Re: [ns] (yet another) doubt on CSThresh_ and RxThresh_
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? -Sita > > On Wednesday 08 February 2006 15:24, Sita S. Krishnakumar wrote: >> I am using TwoRayGround and for different distances, I get different >> RXThresh but Pt_ generated is always the same >> Also, as you increase the distance the RXThresh value goes down. And I >> am >> not sure if all Pt_ values being the same is correct either. > > This is correct. It does not make sense to vary Pt_. In practice you have > a > tranceiver that sends with a given power and does not care about how far > someone is away. 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. > > Of cause you can increase Pt_ and RXTresh by the same factor to keep the > maximum distance constant. > > Daniel. > -- > 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] (yet another) doubt on CSThresh_ and RxThresh_
On Wednesday 08 February 2006 15:24, Sita S. Krishnakumar wrote: > I am using TwoRayGround and for different distances, I get different > RXThresh but Pt_ generated is always the same > Also, as you increase the distance the RXThresh value goes down. And I am > not sure if all Pt_ values being the same is correct either. This is correct. It does not make sense to vary Pt_. In practice you have a tranceiver that sends with a given power and does not care about how far someone is away. 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. Of cause you can increase Pt_ and RXTresh by the same factor to keep the maximum distance constant. Daniel. -- 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_
I am using TwoRayGround and for different distances, I get different RXThresh but Pt_ generated is always the same Also, as you increase the distance the RXThresh value goes down. And I am not sure if all Pt_ values being the same is correct either. I was also thinking that the distance need not be all the way to the neighbor node, just midway distance, but in that case nothing gets sensed. ie (1)30m--(2) I thought if I got the RXThresh for 20m and used it, it will be able to sense each other's packets, but it does not. Any comments ns-users? Thanks, Sita > Yes I am using threshold.cc > > however the three values given for the wavelan are > > for > Range Pt_ > 40m = 8.5872e-4 > 100m = 7.214e-3 > 250 = 0.2818 > > You can bung that Pt_ value in threshold.cc and the distance you require > to calculate the Rxthresh > and then accordingly set the CSTHresh = RXThresh, to limit the CSThresh > afftecting other node. (well thats what I have done anyway) > > regards > > Qasim > > >> Are you sure you are configuring your node with the correct call ie >> using >> the new Phy/WirelessPhy? >> Also how are you arriving at the Pt_ values, using threshold.exe? >> -Sita >> >> >>> Well the problem I am having at the momment is that I can set different >>> nodes with different Pt_ values and different RXThresh values. Even >>> when >>> I >>> check those values with the recpective nodes, they give me the values >>> that >>> I have set. But when I run the simulation, The first CSThresh value is >>> set >>> for all the nodes. so if the first node should only,have 40m range and >>> the >>> second a 100m range, bot the nodes are set for 40m range >>> Can u please clarify ur question. I am not sure if it is working, but I want to make some nodes more powerful than the rest. But the threshold value for the range is not receiving any packets. -Sita > Hi Sita > > Can you manage to set different ranges for different nodes > > regards > > Qasim > >> Hello, >> I am trying to simulate a network where the interrow spacing is 19m >> and >> intercolumn spacing is 24m. I have the node's sensing range as 15m. >> >> Looking at some old mail in this mailing list: >> >> It depends on what carrier-sensing range do you want. If you use the >> default values, your carrier-sense range will be about twice the >> receiving >> range. If you would like to see the effects of hidden nodes in your >> simulation, you should set carrier-sensing range same as the >> receiving >> range. So, if you want to set receiving range 'd_1' and carrier >> sensing >> range 'd_2' (you must have d_2>d_1), then threshold.cc with 'd_1' >> provides >> you the RXThresh_ and the same program with input parameter 'd_2' >> will >> give you CSThresh_. >> >> I generated RxThresh_ using the threshold program and varied it as >> mentioned above. The source generates packets but it is not picked >> up >> by >> any other node. why? >> Also, changing Pt_ alone to control transmission range - is that >> acceptable? >> Any suggestions welcome. >> Regards, >> Sita >> >> > > > >>> >>> >>> >> >> >> > > >
Re: [ns] (yet another) doubt on CSThresh_ and RxThresh_
