Minimizing power is rule #2 per Paul Banan. SOME KINDERGARTEN RULES (written in 1994)
To take the fullest advantage of our new technology with its sharing of a common resource requires that our smart transmitters and receivers cooperate. This may sound complicated, but the rules to make maximum effective use of the shared band are simple -- primarily a matter of common decency in sharing resources. The rules are somewhat similar to those you learned in kindergarten, assuming you lived in a tough neighborhood. Rule #1. Keep away from the big bullies in the playground. (Avoid the strongest signals.) Rule #2. Share your toys. (Minimize your transmitted power. Use the shortest hop distances feasible. Minimize average power density per Hertz.) Rule #3. If you have nothing to say, keep quiet. Rule #4. Don't pick on the big kids. (Don't step on strong signals. You're going to get clobbered.) Rule #5. If you feel you absolutely must beat up somebody, be sure to pick someone smaller than yourself. (Now this is a less obvious one, as weak signals represent far away transmissions; so your signals will likely be attenuated the same amount in the reverse direction and probably not cause significant interference.) Rule #6. Don't get too close to your neighbor. Even the weakest signals are very strong when they are shouted in your ear. Rule #7. Lastly, don't be a cry baby. (If you insist on using obsolete technology that is highly sensitive to interfering signals, don't expect much sympathy when you complain about interfering signals in a shared band.) Bob On Thu, Aug 30, 2018 at 12:12 PM bkil <bkil.hu...@gmail.com> wrote: > Full-duplex still needs some work, but there is definite progress: > http://www.ti.rwth-aachen.de/~taghizadehmotlagh/FullDuplex_Survey.pdf > > https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/TR-1.pdf > https://sing.stanford.edu/fullduplex/ > > https://spectrum.ieee.org/tech-talk/telecom/wireless/new-full-duplex-radio-chip-transmits-and-receives-wireless-signals-at-once > http://fullduplex.rice.edu/research/ > > On Mon, Aug 27, 2018 at 9:46 PM Jonathan Morton <chromati...@gmail.com> > wrote: > >> > On 27 Aug, 2018, at 10:11 pm, Bob McMahon <bob.mcma...@broadcom.com> >> wrote: >> > >> > I guess my question is can a WiFi transmitting device rely on primarily >> energy detect and mostly ignore the EDCA probability game and rather search >> for (or predict) unused spectrum per a time interval such that its digital >> signal has enough power per its observed SNR? Then detect "collisions" >> (or, "superposition cases" per the RX not having sufficient SINR) via >> inserting silent gaps in its TX used to sample ED, i.e. run energy detect >> throughout the entire transmission? Or better, no silent gaps, rather >> detect if there is superimposed energy on it's own TX and predict a >> collision (i.e. RX probably couldn't decode its signal) occurred? If >> doable, this seems simpler than having to realize centralized (or even >> distributed) media access algorithms a la, TDM, EDCA with ED, token buses, >> token rings, etc. and not require media access coordination by things like >> APs. >> >> The software might be simpler, but the hardware would need to be >> overspecified to the point of making it unreasonably expensive for consumer >> devices. >> >> Radio hardware generally has a significant TX/RX turnaround time, >> required for the RX deafening circuits to disengage. Without those >> deafening circuits, the receivers would be damaged by the comparatively >> vast TX power in the antenna. >> >> So in practice, it's easier to measure SNR at the receiver, or indirectly >> by observing packet loss by dint of missing acknowledgements returned to >> the transmitter. >> >> - Jonathan Morton >> >> _______________________________________________ >> Make-wifi-fast mailing list >> make-wifi-f...@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/make-wifi-fast > > _______________________________________________ > Make-wifi-fast mailing list > make-wifi-f...@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/make-wifi-fast
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