Long Range WiFi -- Posting right now using "long range" wireless

[sailingdog]

At longer distance, the vertical beam angle is less of an issue. It is really only at shorter distances that it is a significant issue. The further you are from the WiFi hotspot, the more height the vertical beam angle will cover.

[Bene505]

Originally Posted by richardhula

Hmm I think that might be an issue with your machine. My Bullet is left on permanently at the moment. As soon as my laptop boots up or its brought out of sleep mode, it connects. This is true with direct LAN connection or with my present setup, Bullet->802.11n WLAN router->laptop WLAN adaptor.

In that case, you may have to power-up the Bullet after powering up the router. When I directly connect the laptop (via wires), I have to power up the Bullet last. The same thing may be happening with a direct connection to the router. Not sure. It is certainly no big deal though.

Regards,
Brad

[DropTop]

Originally Posted by sailingdog

At longer distance, the vertical beam angle is less of an issue. It is really only at shorter distances that it is a significant issue. The further you are from the WiFi hotspot, the more height the vertical beam angle will cover.

correct, but the closer you are the stronger the signal will be, and the more signal reflection you will have, so you will still have a useable signal, even if each side's antenna is not in the focused part of the beam. Plus the beam widths are not hard edges, look at a antenna RF radiation patterns in the specs and you will see that there are significant amounts of RF energy being pumped out in other directions beyond the advertised beamwidth. look at page 2 of the PDF linked below for an example.

http://www.streakwave.com/mmSWAVE1/Video/Pawod24-v2.pdf

[Bene505]

Originally Posted by sailingdog

At longer distance, the vertical beam angle is less of an issue. It is really only at shorter distances that it is a significant issue. The further you are from the WiFi hotspot, the more height the vertical beam angle will cover.

That's true if your antenna is at a different height that the shore-side antenna. If there are surrounding cliffs, for instance with houses on top.

That's less true is you are purely concerned about pitching* at anchor. Then extra beamwidth will really help you. I find that our boat doesn't pitch that much usually. (50' boat, 10 foot water depth, 3 miles of fetch, monohull.) But the 30 foot boats around us have pitched up and down 20 degrees from horizontal in a blow. (Remember Mainsails videos of anchorages up there?) That's not the normal conditions at the anchorage, but it is a time when you would want connectivity to see where the storm is going.

As another thought on this, the TCP/IP protocols have some provision for lost packets, IIRC, so if you have the occasional extra pitch, you may still have service -- it simply retransmits that part of the packet that was lost.

Boats usally don't rock (actually roll) at a mooring/anchor as much as they simply pitch with the approching wind swell. That is, unless you are exposed to swells at your anchorage, in which case you may actually need a big verticle beamwidth to accomodate more intense rolling.

I believe that for 95% of what I need, a high-gain, omni-directional antenna works best. 12 db is great. I'd go even higher (and narrower beamwidth) if I could.

Regards,
Brad

[sailingdog]

Originally Posted by Bene505

That's true if your antenna is at a different height that the shore-side antenna. If there are surrounding cliffs, for instance with houses on top.

That's less true is you are purely concerned about pitching* at anchor. Then extra beamwidth will really help you. I find that our boat doesn't pitch that much usually. (50' boat, 10 foot water depth, 3 miles of fetch, monohull.) But the 30 foot boats around us have pitched up and down 20 degrees from horizontal in a blow. (Remember Mainsails videos of anchorages up there?) That's not the normal conditions at the anchorage, but it is a time when you would want connectivity to see where the storm is going.

As another thought on this, the TCP/IP protocols have some provision for lost packets, IIRC, so if you have the occasional extra pitch, you may still have service -- it simply retransmits that part of the packet that was lost.

Only for TCP connections, not UDP ones.

Boats usally don't rock (actually roll) at a mooring/anchor as much as they simply pitch with the approching wind swell. That is, unless you are exposed to swells at your anchorage, in which case you may actually need a big verticle beamwidth to accomodate more intense rolling.

I believe that for 95% of what I need, a high-gain, omni-directional antenna works best. 12 db is great. I'd go even higher (and narrower beamwidth) if I could.

Regards,
Brad

This is why I generally recommend a NS2 type device rather than a Bullet with Omni setup for most monohulls.

[DropTop]

Originally Posted by sailingdog

Only for TCP connections, not UDP ones.

true, but the transmitting radio will retransmit frames that don't get ack'd by the receiving side regardless of what transport protocol is being used (it happens at layer 2, TCP/UDP packets start at layer 3). The number of retransmits varies based on the vendor, but a typical value is 4 retransmits before the frame is dropped.

this means that even UDP packets that are dropped on the wifi link will be retransmitted (at least a few times), just with a little delay.

[Bene505]

Originally Posted by sailingdog

...This is why I generally recommend a NS2 type device rather than a Bullet with Omni setup for most monohulls.

Don't multihulls rock more in a swell?

Besides that, is the NS2s omnidirectional? You definitly want omnidirectional, unless you are the type of person that aims your solar stick every couple hours. Or if you want really really really long range on windless days and don't mind periodic aiming.

Regards,
Brad

[richardhula]

Originally Posted by Bene505

Besides that, is the NS2s omnidirectional? You definitly want omnidirectional,
Regards,
Brad

NS2's have dual polarization 10-11 dB gain antenna with about 55° beam width horizontal & vertical, so probably better than bullet/omni IF pointing roughly in the right direction.

They just don't look right on a boat though

[hardin45lover]

Sounds like all of these work better then my crappy SKYMATE and the wont even return mails or calls BEWARE!

[sailingdog]

Originally Posted by Bene505

Don't multihulls rock more in a swell?

Generally, no. Unlike monohulls, the extreme beam and initial stability of the multihull generally limits rocking to a fairly small motion. I've been in anchorages where the incoming swell made it very uncomfortable for monohulls, to the point where some would weigh anchor and leave for another anchorage. If the swell is just at the right frequency, you can get a monohull to really roll a lot, if the swell and the boat are at the boat's resonant frequency.

Besides that, is the NS2s omnidirectional? You definitly want omnidirectional, unless you are the type of person that aims your solar stick every couple hours. Or if you want really really really long range on windless days and don't mind periodic aiming.

Regards,
Brad

The fact that the NS2 covers about 60˚ of horizontal angle means that unless the wind or current really shifts, there is not a lot of need to re-point an NS2.