Are you sure you are configuring your node with the correct call ie using the new Phy/WirelessPhy? Also how are you arriving at the Pt_ values, using threshold.exe? -Sita > Well the problem I am having at the momment is that I can set different > nodes with different Pt_ values and different RXThresh values. Even when I > check those values with the recpective nodes, they give me the values that > I have set. But when I run the simulation, The first CSThresh value is set > for all the nodes. so if the first node should only,have 40m range and the > second a 100m range, bot the nodes are set for 40m range > >> Can u please clarify ur question. >> I am not sure if it is working, but I want to make some nodes more >> powerful than the rest. >> But the threshold value for the range is not receiving any packets. >> -Sita >> >> >>> Hi Sita >>> >>> Can you manage to set different ranges for different nodes >>> >>> regards >>> >>> Qasim >>> Hello, I am trying to simulate a network where the interrow spacing is 19m and intercolumn spacing is 24m. I have the node's sensing range as 15m. Looking at some old mail in this mailing list: It depends on what carrier-sensing range do you want. If you use the default values, your carrier-sense range will be about twice the receiving range. If you would like to see the effects of hidden nodes in your simulation, you should set carrier-sensing range same as the receiving range. So, if you want to set receiving range 'd_1' and carrier sensing range 'd_2' (you must have d_2>d_1), then threshold.cc with 'd_1' provides you the RXThresh_ and the same program with input parameter 'd_2' will give you CSThresh_. I generated RxThresh_ using the threshold program and varied it as mentioned above. The source generates packets but it is not picked up by any other node. why? Also, changing Pt_ alone to control transmission range - is that acceptable? Any suggestions welcome. Regards, Sita >>> >>> >>> >> >> >> > > >
Re: [ns] (yet another) doubt on CSThresh_ and RxThresh_
Can u please clarify ur question. I am not sure if it is working, but I want to make some nodes more powerful than the rest. But with the threshold value for a given range, nodes are not receiving any packets. -Sita > Hi Sita > > Can you manage to set different ranges for different nodes > > regards > > Qasim > >> Hello, >> I am trying to simulate a network where the interrow spacing is 19m and >> intercolumn spacing is 24m. I have the node's sensing range as 15m. >> >> Looking at some old mail in this mailing list: >> >> It depends on what carrier-sensing range do you want. If you use the >> default values, your carrier-sense range will be about twice the >> receiving >> range. If you would like to see the effects of hidden nodes in your >> simulation, you should set carrier-sensing range same as the receiving >> range. So, if you want to set receiving range 'd_1' and carrier sensing >> range 'd_2' (you must have d_2>d_1), then threshold.cc with 'd_1' >> provides >> you the RXThresh_ and the same program with input parameter 'd_2' will >> give you CSThresh_. >> >> I generated RxThresh_ using the threshold program and varied it as >> mentioned above. The source generates packets but it is not picked up by >> any other node. why? >> Also, changing Pt_ alone to control transmission range - is that >> acceptable? >> Any suggestions welcome. >> Regards, >> Sita >> >> > > >
Re: [ns] (yet another) doubt on CSThresh_ and RxThresh_
Can u please clarify ur question. I am not sure if it is working, but I want to make some nodes more powerful than the rest. But the threshold value for the range is not receiving any packets. -Sita > Hi Sita > > Can you manage to set different ranges for different nodes > > regards > > Qasim > >> Hello, >> I am trying to simulate a network where the interrow spacing is 19m and >> intercolumn spacing is 24m. I have the node's sensing range as 15m. >> >> Looking at some old mail in this mailing list: >> >> It depends on what carrier-sensing range do you want. If you use the >> default values, your carrier-sense range will be about twice the >> receiving >> range. If you would like to see the effects of hidden nodes in your >> simulation, you should set carrier-sensing range same as the receiving >> range. So, if you want to set receiving range 'd_1' and carrier sensing >> range 'd_2' (you must have d_2>d_1), then threshold.cc with 'd_1' >> provides >> you the RXThresh_ and the same program with input parameter 'd_2' will >> give you CSThresh_. >> >> I generated RxThresh_ using the threshold program and varied it as >> mentioned above. The source generates packets but it is not picked up by >> any other node. why? >> Also, changing Pt_ alone to control transmission range - is that >> acceptable? >> Any suggestions welcome. >> Regards, >> Sita >> >> > > >
Re: [ns] (yet another) doubt on CSThresh_ and RxThresh_
Can u please clarify ur question. I am not sure if it is working, but I want to make some nodes more powerful than the rest. But the threshold value for the range is not receiving any packets. -Sita > Hi Sita > > Can you manage to set different ranges for different nodes > > regards > > Qasim > >> Hello, >> I am trying to simulate a network where the interrow spacing is 19m and >> intercolumn spacing is 24m. I have the node's sensing range as 15m. >> >> Looking at some old mail in this mailing list: >> >> It depends on what carrier-sensing range do you want. If you use the >> default values, your carrier-sense range will be about twice the >> receiving >> range. If you would like to see the effects of hidden nodes in your >> simulation, you should set carrier-sensing range same as the receiving >> range. So, if you want to set receiving range 'd_1' and carrier sensing >> range 'd_2' (you must have d_2>d_1), then threshold.cc with 'd_1' >> provides >> you the RXThresh_ and the same program with input parameter 'd_2' will >> give you CSThresh_. >> >> I generated RxThresh_ using the threshold program and varied it as >> mentioned above. The source generates packets but it is not picked up by >> any other node. why? >> Also, changing Pt_ alone to control transmission range - is that >> acceptable? >> Any suggestions welcome. >> Regards, >> Sita >> >> > > >
