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[benji09]

 I notice nobody has come back to you on your last comment.  I have dealt with V24/V28 interfaces in the past, which do have the RTS,CTS,CD etc connections, but does ethernet have the equivalent protocols that provide this facility. Assuming it does, what would you be wanting to do with it if it exists. Were you thinking of using it to turn off or on, your garden link to the outhouse remotely?

[Weaver]

That isn’t ethernet it’s 802.11 which has CTS/RTS protocol messages as an option; yes it is familiar from the days of RS232, but now these are Wi-Fi-specific. Ethernet flow control is something else. And this is not flow control like in RS232, it’s more like ‘permission to talk’ like token ring so there is no chaos of collisions any more for packets greater than a certain length, for those longer packets you wait until it’s ‘your turn’. It is to address the hidden station problem, where a station might be 2 radii away, a whole diameter, so it can hear the AP but not the station in the far side so that collisions get out of control and switching to a time-managed system is the way of sanity. It can be omitted for very short packets, where the risk of collisions is less because of the short length, and the relative cost of the CTS/RTS overhead would be really high compared with the small amount of payload data being delivered. My kit has a configurable packet length threshold for the point where it is to apply this technique selectively.

[Alex Atkin UK]

One thing comes to mind, I would have a bad hidden station problem, so would want to force RTS/CTS or whatever it’s called

I'm confused, why would you have a hidden station problem?

[Weaver]

I could have one if I have a station in the garden, an omni AP in the office window and a distant station inside the hiuse in the opposite side to the garden, such as in the kitchen. Then the device in the garden would have little chance of hearing the station indoors on the far side of the inside of the house, so a classic hidden station problem. You lose a little performance because of the protocol overhead but it’s more predictable than having a lot of undetected collisions, so the worst case is less bad. And you can tune it on good APs to set the triggering minimum PDU length length threshold for it to kick in only for the longer PDUs, which present a bigger collision risk and a greater cost of corruption due to much larger amount of lost data from that big payload when one PDU is corrupted by a collision and we then also have a longer period of having to wait while the garbled PDU keeps on going past. I have tried 256 bytes, instead of - whatever - 2347 bytes max [?] (what is it?) not sure where the optimum lies.

[Alex Atkin UK]

Well you'd put them on different channels.

Plus as has already been pointed out, if this is only for the Internet, I doubt you'd even notice a problem as the WiFi speed should be vastly faster than your broadband is.

This is obviously also another benefit of having a directional outdoor WiFi antenna, less signal will actually make it indoors and you've a better chance of 5Ghz working so can avoid clashing channels more easily anyway.

[Weaver]

In any case a directional antenna is almost a must, the only option that makes sense. I don’t have any such kit though; it would mean some research, recommendations.

The system is not only for internet access; occasionally there is inter-station traffic, when Janet sends me a picture directly across the WLAN for example and I’m thinking about getting the Raspberry Pi going as a little file server. I currently get 300 Mbps across the 802.11n WLAN. If I ever get the Cisco WAPs going, which I can do now I’ve been offered help with them, then I can get much much higher speeds in 5GHz than the limits of this depth of MIMO and 802.21n’s limits will allow, using 802.11ac wave 2’s capabilities instead.

I need to look into the Mikrotik kit mentioned earlier, was it? I’ve always been a but if a fan, not that I know too much about it, I’ve just read a few snippets of the bumph.

[benji09]

  Alex has said it all. I had a quick look at the Mikrotec site the other day, and if I read it correctly, the 5Ghz channel used was way outside even the extended WiFi range. Therefore a computer would not even accidentally lock onto the channel used by the dish. Probably a mast mounted dish would be easier to fix, than drilling your stone walls. It need not be too high up, only enough to be clear of people or stray sheep blocking the xmission path. As far as your interstation traffic is concerned, fine having greater than 300 Mbs or more WiFi, it is nice to have, but do you really need it?  One photo would take 6 times as long at say 50Mbs. That would mean your photo would take maybe 1 minute instead of 10 seconds. Would this time scale really matter to you?  You were previously worried about WiFi congestion from your neighbour.  By selecting a lower speed, the number of carriers your router is transmitting to carry your data is half the number a wider channel would be transmitting. So for the same transmit power, your signals are twice as strong  ( +3db ). Also, if the routers DSP is carried out correctly, your received bandwidth would also be half as much as the wide bandwidth signal. Half the bandwidth means half the received noise  ( 3db down ), meaning your WiFi signals appear 6db higher above the noise level than would otherwise have been. If your new neighbour goes wideband, you may still move your channels away from him, and also your signal in your home should be well above any potential interference. I hope my post makes sense, and also accurate logic............     

