Re: [ns] Underwater Channel in basic NS2
Hi Dewald, Dewald Nolte wrote: > In ns-miracle the documentation claims that the underwater channel > works and that some basic MACs are provided, but in one of the mails > in the mailing list I read that some of the routing protocols are not > yet supported? Basically the underwater-miracle module provides only Channel, PHY and MAC, and relies on nsmiracle for the rest of the protocol stack. The current release of nsmiracle provides only static routing. The future release will include support for routing protocols such as AODV. However, the release date for this version of nsmiracle cannot be predicted at this moment. > Also if I go the basic ns way I have to fix the code > myself. It has some errors at the moment. Doesnt seem too difficult to > fix though. > > 1. In the underwater-phy.cc of the unsupported underwater code, lambda > is defined as: > lambda_ = SPEED_OF_LIGHT / freq_; > Considering that its an underwater channel, should it not then be > the speed of sound?? I guess this value was not used in practice. What I remember of the ns2 underwater module is that is basically used the underwater-phy as an entry point for some other external code. Most of the code copied from the ns2 wireless-phy is not actually used. However, you need to read the code yourself to really understand it. I guess it could be very difficult to contact the original developers of that module. > I want to implement my own MAC for the underwater environment. I am > looking to use the RTS, CTS, DATA, ACK handshake to implement MACAW. > Some of this is already implemented in the 802.11 MAC. So I will try > to port that to MACAW. So basically I want to try and use the > framework supplied by the 802.11 code and just change what is > necessarry to implement my MAC (MACAW). The problem is I dont have > enough experience with ns to write my own MAC > from scratch, so im doing it this way. > > 2. Now would it be easier to go with ns-miracle, or try to integrate > the unsupported code for the > basic ns and use that to keep the routing modules intact? > > 3. And lastly, can the 802.11 MAC run on the underwater physical layer > as it is? Just for >starters, I will try to port it eventually to the MACAW protocol... > What I can tell you (just my opinion of course) is that dealing with the ns2 underwater module at the PHY and MAC layer is a real mess. This is the main reason why we wrote the underwater-miracle module almost from scratch. Nicola
Re: [ns] access dei80211mr rate adapter rate
ryan m wrote: > I have an adhoc network, which I'm using dei80211mr-1.1.1 (with > activating the included rate adaptation on each node) to simulate > 802.11g with rate adaptation. Is there a way to determine the current > rate being used (call RateAdapter::getCurrMode() ) from dsragent.cc? That's cross-layer information exchange. Unfortunately there is no standard way of doing it in ns2. You need to develop an ad-hoc* solution, such as extending dsragent and allowing it to have a pointer to the rateadapter instance so that it can call its methods. * here I mean "ad-hoc" in the sense of "designed explicitly for this particular case" > > I'm working with a modified version of DSR known as FRESH that uses a > table of contact times on each node as a metric. A node looking for a > route will broadcast a request to it's neighbors asking when they last > saw the destination, and each neighbor will respond to the source of > the broadcast. My question is, is the rate adapter sophisticated > enough that each response will be sent at a rate appropriate for the > communication conditions between the particular responding neighbor > and the source? Secondarily is there a way to determine the rate each > particular response was sent at, from within dsragent.cc? RateAdapter itself defines only an API and provides some convenience methods/variables, however it implements no actual rate adaptation scheme. So the answer is: it depends on the actual rate adapter you're using. Each of the classes inheriting from RateAdapter implements a different rate adaptation scheme. The two distributed with dei80211mr are ARF and SNR. Both will work in ad-hoc mode, however with some caveats: 1) the ARF implementation we provide uses a single set of counters for all tx successful / failed events, so the behaviour in ad-hoc mode is not reasonable if the same STA sends often packets to different destinations, while it is more reasonable if the destination remains the same for a number of consecutive transmissions. 2) the SNR implementation records for all nodes the received SRN of the last received transmission, and the rate is chosen per-destination using that SNR value. So this scheme should work fine in ad-hoc mode, of course the SNR information for a given node will be only as recent as the last received packet from that node. If you have particular needs you can of course implement your own rate adaptation scheme by inheriting from the RateAdapter class. Nicola > > thank you for your time, > Ryan >
Re: [ns] dei80211mr-1.1.1 "Tabella non inizializzata 1"
