Subject: [manet] MPR election in standard OLSR and Clusterhead Election in Hierarchical OLSR

From: "Aisling ODriscoll" <[email-masked]>
Date: Thu, 30 Aug 2007 14:40:47 +0100

Hello,

I have two queries, one relating to MPR election in OLSR and the other
is more a request for advice regarding Cluster Head election for OLSR:

1.	I read in the OLSR draft that MPR set recalculation should occur
when changes are detected in the symmetric and symmetric strict 2 hop
neighbourhood. So is it correct to say that during network setup and
discovery when HELLO messages are received with asymmetric and
subsequently symmetric neighbours in the HELLO message data, that the
MPR for that node is computed every time i.e. MPR computation is
happening upon receipt of every HELLO msg that causes a neighbourhood
change? It continues to do this until a stable set of MPRs are found
(assuming no mobility at the moment)? I had originally thought that MPR
calculation occurs after a pre-defined period of time. 

2.	I am implementing hierarchical OLSR. I want to elect a cluster
head based on a weighted metric transmitted in the HELLO messages. When
a node receives this HELLO message it will store the metric along with
the originator neighbour IP address in its neighbour table. I thought
that after a period of time all nodes would run an algorithm to
determine if they had the highest metric compared to that of their
neighbours and hence would elect themselves as the CH and notify their
neighbours. However I am not sure as to what how I should define this
time (or if I should even do it this way since MPRs are computed every
time a change is noted if point 1 is correct) - I need to ensure that
the network has first converged and that all nodes have communicated
their HELLOs and built their neighbour tables before I make the decision
to elect the CH- the question is when to make that decision as making
the decision too soon could mean its not based on a fully converged
neighbour set.

Any advice/comments would be greatly appreciated.

Kind Regards,

Aisling O' Driscoll.

_______________________________________________
manet mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/manet

---

From: "Dearlove, Christopher \(UK\)" <[email-masked]>
Date: Thu, 30 Aug 2007 15:44:57 +0100

Comment with >. I don't have a comment on point 2.

> It is defined as recalculating it every time. But waiting for a
(short) period after a node
> starts up is, I think, perfectly reasonable behaviour. Note that
there's no reason to calculate
> an MPR Set other than to report it in a HELLO message, but on the
other hand a recalculated
> MPR Set may be a reason to send a HELLO message.

********************************************************************
This email and any attachments are confidential to the intended
recipient and may also be privileged. If you are not the intended
recipient please delete it from your system and notify the sender.
You should not copy it or use it for any purpose nor disclose or
distribute its contents to any other person.
********************************************************************

---

From: "Aisling ODriscoll" <[email-masked]>
Date: Fri, 31 Aug 2007 11:23:24 +0100

Thanks to both Chris and Mathieu for the replies.

-----Original Message-----
From: Dearlove, Christopher (UK) [mailto:[email-masked]] 
Sent: 30 August 2007 15:45
To: Aisling ODriscoll; [email-masked]
Subject: RE: [manet] MPR election in standard OLSR and Clusterhead
Election inHierarchical OLSR