best firmware for long range transmission?

[anoukaimee]

Your agreement with your friend to consensually share one ISP account is probably contrary to the ISP's service agreement, but I'm not telling. However, stealing Wi-Fi from the coffee shop is not a good idea.

It's a notorious cable company with a horrible reputation on broadband fora and with almost all of its clients, so I couldn't care less. They've screwed me to the tune of $200 over the past six months (charging me for a modem when they had on record that I had my own, etc.). They're an absolute snake oil racket, and even if it is in violation of their agreement, they've violated their agreement with me (and probably every other client with whom they contract, to one degree or another).

And just to clarify: I never implied I meant to "steal" from a coffee shop, etc. I was just repeating the hypothetical (which, albeit, did indeed seem to suggest it was acceptable example to steal wifi) of range gain and the means to do so. That's an absolute no-no in my book, but as far as I'm concerned, if my friend is overpaying a totally disreputable ISP that has a monopoly in this market, and generously willing to share his bandwidth because I am on a fixed income, I'm thrilled to do it.

Thanks for the caution though--sincerely, I do appreciate it.

 

[anoukaimee]

Given the size of your building, an easier solution IMO is that: bring your RT-AC56U to your friend's place. Locate a few candidate spots that are convenient as well as providing good WiFi coverage at his place. Then bring your smartphone (with Acrylic) back to your apartment. For each candidate spots in your friends' apartment, locate the sweet spots in your place that give you the strongest signal.

Thanks. That would definitely be the easiest solution, but do you really think that would be as effective as getting a high gain omnidirectional antenna? We are now having BIG problems sharing--I'm getting almost nothing and not able to stream on my Roku.

Reading that I can take apart the AC56U and install antenna, it is something I am willing to try... actually pretty good at hardware stuff. Or if find too hard, willing to splurge for a new router with antenna for his apartment and then an omnidirectional antenna to to attach to it, if needed, and then use the AC56U as a repeater (or bridge?) in my apartment.

Optionally, I've been looking at these antenna, and some seem mounted in different ways. Almost all screw in to replace an existing antenna, but others seem to attach differently. But I'm not really clear how. Most often they attach to or sit in the window. Wondering if there is any antenna of the type that can be attached to a source router by USB or ethernet?

I have also found this antenna that attaches to the computer http://www.radiolabs.com/products/wireless/networking/high-gain-wireless-kit.php, but the price point is totally prohibitive (plus a big pain since I have a laptop, and I'm not sure that it would help with peripheral devices like my phone and Roku). Would a high gain antenna attached to my computer be of any help? Or if I installed a high gain antenna to a new router in my apartment help--does it need to be at the ISP source connection point, or can it be at the remote site?

Thank you! Finally beginning to understand this (a little).

 

[anoukaimee]

The downside to high gain antennas is that it also makes the AP more prone to interference from adjacent networks, and that the benefit is only one way - e.g. more gain (or higher power) at the AP just unbalances the link, the clients need to change as well.

Would installing high gain antenna on both ends overcome this? They are extremely cheap from what I can see.

 

[sfx2000]

Also drivers allow users to adjust TX power on WiFi cards. How does that play in the TX power control algorithm? Apparently the adjustment can reduce/increase max tx power allowed within regulations that can offset the auto reduction effect in your argument (?).

Interesting tidbit - Drivers might allow people to turn up power, but only to a certain limit - the Chip is hardcoded by the region to limit power in any event, at least for Broadcom, which is what is currently in discussion on this thread...

https://www.broadcom.com/docs/linux_sta/README.txt

This is for the linux driver, but the Windows and Mac drivers behave the same, as the RTOS inside the chip is the same, and that's where the limit is set.

TX POWER EXPLAINED
------------------
'iwconfig eth1 txpower' & 'iwlist eth1 txpower' set and get the drivers
user-requested transmit power level. This can go up to 32 dbm and allows
the user to lower the tx power to levels below the regulatory limit.
Internally, the actual tx power is always kept within regulatory limits
no matter what the user request is set to.

Interesting, eh?

 

[sfx2000]

Would installing high gain antenna on both ends overcome this? They are extremely cheap from what I can see.

Not really... as they increase everything, noise and good signal, so it's generally a net zero, and can actually impair performance by increasing the number of adjacent networks that you are not associated with.

 

[ColinTaylor]

Not really... as they increase everything, noise and good signal, so it's generally a net zero

I see this as the fundamental disagreement between yourself and @dlandiss. Surely the whole point of a high gain antenna is to increase the signal strength without substantially increasing the noise* (i.e. an increase in the SNR). At least it used to be when I was studying for my radio exams. If that were not the case, then by your argument there would be no need for anyone to create anything other than an Omni-directional antenna.

*Assuming the antenna is properly constructed and tuned.

 

[dlandiss]

I see this as the fundamental disagreement between yourself and @dlandiss. Surely the whole point of a high gain antenna is to increase the signal strength without substantially increasing the noise* (i.e. an increase in the SNR). At least it used to be when I was studying for my radio exams. If that were not the case, then by your argument there would be no need for anyone to create anything other than an Omni-directional antenna.