ryan m wrote: > hello, > I'm using dei80211mr-1.1.1 and ns-allinone-2.31 and I want to simulate > a typical 802.11g ad-hoc network, so I set the following parameters to > that end. > > $mac($i) dataMode_ Mode54Mb > $mac($i) basicMode_ Mode2Mb > > With these settings (and several others) I'm getting the error > "Tabella non inizializzata 1" repetatly to cerr, Ok I'll translate that error message to something more meaningful for english speakers in the next release ;-) This error occurs when a Packet Error Rate value cannot be found for some PHYMode. The common reason for the error is that you did not load the correct Packet Error Rate table into an instance of a PER object. In the adhoc_tcp.tcl script this is done using the following command: set per [new PER] $per loadPERTable80211gTrivellato but that table is for 802.11g modes only. If you try, e.g., to use Mode1Mb in the same simluation script, you'll get the error you mentioned. In dei80211mr we provide also a PER table for 802.11b, which is loaded using this command: $per loadPERTable80211bIntersilHFA3861B You can also define your own PER table if you wish. Just have a look at src/per_table_*.tcl to see how to do it. The last four values for each row are: PHYmode packetsize SNR(dB) PacketErrorRate Regards, Nicola
Re: [ns] dei80211mr dsr seg fault
Hi Ryan, when using DSR, you need to use a CMUPriQueue instead of a Queue/DropTail/PriQueue. This issues is due to the DSR implementation, and is not related to dei80211mr. I tried this on the adhoc_tcp.tcl script and I was able to run DSR successfully with no segfault. Regards, Nicola ryan m wrote: > hello, > Has anyone has any luck with using dei80211mr with DSR? When I > take the the adhoc_tcp.tcl script from the sample directory in the > distribution and change the routing protocol to DSR and change NOTHING > else ns Segmentation faults when I run the script. Would you know > what has to be changed about the script to make it work with DSR? Or > even better have a script handy that uses dei80211mr, dsr, and output > from setdest for mobility? > > Thank you for any help you might offer, > Ryan >
Re: [ns] dei80211mr MAC parameters
Hi Ryan, ryan m wrote: > there is a parameter for the mac, $mac($i) dataMode_ $PHYDataRate , > and one possibility for PHYDataRate is Mode6Mb. What are the other > possibilities, in particular I'd like to know the option for 802.11g > multirate, and if possible 11MB unirate. The rates supported are listed in src/phymodes.h > > the other question is about the parameter $mac($i) basicMode_ Mode6Mb, > is this the basic rate for the multirate beacons and broadcast > packets? In the current version it is used for all control frames, i.e., RTS, CTS and ACK, as well as for all broadcast packets. > Are the possibilities for this parameter the same as for the > other parameter? Yes > If my interpretation of the parameter is correct; > 2MB is the correct basic rate for 802.11g right?, what is the correct > value for setting it to that? I suggest checking the 802.11 standard for this matter. Regards, Nicola
[ns] Setting up a simple cross layer architecture
Hi Veronica, I understand your concerns... the Miracle library itself is sufficient for implementing cross-layer interactions, however the API itself is somehow difficult to understand at first sight. To address this issue, Marco Miozzo and I resurrected the Sandbox library which was provided with the very first release of Miracle. The Sandbox provides a sample didactical implementation of a cross-layer interaction framework, and should help you understanding how cross-layering is implemented in Miracle. We updated the Sandbox so that now it works with the nsmiracle-1.1.1 release (i.e., the latest). You can find it on our nsmiracle web page: http://www.dei.unipd.it/ricerca/signet/tools/nsmiracle Regards, Nicola Veronica Sentongo wrote: > I'm doing an undergraduate thesis on Cross Layer Design Optimisation > and I'm trying to set up basic cross talk between layers. I need to > learn how to set up the Cross Layer Manager and how to send and > retrieve information from these layers using NsMiracle. > > I've been looking at the NsMiracle documentation available on the > internet and the example tcl scripts that come with the inital > nsmiracle package. In particular, I have been looking at the example > umts_cbr.tcl in the Samples folder. > > I want to set up a Cross Layer Manager between the Physical and > Application (CBR) layers and see the effect of changing the packet > size and period in the application layer, through the Cross Layer > manager, on throughput, PER and RTT in the physical layer for real > time applications. > > There is currently no available documentation in either the sample > files or the NsMiracle documentation available. Could you please let > me know how I can do this or send us example files where this has been > implentation. Your help would be greatly appreciated. > > Thank you > ___ > nsmiracle-users mailing list > [EMAIL PROTECTED] > https://mail.dei.unipd.it/mailman/listinfo/nsmiracle-users
[ns] dynamic libraries on cygwin
Hi all, I am glad to announce that support for dynamic libraries in ns is finally available also on cygwin. Here are the relevant links: The new patch by Federico Maguolo: http://www.dei.unipd.it/~maguolof/new-patch-dl-ns-2.31 The installation procedure for cygwin: http://www.dei.unipd.it/~baldo/ns_dl_patch/Installation.html Updated information for developers: http://www.dei.unipd.it/~baldo/ns_dl_patch/Developer_s_manual.html Finally, some dynamic libraries which we updated to make them work on Cygwin: TCP Veno and Eurane UMTS http://www.dei.unipd.it/~baldo/ns_dl_patch/Sample_dynamic_ns_modules.html dei80211mr version 1.1.1 http://www.dei.unipd.it/ricerca/signet/tools/dei80211mr Feedback welcome! Regards, Nicola
