Archived posting to the Leica Users Group, 2018/04/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Brian, I had been told that repeaters/extenders are not the way to go and you have explained why very well. Do you have an opinion on these new 'Mesh' routers? --Bob On Sun, Apr 22, 2018 at 4:42 PM, Brian Reid <reid at mejac.palo-alto.ca.us> wrote: > In a technologically perfect world, everything would be connected with > wires. They are fast and reliable. > > WiFi is a convenient substitute for short wires, but it is not magic. If > the WiFi sending and receiving unit have trouble talking to each other, > they will slow down in the hopes of making it work. > > WiFi repeaters/extenders are a really bad idea. Here's why. > > Suppose you have devices A and B trying to talk to each other. A sends a > message and B receives it. If, perchance, B is trying to send a message at > the same time, then A's message does not get through and A has to try > again. //??So does B, because its transmission was stepped on. > > If A and B are far apart and both of them are trying to send something, it > can be a factor of 10 to 20 slower than it ought to be, because the > airwaves are busy and unreliable and both ends are gyrating to find a time > slot in which it is safe to send. > > Now add a single extender, M. A sends to M and M sends to B. The > transmission pattern goes like this: > > A sends to M > M sends to B > > this occupies exactly twice as much air time as A sending directly to B, > so now a single transmission uses two slots instead of one. So if B is > trying to send, there are two opportunities for interference, one with the > A-M transmission and the other with the M-B transmission. > > When you print, the printer needs to respond that it has received that > lump of data and is ready for the next one. So the conversation ought to go > like this: > > A to B: here is some data > B to A: thanK you. Send more. > A to B: here is some data. > > If you have a repeater, the conversation goes like this: > > A to M: here is some data for B > M to B: here is some data > B to M: thank you. Send more. > M to A: thank you. Send more > A to M: here is some data > M to B: here is some data > > If there is another computer in the mix, that is neither A nor B, then it > is also trying to find a time slot that is not being used. The use of a > repeater doubles the number of time slots needed for a conversation. > > I run wires as close as I can get them to where the computers and printers > are, and then I use WiFi for the final connection. > > Also, all WiFi is not created equal. If you have a WiFi router that is > older than 3 years you should drive a heavy truck over it. Unless you are > an expert you should use WiFi routers that employ the 802.11ac protocol. > That's "ac", not"ad" or "af" or "n" or anything else. "ac". Don't buy > "802.11ac Wave2"; it is not ready for general use. > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >