, even in a static indoor environment (one where anything remains at its position, no people moving, no doors opened/closed etc.) the signal strength between a pair of stationary WLAN transmitters will not be constant. You will find more information and references to other peoples' work in my thesis (http://deposit.ddb.de/cgi-bin/dokserv?idn=980478588) or in the papers of my collegues that continued / extended my work (http://wwwivs.cs.uni-magdeburg.de/EuK/forschung/publikationen/index.shtml). So my advise - start your work with a discussion of the properties of the environment, than that of your devices, and finally that of your protocol. From all this you can derive the performance of your communication / application with reasonable confidence. And don't forget - transmission power is a property of your devicey, but transmission range is not. It is a result of the combination of transmitter, receiver, environment, and signal encoding. Daniel. Daniel Mahrenholz [EMAIL PROTECTED] wrote: Hi, Gabrial Monty schrieb: I have to simulate an infrastructured wireless network behavior using different wireless cards specifications. I want to test the network performance using 802.11a cards with high transmit power level (not less than 600 mW). I have choosen the XtremeRange5 card but what I have realized is that its outdoor range is over 50 km and it indoor range is 150 m, during simulation if two nodes are further than 150 m the link throughput is 0, so is it realistic to assume that I deal with indoor networks? what I mean I am dealing with similar networks topology to wireless mesh networks, can I assume this network to be indoor and apply this NIC card specifications Basically there is no difference if you increase the transmission power or use a high gain antenna. So, apart from the transmission power, the sensitivity of the transceiver is what makes the most important difference between two wireless cards. Before you proceed with your work you should read something about wireless propagation. Just as an example, an outdoor range of 50km is only possible if the transmitter is placed high enough above ground. Otherwise you will not have a free line of sight and fresnel zone. When I remember right, for 50km distance the transmitter needs to be placed about 80m above ground. The environment defines how the transmitted signal is attenuated. Just imaging you are inside a metal elevator - then you probably get an indoor range of 1m. To answer your question: NO, it is absolutely not realistic to deduce from a result of 150m transmission range to be in an indoor scenario. I suggest that you start by selecting a propagation model that mimics the effects experienced in an indoor environment (e.g. multipath propagation, shadowing, interference ...). If you have such a propagation model, you can start to investigate effects caused by the transmission power, cars specification, protocol ... whatever you like. Hope that gets you started, Daniel. - Never miss a thing. Make Yahoo your homepage.
Re: [ns] About wireless cards specifications simulation
Hi, Gabrial Monty schrieb: I have to simulate an infrastructured wireless network behavior using different wireless cards specifications. I want to test the network performance using 802.11a cards with high transmit power level (not less than 600 mW). I have choosen the XtremeRange5 card but what I have realized is that its outdoor range is over 50 km and it indoor range is 150 m, during simulation if two nodes are further than 150 m the link throughput is 0, so is it realistic to assume that I deal with indoor networks? what I mean I am dealing with similar networks topology to wireless mesh networks, can I assume this network to be indoor and apply this NIC card specifications Basically there is no difference if you increase the transmission power or use a high gain antenna. So, apart from the transmission power, the sensitivity of the transceiver is what makes the most important difference between two wireless cards. Before you proceed with your work you should read something about wireless propagation. Just as an example, an outdoor range of 50km is only possible if the transmitter is placed high enough above ground. Otherwise you will not have a free line of sight and fresnel zone. When I remember right, for 50km distance the transmitter needs to be placed about 80m above ground. The environment defines how the transmitted signal is attenuated. Just imaging you are inside a metal elevator - then you probably get an indoor range of 1m. To answer your question: NO, it is absolutely not realistic to deduce from a result of 150m transmission range to be in an indoor scenario. I suggest that you start by selecting a propagation model that mimics the effects experienced in an indoor environment (e.g. multipath propagation, shadowing, interference ...). If you have such a propagation model, you can start to investigate effects caused by the transmission power, cars specification, protocol ... whatever you like. Hope that gets you started, Daniel.
Re: [ns] Which is the best Opreating System for NS2.27 emulation
M Lee schrieb: Hello: I want to know which is the best Opreating System for NS2(2.27--2.32)?especially for emulation. linux Redhat9 ? linux Debian? Free BSD? Thanks! Debian - if you use Debian, you can install the whole emulation extension using apt-get / aptitude. Furthermore, NSE has been developed and tested on Debian for a long time. Daniel.
Re: [ns] Somthing wrong when I patch NS-2.27 with Emulation Extensions
Hi, you need to install the kernel headers (or the complete kernel sources) to compile this emulation extension. Daniel. M Lee schrieb: Hello: I have install NS-2.27 on* Linux Redhat9* and patch it with NS-2 Emulation Extensions : *Distributed Clients Emulation Patch against ns-2 2.27, examples [**TGZ *http://ivs.cs.uni-magdeburg.de/EuK/forschung/projekte/nse/ns2emu-dstapp.tgz *]* Every thing is OK until I type make, the following info coming: . /filter_core -I./asim/ -I./qs -o common/scheduler.o common/scheduler.cc *common/scheduler.cc:53:21: asm/msr.h: No such file or directory common/scheduler.cc: In member function `void RealTimeScheduler::sync_cputicks()': common/scheduler.cc:1059: `rdtscll' undeclared (first use this function) common/scheduler.cc:1059: (Each undeclared identifier is reported only once for each function it appears in.) make: *** [common/scheduler.o] Error 1* * * * Anyone met this before? *How can I do?* * ** * Thanks!* ** * * * *
Re: [ns] why my TCL file cannot run ..?
AZHAR MOHD ARIS schrieb:
The good news is i succesfully installed NS2 in my Ubuntu Linux OS.
The bad news is :D i found an error when execute the command ns
singlehop.tcl
[EMAIL PROTECTED] :/usr/local/ns2/projek$ ns singlehop.tcl
num_nodes is set 3
invalid command name Propagation/SimpleDistance
while executing
Propagation/SimpleDistance create _o24
invoked from within
catch $className create $o $args msg
invoked from within
if [catch $className create $o $args msg] {
if [string match __FAILED_SHADOW_OBJECT_ $msg] {
delete $o
return
}
global errorInfo
error class $...
(procedure new line 3)
invoked from within
new $propType_
(procedure _o3 line 29)
(Simulator node-config line 29)
invoked from within
$ns_ node-config -mobileIP OFF \
-adhocRouting NOAH \
-llType LL \
-macType Mac/802_11 \
...
(file singlehop.tcl line 22)
For me its seems that you implemented a new propagation model but forgot
to make it available on the tcl layer.
Check the following:
- Makefile compiles your new propagation model
- the final binary contains the new model
- the new model is registered with tcl using the right name
Daniel.
--
Dr.-Ing. Daniel Mahrenholz
rt-solutions.de GmbH
Oberländer Ufer 190a
D-50968 Köln
Web: www.rt-solutions.de
rt-solutions.de
networks you can trust.
Re: [ns] Movement of nodes should be modifiable during runtime of an ns-2 simulation
Hi Bjoern, Schuenemann, Bjoern schrieb: I'd like to make a simulation with ns-2 where the movement of the nodes is modifiable by another program during the runtime of the ns-2 simulation. How could I realize this? It seems that modifications of trace and movement files are ignored by ns-2 after the files are read in by the TCL script I think the problem is that after reading the movement files all events that actually control the movement are already in the event queue. One of my students implemented an external movement control some years ago for the emulation mode. Basically he adds a listening socket that takes simulator control commands from an external program, converts them to TCL code and evaluates them. Then he ran the simulation for an infinite time (and send a stop command from the external controller to exit) and could move the nodes around as he liked. But, this only works in emulation mode. The reason is, if you are in the normal simulation mode, time will jump from event to event. And if there is the last movement event in the queue, the simulator possibly will jump to the final stop event and quit. So, only emulation ensures that your simulation time does not runs too fast. I took a quick look but could not find the diploma thesis / code of the student. I will spend more time searching if you like. Title of the thesis was Eine dynamische WLAN-Emulationsumgebung auf Basis des NS-2, Thomas Kiebel, Diplomarbeit, 2005. Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] How can i set transmission difference rage
Phitsanu Eamsomboon schrieb: Dear All My name is Phitsanu from Thailand , I to do my research about ad hoc network , In my research having 100 mobile nodes but I want to set 50 nodes can communicated in 250 m and another 50 node communicated in 500 node . How can I set in tcl for NS-2 ? Use antennas with different gains. Change the global settings for the antenna gain before you create a node. That means, set it to (for example) to 2dBi for the first 50 nodes and 8dBi for the next 50. Use the propagation.cc utility to calculate the exact parameters (search the list for details). But be aware, the transmission range depends on both, the sender and the receiver. That means, if you have two kinds of nodes (A and B) you get 3 different combinations and hence communication ranges (e.g. A-A: 250m, A-B: 400m, B-B: 500m). Hope this helps, Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] Is there exist any IRC for ns2
Scottie schrieb: I had do a google search and hardly find any of IRC for ns2. Regards, Scottie 4th hit with Google for irc ns-2 : http://mailman.isi.edu/pipermail/ns-users/2005-November/052772.html Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] TCP packet size and Wireless channel delay settings?
