Error while running laa-wifi-indoor example

[Moawiah Alhulayil]

while i am running the laa-wifi-indoor example, i have got an error as below:

assert failed.  cond="m_backoffSlots == 0" , file =../src/wifi/model/dcf-manager.cc , line 138

terminate called without an active exception

Please, how can i solve this issue?

[Konstantinos]

Hi,

Please provide more details for the scenario you run.

Have you modified the code at all? Which parameters you use? etc

Are you using the latest release from the codebase?

Regards

K

[Moawiah Alhulayil]

Thanks for your reply.

If i want to change the parameters like number of cells of number of users, can i do that by changing that from the file .cc and then run the file?. One more question, i need to have graphs  (latency and throughput) of the indoor coexisting scenario when i am changing some parameters like CellA: Lte and CellB: Wifi then CellA: Laa and CellB: Wifi then to change like the DutyCycle for Lte and to change like UDP to TCP...etc. How can i do that and to have the graphs for latency and throughput?

Regards.

[Tom Henderson]

This is an intermittent issue with the DCF model used in the coexistence
code.

You can possibly work around it by using a different RngRun run number,
such as
./waf --run 'laa-wifi-indoor --RngRun=3 ..."

and hope that the assert does not happen for some runs. Sorry but this
is the situation until the laa code is upgraded to the latest wifi code
in ns-3-dev.

> If i want to change the parameters like number of cells of number of
> users, can i do that by changing that from the file .cc and then run the
> file?.

It is likely going to require changes to both the example program
(laa-wifi-simple, laa-wifi-indoor) and the scenario helper. Some things
may be easier (e.g. number of users) than others (e.g. number of
operators). You will have to read the code and try it yourself.

> One more question, i need to have graphs (latency and
> throughput) of the indoor coexisting scenario when i am changing some
> parameters like CellA: Lte and CellB: Wifi then CellA: Laa and CellB:
> Wifi then to change like the DutyCycle for Lte and to change like UDP to
> TCP...etc. How can i do that and to have the graphs for latency and
> throughput?

There is already an extensive scripting framework in the
laa-wifi-coexistence/experiments/ directory, so I suggest to study
exactly how those plots are generated and then consider what you may
need to change.

- Tom

[m.alh...@gmail.com]

Thanks for your reply.

Can i change the topology easily? like Base station spacing and the dimensions for the BSs ? just what i need is to edit the indoor.cc script?

[Tom Henderson]

On 05/05/2017 06:31 AM, m.alh...@gmail.com wrote:
> Thanks for your reply.
>

> Can i change the topology easily? like Base station spacing and the
> dimensions for the BSs ? just what i need is to edit the indoor.cc script?

You can change some things easily; it depends.

If you run './waf --run laa-wifi-indoor --PrintGlobals' you can see the
options that are changeable from the command line.

If you read through the laa-wifi-indoor.cc script, there may be some
other things you can change by modifying code.

Some other things, you would have to modify the scenario helper. In
particular, the scenario is pretty hardcoded to support two coexisting
operators, not more than two, although the number of base stations and
UEs in each operator network, the layout of nodes, etc. should be
changeable.