CSMA/CA with and without RTS/CTS

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Күн бұрын

The wireless protocol CSMA/CA (Carrier Sense Multiple Access/ Collision Avoidance) is really important for reducing the number of data collisions in WiFi. An extension of it, with Request to Send and Clear to Send messages, can reduce the problem of 'hidden nodes'.
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Пікірлер: 17

@llucas9158 5 жыл бұрын

Your videos are so awesome, and it helped me a lot!!!

@michaelmorris7190 Жыл бұрын

You forgot about the random back off timer. This way both node won't send a request to send. When the node with the selected back off timer is selected. It sends a RTS. This is how nodes don't send data at the same time.

@Jasmine-tr7yf 5 жыл бұрын

Thank you!! :)

@happyshyy 5 жыл бұрын

Thanks for nice video. But I am wondering about transmitting frame in the idle state. When I watched other video about csma/ca, the station do 'carrier sensing' process before transmitting the frame. And after IFS period, transmitting STA generates random back-off period to avoid collision. However, when the media state is idle, I cannot find out the part of generating back off delay from your video. Please explain about this process in detail.

@sirorco1 3 жыл бұрын

Thanks !

@annaphuong3260 5 жыл бұрын

What if CTS is lost? Let's say device 1 get the CTS, but device 2 doesn't know about this. So device 2 sends a RTS while device 1 is transmitting its data. Will we still have a collision?

@michaelmorris7190 Жыл бұрын

No because there is data transmitting before the RTS the network must be idle. No data passing.

@anhhieu1928 3 жыл бұрын

Consider CSMA/CA protocol in Wifi networks that working in adhoc mode. Can you evaluate the performance of the protocol without RTS/CTS scheme when the number of nodes within a communication range increases from 2 to 30.

@viethoang1730 2 жыл бұрын

Ô ơi ô có câu trả lời cho cái này ko

@ammaarhtc 5 жыл бұрын

What is the difference between a virtual and physical machine. Any advantages and disadvantages. Do u have a video on this

@ComputerScienceTutor 5 жыл бұрын

Bit of an old video but it's mentioned at the start here: kzfaq.info/get/bejne/l82BhquXrc7ain0.html&ab_channel=ComputerScienceTutor.

@ammaarhtc 5 жыл бұрын

I forgot to say but thanks.

@S3Kglitches 4 жыл бұрын

How long is the waiting for ACK before the sender node decides that the data has not been delivered?

@pront5208 3 жыл бұрын

He said it can be dynamic and can be calculated based on the current congestion of the network.

@mixvideos1202 2 жыл бұрын

can somone please answer my simple question how can c and b sense each other? through what

@Flomaster10000 4 жыл бұрын

Dude, this is just wrong. If the channel is idle you do not send immediately. You first wait a random amount of time, called Inter Frame Space (IFS). This way, you avoid collisions with data that is already sent, which have not received yet. Then, you pick a random number of slots of the contention window. This way, if multiple senders want to transmit something, they do not collide which each other.

@ComputerScienceTutor 4 жыл бұрын

Yes, but this is above the level this video is intended at