Farzaneh Razavi Armaghani schrieb: I'm monitoring the TCP throughput over 802.11 in wireless networks in my scenario. When I change the TCP packet size, I can not see any change in TCP throughput? is it alright? I'm using the command Agent/TCP set packetSize_ 1460 in my TCL script and I'm calculating the throughput using this equation: (total received bytes in server * 8)/simulation time. Is it correct? Also, How can I set the wireless channel delay to 25 microsecond in my TCL script Delay on the wireless link is defined by physical laws. However, you could increase the error rate to cause retransmissions on the MAC layer. Or you could introduce a processing delay in the agent. Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] Is there a data rate limitation for ns emulate?
jerry zhao schrieb: I want to build a scenrio to emulate video streaming. my real network topology is: A- - - - B- - - - -C The NS was installed on Computer B. The data rate is relative big(more than 30Mb/s). There is always warnings RealTimeScheduler: warning:slop ... exceed limit And some packets are lost, but the bandwith is enough to transmit the video data. Could anyone tell me if there is a data rate limitation for ns emulate? Any advice would be appreciated ns-2 defines no limitation. However, ns-2 needs to process data packets almost in real-time and hence is limited by the speed of your hardware / operating system. If you emulate a wired network ns-2 will perform quite well. But for a wireless network performance requirements are much stronger (standard ns-2 will not be able to work at all for wireless networks in most cases). But even if your CPU is fast enough, the operating system can introduce short but significant delays. To avoid them you should try the following: - set ns-2 to run with real-time priority - disable tracing - use a multi-core / CPU system and pin ns-2 to one CPU / core - disable other applications that write to the disk - if you need tracing, buffer output in memory (ram disk) For high-throughput emulations of wired networks you should consider a different emulator like NIST Net. This should improve your results. Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] verying link capacity dynamically
bhaskar sardar schrieb: Is there any way to dynamically change the bandwidth of a wireless link. I mean, during first 10 sec of the simulation BW is 1 Mb, for next 10 seconds BW is 2 Mb and so on. This is required when a user moves very fast. A wireless link does not have a link bandwidth. Maybe you mean the trasmission data rate. If so, use the new 80211 MAC layer with multirate support. If you really need links with defined bandwidth, you first need to implement a bandwidth management / admission control which is quite difficult in wireless networks. Regards, Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] Changing NS Unit disk model of radio range
Hi, Faisal Aslam schrieb: I am using cmu extension to simulate a wireless-sensor protocol. I believe NS-2 only support unit disk transmission range model. However, unit disk model is not realistic. 100% true. I wish to have model that has following (1) Each node selects its transmission range (say c) using uniform distribution from say [a, b]. Simply modify the antenna gain or transmission power before creating a node. (2) Each node randomly selects few nodes near the border of circular transmission range to be out of range. It is because in practice transmission range is not exactly circular. You will need to implement (maybe there is already an implementation) a directional antenna. Also using the Shadowing propagation model introduces some probabilistic effects. To select particular nodes that are not in range you could implement a new propagation model that uses some kind of lookup table to determine the reception of a packet. Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] Memory problems
Hi, Ángel Cuevas Rumín schrieb: I am having some problems with my simulations. I am generating quite a lot packets and at some point during the simulation, it finishes with this messages in the screen: terminate called after throwing an instance of 'std::bad_alloc' what(): St9bad_alloc It seems there is not more free space to allocate new entities. I have tried to free memory by freeing packets (Packet::free(p)). I have also tried some other solutions but they didn't work. I would appreciate any kind of help from someone who had the same problem in the past or someone who knows which is the problem. For any memory problem I suggest to use valgrind (http://valgrind.org). It saved my day several times. Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] advice (relatime protocol implementation on ns-2)
Hi, koleti suresh schrieb: Please advice me how to implement real time protocol(it should work on linux) on ns-2 ? can any one tell that in which applications we willl use ns-2? let me conform whether this tool is used for real time implementation of a protocol or not? my basic doubt is i want to implement new protocol for linux. whether i can use this tool for development purpose ? If you try to implement a new protocol for linux and need to test it in ns-2, our extension may be a solution for you: http://ivs.cs.uni-magdeburg.de/EuK/forschung/projekte/gea/index.shtml http://ivs.cs.uni-magdeburg.de/EuK/forschung/publikationen/pdf/2005/gea.pdf If you find this approach suitable for your needs, contact me to get the extension. Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] help ! for increase communication rage to 1600 m
Hi, adjusting transmission power and thresholds is not sufficient for such a long distance. You also need to adjust MAC timeout values. Citing from my own mail with subject Re: [ns] MAC/802.11 STA error on ACK - The Linux driver for the madwifi cards includes a utility to calculate all relevant timeout values. Maybe it is a starting point for you. If you do not have access to a madwifi card I could ask a colleague for assistence. Look here for some information: http://forums.wi-fiplanet.com/showthread.php?t=6488 Faisal Aslam schrieb: Read the section of transmission models in NS-2 manual. You should check which transmission model (e.g. FreeSpace, TwoRayGround, Shadowing) is in use. You should try to adjust the RXThreah_ using threshold.c as described in the NS manual. regards, Faisal Phitsanu Eamsomboon wrote: My name is Phitsanu from Thailand , I use ns-2 for to do my research . May I trouble you for ask you some question , I try to increase Transmission rage is 1600 m by increase Pt but It still can communicate in 500 m range , How can I increase transmission rage is 1600 m if I use TwoRayGrounf model. How can I calculate , Please recommend me !!! Regards, Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] shutting down link or node with wireless topology
Hi, [EMAIL PROTECTED] schrieb: I am a new ns user i am trying to simulate a wireless topology using OLSR as a routing protocol. I need to simulate a link failure for a short period of time to study the reactions of OLSR to the failure In a wireless scenario you do not have links, so you cannot shut them down. One option is to simply move a node out of the transmission range of another. This may become difficult for a large number of nodes. You could also extend the node to implement something like a MAC filter so that a node simply ignores messages from individual sources. But im not aware of any such solution currently existing. You could also modify the propagation model to create very specific transmission failures, e.g. drop all packets from a specific node (node failure). Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] How MAC finds out that there is no more traffic?
Hai T. Vu schrieb: I am working on Mac protocol for wireless network. Let say I have node_(1) with cbr traffic sending to node_(0). The cbr traffic will be like this: start at 1.0, stop and 2.0, (re)start at 3.0 and stop again at 4.0 second. My question is that: at 2.0, how Mac finds out that the traffic is indeed done? For example, if node_(2) is a mobile phone, and cbr traffic is the voice call, then at 1.0 it needs to set up the call and after 2.0 second it needs to tear down the call. If you know how to do this, please help me. I appreciate any help. Usually a MAC will not care about calls etc, it only handles individual data packets. In your terms, the MAC layer knows that there is no more traffic if its input buffer is empty. If you need a MAC layer that is aware of the duration of a call you need to implement some cross-layer interaction, i.e. the layer handling the voice connection needs to pass this information down to the MAC layer e.g. to (de)allocate ressources on the medium. Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] help required regarding analysis of tracefile
Hi, harpreet schrieb: Hi. I want to analysis trace file which looks like (not exactly ) data given below. Here are NS Manual's example + 1.84375 0 2 cbr 210 --- 0 0.0 3.1 225 610 - 1.84375 0 2 cbr 210 --- 0 0.0 3.1 225 610 r 1.84471 2 1 cbr 210 --- 1 3.0 1.0 195 600 r 1.84566 2 0 ack 40 --- 2 3.2 0.1 82 602 + 1.84566 0 2 tcp 1000 --- 2 0.1 3.2 102 611 - 1.84566 0 2 tcp 1000 --- 2 0.1 3.2 102 611 r 1.84609 0 2 cbr 210 --- 0 0.0 3.1 225 610 + 1.84609 2 3 cbr 210 --- 0 0.0 3.1 225 610 d 1.84609 2 3 cbr 210 --- 0 0.0 3.1 225 610 - 1.8461 2 3 cbr 210 --- 0 0.0 3.1 192 511 r 1.84612 3 2 cbr 210 --- 1 3.0 1.0 196 603 + 1.84612 2 1 cbr 210 --- 1 3.0 1.0 196 603 - 1.84612 2 1 cbr 210 --- 1 3.0 1.0 196 603 + 1.84625 3 2 cbr 210 --- 1 3.0 1.0 199 612 Ok. last field is packet identifier right? and it's unique. But 1st line 610 packet enque and next deque. but 7th line 610 packet again received and enque and dropped. How can this happen? packet identifier is not unique? Line 1: packet #610 enqueued on node 0 Line 2: packet #610 dequeued on node 1 Line 7: packet #610 received on node 2 from node 0 Line 8: packet #610 enqueued on node 2 (now with new destination / next hop 3) Line 9: packet #610 dropped If you receive a packet, the receiver is still the destination. Hope this clearifies you problem., Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] Ns2 with threads
Hi, Jose M.Herrera schrieb: A question. Does they know if Ns2 support threads Usually not - but you can get a version that uses threading internally. The question is for what you need threading? Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] how to computer the Transmission range
Mohammed Abu Hajar schrieb: Is there any utility in NS-2 that compute the transmission range of a wireless node like in glomosim simulator you type at the command line: radio_range config.in it's gives the range in m like 375m. Look in the indep-utils/propagation directory. But keep in mind - in reality you do not have anything like a discrete transmission range. Instead you have regions with different receive probabilities. Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] Lucents WaveLAN propagation model
Mohammed Abu Hajar schrieb: How can I implement(write) Lucent’s WaveLAN propagation model in ns-2 tcl script file?, is it like: set opt(prop) Propagaion/TwoRayGround, or set opt(prop) Propagaion/FreeSpace, or set opt(prop) Propagaion/Shadowing. Don't mix the modelling of a transmitter with the modelling of the signal propagation. The model of the card (see answer from Ran Ren) defines what signal is generated (frequency, power), the antenna characteristics (gain), and what signals the card is able to receive (*Thresh). The propagation model defines how the signal changes (signal strength degradation, noise, etc.) between the transmitter and the receiver. If you have more specific questions, don't hesitate to ask me. Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] strange bug in ns2 - halted forever (more details) ?
tdinhtoan schrieb: I got the following bug in ns2: I run a Tcl file, after running for a while, it is halted forever (of course it is expected to run more), and I could not get the results at all. There is no infinite loop in my code. My simulation is a wireless mesh network topology consisting of several nodes, and I run UDP flows between nodes. I compute the throughput of each node and output them to the screen every 5ms. The bug is like this: After outputing the results several times (say 5 times, for example), it is halted and does not outputs more results, but I program it to output the results 10 times. Sometimes, with some topologies, it works as expected - running to the final, and sometimes with other topologies, it does not work. I don't know this bug, but I suggest to do the following: 1. Check if you flush the output after you write your statistics. This is a mistake I made several times. 2. Look into the trace file (enable it if necessary) if the simulation generates events during the time it seems to be halted 3. Run the simulation inside a debugger and break it when it hangs to see whats going on. Maybe you managed to create an infinite loop of events triggering itself over and over again. Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] Lucents WaveLAN propagation model
Mohammed Abu Hajar schrieb: Yes, realy I want to simulate the performance of DSR routing protocol using NS-2 , I did that and compare my results I got with a published paper called Performance omparison of Two On-Demand Routing Protocols for Ad Hoc Networks , but unfortunatly there were some differences among figures relayed to: Normalize Routing Load , Average End to End Delay, Packet delivery Ratio. I am using the same parameters used in the paper , but there is a statement menssion in the peper talks You may use the same parameters - but do you use the same version of ns-2? Small code changes can have a significant effect. The radio model uses characteristics similar to a commercial radio interface, Lucent’s WaveLAN [14, 15]. WaveLAN is modeled as a shared-media radio with a nominal bit rate of 2 Mb/s and a nominal radio range of 250 m. I am didn't understand how I write this parameter in my TCL script file , So I think the differences in my results related to this point. If I remember right, these are the default values included in tcl/lib/ns-default.tcl or ns-node.tcl . Look there or in the tutorials mentioned in the ns-2 wiki for examples to setup wireless nodes. If you use a current ns-2 version, my guess is that the code makes most of the difference. Personally, I never used this setup because a) the Lucent WaveLAN adapter has significant differences to currrent WiFi cards and b) all models that include a fixed communication range deliver results not applicable to real-world scenarios / applications. My personal advise - at least you the ShadowPropagation model. It is not perfect but creates many problems you have to cope with in the real world. More about this topic and the setup used for my research can be found in my thesis at http://diglib.uni-magdeburg.de/Dissertationen/2006/danmahrenholz.htm Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] how to pass PHY layer information to upper layers?
sri_seeta_ram schrieb: I want to pass the Received Power of the packet from PHY layer to the protocol agent. how can i achieve this in ns2? I found the Received power in wirelessphy.cc and mac-802_11.cc i.e PHY and MAC layers. how can i pass this info to LL and then Routing agent...? A Packet in ns2 contains all configured headers in parallel. So, if you can access information on one layer (e.g. PHY), you can also access it on other layers. If the information is not contained in a header you need to add a new header to the packet structure. In this header you can store your information and pass it around. Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] MAC/802.11 STA error on ACK
[EMAIL PROTECTED] schrieb: I sent CBR packets from node 0 to node 1. The distance between the two nodes is changing. I found that when the distance is more than 700m, the transmitter seems always drop the ACK coming back from the receiver, and give an error state of STA. When the distance is below 500m, everything is fine. I attached some trace below. Is this caused by the long propagation delay of 700m? If so would change the retransmit timeout solve the problem? How can I do that? Or is there any other suggestion on the reason? Increasing the retransmission timeout is not enough. You will need to increase other timeouts as well. The Linux driver for the madwifi cards includes a utility to calculate all relevant timeout values. Maybe it is a starting point for you. If you do not have access to a madwifi card I could ask a colleague for assistence. Look here for some information: http://forums.wi-fiplanet.com/showthread.php?t=6488 Regards, Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] Doubt........plz help me
Shailesh Gamit schrieb: hello to every ns users, i have a doubt that in ad hoc network the links are wireless, so when we send the packets using any protocol i.e aodv, dsr. then the receiving is done at the node which is specified in destination address. But if we consider real scenerio of wireless links than all the packets sent are always BROADCASTED and received by all the node. In simulation it is not the same You are wrong. There is nothing like a wireless link. All nodes are attached to a Channel object that is a broadcast medium. If a node transmits a packet, the simulator calculates the receive power for all nodes attached to the channel. If the signal is strong enough, the node will receive the packet. But if the destination address does not match, it will simply ignore it. Regards, Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] definition of sending / receiving threshold per mobile node
Hi Markus, Leitner, Markus schrieb: I am currently working on a project dealing with simulation of mobile nodes. To describe relevant network topologies I am searching for a possibility to define the receiving threshold individually per node (e.g. mobile node A has a receiving threshold of X, while all other nodes have a receiving threshold of Y). I know how to set the receiving threshold in principle via RXThresh_ but I unfortunately did not find any way of specifying this per node. Is anybody aware how to implement this? I don't know if the following works for the threshold (it did for the antenna gain). Just give it a try. Set the threshold before you create a node. The node constructor will copy the value and you can change it later without changing the properties of already existing nodes. Maybe this is a bug - but we used it as a feature. Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln Web: www.rt-solutions.de rt-solutions.de networks you can trust.
Re: [ns] what is the transmission range fo mobile nodes
Satish B schrieb: I want know what is the transmission range(ie upto maximum what distance it can send/receive packets with other nodes)of the mobile nodes in ns2.If I want to set with new range how to send it.please let me know this. Thank you . This question has been answered multiple times. Transmission range is NOT a parameter you can set. It is the result of the signal propagation. To change the transmission range you can adjust the transmission power, receive thresholds, antenna gains, and propagation parameters. The propagation.cc utility (indep-utils/propagation/) helps you to calculate these parameters. Additionally, you should study some hardware specs to get realistic values. Daniel. -- Dr.-Ing. Daniel Mahrenholz rt-solutions.de GmbH Oberländer Ufer 190a D-50968 Köln rt-solutions.de networks you can trust.
Re: [ns] threads in NS-2
Savitri P. Pandharikar schrieb: Is it possible to create threads in NS-2,I am using Linux platform for NS-2. In general - yes. But for what purpose? You cannot run the simulation with multiple threads. But you can off-load certain tasks like output compression to separated threads. All simulations are event-based and do not need threads. Daniel.
Re: [ns] Compilation Error ns2.1b8a
Mohammad Haseeb Zafar schrieb: Hi I got following error while compiling ns2.1b8a. Please help. Haseeb c++ -c -DTCP_DELAY_BIND_ALL -DNO_TK -DNIXVECTOR -DTCLCL_CLASSINSTVAR -DNDEBUG -DUSE_SHM -DHAVE_LIBTCLCL -DHAVE_TCLCL_H -DHAVE_LIBOTCL1_0A7 -DHAVE_OTCL_H -DHAVE_LIBTK8_3 -DHAVE_TK_H -DHAVE_LIBTCL8_3 -DHAVE_TCL_H -DHAVE_CONFIG_H -I. -I/bonhome/haseeb/work/ns-allinone-2.1b8a/tclcl-1.0b11 You should provide more information, especially the version of gcc/g++ you are using. NS2.1b8a is very old. So, you will need an old gcc / binutils to compile it. Daniel.
Re: [ns] Simulating channel Hopping in ns2
Hi, gaurav deshpande schrieb: Hi all, We intend to implement channel hopping using ns2 simulator. Has anyone tried to implement hopping in ns2? Our approach: We found that each channel (class WirelessChannel) keeps a linked list of all nodes listening on that channel. For a mobilenode to hop we wrote code to dynamically add and remove the node from this list. However, on running ns we get a segmentation fault. The code we wrote looks something like: MobileNode* n = node that hops; WirelessChannel new = next channel to hop to; WirelessChannel current = current channel of node n; new.addNodeToList(n); current.removeNodeFromList(n); It would be great of someone share thier experience in implementing channel hopping in ns2. I cannot help with the channel hopping. But to find problems with linked lists etc. in the C++ part of the code it is always a very good idea to run ns-2 using valgrind. Simulations will use a lot more time to run, but every strange or wrong memory access will be recognized. Daniel.
Re: [ns] How can i measure the bandwidth in use?
wang laye schrieb: Hi, I am simulating a QoS Routing Protocol,in this protocol,the available bandwidth of node is caculate according: Available Bandwidth=Total Bandwidth - Reseved Bandwidth - Bandwith In Use My question is:In C++, to a mobile node,How can i measure (or caculate) the bandwidth in use? Any suggestion is appreciated! You should explain your network a little more, are you suing APs or an ad hoc network? Determining the available bandwidth in a wireless network is quite complicated because it depends on the behavior of the nodes around you (even if they are out of communication range). I used the following approach: instead of bandwidth I used air time (to account for different transmission speeds), that is the time a node utilizes the wireless channel in its region for a transmission. To reserve air time I used a beacon-based multi-hop reservation protocol. Additionally, to measure lost air time, that is air time than cannot be used because of interference from nodes out of communication range (or e.g. a microwave oven) I measured the time a packet to be transmitted spends in the output buffer of the transmitter. Changes in this time indicate a change in the available air time. You see, the task you are going to solve cannot simply be accomplished by calculating a value out of available variables. If you have more questions, don't hesitate to ask me. Daniel.
Re: [ns] Need tunctl command for cygwin
Emin Gencpinar schrieb: We installed ns-2 emulation (nse) both over Linux and (by cygwin) Windows machines. NSE uses tunctl command for tun / tap interfaces to manage the network. We have successfully installed the tunctl command source code for Linux under sbin directory, but we could not find any tunctl command source code valid for cygwin. Compilation error for the same source code in cygwin. tunctl is a tool to manage the TUN/TAP driver of the linux kernel. There is a TUN/TAP driver for Windows developed by the OpenVPN folks. But I suspect that is configured in a different way. If you are using the nse extension for wireless emulation you should give up on Cygwin, you have to run it on Linux. But it is possible to integrate Windows clients in such a setup. Daniel.
Re: [ns] Multiple source files
Keita Rose schrieb: I am trying to run a mobile scenario using multiple source files, how do I go about implementing that is NS-2 if it is at all possible. I'm not sure, I got you right. But I did the following in order to simulate different topologies with the same set of applications. I first build a core simulation script, e.g. one that creates the simulator objects, configures everything, etc. Then I include the script that creates the topology (given by a command line parameter) into this core script. The remaining part of the core script configures the applications and runs the simulation. Now, in order to investigate different topologies, I wrote a control script, that iterates over the list of available toplogies and calls the simulation script with the name of the topology script as a parameter. You should be able to do something similar. Daniel.
Re: [ns] how to detemine channel used by 802.11 nodes
m w schrieb: I was just wondering as to how we can know which channel is 802.11 node is using. Is it possible to find it from somewhere regarding the channel used information. 802.11b uses three channels so which channel a specific node is using, how can we get to know that ? Please help me at your earliest. I am pressed in time. Wireless communication in ns-2 uses one or more channel objects. All channel objects are independent from each other. That means, if you use different channels you will not have cross-channel noise, interference and such things. Some times ago someone asked how to model such cross-channel effects and I proposed to derive a new channel object that knows about its neighbor channels and than introduces such errors. But I don't know how this evolved. If this is of interest for you, you should search the maiing list archiv and contact the author. Daniel.
Re: [ns] TX Range Problem Still not Clear
Abdulaziz Barnawi schrieb: I have been looking for a solution on how to set a TX range for a Base Station that is different (e.g. much larger) from other nodes in the network. Unfortunately all the solutions I have tried (including ones already posted on the this list) will set the same TX range for all nodes including BS. If you change the node-config during the creation of nodes (e.g. by setting different antenna gains) you will get different transmission ranges. You can safely assume that the antenna of the BS has a higher gain that that of mobile stations. Daniel.
Re: [ns] Performing several runs of same simulation
[EMAIL PROTECTED] schrieb: we try to perform several runs of the same simulation and can't find a hint in the manual how to manage this. Is there a possibility to do it by a for (; numberOfRuns;) or an other tcl-method? Or should we simply write a shell script calling our tcl file several times? Just call your tcl script several times. But do not forget to initialize the random seeds to different values. Otherwise you will get the same results every time. Daniel.
Re: [ns] tuning up wireless phy layer
Balazs Kovacs schrieb: I am simulating some communication performance with 802.11. My simulations always fail to show the results I expect because the wireless-phy seems to be overloaded. Is there any possibility to tune the throughput? I set datarate and basicrate to 54 mbps but this cause very slight improvement, while setting these rates to higher values makes no sense and no better results. I have 2.29. You should describe your simulation setup in more detail, especially what propagation, antenna, and threshold values you are using. Increasing simulation area and number of nodes cause much worse results. With AODV on a 1000x1000 area with 140 nodes and 30 parallel CBR flows (64byte*10/sec) I get more than 10 percent packet loss. 10% packet loss sounds quite normal in such a setup. That much nodes grouped together very close causes a lot of interference , collisions etc. Btw - you will be shocked to see how bad AODV performs in a real-world setup. Daniel.