*Assuming the antenna is properly constructed and tuned.

Colin, "it all depends" (as I am sure you have heard before!

We should consider the two major roadblocks: Noise and Interference.

Interference will remain the same unless one of the signals is so strong that it overloads the receiver. If you boost the Desired Signal and the Interfering Signal by the same amount, the ratio Desired/Interfering remains the same. Interference from radios significantly higher or lower in altitude than the router will be reduced because the gain antenna sacrifices coverage above and below in favor of better coverage horizontally.

Noise has two more categories: Internal and External. External Noise will again be increased by the same multiplier as the Desired Signal, and so their ratio will not change. Internal Noise (thermal noise, shot noise, popcorn noise) will not experience the gain since they come inside the silicon circuits after the antenna. Therefore the portion of the Signal/Noise ratio due to Internal Noise will be improved.

As another frequent poster here says, it ain't all predicted by theory. In practice incidents crop up that we did not anticipate and so did not include in our theory. And in practice gain antennas on my access point more than doubled performance in a brick outbuilding 62' away.

 

[ColinTaylor]

Thanks @dlandiss . I follow that from the perspective of the just the receiver. But I was thinking of it in terms of where the transmitter has a high gain directional antenna pointed at the receiver. The receiver sees the same noise and interference but the transmitter's signal has increased. Or am I missing something obvious.

 

[dlandiss]

Thanks @dlandiss . I follow that from the perspective of the just the receiver. But I was thinking of it in terms of where the transmitter has a high gain directional antenna pointed at the receiver. The receiver sees the same noise and interference but the transmitter's signal has increased. Or am I missing something obvious.

Good point! How did I miss that?

Be careful about "directional." All antennas beyond isotropic are directional. In a vertical dipole the maximum signal strength will be right angles to the antenna--thus the radiation patterns attached to post #4. What the "gain" antennas do is flatten that pattern, stealing signal from above and below and redirecting it horizontally (still assuming vertical dipoles). In 3 dimensions the pattern looks like a doughnut (attached).

There are other forms of high gain antennas which concentrate the energy even more--see Yagis, log periodics, parabolic reflectors, etc. The DirecTV dishes on people's roofs are parabolic with enough gain to receive a 10-watt or so transmission from 22,500 miles up.

 

[ColinTaylor]

Thanks dlandiss. Post #23 referred to "high gain antenna on both ends" so I had in my mind two directional (i.e. Yagi, panel, grid) antennas pointed at each other. Basically, wireless point-to-point. That was probably a mistake as he was probably talking about dipoles with a "flattened donut".

Back in the day, when I was making my own 2-meter antennas, I also found that theory and reality rarely aligned. You can get some interesting reflections off of all sorts of things.

 

[dlandiss]

Back in the day, when I was making my own 2-meter antennas, I also found that theory and reality rarely aligned. You can get some interesting reflections off of all sorts of things.

Would you believe we once built an array of 4 2-meter cubical quads stacked 2 over 2? Worked quite well until the first windstorm...........

But yes, if you can afford enough gain to make the link basically point-to-point your performance will be outstanding. Won't do as much for cell phones, iPads, etc.

 

[sfx2000]

Thanks @dlandiss . I follow that from the perspective of the just the receiver. But I was thinking of it in terms of where the transmitter has a high gain directional antenna pointed at the receiver. The receiver sees the same noise and interference but the transmitter's signal has increased. Or am I missing something obvious.

We get into an odd area here, and for some, it's counter intuitive - in Broadcast, or point to point, where the transmitter and receivers are on an assigned channel - higher gain works... on narrow band amateur radio (HAM, CB Radio, etc), again, it works...

On single frequency networks, like 3G, LTE, and cdmaOne, we really need everyone to keep power low, and at the same level at the Base Station - because we look not just at the physical energy on the channel, but the actual code energy (this is referred to as Eb/No, sometimes as Ci/Nr or Ec/Io, these all basically mean the same thing).

WiFi is similar to the other SFN's, in that the stations are designed around a set point, but it's not as sophisticated And much less control over adjacent networks - which makes staying within design parameters that much more important.

Which goes back to the point that WiFi does do a level of open-loop AGC, and I see it in my data - it's driven by two factors - the RF link (RxAGC) and the Eb/No (or CINR)... RxAGC determines the Tx level based on the Rx Level, and Eb/No determines the rate set used based on bit error rates (and retransmissions) - and this is pretty consistent across different AP's and clients and chipsets...

Add more gain, get more noise, add more power, and the other end reduces power, and this makes things asymmetric and unbalanced as one usually increases power (to a limit) on one end, and misses the other end.

In an Analog world (AM/FM/1G cellular) more power/more gain makes sense... in a digital world, esp. now that we're well into single frequency networks - digital modulation gain is more important, lower power is better, and more spatial streams (SU-MIMO is huge, along with Space Time Block Codes).

