Re: [6tsch] simulation for random schedule allocation

[Xavier Vilajosana Guillen <[e-mail]>]

Hi Yoshihiro,

you are right, the formulation of the sentence is not correct. Should be:

“Topology: Random, where each node requests a random number of neighbours
between 2 and 10.”

this means that each node when created requests a number of neighbors
between 2 and 10, meaning that other nodes when are created also request
that number of neighbours and therefore a node can have more than 10
neighbours, because other nodes selected it as a neighbour. From the
simulation results I see that nodes have between 5 and 11 neighbours
usually.

However, from the numbers you point, 28 represents the number of allocated
links (number of allocated cells in the schedule) to its neighbours, there
might be more than one link to a neighbour in that case.
regards,
Xavi

Xavi


On Wed, Jun 26, 2013 at 7:28 AM, <[e-mail]> wrote:

>  Hi Xavi,****
>
> ** **
>
> Thank you very much for the simulation.****
>
> ** **
>
> I am trying to understand the simulation model from your description and
> the result.****
>
> ** **
>
> “Topology: Random, where each node has a random number of neighbors
> between 2 and 10.”****
>
> ** **
>
> “****
>
> ************************ requesting 1 links****
>
> Node,Allocated Links,Collisions,Percentage****
>
> 0,28,0,0.0****
>
> “****
>
> ** **
>
> In the above result, does Node 0 actually have 28 neighbors?****
>
> ** **
>
> Regards,****
>
> Yoshihiro Ohba****
>
> ** **
>
> *From:* [e-mail] [mailto:[e-mail]] *On Behalf
> Of *Xavier Vilajosana Guillen
> *Sent:* Wednesday, June 26, 2013 3:46 AM
> *To:* [e-mail]
>
> *Subject:* [6tsch] simulation for random schedule allocation****
>
> ** **
>
>
> ****
>
> Hi all,
>
> I prepared a little simulation to see how random schedule allocation
> behaves. (I have the code in Java in case someone is interested)
>
> here there are some details (everything can be tuned in case someone wants
> to point me to a special case)
>
> Network: 50 nodes
>
> Topology: Random, where each node has a random number of neighbors between
> 2 and 10.
>
> Each node requests a link to each of its neighbors. This is done from 1 to
> 10 times (i.e 10 tests, the first requesting 1 link to each neighbour, the
> second 2, etc.. up to 10 links to each of the neighbors, can be configured)
>
> The slotframe is 101 slots and 16 channels.
>
> The simulation prints statistics for the test (and the collisions if we
> are interested.)****
>
> I used pseudo random generator from the java language assuming it provides
> uniform or almost uniform distribution.****
>
> The allocation counter counts both the number of links allocated as tx and
> the number of links allocated as rx due to a neighbour allocating a link to
> the actual node. The percentage is the % of collisions w.r.t the allocated
> links. ****
>
> Worst case is around 11% when allocating 10 links to each neighbour in
> that 50 node network.****
>
> I can play more on it but I wanted to share that initial results.****
>
> please see attached file for the results.****
>
> regards,****
>
> Xavi****
>