ACK for Broadcast Message with 802.11 & 802.11p [closed]

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I'm aiming to do some Network Simulation (specially VANETs) with Omnet++, Mixim Project & Sumo.

Some one can give me more clarification about broadcasting message with 802.11, i.e what i want to know is "When performing broadcast message, is there any ack with 802.11 ? "

Currently what i know is regarding the 802.11p version who currently didn't perform any ack for broadcasted messages.

Thanks for all guys.

Answer 1

ACKs under 802.11 in general and 802.11p more specifically work as following (for a sender X and one or more recipients Y,Z)

• UNICAST: X sends a message and triggers a timer, Y receives the message and sends back an ACK, if the ACK is lost or not received before timer expiry then X retransmits the frame
• BROADCAST: X sends a message but does not trigger any time. Upon receipt, Y does not send an ACK. Indeed, in Broadcast mode, there are no Timers nor ACKs.

Answer 2

As you said there is no ack for 802.11 because the protocol is UDP. You can have broadcasting and information about each node packet transmission. Could you please to say your problem very clear. broadcasting is based on your routing protocol. some is unicast and some else broadcast. however, beacon messages are always broadcasted.