How to change the topology after the simulation start

[hongyu deng]

Hi All:

      I want to change the network topology after simulation begin(using PointToPoint topology to communicate between two nodes),How can i do to ensure the simulator running regularly!Such as the above picture,there are 3 constantpostion node and a constsntvelocity node,the constsntvelocity node will select a node between the three to guarantee the communication on the rail.

      Thanks for your answer!

[Konstantinos]

Hi,

P2P is designed to create WIRED links, not wireless. Perhaps the name is misleading, I can understand. But you should also read the documentation that explains that.

If you are using wireless, then when the SINR from the first node goes below a certain threshold, the connection is lost, i.e. packets are not received. 

Having said that, the topology would change 'automatically'. 

Regards,

K.

[hongyu deng]

Hi Konstantinos

    I have a project in high-speed railway,about cognitive radio,we want to use the exist basestation which deploys near the railway.When 

the train running to the next basestation,it should link to the nearly basestation to keep communication regularly.the three nodes 

in the picture represents the bs,the one node represents the train.

    What dayou mean is if Iuse the model like the picture in ns3 can't achieve the founction? your mean is only the WIRED link can

use P2P link?the wireless nodes can't use this topology?

    Thanks!

Regards,

Deng, 

--
You received this message because you are subscribed to a topic in the Google Groups "ns-3-users" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/ns-3-users/QURPfBz1E9w/unsubscribe.
To unsubscribe from this group and all its topics, send an email to ns-3-users+...@googlegroups.com.
To post to this group, send email to ns-3-...@googlegroups.com.
Visit this group at http://groups.google.com/group/ns-3-users.
For more options, visit https://groups.google.com/d/optout.

[hongyu deng]

Hi Konstantinos

    I have a project in high-speed railway,about cognitive radio,we want to use the exist basestation which deploys near the railway.When 

the train running to the next basestation,it should link to the nearly basestation to keep communication regularly.the three nodes 

in the picture represents the bs,the one node represents the train.

    What do you mean is if I use the model like the picture in ns3 can't achieve the function? your mean is only the WIRED link can

use P2P link?the wireless nodes can't use this topology?

    Thanks!so sorry for my poor english.

Regards,

Deng, 

2015-11-26 21:45 GMT+08:00 Konstantinos <dinos.k...@gmail.com>:

--

[Konstantinos]

Hi,

I did not say that wireless nodes can't use this topology.

What I said is that the point-to-point helper constructs wired links, not wireless.

The fact that you want a point-to-point wireless link between the train (a STA wireless node) and a base station, does not mean that you will use the PointToPointHelper class to create it. 

When you build a simple wireless network with a STA connected to a BS, that is considered as a p2p link between them. That's why I mentioned in my previous reply that the names may be misleading. 

Regards,

K.

To unsubscribe from this group and all its topics, send an email to ns-3-users+unsubscribe@googlegroups.com.

[hongyu deng]

Hi,

   Thanks very much K,now i understand you mean.What I want to do is to achieve commuication between mnobile phone and base statio.How can i do to achieve this topology in ns3?

   And if the mobile move nearly next base station,it can auto connect to that base station.

   What should i to do get this topology.

  Thanks for your patiently answer!

Regards,

Deng,

​

To unsubscribe from this group and all its topics, send an email to ns-3-users+...@googlegroups.com.

To post to this group, send email to ns-3-...@googlegroups.com.
Visit this group at http://groups.google.com/group/ns-3-users.
For more options, visit https://groups.google.com/d/optout.

--
You received this message because you are subscribed to a topic in the Google Groups "ns-3-users" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/ns-3-users/QURPfBz1E9w/unsubscribe.

To unsubscribe from this group and all its topics, send an email to ns-3-users+...@googlegroups.com.

[Konstantinos]

Hi Hongyu,

Are you simulating a cellular (LTE) network or wifi? From your current figure I assume that you want LTE.

See the examples in /src/lte/examples/lena-x2-handover.cc and lena-x2-handover-measures.cc

The first is user initiated handover between BS at some particular time, while the second is 'automatic' based on UE measurements.

For more information please read the documentation.

Regards,

K.

To unsubscribe from this group and all its topics, send an email to ns-3-users+unsubscribe@googlegroups.com.

To post to this group, send email to ns-3-...@googlegroups.com.
Visit this group at http://groups.google.com/group/ns-3-users.
For more options, visit https://groups.google.com/d/optout.

--
You received this message because you are subscribed to a topic in the Google Groups "ns-3-users" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/ns-3-users/QURPfBz1E9w/unsubscribe.

To unsubscribe from this group and all its topics, send an email to ns-3-users+unsubscribe@googlegroups.com.

[hongyu deng]

Hi K,

   Thanks very much,i need a middlemen to transform the 4G to WIFI,and the middlemen can handover to different base station at different site,because the train keeps moving forward.Do you have any other better advice?

   I will read the relevant documentation which your recommendation.

   Sorry for so late to reply you.☺

Regards,

Deng.

K.

To unsubscribe from this group and all its topics, send an email to ns-3-users+...@googlegroups.com.

To post to this group, send email to ns-3-...@googlegroups.com.
Visit this group at http://groups.google.com/group/ns-3-users.
For more options, visit https://groups.google.com/d/optout.

--
You received this message because you are subscribed to a topic in the Google Groups "ns-3-users" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/ns-3-users/QURPfBz1E9w/unsubscribe.

To unsubscribe from this group and all its topics, send an email to ns-3-users+...@googlegroups.com.

To post to this group, send email to ns-3-...@googlegroups.com.
Visit this group at http://groups.google.com/group/ns-3-users.
For more options, visit https://groups.google.com/d/optout.

--
You received this message because you are subscribed to a topic in the Google Groups "ns-3-users" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/ns-3-users/QURPfBz1E9w/unsubscribe.

To unsubscribe from this group and all its topics, send an email to ns-3-users+...@googlegroups.com.

[Tommaso Pecorella]

Hi,

sorry to say, but I'm always deeply touched by how many people are re-inventing the wheel, over and over, trying to find a better wheel, only to find out that there was already a wheel, and that its design can be improved, but only slightly.

What you are asking for is called Mobile IP, and one of its variants will do (MIPv6, PMIP, whatever-you-want-to-call-it). Even HIP could do, but I'm not sure about its latency in a mobile environment. Even MP-TCP will do, if you stick to TCP and you have enough time to change from one leg to another. Then there are all the Wi-Fi / LTE coexistence models (largely based on Mip and derivatives), and so on.

So, my question is: have you studied a bit of literature or some idiot gave you a task without giving you any hint at where to look for existing solutions ?

Or you have a solution you think it's better than the existing ones and you're thinking to simulate it ?

In the first case, please go to whoever gave you the task and kick him/her in the nuts.

In the second case, you must first clarify (to yourself, we don't really care and we don't want to know) what you want to do and how, then you think to how to simulate. not the opposite.

T.

[Madan Pande]

Tomasso Sir,
                          Perhaps what you are seeing are a number of guys trying to figure out how to do 5G arch with NS-3, and as you have pointed out without caring about relevant protocols, or even reading the relevant papers on possible architectures. Two current pproaches are:
 i) those which are simpler and are extensions to LTE-A and use LTE-U in 5Ghz band with WiFi APs in the unlicensed band as well ... this is a complex hetnet approach but requires CA and careful ABS to match WiFi "listen before transmit"  ... But this will be patch work good enough (if you succeed somewhat) for an MS thesis...

ii) The formal approach and preferred approach that would use special controller nodes for LTE and WiFi along with OpenFlow 1.1 for open network arch ... I believe NS-3 is the only open source simulator which  slowly but surely building towards that...

2. If a group was to take a collective approach they might succeed to a an extent but unfortunately, the arch std is for 2020 and a moving target ...

I am always impressed the way you break every thing down to basics / fundamentals, and I believe without which no research can be accomplished.

NS-3 users owe you a lot indeed to learn what they did not in the class... Please keep guiding us all...

Regards,
madan

You received this message because you are subscribed to the Google Groups "ns-3-users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to ns-3-users+...@googlegroups.com.

[hongyu deng]

Hi Tommaso,

Sorry for my studies shallowly,thanks for your work.

Regards,

Deng,

[Tommaso Pecorella]

Hi,

thanks madan for your kind words. I should be more kind as well.

Deng: don't feel sorry, nobody knows everything at the beginning. The fault is not on you, it's on who didn't point you in the right direction.

T.