Re: [ns] Warning everyone is ignoring (please use -channel)
Amer Filipovic schrieb: Can anyone tell me how to get rid of that warning at the beginning of the wireless simulations warning: Please use -channel as shown in tcl/ex/wireless-mitf.tcl It is getting on my nerves :P As you can read - modify each test script to use the wireless channel as shown in the example file (explanation is in the file; a three-liner a suppose). I agree that this warning is anoying - so if you can offer some time for the modification, please provide a patch and I will spend some time to integrate it into the CVS version (if the other developers don't have any objections). Daniel.
Re: [ns] Mobile nodes: radius
Andrea M schrieb: Hello, I found this string in NS Manual, how can I use it? [quote]$mobilenode radius r The radius r denotes the node's range. All mobilenodes that fall within the circle of radius r with the node at its center are considered as neighbours.[/quote] I used it like: $node_(0) radius 50 but It seems to do not work. This must be a very old piece of code and does not make any sense at all. In practice there is nothing like a transmission radius. If a node receives a packet depends on the propagation model. If you need a specific transmission radius (which btw is not really realistic) you can calculate the corresponding propagation parameters using the propagation.cc helper tool. Better setup the propagation parameters to reflect the conditions in the simulated environment and see what happens. Daniel.
Re: [ns] packet loss rate on ad hoc network
ns user schrieb: i'm beginner with ns2.29, anr i'm trying to calculate the number of collisions (or packet loss rate) made on a node in an ad hoc network. You need to enable MAC tracing. Then go through the generated trace file and lock for lines where packets are dropped because of a collision. This should look like: d . COL To get the packet loss rate you should count send and received packets on the MAC or AGT layer that are not broadcast. The lines look like: s .. MAC ... r .. MAC ... or s .. AGT ... r .. AGT ... For broadcast packets (destination -1) you first need to define what a lost packet is. You will find the exact format in the ns2 documentation (trace file format) Daniel.
Re: [ns] Simulating an embedded ad-hoc wireless protocol
Jeff, you tried to compile GEA in the wrong order. You have to: 1. install GEA using ./configure make make install in the GEA source directory. 2. compile ns Step 1 will compile and install the native GEA version. This is not required for ns-2 at runtime. But you need the different include files that usually will be installed in /usr/local/include/gea. If you need them to be installed in a different directory you can call a ./configure --prefix=install dir. This should be a directory that ns-2 uses during its compilation. Otherwise you have to modify the ns-2 Makefile. Daniel. Jeff Schwentner schrieb: 1) I applied ns_2.28-4.diff to ns_2.28.orig, and had an error when trying to compile. When I attempted a make after configure, I got the following error: $ make c++ -c -DTCP_DELAY_BIND_ALL -DNO_TK -DTCLCL_CLASSINSTVAR -DNDEBUG -DUSE_SHM -D HAVE_LIBTCLCL -DHAVE_TCLCL_H -DHAVE_LIBOTCL1_9 -DHAVE_OTCL_H -DHAVE_LIBTK8_4 -DH AVE_TK_H -DHAVE_LIBTCL8_4 -DHAVE_TCL_H -DHAVE_CONFIG_H -DNS_DIFFUSION -DSMAC_NO _SYNC -DCPP_NAMESPACE=std -DUSE_SINGLE_ADDRESS_SPACE -Drng_test -I. -I/usr/ns-al linone-2.29/tclcl-1.17 -I/usr/ns-allinone-2.29/otcl-1.11 -I/usr/ns-allinone-2.29 /include -I/usr/ns-allinone-2.29/include -I/usr/include/pcap -I./tcp -I./sctp -I ./common -I./link -I./queue -I./adc -I./apps -I./mac -I./mobile -I./trace -I./ro uting -I./tools -I./classifier -I./mcast -I./diffusion3/lib/main -I./diffusion3/ lib -I./diffusion3/lib/nr -I./diffusion3/ns -I./diffusion3/filter_core -I./asim/ -I./qs -I./diffserv -I./wpan -o gea/gea.o gea/gea.cc gea/gea.cc:1:21: gea/API.h: No such file or directory gea/gea.cc:3: error: `gea' has not been declared gea/gea.cc:3: error: expected constructor, destructor, or type conversion before GEA gea/gea.cc:3: error: expected `,' or `;' before GEA make: *** [gea/gea.o] Error 1 2) It looks like the patched version is missing a file. I then tried using gea source (libgea_1.1) instead of gea directory of the patch, and got the following error when performing make: $ make make: *** No rule to make target `gea/gea.cc', needed by `gea/gea.o'. Stop. I’m obviously doing something wrong here, but I don’t know what. What steps are required to compile ns with gea?
Re: [ns] Simulating an embedded ad-hoc wireless protocol
Hi Jeff, Jeff Schwentner schrieb: So if I understand correctly, I would embed our custom packets in UDP packets. This would include the RTS/CTS/ACK MAC packets in addition to the actual data packets. The MAC layer, as far as ns-2 is concerned, would just be a pass-through (not sending its own RTS/CTS). Yes - at the moment this would result in all packets being encapsulated into UDP packets. In our case we have some kind of extended MAC layer. We do not replace the standard 802.11 MAC but we do not use RTS/CTS and only broadcast communication and so no ACKs. Currently we do not have the pass through MAC because our protocols are intended to work on COTS hardware. But for you this probably will not work if you like to replace/modify the whole MAC behavior and its timing. Do you have an example that I can compile and run with ns-2 (I'm using 2.29 on Cygwin)? In either case, I would greatly appreciate any documentation you can point me to get started! We have some code examples in the source code archive in our repository. So far we did not try to compile GEA on cygwin but there should be no problem. But you need to use the modified ns-2 (available from our repository). Daniel.
Re: [ns] Simulating an embedded ad-hoc wireless protocol
Hi, Jeff Schwentner schrieb: Has anyone simulated a mobile node using only send/receive functions with ns-2? I have an ad-hoc wireless protocol that has been implemented and fielded in an embedded system. I would like to simulate it for performance benchmarking. My problem is that the code is written in C and it has it's own custom implementation for the MAC, routing protocol, queueing, etc. I have just started looking into ns-2, and from what I understand, it requires the MAC, routing protocol, and message queue to be in seperate classes (inheriting from Agent, Mac, etc.). Is it possible to use ns-2 to simulate a node at the transport layer, and treat the rest as a black box? If not, do you have any suggestions/comments for simulating this firmware? We are using our native protocol implementations inside ns-2. To do so we implemented a small adaptation library called GEA. Maybe this could be of help for you. But it would require some modifications to your code (depending on the way the firmware is implemented). There is also a project/extension that allows to use the native TCP/IP stacks of different operating systems in ns-2 (called network craddles). I do not know more about this but you will find a link on the Contributed Code page in the ns-2 wiki. Maybe this could be a solution. The last chance would be to use network emulation. Daniel.
Re: [ns] Building Problem!
Enzo Memmolo schrieb: hello everybody, when I compile ns2 source code I find the follow error: dsr/dsragent.cc: In member function ‘void DSRAgent::handleFlowForwarding(SRPacket, int)’: dsr/dsragent.cc:828: error: ‘XmitFlowFailureCallback’ was not declared in this scope It is unclear to me which version of the code and compiler you are using. But it looks very similar to an error that I encountered with the CVS version and the latest gcc version. You should look into the file if you can find the missing function. In my case it was declared at the end of the file without a forward declaration. If so, you just need to move it to the beginning of the file or add an forward declaration for the function at the beginning. Daniel.
Re: [ns] Modifying 802.11 wireless Channel Propagation Delay
Hi, Bahman Kalantari Sabet schrieb: 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. Increasing the propagation delay only makes sense by increasing the transmission range. Otherwise it is unrealistic. Any ideas, please let me know. I think what a really need is to introduce a processing delay on the nodes. If I remember right, someone explained how to do this 2-3 days ago. Daniel.
Re: [ns] Wireless transmissions look like they take no time
Hi Paul, Paul Vincent Craven schrieb: I'm trying a very simple wireless simulation while I'm learning to use ns-2. The output of it seems to show the wireless transmissions happening instantly: s 10.0 _0_ AGT --- 4 cbr 1000 [0 0 0 0] --- [0:0 1:0 32 0] [0] 0 0 r 10.0 _0_ RTR --- 4 cbr 1000 [0 0 0 0] --- [0:0 1:0 32 0] [0] 0 0 s 10.0 _0_ AGT --- 5 cbr 500 [0 0 0 0] --- [0:0 1:0 32 0] [1] 0 0 r 10.0 _0_ RTR --- 5 cbr 500 [0 0 0 0] --- [0:0 1:0 32 0] [1] 0 0 s 11.0 _0_ AGT --- 8 cbr 1000 [0 0 0 0] --- [0:0 1:0 32 0] [2] 0 0 r 11.0 _0_ RTR --- 8 cbr 1000 [0 0 0 0] --- [0:0 1:0 32 0] [2] 0 0 s 11.0 _0_ AGT --- 9 cbr 500 [0 0 0 0] --- [0:0 1:0 32 0] [3] 0 Your trace file only shows packets going from the agent to the routing layer on node 0 - this takes zero time. There are no packets transmitted or received by another node. You should set -macTrace ON to see if you are transmitting packets on the MAC layer. Daniel.
Re: [ns] the more realist model taking in consideration the obstacl
Hi, www triste schrieb: Hello everybody i want to use a realist propagation model,because i think that TwoRayGround usually used in ns2 is not realist because it is not taking in consideration the obstacls,i find in ns titoriel shadowing model is it realist?thanks for informations The shadowing model is a good start because it produces a lot of effects experienced in the real world. But it is only useful for a generelized environment, that means if you like to simulate randomly placed nodes. But if you need to simulate nodes in an actual environment (e.g. a floor in an office building) it is not so good. You can try the shadowing visibility model which gives limited support for obstacles. But you need to cross check / calibrate your simulation results with a real setup because it is not as accurate as a ray tracing like propagation model (which to my knowledge is only available in ns-2 using a commercial propagation calculation tool). If you need more information or want to share your experiences on this topic, you can ask my directly because our group is currently working on this topic. Daniel.
Re: [ns] why noone wants to help me? :(
Hi, [EMAIL PROTECTED] schrieb: I'm sorry that I am writing in such way, but I really need help. I am trying to install ns-2.1b7a because I want to patch gprs wrote by Richa Jain. I tried installing it and I have such error: tclcl-mappings.h: In static member function #8216;static int TclObjectHelperT::dispatch_(void*, Tcl_Interp*, int, char**)#8217;: tclcl-mappings.h:51: error: incomplete type #8216;Tcl#8217; used in nested name specifier tclcl-mappings.h:52: error: invalid use of undefined type #8216;struct Tcl#8217; tclcl-mappings.h:41: error: forward declaration of #8216;struct Tcl#8217; tclcl-mappings.h:57: error: invalid use of undefined type #8216;struct Tcl#8217; tclcl-mappings.h:41: error: forward declaration of #8216;struct Tcl#8217; make: *** [Tcl.o] Error 1 tclcl-1.0b10 make failed! Exiting ... See http://www.isi.edu/nsnam/ns/ns-problems.html for problems I don't know what to do? I have fc4. I cannot patch gprs to ns-2.29 beacuse it doesn't work. You have two options - if you really need to use a very old version of ns-2 you should install a matching compiler/linker tool chain and libraries. Your second option is to adapt the patch to the current version of ns-2 and the default compiler of your distribution. The second option surely requires a lot more effort but would be valueable for many other peoples. Daniel.
Re: [ns] Installing NS 2.29.2
Ethan Giordano schrieb: It would be nice if that info got posted to an ns-2 wiki. Does the ns-2 project have an official wiki? It may prove slightly more efficient than the mailing lists if we all used it. Yes, it has - http://nsnam.isi.edu/nsnam/index.php/Main_Page Daniel.
Re: [ns] HELP URGENT
Hi, anil reddy schrieb: hello, While executing the wireless program below ,we have some config problems, the sent packets and the NAM file are not being displayed , the output is also given below. plz help its urgent Any help will be appreciated .. Wireless emulation is almost impossible with the default ns-2 because of the internal timimg of the simulator. You can find an improved version at: http://wwwivs.cs.uni-magdeburg.de/EuK/forschung/projekte/nse/index.shtml You can find an explanation of the problems in the default ns-2 in the paper Real-Time Network Emulation with ns-2. If you have any problems with the improved version, don't hesitate to ask questions on the nse mailing list (see web pge fpr details). Daniel.
Re: [ns] wireless-nodes-finding bandwidth in C++
Mahesh schrieb: is there anyway to find the bandwidth of a wireless node in the ns-2 (C++ ) DSR code. And is there any way to find the bandwidth of a wireless node in the TCL script. And also i need to know how to find the bandwidth of the neighboring nodes in a wireless network in NS-2 ( C++ ) DSR code. I am trying to implement an admission control protocol in DSR which requires me to find the bandwidth of a node as well as the bandwidth of the neighboring nodes. Since i am new to ns-2, i couldn't find it. Before you start to implement an admission control protocol you should become more familiar with the nature of wireless communication. It is a common misunderstanding that bandwidth is assigned to individual nodes. In the wireless setup you only define the transmission speed of the node. Wireless communication uses a shared medium and so a node has to share the channel access with all nodes that are within interference range. Additionally you should keep in mind that a message from one node to a target multiple hops away probably consumes bandwidth multiple times - just as an example, a message consumes bandwidth at the node when the node transmits the message, and when the neighbor and most likely the 2-hop neighbor forward it towards the destination. btw - this question has been asked multiple times before on this list. Regards, Daniel.
Re: [ns] Bandwidth of wireless channel
Vinod schrieb: Actually, my problem involves calculating the effective bandwidth of a wireless node (more specifically in a MANET). I guess the bandwidth_ variable of MAC or Phy layers dont give this value. I am using the default parameters given in the AODV implementation. To put it more clearly, suppose node 'S' wants to send a pkt to 'R'. This pkt can either be forwarded through 'A' or 'B' (A B are one hop neighbors of S) depending on the bandwidth. So, I am planning to calculate the effective bandwidths of A and B and choose the node based on it. Can you (or anyone) suggest a way for this. I would be thankful If nodes A and B are direct neighbors of S it is most likely that A and B have to share the medium either because they are in direct communication range or through the physical carrier sense. If I understand you right, you try to compute the bandwidth that one node (e.g. S) can use to transmit a packet. A node has to share the medium with all nodes within interference range. So if S wants to transmit a packet via nodes A, D, and F to R and A,D are within interference range of S then the available bandwidth of S will reduce three times by the bandwidth required to transmit the packet. This is because the packet utilizes the medium (from S's point of view) when S transmits it, and when A and D forward it. Beyond this point S will not be influenced by the further forwarding of the packet because it is out of interference range. In your case you have to take all possible routes and calculate the changes in the channel utilization for every node along the route or at least within your own interference range to know what effect the route decision will have on your available end-to-end bandwidth. Hope this clarifies more than it confuses, Daniel.
Re: [ns] Values to be set in the TCL file to make the transmission range 100m
Sasan Sahraei schrieb: transmission range defined internally by distCST_ This is only the maximum assumed interference range for a propagation model and will be used to speed up the calculation of packet receivers. the transmission range is suppose to be calculated using the parameted below (as you mentioned) and propagation model however by looking at the Wireless Physical code, the propagation model is not implemented yet and thus the result is as -1 which is wrong. You have various implemented propagation models (e.g. FreeSpace, TwoRayGround, Shadowing). Maybe you just look at the base class for all propagation models. The transmission range is defined by the antennas of the transmitter AND the receiver, the transmission power, signal attenuation, modulation scheme (which results in different receiver sensitivities / RX treshhold) and so on. It is nothing you can compute solely by looking on the transmitter. Just as a little example: two laptops equiped with usual WLAN interface adapters may have a transmission range of 300m in an open area. But with good external antennas you can boost this whithout amplification up to 150km (http://www.wifi-shootout.com/). As a personal advice for every WLAN simulation - use the Shadowing (or better) propagation model if possible. I can provide ready to use parameter sets for different environments if necessary. Daniel.
