[manet] Re: Comments Solicitation on a new draft for MANETs

[Nour-eddine.KETTAF at uha.fr]

Hi Alicia, 

Thank you for your interest :)

>Dear Noureddine:

>I have read your draft and, as you suggested, I enclose my comments.

>In my opinion, the main disadvantage of your routing protocol is related to 
>the measurement of the QoS parameters. I mean, how can you know the channel 
>bandwidth in wireless networks? As far as I know, this parameter varies 
>with the movement of nodes. If the reservation of the resources is 
>performed, how can you assure it is maintained? Additionally, the 
>interferences of nodes should be taken into account.

The proposed protocol deals mainly with the IP layer, however, the problem of bandwidth estimation is related to the MAC layer which is not actually the scope of MANET WG. In our draft we assumed that the estimation is based on an efficient and reliable mechanism to avoid the problems related to hidden and exposed nodes. On the other hand, we provided a solution for this problem (available bandwidth estimation, mobility, interferences, etc.) I will communicate it to you asap.

>Another issue is related to the forwarding of Route Request messages. For 
>example, if node A sends a RREQ to node D and nodes B, an intermediate 
>node, receives it, it will reply to  the first RREQ it receives (according 
>to the RREQ_ID). Therefore, only one route is discovered per RREQ (not 
>including the reverse routes), and it will be associated to the minimum 
>delay. But what happens if my QoS requirements do not include any 
>restriction about delay but about Bandwidth? Maybe, it will be recommended 
>to use an alternative path.

The route request is sent by broadcast to reach the maximum possible of nodes present in the network to obtain many routes, thus, to reduce the overhead the intermediate node re-transmits the first received RouteRequest. Since the cost related to the sub-path (intermediate node -> destination) will be equal , so it is better (in our opinion) to re-transmit one instead of several route requests.

>I also wondered if you have performed any simulation work about this 
>routing protocol.

YES, 

>I hope that my comments can help you.

Thank you again, and if you have other comments, please, don't hesitate ;)

Regards,
Noureddine Kettaf




At 10:32 23/06/2006 +0200, you wrote:
>Dear members,
>
>We proposed a new draft describing a new protocol based on simple 
>mechanisms to provide QoS in MANETs.
>
>The draft is available at:
>
>http://www.ietf.org/internet-drafts/draft-kettaf-manet-acor-00.txt
>
>Please take a minute to read it and if you have any comments, please email 
>me.
>
>Best Regards,
>
>Noureddine Kettaf
>-------
>Noureddine Kettaf
>Haute Alsace University
>34, rue de Grillenbreit 68008 Colmar
>France
>
>Phone:+33 (0) 389 202 368
>Fax: +33 (0) 389 202 359
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Alicia Triviño                               / Tl. +34-95.213.71.91
Dpto. Tecnologia Electronica
E.T.S. Ing. Telecomunicacion
Universidad de Malaga
Campus Universitario de Teatinos
29071 Malaga, Spain

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