Subject: Re: node routing status

From: Ken Carlberg <[email-masked]>
Date: Thu, 17 Feb 2000 18:44:37 -0500

> We can 
> envision allowing users to stop routing if their remaining battery 
> power falls below a certain threshold, but how should this problem 
> be handled otherwise?  

caveat:  the following is just a casual thought inspired from some other
unrelated work, so i'm sort of speaking off the top of my head (and from 
left field.... :-)

but, what if you use (or add to the mix) a probabilistic approach decided
by the first member of the group?  by this i mean something like this:

  - first node active in the group uses a default (configurable) parameter 
    that states that X% (e.g., 33%) of all nodes act as routers.
  - when a subsequent node become active, antecedent(s) informs it that
    the policy is that 33% of nodes are routers.  
  - the new node then generates a random number to see if its to be a
    router or not

one can do variations to the theme, but what is attractive (to me :-) is 
that its a simple way of determining policy and having a starting reference 
point by which one can evolve.

the downside is that it takes away a measure of control of ones own 
resource, but that may be the price to pay in order to play in a 
particular area.

cheers,

-ken

---

From: Nick Triantafillis <[email-masked]>
Date: Fri, 18 Feb 2000 00:59:32 +0000

>  - the new node then generates a random number to see if its to be a

That doesn't achieve fairness throughout the network and maybe it will make
things worse if there isn't a way of relieving occasionally those hosts from
their "routing duties". I would imagine it will also generate more partitions
in the network and its performance will decay as a result of that.

Perhaps a better approach would be some sort of voting scheme were >1 nodes
will decide on that percentage and on who is going to act as a router. After a
certain period of time the routers turn off routing gradually and the rest
take their place as long as the network doesn't become partitioned.

Regards,

Nick

---

From: Ken Carlberg <[email-masked]>
Date: Fri, 18 Feb 2000 08:14:03 -0500

> That doesn't achieve fairness throughout the network 

could you define fairness in this context?  The term is used a lot and
so can be overloaded with different meanings.

> and maybe it will make

anything less than having all nodes act as potential routers can lead
to partitions and/or decay in performance.  but yes, the approach is 
non-deterministic that sort of demands an evolving strategy to accompany 
it.  by the same token, the nature of ad-hoc networks is that conditions 
can/must be expected to change over time.  the trick is to have an easy
starting point which evolves and can work under extreme conditions -- e.g.,
all nodes coming up at the same time versus gradual activation of nodes.

> take their place as long as the network doesn't become partitioned.

voting can be interesting.  if some variation were to be explored, my desire 
would be to constrain it to subsets of nodes, as opposed to system-wide.

cheers,

-ken