[Alex Atkin UK]

The Wireless Wire uses 60Ghz, there's practically zero chance of crosstalk at such a high frequency but it would need perfect line of sight.

The only question is, exactly how far can it reach as they mention the rather ambiguous 200m or more.

[Weaver]

60GHz - excellent. Wonder if it will go through glass?

[benji09]

 Weaver, If 10Ghz from a satellite to a high gain dish behind a window does not work, I would have thought that 6x that frequency would be unlikely. Obviously the signal from down your garden would be higher strength, but I would not think it would work. But you could try it. Anyway, I would have thought a dish aerial in your home might be inconvenient. It was for this reason, in an earlier post, I suggested a link using the lower 2.4Ghz frequency which might be more reliable way to go, due to the lower path loss and also lower attenuation through the glass.
  I think BT was also looking at a short range 60Ghz distribution system in the past.

[Alex Atkin UK]

I think part of the reason it can perform so well is it basically will pass through nothing, so its not going to cause crosstalk with anyone nearby but need absolutely clean line of sight.

[Weaver]

I love the Wireless Wire kit, but cannot mount an external antenna easily: gale force winds every few months rip such things off and that corner of the house is the most exposed unless I could put up some form of physical wind-shield to the right hand side of the antenna, plus there’s the problem of how to get outside which isn’t unsolvable because the DSL comes in through the upstairs roofline in that corner- the southeastern corner of the office, directly facing the summerhouse. It’s a bit too high up although not the end of the world; could run the cable down the outside concrete wall. The killer problem is wind, it wouldn’t last five minutes. So I’ve always thought about something behind glass as I did before with the 5GHz TP-Links.

[meritez]

The Wireless Wire uses 60Ghz, there's practically zero chance of crosstalk at such a high frequency but it would need perfect line of sight.

The only question is, exactly how far can it reach as they mention the rather ambiguous 200m or more.

I've read reports of 5Km using the 5ghz dishes

[Weaver]

And zero chance of it working behind glass over 50m or so? Might be able to avoid being behind glass at the one end. Our satellite installer could run some sort of cable outside to an antenna and my good neighbour might be able to shield it on the right = south and west. The house itself is a shield to the west, would need shielding from the south and the line of sight from the house to the summerhouse is a little to the south of east, or to the east of southeast. Haven’t used a compass. At the summerhouse, the antenna would be facing northwest on the north wall, so 100% sheltered by the summerhouse itself. The summerhouse is basically a shed with lots of glass. Its doors face east and there is glass on the east north and south sides with no windows on the west ‘back’ side where it is exposed to the elements. It is slightly lower than the house.

[meritez]

And zero chance of it working behind glass over 50m or so? Might be able to avoid being behind glass at the one end. Our satellite installer could run some sort of cable outside to an antenna and my good neighbour might be able to shield it on the right = south and west. The house itself is a shield to the west, would need shielding from the south and the line of sight from the house to the summerhouse is a little to the south of east, or to the east of southeast. Haven’t used a compass. At the summerhouse, the antenna would be facing northwest on the north wall, so 100% sheltered by the summerhouse itself. The summerhouse is basically a shed with lots of glass. Its doors face east and there is glass on the east north and south sides with no windows on the west ‘back’ side where it is exposed to the elements. It is slightly lower than the house.

https://mikrotik.com/product/wap_60g_ap

Ap for the wall, outside

https://mikrotik.com/product/wap_60g

CPE end can be used indoors, good for 200 metres, what kind of glass?

The link will even work through most windows, depending on their material

https://mikrotik.com/product/wireless_wire