(MU-MIMO gives and takes - more energy on the like, but also more non-orthoginal interference for the non-MU stations on the same BSS, and it's not very friendly when there are adjacent BSS's - and that cuts both ways)

In the digital realm, it's not power and gain - it's interference that is the limiting factor - and higher gain, higher power AP's in the WiFi sector, it increases interferences, both intentional, and the unintended side effects...

I've been doing this stuff for close to 25 years now (actually longer) as my day time job as an engineer and a personal interest...

Anyways, you now know my thoughts, and I've provided an informed opinion - make your own choices - if it works, great! There's enough latitude in the specs across the board, that corner cases will work...

 

[sfx2000]

All antennas beyond isotropic are directional.

I'd be careful to say "Directional" - that depends on the antenna design - a dipole is usually consider omni in the horizontal sense, but the pattern, depending on the length is flattened...

Patches/Panels, Yagi's, Dipole arrays, etc - we can make them directional - and PIFA's have very interesting patterns - want to see something weird, look at the 2.4GHz patterns on most smart phones.

 

[ColinTaylor]

Thanks @sfx2000 that's certainly food for thought.

 

[sfx2000]

Thanks @sfx2000 that's certainly food for thought.

Some to consider... high gain antenna's don't help so much... which confirms pretty much my perspective.

http://www.smallnetbuilder.com/wireless/wireless-reviews/32774-linksys-high-gain-antennas-reviewed

@thiggins - he also did an article, but I can't find it at the moment regarding higher Tx Power... what's more important is the dB ratio from AP to client (and back), and there, we try to keep that ratio less than 20 dB, and this is pretty evident in all Tim's testing, as that's generally where the cliff is...

 

[ColinTaylor]

Some to consider... high gain antenna's don't help so much... which confirms pretty much my perspective.

Hmm, I would interpret those results slightly differently... The first set of "open air" tests were outside the direction of gain and therefore invalid (or rather, confirms what we would expect). However, when re-testing from within the path of gain he saw improvements:

Now things make more sense. The new same-floor location shows around 3.5 x throughput improvement for downlink (7.7 Mbps to 28 Mbps )and more than 2x improvement for uplink (16.8 Mbps to 37.7 Mbps) for 5 GHz, which has the higher gain. In 2.4 GHz, which has only a moderate gain change of less than 2dB best case, there's a slight throughput loss in downlink and only 25% gain for uplink.

Of course this is only one specific case. Probably the best advice would be for people to try and test these things out for themselves, with the option of returning them if they don't help. But be prepared to be disappointed.

I think this is very much a case of YMMV!

 

[dlandiss]

a dipole is usually consider omni in the horizontal sense, but the pattern, depending on the length is flattened...

True for vertical dipoles, but horizontal dipoles are definitely directional. I experienced that 57 years ago, and learned why 52 years ago. And even vertical dipoles are directional if you concur that "up" is a direction..........

 

[TonyH]

I'm not sure exactly how much substance in SFX's explanation. His original assertion apparently ignores the possibility that the clients may install a higher gain antenna as well e.g. possible on PCIe / USB WiFi cards.

If "open loop power control" designed in 802.11, it might be good news. Users can adjust TX power on client side through parameters exposed by drivers. That's certainly fashionable on Windows and Android...at the expense of battery life for mobile devices.

Back to OP's problem, I read else where that it's an old building with 8 apartments on more than one floor. Higher gain antenna is a very good and inexpensive suggestion if applicable. Ruling that out maybe a cheap WiFi repeater off e-Bay, placed in OP's apartment. Another option is a point-to-point WiFi bridge..may get that off e-Bay as well. OP could get increasing reliability of WiFi access respectively.

 

[sfx2000]

True for vertical dipoles, but horizontal dipoles are definitely directional. I experienced that 57 years ago, and learned why 52 years ago. And even vertical dipoles are directional if you concur that "up" is a direction..........

hehe - X vs. Y axis - fair enough...

Want to see something weird - look at the 2.4GHz antenna patterns for most smartphones - since the radiated elements are shared with both Bluetooth and WiFi, and with SAR concerns, along with positions - they end up being this blobby looking thing in 3-d... Mobile phones are really tough, and I've got a couple of friends (Greg and Jordi) that are absolute masters at that stuff...

 

[anoukaimee]

Sorry to the experts posting here, but I've absorbed the info here (and elsewhere) better; we're talking about high gain directional antenna, right? Understanding that and the article linked above, it doesn't look like it would benefit us, where we are on different floors. Gotcha (I think).

What about unidirectional antenna, specifically dual-polarized? Would they help at all? I know I'm out of my depth but was just wondering if that would be of any benefit, and if so, would having it downstairs or upstairs be better?

I did check out some more info, and found that Ubiquiti gets rave reviews. Someone on Reddit suggested their Airmax antenna, but a Ubiquiti rep said no go, need LOS for that. She suggested the Nanostation Loco M5 set as a repeater in my apartment. Again, no antenna, but rave reviews and they're running about $65 on Amazon right now. Going to do a little research and will probably go with that (unless anyone has a better idea?).

Thanks so much!