Hi Steven, Thanks for responding. My comments are inline.
On Thu, Aug 18, 2016 at 7:11 PM, Steven Galgano <[email protected]> wrote: > Vijay, > > Both NEMs are set to use the '2ray' propagation model. Only location > events are used by the emulator physical layer with this configuration. > Pathloss events will be ignored. > > nem 2 phy propagationmodel = 2ray > nem 3 phy propagationmodel = 2ray > > Thanks for pointing out the mistake. I changed the "pathloss mode" (the "propagationmodel" parameter in phy xml) of the nem3-nem1 net in CORE to "precomputed" and ran the experiment again. Surprisingly, the nodes were not even pingable this time, with a "network unreachable" error. >From the phy EventReceptionTable it appears 6 location events are being > published. Location events have id 100. > > nem 2 phy EventReceptionTable > | Event | Total Rx | > | 100 | 6 | > > nem 3 phy EventReceptionTable > | Event | Total Rx | > | 100 | 6 | > > From NEM 2 phy BroadcastPacketDropTable0, it looks like all the packets > from 3 are being dropped because the transmit frequency is not in the > configured frequency of interest list (Not FOI). > > nem 2 phy BroadcastPacketDropTable0 > | NEM |...| Rx Sensitivity | Propagation Model |...| Not FOI |... > | 1 |...| 42 | 0 |...| 0 |... > | 3 |...| 0 | 1 |...| 42 |... > > nem 3 phy BroadcastPacketDropTable0 > | NEM |...| Rx Sensitivity | Propagation Model |...| Not FOI |... > | 1 |...| 0 | 1 |...| 41 |... > | 2 |...| 0 | 1 |...| 42 |... > > Looking at your configuration, NEM 2 and NEM 3 are set to different > frequencies: > > nem 2 phy frequency = 2347000000 > nem 2 phy frequencyofinterest = 2347000000 > nem 3 phy frequency = 4560000000 > nem 3 phy frequencyofinterest = 4560000000 > > I should have clarified this - the mobile node is supposed to be connected to two radio networks, and it is the nem2-nem1 network that the question is about. Nem3 belongs to a different network. For the purpose of this question, nem3 can be ignored. > I don't see any config, stats or tables for NEM 1 but NEM 2 did receive > over-the-air frames from NEM 1 but dropped them because the receive > power was below the receiver sensitivity. See 'Rx Sensitivity' column of > above table. > > From the EMANE docs, I assume that the RxSensitivity is controlled by the following equations: rxPower = txPower + txAntennaGain + rxAntennaGain − pathloss rxSensitivity = −174 + noiseFigure + 10 log(bandWidth) If RxPower < RxSensitivity, then the packet is discarded (and hence packet loss ensues) Question: When do I see a packetloss, suppose that I am pinging nem1 from nem2 or viceversa? In my case, from the pathloss events, the minimum rxpower was rxPower = txPower + txAntennaGain + rxAntennaGain − pathloss = 0 + 0 + ? [rxAntennagain?, assumed to be 0] - 116.266264 = -116.266264 RxSensitivity = -174 + 4 + 10 log (1000000) = -110 In this case, packetloss should have happened. But I did not see any packetloss in my earlier experiments. It does not appear any over-the-air traffic was completed to NEM 2 or > NEM 3 (from stats): > > nem 2 transport processedUpstreamPackets = 0 > nem 2 mac processedUpstreamPackets = 0 > nem 2 phy processedUpstreamPackets = 97 > nem 3 transport processedUpstreamPackets = 0 > nem 3 mac processedUpstreamPackets = 0 > nem 3 phy processedUpstreamPackets = 97 > > All upstream traffic (inbound traffic) was dropped in the physical layer. > > General questions: a) Is it possible that only the location information is provided by EMANE events, and CORE computes the pathloss and packet loss for those location events ? If yes, even in the previous case where the pathloss was set to 2ray while location events were being given by EMANE, there should have been some packetloss. b) Referring to my RxSensitivity above: nem 2 phy BroadcastPacketDropTable0 | NEM |...| Rx Sensitivity | Propagation Model |...| Not FOI |... | 1 |...| 42 | 0 |...| 0 |... | 3 |...| 0 | 1 |...| 42 |... Given the formula for RxSensitivity, How can sensitivity be 0, when noise figure is kept at 4dB and bandwidth at 1MHz ? c) Why does the EventReceptionTable above show very few events (location in this case) when the mobile node is moving almost all the time ? d) The documentation (pdf and ppt) may be dated - the "pathlossmode" to "propagationmodel" change is not found in the document. Attaching config, stat and table output of nem1 (node1) and nem2 (node2) - these outputs were taken at more or less the same time from the nodes. NOTE: emaneeventservice reports event ID 100 for location events and event ID 101 for pathloss events. -- > Steven Galgano > Adjacent Link LLC > www.adjacentlink.com > > > On 08/18/2016 01:53 AM, Vijayasarathy Rajagopalan wrote: > > Hi All, > > > > I am trying to emulate a simple network of two nodes - a ground node, > > and another mobile node which, from an elevation, moves up from the > > ground node at around 45 degrees for a certain duration, makes a circle > > with a specific radius at that point, and comes back to the same point > > where it started. The idea is to set up opportunistic contact between > > the two nodes. For the purpose of simplicity, I have made a IEEE802.11bg > > wifi connectivity between the two nodes, with the default values given > > by CORE (txpower of 0 dbm and frequency of 2.347 GHz). I use EMANE > > events to trigger the above mobility. For the mobility model, I have > > used MNM tools to generate an EEL file which contains GPS location and > > pathloss events per second for a duration of 10000 seconds. > > > > > > > > The problem is the following: While the location events are duly > > recognized by CORE, I suspect that the pathloss events are not being > > recognized properly. Going by a previous post on the EMANE users group, > > I have attached the output of the following emane shell commands: 1) > > emanesh localhost get stat '*' all (stats.txt) 2) emanesh localhost get > > table '*' all (tables.txt); 3) emanesh localhost get config '*' all > > (config.txt). From the table output, I see no indication of pathloss > > events received in the mobile node, against the ForwardPathLoss and the > > ReversePathLoss tables (while emaneeventservice executed with debug > > level info reports sending pathloss message). > > > > Also, a visual indicator (I presume) for pathloss at some point in the > > motion should be packet loss. I have empirically determined that > > connectivity between nodes for the above values should stop roughly > > around 1500-2000 metres between them (assuming all default values for > > IEE802.11bg for EMANE in CORE network emulator). I observe that even > > beyond this point, there is no packetloss (as pathloss should have > > caused), and neither does visual adjacency in CORE disappear/turn grey. > > > > Appreciate any assistance that I may get from the forum. > > > > Thanks, > > Vijay > > > > > > > > _______________________________________________ > > core-users mailing list > > [email protected] > > http://pf.itd.nrl.navy.mil/mailman/listinfo/core-users > > >
config_nem1
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config_nem2
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stat_nem1
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stat_nem2
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table_nem1
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table_nem2
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