Re: [ns] Bandwidth of wireless channel
Vinod schrieb: im working in qos routing in mobile adhoc networks. can anyone tell me why the default value of bandwidth is 0 in link layer of type LL (wireless routing simulation). Does that mean its not used or something else? I can see that the delay value is set to 25us by default. Also, can anyone tell me whether i can have cost param attached to wireless links as we can do in wired? The short answer - there is nothing like a wireless link. Wireless communication uses a broadcast medium. Links are only logically defined by your MAC layer or routing protocol. Additionally you do not have something like a universal bandwidth of the wireless channel. This depends on your technology, modulation schemes etc. So you have to setup this value depending on your model technology (e.g. 2 Mbit/s for a WLAN using BPSK modulation). Daniel.
Re: [ns] Real time Play with NS-2 emulator
[EMAIL PROTECTED] schrieb: I am just putting this question out there to see if it is possible to implement. Right now I only have access to one laptop. I am running ns-2.27 with pclinuxos. So far I was able to 'make nse' and did not return any error messages however I still can't run the pingdemo.tcl. But the question is this: I want the emulator to be able to read a tracefile (a large one perhaps that of a half an hour show) in real time and at the same time output the packets perhaps to a reciever tracefile that is constantly updated as packets arrive. Next the tracefile is read by a real time player such as VLC (I think it has real time capabilities) and outputs the video So I can readily view the real-time video as it is being emulated. I have to all this in one machine or the laptop. Is it possible or has anyone done anything like this before that can offer me some direction? Thank you. I assume that you actually mean a packet dump / capture file (e.g. pcap format) when you say tracefile. The ns-2 tracefiles does not contain any application data and therefore is not suitable to be used as input for any application like VLC. What you need is a setup where you have nse and two virtual machines - one that replays the packet dump and the second that runs VLC. To replay a PCAP file you need to implement a tool similar to tcpreplay or simple-replay. To get a receiver tracefile as you name it, you can capture the packets on the second virtual machine using tcpdump. But this will not be necessary as you can feed them directly into VLC. Hope, this helps. Daniel.
Re: [ns] compile ns-allinone-2.29.2 error on fedora core 5
landrew126 schrieb: Hi,everybody I think I must send this letter again,for I didn't post the errormessage to you. The following is the error message I got when complingns-2.29: g++ -c -Wall -DTCP_DELAY_BIND_ALL -DNO_TK -DTCLCL_CLASSINSTVAR-DNDEBUG -DLINUX_TCP_HEADER -DUSE_SHM -DHAVE_LIBTCLCL -DHAVE_TCLCL_H-DHAVE_LIBOTCL1_11 -DHAVE_OTCL_H -DHAVE_LIBTK8_4 -DHAVE_TK_H-DHAVE_LIBTCL8_4 -DHAVE_TCL_H -DHAVE_CONFIG_H -DNS_DIFFUSION-DSMAC_NO_SYNC -DCPP_NAMESPACE=std -DUSE_SINGLE_ADDRESS_SPACE -Drng_test-I. -I/home/landrew/WsnSimulator/ns-allinone-2.29/tclcl-1.17-I/home/landrew/WsnSimulator/ns-allinone-2.29/otcl-1.11-I/home/landrew/WsnSimulator/ns-allinone-2.29/include-I/home/landrew/WsnSimulator/ns-allinone-2.29/include-I/usr/include/pcap -I./tcp -I./sctp -I./common -I./link -I./queue-I./adc -I./apps -I./mac -I./mobile -I./trace -I./routing -I./tools-I./classifier -I./mcast -I./diffusion3/lib/main -I./diffusion3/lib-I./diffusion3/lib/nr -I./diffusion3/ns -I./diffusion3/filter_core-I./asim/ -I./qs -I./diffserv -I./satellite -I./wpan -o dsr/dsragent.odsr/dsragent.ccdsr/dsragent.cc: In member function ‘voidDSRAgent::handleFlowForwarding(SRPacket, int)’:dsr/dsragent.cc:828: error: ‘XmitFlowFailureCallback’ was not declaredin this scopedsr/dsragent.cc: In member function ‘voidDSRAgent::sendOutPacketWithRoute(SRPacket, bool, Time)’:dsr/dsragent.cc:1385: error: ‘XmitFailureCallback’ was not declared inthis scopedsr/dsragent.cc:1386: error: ‘XmitFlowFailureCallback’ was not declaredin this scopedsr/dsragent.cc:1403: error: ‘XmitFailureCallback’ was not declared inthis scopemake: *** [dsr/dsragent.o] Error 1 This is a problem with the latest gcc version. To fix it, you can modify the files by moving the Xmit*Callback functions to the beginning of the file. Otherwise you could get updated versions of the files from the CVS - I already fixed this 3 weeks ago. You can also downgrade your gcc to a 3.3 version. Daniel.
Re: [ns] a comparison between the wireless routing protocols
Hello Alexandra, Alexandra Cioroianu schrieb: Hello ns users! I,m working with ns 2.29 in Mandriva 2006 and i need to make a comparison between the existing wireless routing protocols(DSDV, AODV, DSR...). I thought about creating Xgraph files that would show the traffic, delay, speed...,but i don't know what topologies to use to be relevant. Shall i start with the examples in the tutorial? Has anyone made this before or anyone knows some steps to be followed? Any ideas, sugestions would help me An important advice from me: test the performance of the protocols using different propagation models - at least compare them using the TwoRayGround and the Shadowing model. Additionally, it can't hurt to have some bottlenecks in your topology. Either place the nodes by hand or use a random topology e.g. on a 100x5000 m grid. Daniel.
Re: [ns] Does ns2 support simultaneous processing ?
On Friday 31 March 2006 17:33, Saurabh Sinha wrote: I just wanted to know that whether ns2 supports threads or not? Like can more that 2 two stations transmit at the same time It will of gr8 help if some one can post a suggestion Yes and no - ns2 itself does not use threads. But the event-based processing model does not need threads to allow for concurrent threads of control. That means two station can perform actions at the same moment in time. The simulator will serialize them and compute them sequentially. An event-based simulation does not need to care about real-time (wall clock time), it has its own time base and so can compute as much events (happening) at the same time as you need. The simulation time will stand still during the processing of an event and will jump to the execution time of the next event that has to be processed. Hope this answers your question. Daniel. -- Dipl.-Inf. Daniel Mahrenholz, University of Magdeburg, Germany Homepage: http://ivs.cs.uni-magdeburg.de/~mahrenho
Re: [ns] statement has no effect with CURRENT_TIME
On Tuesday 21 March 2006 13:46, elise hu wrote: My code compiles and is built into ns - however i have a warning : warning: statement has no effect for pretty much every line looking like : expire_time = CURRENT_TIME + nb_freshness_*t_br_; (i have a few) - so that's a bit worrying. CURRENT_TIME is defined as : #define CURRENT_TIME Scheduler::instance().clock(); Remove the ; at the end Daniel. -- Dipl.-Inf. Daniel Mahrenholz, University of Magdeburg, Germany Homepage: http://ivs.cs.uni-magdeburg.de/~mahrenho
Re: [ns] Integrate program
On Tuesday 21 March 2006 13:35, . . wrote: I am going to do a simulation of dns in NS-2. Is there any way i can integrate Bind or a similar application in NS-2 or is it better to implement it from scratch? I want to use Bind or similar because it is relevant for the testing. I don't want to use another simulator, it have to be NS-2! Network emulation will be the right choice for you. If you dont need the actual DNS functionality you should try to implement small traffic generators to mimic a DNS server and client. Daniel. -- Dipl.-Inf. Daniel Mahrenholz, University of Magdeburg, Germany Homepage: http://ivs.cs.uni-magdeburg.de/~mahrenho
Re: [ns] CSThresh_ and RXThresh_
On Monday 20 March 2006 08:27, Ashraf Bourawy wrote: in addition, in ns-2, the transmission range is set to approximately 250 m...and the distCST_ is 550 m my question is, why is this huge difference? as this will affect the performance...and is it required by the standard? I just couldn't find anything supporing this issu.I would appreciate it, if anyone could tell me where I can find any explanation about this issue.. It is a common missunderstanding that the transmission / carrier sense (interference) range is set to 250 / 550m. They are just the results of the choosen propagation model, transmission power, antenna gains, TX/CS thresholds. I have to emphasis it again: you CANNOT set the transmission range of a WLAN device (you can only set all named parameters to result in a desired range). The default values in ns2 are not very realistic. If you are developing new WLAN protocols you should at least use the Shadowing propagation model. Daniel. -- Dipl.-Inf. Daniel Mahrenholz, University of Magdeburg, Germany Homepage: http://ivs.cs.uni-magdeburg.de/~mahrenho
Re: [ns] Memory leak in TFRC?!
