For my purpose I don't expect everybody to receive the broadcast. Therefore this solution doesn't match it. Morever, IEEE 802.11 doesn't allow RTS/CTS mechanism prior a brodcast transmission. As a consequence of this, modifications on the standard must be done and that's what I would like to avoid.
Thanks anyway.
Joan
"Philippe Jacquet" <philippe.jacquet@inria.fr>
01/27/04 10:59 AM
To: Joan Martin/ACN/RESEARCH/PHILIPS@EMEA1
<manet@ietf.org>
cc:
Subject: Re: [manet] Selective Acknowledgement
Classification:
The problem differs if you want to check that all neighbor receives the broadcast or check that at least one neighbor receives it.
For the first problem, in HIPERLAN 1, long time ago, we proposed a collision signal after each transmission. When a node receives a corrupted packet it emits a collision signal burst just after the packet. The signal is just energy and can aggregate with other signals. When the broadcaster senses signal after its packet transmission, it inferes collision and retransmits.
In IEEE 802.11 you can use the RTS CTS mechanism with broadcast. Of course there are no CTS. Therefore if the broadcaster senses signal after its RTS, then it just backoff transmission.
Philippe
----- Original Message -----
From:joan.martin@philips.com To:manet@ietf.org Sent: Tuesday, January 27, 2004 9:19 AM
Subject: [manet] Selective Acknowledgement
Hi,
Does anybody know any literature about selective acknowledgement applied to manet (802.11). Concretely, selective acknowledge in response to a broadcast transmission.
The IEEE 802.11 MAC specification does not allow acknowledging on receiving a broadcast transmission. Therefore how could I design a mechanism which ensures me that at least one neighboring node has received the broadcast message (imagine a critical application, e.g. car accident warning, in which you cannot permit a broadcast message "to be lost on the air")