Tips to extend range of Mikrotik GrooveA 52ac?

[DougMc]

Hello,
We've successfully used the Mikrotik Groove to access shore wifi from a mooring thanks, in no small part, to the Island Time PC configuration file and instructions. That's a real time-saver and well worth the small fee.

We were able to connect to shore wi-fi well enough to manage the on-line proctored covid testing for 6 people, which was quite convenient and convinced me that, although not a panacea, the system is very worth having.

We found that we could only get an IP address from the strongest signals and the range, through a mooring field, was not as long as I would like. (I know it's only wifi, but it would be nice to do a bit better)

So, now I'm looking for tips to extend the range. When operating, I hoisted the groove on a spare halyard to a bit less than spreader height and pulled it about 6 feet away from the mast and shrouds. The antenna was pretty nicely vertical.

Should I be going for more height? Should I try a higher gain antenna? If so, any particular models that seem to work well?

Best regards
Doug

[Flatswing]

Have you reached out to Bob Stewart - Island Time PC? He is very responsive & very helpful.

[DougMc]

Originally Posted by Flatswing

Have you reached out to Bob Stewart - Island Time PC? He is very responsive & very helpful.

I did, in part because I wondered if he sells or recommends an alternative antenna.

Doug

[Jammer]

You're doing everything right.


Which antenna are you using? The short fiberglass rod? The only way to get more range is to use a high-gain antenna pointed accurately at the AP. Hard to do at anchor because of swing, you get a limited arc of coverage with any high-gain antenna.


Here is an example of a high-gain antenna that will improve your range, but it has to be pointed +/- 10 degrees to see much improvement:


https://www.amazon.com/gp/product/B0...YKSDHPGL&psc=1


Parabolic antennas will give you all kinds of range on land but they can't be aimed accurately enough at sea unless you make some sort of fancy motorized mount:


https://www.amazon.com/Premiertek-Di...s%2C523&sr=8-4

[DougMc]

Originally Posted by Jammer

You're doing everything right.


Which antenna are you using? The short fiberglass rod? The only way to get more range is to use a high-gain antenna pointed accurately at the AP. Hard to do at anchor because of swing, you get a limited arc of coverage with any high-gain antenna.


Here is an example of a high-gain antenna that will improve your range, but it has to be pointed +/- 10 degrees to see much improvement:

I'm using the short fiberglass antenna that comes with the groove.

I don't want to use a directional antenna, because of swinging at anchor or on a ball, as you say. But I am curious about whether a higher gain omini antenna might be helpful.

thx,
Doug

[rslifkin]

I've been using the Groove with the included antenna on my boat. With it mounted about 13 feet above the water, I've been shocked by the range a few times. I've had a usable connection at 3/4 of a mile over open, unobstructed water on 5ghz. And over a mile on 2.4ghz.



How easy it is to achieve good range will depend on a lot of factors. Not just your antenna (for an omnidirectional setup you can do a bit better than what the Groove comes with, but not a lot). Turning up the transmit power on the Groove a little may help in some (but not all) situations. If you've got more obstructions (trees, masts, etc.) around you, they will all degrade signal. The equipment you're trying to connect to at the other end will be a big factor as well.



Keep in mind that the Groove only does 2.4 or 5ghz, not both at the same time. So make sure you check both bands to see if you can get a better connection on one vs the other. 2.4 will generally be longer range, but the airwaves are more crowded, so depending on what's around you, it can often be worse for performance than 5ghz.

[skipgundlach]

Originally Posted by rslifkin

I've been using the Groove with the included antenna on my boat. With it mounted about 13 feet above the water, I've been shocked by the range a few times. I've had a usable connection at 3/4 of a mile over open, unobstructed water on 5ghz. And over a mile on 2.4ghz.



How easy it is to achieve good range will depend on a lot of factors. Not just your antenna (for an omnidirectional setup you can do a bit better than what the Groove comes with, but not a lot). Turning up the transmit power on the Groove a little may help in some (but not all) situations. If you've got more obstructions (trees, masts, etc.) around you, they will all degrade signal. The equipment you're trying to connect to at the other end will be a big factor as well.



Keep in mind that the Groove only does 2.4 or 5ghz, not both at the same time. So make sure you check both bands to see if you can get a better connection on one vs the other. 2.4 will generally be longer range, but the airwaves are more crowded, so depending on what's around you, it can often be worse for performance than 5ghz.

We routinely connected under way as much as 7 miles out, including in the Bahamas, when open sites were common.

Ours was a 7° downtilt 8dbi omni stick antenna, and was the standard Ubiquiti early bullet from Island Time PC.

Bob Stewart is the king of customer support, and now sells the Groove products, but will offer free advice as well. rstewart@islandtimepc.com...

