[Ns-developers] GSoC + WiPreSS

[paolo.pilia@telecompress.net]

Dear Ruben ,

below some details about the ideas for the class ns3::antenna.
I'm writing a Proposal on sochop database, it will be a summary of  
this discussion integrated with some addition.


Quoting Ruben Merz <ruben at net.t-labs.tu-berlin.de>:

> Dear Paolo
>
> Comments below
>
> On 3/31/09 1:50 PM, paolo.pilia at telecompress.net wrote:
>> Quoting Ruben Merz <ruben at net.t-labs.tu-berlin.de>:
>>
>>> Dear Paolo
>>>
>>> On 3/29/09 6:18 PM, paolo.pilia at telecompress.net wrote:
>>>> Dear NS3 developers,
>>>>
>>>> I want inform ns-3 developers about the new project WiPreSS ( Wireless
>>>> Prediction and Simulation Software - info on telecompress dot net).
>>>> I'm working to integrate ns-3 for simulation.
>>>
>>> Would you give us a bit more details than what is on
>>> http://telecompress.net/ ? How does really ns-3 relate to it? Which
>>> parts of ns-3 do you want to use?
>>>
>>
>> WiPreSS is a free solution for wireless network design and testing.
>> Basically it will be a really-free alternative to Radio Mobile, with
>> some additional features.
>> It calculate the radio propagation in a real scenario. Importing data
>> of terrain (altitude) from DEM repositories and combine it with
>> builds-data from shapefile.
>> Ns3 is the best candidate for testing a wireless application after the
>> design.
>> I'm working also to develop another kind of simulation based on it++
>> for custom trasmission channel ( p2p radio link) with definition of
>> modulation, coding, filter.
>>
>>>> At this moment the radio propagation tool of ns3 is so poor. I'm going
>>>> to register in socghop and present my candidature as student for GSoC on
>>>> antennas module.
>>>
>>> Could you please elaborate on how you would work on this project. What
>>> kind of antenna radiation pattern model would you implement? How would
>>> you implement it? Maybe even validate it?
>>>
>>
>> The innovation (confronting with actual ns3) in an antenna class that
>> compute the 3d pattern of antenna reading the specifications file (MSI
>
> Ok, an antenna class might be a good start. But then, where would
> integrate such a class in the current ns-3 codebase? Typically, such a
> class should interface with the propagation models. So, how would you
> do that?

The classical formula used add diversity terms of tx and rx antennas in
Friis .
It's possible to maintain that formula and use
the additional loss.

>
>> or ANT). These files are used by the antennas vendor. It make possible
>> to test a radio connection with a chosen antennas (for example select
>> a Kathrein specific model).
>> 3D pattern is result of horizontal and vertical diagram combination.
>
> Well, before a full 3D radiation pattern, I would start with a simpler
> 2D pattern. Also, the implementation of a radiation pattern implies
> that nodes must have an orientation. This is not yet supported in ns-3.
>


I assume the North on Y direction, Est on X direction.

* in 2D

+ fixed nodes:
the orientation is related to antennas , it have to be set in the
configuration of antenna with phi (orizontal angle between North and
direction of max radiation).
After configuration the radiation pattern is allocated in a vector of
360 element.
This permit to consider all nodes directed to north.

+ mobile nodes:
If the choose is to make a good simulation of real world, it is
need a correction of orientation each times the direction of moving
change. In term of mobility model is an addition of int
mobility::getdirection

For antennas class as to be implemented a setdirection method
that set the index  for the vector. antennas::getdirectivity return
the element of vector correspondent to the index.

* In 3d

+ a deltatetha (tilt - angle between horizont and
direction of max radiation) have to be setted in addition to deltaphi   
. the vector of directivity became a matrix

+ getdirection() set &deltaphi &deltatetha , in addition a get  
deltaphi() method for 2d moving.


>> I've an implementation of this class for WiPreSS.
>>
>> I'm going to add the function for elements combination in array.
>> It's simple implementable with defined elements, positions and phases.
>>
>> About propagation model I'm going to write the code.
>
> There are already propagation models in ns-3. Assuming the work on the
> antenna is done, what would you propose?
>
>> Validation is planned (Wipress is a thesis project).
>
> Could you please elaborate on this?


About antennas the validation is done using classical validated formulas.

The critical point is in the combination of vertical and horizontal radiation
pattern. That's a question of precision,  will be never perfect
considering that each antenna element has not the exact radiation pattern
declared.

However I'll confront result with scientific literature and know case.
I have to product documentation about it for thesis too.

>
>>
>> On side of propagation model I'm working to combine multi-path
>> propagation model (it++) with ray tracing.
>> Actually the realization it's related to the critical aspect of
>> processing environment.
>
> That would be very interesting but I fear this is way too much.
> Actually, this is likely another project in itself.

    ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^


Paolo

>
> Ruben
>
>> The goals are simple defined in the equation:
>> Antennas::3dpattern + environment::raytracing + channel::multipath =
>> diversity simulation
>>
>>
>>
>>
>>> Best
>>> Ruben
>>>
>>>> Regards,
>>>> Paolo Pilia