Re: [ns] Ns miracle Sandox library
Hi Veronica, the Sandbox library was included in the very first release of nsmiracle in order to demonstrate the functionalities of the miracle framework; however, it is not needed in order to implement cross-layer interactions. The cross-layer message exchange facility is part of the Miracle library, you just need to implement your own message types and the relative message handling code using the API described in the nsmiracle/clmessage.h header file. Regards, Nicola Veronica Sentongo wrote: > Hello > I'm currently trying to carry out some cross talk across layers but I'm > under the impression that I need to install the Sandbox dynamic library. > I heve installed everything properly but I still am unable to locate the > Sandbox library. > Could someone please let me know wher to find it? > thank you
Re: [ns] 802.11g in ns 2.28
Will Spearman wrote: > I would like to implement 802.11g in ns-2.28 As announced some time ago, an 802.11g implementation for ns2 can be found here: http://www.dei.unipd.it/~rossi/dei80211mr.html Regards, Nicola
Re: [ns] Compute busy/idel period of mobile node in ad hoc network
The dei80211mr 802.11 implementation just announced http://mailman.isi.edu/pipermail/ns-users/2007-June/060526.html provides a new idleSlot variable which counts the number of idle timeslots which are observed by the MAC. This variable can be used for your computations. Nicola Ana Turk wrote: > > Dear All, > > In order to estimate a bandwidth I need to compute a busy or idle > > time of node in period of time. Please how can I do this? > > I use ns-allinone-2.30 under fedora core 6. > Thanks in advance. > > > - > Découvrez une nouvelle façon d'obtenir des réponses à toutes vos questions ! > Profitez des connaissances, des opinions et des expériences des internautes > sur Yahoo! Questions/Réponses.
[ns] dynamic libraries in ns2: how to develop ns extensions withouth recompiling ns
Hi all, at the SIGNET lab, Dept. of Information Engineering, University of Padova, Italy, we've developed a patch for ns2 which enables effective use of dynamic libraries in ns2. We believe that the introduction of this feature substantially improves the current way of developing extensions to ns2. A list of the offered advantages is reported below: * People can develop add-ons for ns2 (e.g. introducing new agents, packet types, protocols) without having to modify the core simulator. * New packet headers and types, as well as packet tracers, could be defined to assist debugging, collection of statistics and inter-module communication. These can also be loaded on demand according to user's needs. * Dynamic libraries can be loaded at simulation time, with no need to recompile the whole ns2 distribution or to keep different ns2 binaries. * The installation of third-party ns2 extensions is made easier, thereby facilitating their dissemination. * Dynamic libraries will make life easier for lab technicians and students. In fact, an official ns2 version can be installed by administrators, and students can just build and use their preferred extensions independently. * ns2 will become more modular and scalable, while at the same time preserving backwad compatibility. We observe that dynamic libraries are natively supported in ns2 (see Tcl load functionality). However, the set of functionalities which can be accounted for by means of this approach is severely limited by the intrinsic structure of the simulator. As an example, new packet types and headers cannot be added to the code. In order to remove these limitations, the patch we developed enables dynamic definition of packet types, headers and their corresponding tracers. Special care has been taken to ensure backward compatibility: the patch has been designed in order not to interfere with the existing functionalities in ns2. We have been testing this patch on different linux systems since summer 2006, and so far we did not encounter any issue. The patch is available at this location: http://www.dei.unipd.it/~rossi/ns2-patch.html Also, a detailed documentation of the modifications introduced by the patch, as well as a tutorial for building ns extensions as dynamic libraries, can be found at this location: http://www.dei.unipd.it/~baldo/ns_dl_patch Finally, we also provide a few sample modules to allow a straightforward evaluation of the benefits provided by our patch. In particular, we provide dynamic library versions of the UMTS implementation by the EURANE project and of the TCP Veno implementation by NTU. The relative packages can be found at this location: http://www.dei.unipd.it/~baldo/ns_dl_patch/Sample_dynamic_ns_modules.html Of course, any feedback on our proposal is welcome! Regards, Nicola
Re: [ns] want information about assert() function
Hai Nam wrote: > assert() is usually used for debugging purpose. I think we can turn > off this function in a "released version" but I don't know how :-( From the man page of assert(): "If the macro NDEBUG was defined at the moment was last included, the macro assert() generates no code, and hence does nothing at all" Regards, Nicola