See his website as well; he builds marine computers (mine for well over 10 years) for boat-house supply or with a buck-boost to 19VDC if you preferred; mine used a 12VDC 24" monitor, too...

[CarinaPDX]

Ideally your antenna should be the same height as the AP's antenna - having it higher or lower, assuming your antenna is vertical, will reduce the signal. If the AP's antenna(s) is not vertical then your antenna should also have the same orientation (i.e. a vertical antenna on one end and a horizontal one on the other is not very effective).A higher gain antenna might help a bit. Directional antennas are not always the best approach.

Getting a good connection is not just about putting out the most power - that is often counterproductive as it can overload the AP's receiver, especially with a high gain antenna. It is also about a good reception, which is why antenna improvements are better than just pumping out more power. Directional antennas both concentrate your signal on transmit, and tend to exclude other signals when receiving. But with wifi there is a whole lot more than that. If your wifi client cannot receive other stations communicating with the same AP then there can be more interference and less throughput (hidden node problem) - remember, this is a shared resource and it works best when everyone plays nicely with each other. It is also an adaptive technology: while the initial connection is made at high power it is usually negotiated down to use the least power needed - again, high power is not the most important thing, working well within the cell is. Also, one of the settings within the AP is the maximum time to wait for a response, which effectively limits the range. By setting this to a low wait time the throughput can be improved, at the expense of longer range: you simply do not know what the maintainer has set this to, and if it is low and you are at a distance there is little you can do to improve things.

Ultimately I would recommend a higher gain omni-directional antenna for use at the dock or in calm water; otherwise just use what you have. You might also adjust the power output, and especially by lowering it; do not just push out maximum power through a high gain antenna (which can be illegal as well as not working well). And just accept that there are limits to the technology.

Greg

[Jammer]

Originally Posted by DougMc

I'm using the short fiberglass antenna that comes with the groove.

I don't want to use a directional antenna, because of swinging at anchor or on a ball, as you say. But I am curious about whether a higher gain omini antenna might be helpful.

thx,
Doug

Take a look at the Laird (formerly; now part of TE) antennas:


https://www.te.com/commerce/Document...pdf%7FOD24M-12


Omnis with gain in your choice of 5, 7, 9, or 12 dBi.


My advice is that you can use up to 5 dBi underway and 7 dBi at anchor and get good results. I am not sure what Microtik is shipping with the Groove but probably one of these. 9 or 12 isn't helpful on a moving platform (like a boat) because to get any improvement you have to be level within about 5 degrees for the 9 and about 2 degrees for the 12. 2 dB extra gain (of the 9 dBi antenna) translates into a very slight improvement in performance and in a calm anchorage you could achieve that. The 12 dBi antenna would IMO not provide any improvement in practice; you will get drops as a result of even the slightest motion of the boat that will create more problems than the gain will solve.


Specifically on your question about height, short answer is you want clear line of sight and beyond that height doesn't matter. A more detailed answer would be that you want to get the antenna at a height where the Fresnel zone is clear of obstructions. The size of the Fresnel zone varies depending on the distance to the AP. There's a calculator and more detail here: https://www.everythingrf.com/rf-calc...one-calculator

[Jammer]

Originally Posted by CarinaPDX

Ideally your antenna should be the same height as the AP's antenna - having it higher or lower, assuming your antenna is vertical, will reduce the signal.

This simply isn't true in most cases. With a low antenna the obstruction losses (from terrain if nothing else) are often greater than the losses due to the antenna pattern.

Getting a good connection is not just about putting out the most power - that is often counterproductive as it can overload the AP's receiver, especially with a high gain antenna.

Again, this simply isn't true with WiFi at longer distances, which is what the OP is asking about. The maximum transmit power isn't great enough to saturate the receiver at the distances of hundreds/thousands of feet that are typical of a boat in a mooring field connecting to an AP on shore.

[Redline452]

I have a 15 dB fibreglass vertical omni on a Ubiquiti M2HP (similar to the Groove, but 2.4 only). Best performance was holding up a Skype call 6 nautical miles out of Burlington VT. The antenna is about as yard long, mounted on what was supposed to be a wind gen support post on the aft arch, so about 10’ above the water.
If I was doing it again I’d probably settle for an 8dB model which would be about half the size, but it does work well. To much gain for use while heeling- the radiation pattern is so flat it only works straight fore and aft unless the boat is sitting level (which is the only time we need wifi, but it’s nice to keep my MarineTraffic feed active (we are station 1781).

[DougMc]

Thanks for the replies, everyone.
I think I'll maybe experiment with a bit more gain using a larger omni. I don't really need the system while under way, so a somewhat disc-shaped radiation pattern is acceptable.

cheers
Doug