D: now you can get much more speed than speedier interfaces than this one ,
D: but the thing is , uh , that we are assuming that for a given transmission , we can uh consider the network as if it were built of a set of static nodes .
D: OK ?
D: Motion will be important for routing ,
D: but for the media access control level , we are considering that motion can be con is not is not important .
D: OK ?
C: Yeah , what I think Maybe some , uh cases why I go this way with my node , and suddenly , I s go out of the scope of the transmission area ,
C: because it 's really a random movement .
C: Then I still hear C: this is during the data transmission .
D: Yeah , but again again , what we are adding with this behavior is , uh uh a little bit more , probably some some uh small part to the uh bit error rate .
C: Yeah ?
C: then D: OK ?
D: Maybe this frame will won't be received properly , and , should eh have to be eh dropped ,
C: Oh , yeah .
D: but anyway ,
D: eh even if nodes are completely static , eh some problems will happen in the wireless transmission ,
D: so
D: we won't have a hundred percent eh perfect eh channel anyway .
C: Yep .
C: Right .
D: So eh if this problem , as you show it probably it 's it 's eh  Y you can you can see that it is not very likely to happen ,
D: because you you you eh have to consider the probability that o of happening this C: Nee .
C: That 's really right ,
D: Hmm ?
C: but what I would like to say is that besides the RTS CTS behavior , you need certain kind of additional MAC layer functionality to deal with these packet .
D: Hmm - hmm - hmm .
C: For example , with transmission or or whatever ,
D: Yeah ,
D: sure , sure .
C: for whatever control , or whatever kind of things , you know .
D: In fact in fact , you know I I I I I maybe I I I had to to prepare a more detailed eh , view ,
D: I I just was trying to do something soft ,
D: not to to bore th the public
D: but of course there are a lot of other smart eh things that are built in , in these protocols ,
C: Right .
C: Yeah .
D: like for example , an automatic , uh acknowledgement .
D: Some protocols used uh in the same way as this RTS and CTS packet some of them use , an eh acknowledge from the receiver ,
D: which is also a short packet ,
D: so you you are getting some kind of link layer uh acknowledgement scheme
D: which can save a lot of data transmissions
D: because eh usually when you send a  a a a frame , you will want to some kind of acknowledgement back .
D: So , if this acknowledgement has to go through the process of a new RTS and a new CTS , well , this takes longer than just a link layer uh , extra packet .
D: That , of course uh is also contemplated in this eh packet length length or included in the RTS and CTS packets ,
D: so , eh , you know , everybody can wait until this uh acknowledgement is also transmitted by the receiver .
D: So
D: in fact , eh nnn some people proposing this mechanism is is showing a a b a big improvement
D: and eh there are a lot of other mechanisms , also regarding and a time - out mechanism , or the time - out algorithm for these retries when you try to send something and you don't succeed , uh , what what you the amount of time you have to wait until you retry again .
D: Well , uh , some people is also proposing different things , different eh algorithms with different results .
D: So , in fact , there are a lot of good D: I just was trying to present a you know the main ideas .
D: So , I I I you know , ask uh You Feel free to ask uh whatever you want ,
D: but I I want to insist that it was just an uh a simplified uh version , a light version .
D: OK ?
D: well , uh you know finally this algorithm , eh , as I was telling , eh what it 's doing is to check with the receiver the power level to be used .
D: And it is very simple to see that some advantages can some advantage can be obtained ,
D: because the difference is eh if you don't have power control , you are using all the time the maximum power ,
D: if you have power control , sometimes you will use less than the maximum power
D: How often do you use less power than the maximum ?
D: Well , this will  this will be connected to the motion pattern .
D: OK ?
D: Depending how nodes are moving ,
D: well maybe all the time all your neighbors are at the maximum distance
D: But , this probably , doesn't l look like uh something very very uh  very likely .
D: OK ?