On Thursday 16 March 2006 15:01, Arne Lie wrote: In my work of enabling a VBR video application on top of TFRC in ns-2.28, I observe that I have gotten a memory leak, which is difficult to trace! Two questions: 1. Anybody having suggestions in how to track this down? (gdb, profiling?) For memory leaks I recomment to use valgrind - it helped a lot in our projects. And yes - it is possible to valgrind ns-2 although it is not that funny. You will need a lot of memory ... good luck. Daniel. -- Dipl.-Inf. Daniel Mahrenholz, University of Magdeburg, Germany Homepage: http://ivs.cs.uni-magdeburg.de/~mahrenho
Re: [ns] Shadowing model
Hi, On Friday 10 March 2006 09:34, cp kothari wrote: hi anyone tried Shadowing propagation model on ns2. i am getting lots of ri\outing overhead in case shadowing model? please reply with details. I use the Shadowing model for all my WLAN simulations because FreeSpace and TwoRayGround are very unrealistic. Compared with these models you will notice a higher routing overhead because you get links with loss probabilities between 0 and 1. This is not a bug, its a feature. Many protocol suffer from the fact that they do not consider link quality. You will find some results in Stepanov et al. On the Impact of radio Propagation Models on MANET Simulation Results, MWCN 2005. Daniel. -- Dipl.-Inf. Daniel Mahrenholz, University of Magdeburg, Germany Homepage: http://ivs.cs.uni-magdeburg.de/~mahrenho
Re: [ns] How to use Error Models with Wireless channels ?
On Monday 06 March 2006 09:26, [EMAIL PROTECTED] wrote:
Could anyone please tell me how to configure error models with a wireless
channel in ns2.28. Actually I tried it as mentioned in the manual like
this:
I use the following code and it works:
proc UniformErr {} {
set err [new ErrorModel]
$err unit packet
$err set rate_ 0.005 # 0.5%
$err ranvar [new RandomVariable/Uniform]
$err drop-target [new Agent/Null]
return $err
}
$ns node-config -IncomingErrProc UniformErr
Daniel.
--
Dipl.-Inf. Daniel Mahrenholz, University of Magdeburg, Germany
Homepage: http://ivs.cs.uni-magdeburg.de/~mahrenho
Re: [ns] How to speed up ns-2 simulations
Hi, On Wednesday 01 March 2006 00:19, Soo-Hyun Choi wrote: 2. As far as my understanding, several hundred nodes with ns-2 might not be a good choice in terms of CPU time, memory consumption, debugging etc etc. If your simulation needs to be run with that many nodes, people usually write his/her own simulator. The sheer number of nodes is not your primary problem - we successfully run wireless simulations using 10.000 and more nodes. This required about 1.5GB memory. The memory consumption grows rapidly if you have a large number of packets, e.g. on high bandwidth (wired) links with long delays, or large input queues on each node. It will be even higher if you forget to remove all unnecessary headers from your packets. For wireless simulations you have a special problem - the CPU consumption grows with the density of the network because propagation has to be computed for every pair of nodes that could affect each other. The third problem is the number of pending events. Depending on the used scheduler it takes significant different times to insert new events. This is especially important if you have a lot of events that are scheduled far in the future. Here you have to test the different schedulers which one performs best for you. -- Dipl.-Inf. Daniel Mahrenholz, University of Magdeburg, Germany Homepage: http://ivs.cs.uni-magdeburg.de/~mahrenho
Re: [ns] (yet another) doubt on CSThresh_ and RxThresh_
On Wednesday 08 February 2006 16:29, Sita S. Krishnakumar wrote: I am not sure I understand what you mean by: If you increase the range at witch you define the signal to be receiveable you have to lower RXTresh because it needs to be lower than the signal at this point. I thought RXThresh is the threshold until which a packet can be received by a node ie. it is the reach of the node. If you want it to receive packets from a farther distance, should the threshold be greater? Usually you define Pt_, RXTresh and then compute the maximum possible transmission range. But if you need a different range you set it fix and compute either Pt_ or RXTresh while keeping the other fix. For a longer distance you need either a higher Pt_ (stronger sender) or lower RXTresh (more sensitive receiver). For the two-ray-ground model it is very easy to compute these values. Take a look into the code and you will find the equation. Daniel. -- Dipl.-Inf. Daniel Mahrenholz, University of Magdeburg, Germany Homepage: http://ivs.cs.uni-magdeburg.de/~mahrenho
Re: [ns] simulation time in ns-2
Hi, On Monday 09 January 2006 14:42, Michael Sidiropoulos wrote: Hello everyone!!I have a question regarding simulation time in ns-2 I am using ns-2.27 version and i have noticed that the calculated throughput in my wireless scenario changes as the simulation time increases.What simulation time should i set to my tcl script in order to getaccurate throughput results?Any point or hint is extremely welcomedThanks for your attention!!! If you like to know the values in a steady state you sould run the simulation for at least several minutes. Especially in the first few seconds you can experience several strange effects. Something I often see is a storm of ARP packets at the beginning of a simulation because all stations start to communicate at about the same time. So, it is sometimes better to discard the results from the first seconds. Daniel. -- Dipl.-Inf. Daniel Mahrenholz, University of Magdeburg, Germany Homepage: http://ivs.cs.uni-magdeburg.de/~mahrenho
Re: [ns] Pleas help:How to access mobile node data out of the agent
Hi Christoph, On Monday 09 January 2006 18:36, christoph schroth wrote: I have a rather critical question, and I would be very happy if someone could write me a brief answer: How can I access mobile node data such as location (X_, Y_, etc.) out of the agent (e.g., MessagePassing Agent). With other words: How do I get a reference to the mobile node wo whom I have attached the agent before? Look into tcl/lib/ns-node.tcl : instproc attach ... how an agent is attached to a node. I didn't tried but you should get the Node reference from the node_ field in the agent. Daniel. -- Dipl.-Inf. Daniel Mahrenholz, University of Magdeburg, Germany Homepage: http://ivs.cs.uni-magdeburg.de/~mahrenho
Re: [ns] How to calculate bandwidth from transmission power?
Hi, On Sunday 08 January 2006 14:19, you wrote: As you said, I have just found that, in NS2, the bandwidth can be set by Phy/WirelessPhy set bandwidth_ 2e6 and it will be constant, even though the transmission power is changed. I am not sure why bandwidth is not related to transmission power. According to my understand, when the transmission power is decreased, the communication range will be decreased. It is logical true. However, decreasing of transmission power should increase SNR. Once SNR increases, the bandwidth or data rate should be decreased somehow. Do you think so? Could you give me an explaination if i am wrong? You have to keep in mind that the received signal strength is not only defined by the sender. You can increase the transmission range just by attaching an external antenna with positive gain to the receiver. So the signal strength is defined by the transmission power, the antenna gains, and the distance. Above this you have the modulation (with a maximum possible bandwidth) that requires a certain SNR. This does not mean that the bandwidth will automatically increase with an increasing SNR because the sender does not know about the SNR at the receiver side. The current 802.11 implementation does not has multi-rate support. There is a new implementation (s. wiki for more information) that has, but I cannot tell you exactly how it works. If you use the current implementation you have to decide for a bandwidth, set it in the PHY layer and set the RXThresh accordingly. Just as an example what you can do with antennas (and an unamplified 802.11b card) lock here: http://www.unwiredadventures.com/unwire/2005/12/defcon_wifi_sho.html They reached more than 125 miles! Daniel. -- +-[Dipl.-Inf. Daniel Mahrenholz / Otto-von-Guericke Universität Magdeburg]-+ | http://ivs.cs.uni-magdeburg.de/~mahrenho Geb. 29 Raum 407 | | mailto:[EMAIL PROTECTED] Tel. +49-391-67-12788 | +--+
