rhester72
Posts: 7
Joined: Fri Apr 29, 2016 3:18 pm

Re: pi 3 wifi range

Sat Apr 30, 2016 9:17 pm

jahboater wrote:Have you tried positioning the Pi3 differently?
If the antenna on the router is vertical, try putting the Pi on edge, so the Pi's antenna is vertical too.
The OnHub model I have has 11 antennas, in both vertical and horizontal positions. At this distance, that ain't the problem. :) If the Pi 3 can't put out enough signal strength, that's that, regardless of antenna orientation.

I'm going to try to borrow a professional signal power meter and measure at various distances and orientations from the Pi which I suspect will bear out what I'm saying - it's not a knock on the device as much as it is, well, you're going to get what you're going to get from a tiny ceramic antenna.

Rodney

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cedarmitch
Posts: 13
Joined: Sun Apr 10, 2016 5:41 am
Location: Nanaimo British Columbia Canada
Contact: Website

Re: pi 3 wifi range

Sat Apr 30, 2016 9:36 pm

Getting a solid WiFi connection here from just a little over 16 metres. Runs well right out of the box. It' s certainly a lot more reliable than my HP Windows 10 laptop which used to occupy the same position. Pi 3b is much more reliable.

Cedarmitch

rhester72
Posts: 7
Joined: Fri Apr 29, 2016 3:18 pm

Re: pi 3 wifi range

Sun May 01, 2016 2:45 am

After a very little bit of low-fi testing using the RPi 3 as an AP, I've found something interesting...the signal strength coming _from_ the device can vary by a factor of 30 (!) at a fixed distance less than 6 inches away, from blindly 'loud' to nearly inaudible.

I'm going to create a graph of fixed-position variable signal strength tomorrow, and then wonder if I have a bum unit (the CanaKit WiFi stick I picked up today for $8 is working marvelously after I blacklisted the Broadcom modules, but buying a WiFi adapter for a device _that includes WiFi_ is a bit irritating!).

Rodney

rhester72
Posts: 7
Joined: Fri Apr 29, 2016 3:18 pm

Re: pi 3 wifi range

Sun May 01, 2016 4:15 am

Eh, I did it quick-and-dirty tonight.

The players:

- Google TP-Link OnHub router acting as WAP (only 2.4GHz considered)
- Raspberry Pi 3 Model B (BCM43438 chipset) as acquired from CanaKit via Amazon in the official Pi Foundation red/white case acting as WAP
- Moto X Pure Edition 2015 phone (Qualcomm MSM8992 Snapdragon 808 chipset) with no case acting as client

Test conditions:

- "Remote" test measured at 14.6 feet (4.5 meters)
- "Local" test measured by propping phone upright horizontally directly against the tested device's antenna housing (propped against the side of the OnHub and the narrow side of the RPi board where the ceramic antenna is)
- RPi running latest Raspbian in CLI-only mode with hostapd running via direct command-line as root, using the kernel/firmware from the "next" branch via rpi-update
- Phone was -not- connected to any AP for the testing, but merely measuring raw signal strength
- Graphs were filtered to focus only on the AP being tested at the time
- Each test was run for 2 minutes

Software used:

- Standard hostapd on the RPi, configured as per https://frillip.com/using-your-raspberr ... h-hostapd/
- Wifi Analyzer, free from the Google Play Store

Myths I'd like to bust before I begin as found from my testing:

- Orientation of the RPi and phone with respect to one another (horizontal vs. vertical, 90 degree angles to one another, etc.) had -no effect- over a 2-minute window, locally or remotely
- Turning power management on or off on the BCM43438 had -no effect- over a 2-minute window, locally or remotely
- Removing the metal heatsinks from both chips on the board had -no effect- over a 2-minute window, locally or remotely
- Removing the RPi from the case and running it 'bare' had -no effect- over a 2-minute window, locally or remotely

Graphs demonstrating the above are deliberately excluded for brevity, so you're going to have to take my word for it, but I was -very- meticulous with the tests.

First test: Phone measuring OnHub router at remote distance

Image

Very solid at -44dBm. From a reliability and performance standpoint, you're talking the equivalent of a fixed 100mbit Ethernet cable. Excellent latency and throughput.

Second test: Phone measuring OnHub at local distance

Image

Ouch, that's a hot signal! (Actual measurement with same tool from a different screen is -2dBm, obviously cut off on the graph)

Third test: Phone measuring RPi at remote distance

Image

Ugh...that's no good. We're averaging about -72dBm, which falls into the category of 'maybe it will work'. Usually, it doesn't.

Fourth test: Phone measuring RPi at local distance (again, allow me to remind netizens out there that this means the separation between the RPi antenna and the phone antenna is approximately _one centimeter_)

Image

I'm going to be generous and say that visually this averages out to around -30dBm...which would be tremendously respectable if it was *consistent*. Why isn't it? (I'm not going to take an easy shot at Broadcom here, because their myriad of historical wireless issues aside, this should be a no-brainer. The client and WAP are *physically touching*!)

Last shot: All 2.4GHz WAPs visible from the location of the OnHub (again, roughly 15 feet from the RPi 3)

Image

A little perspective: This means that the signal strength I'm seeing from the RPi, at a distance of 15 feet, is less than half the strength of service provider broadcasts nearly a quarter mile away and roughly the same strength I'm seeing from a WAP (pchang) in a neighbor's home *250 feet away through two sets of exterior walls*!

Thus, I stand by my original findings that the issue - at least with my device - lies nearly entirely with *transmit* signal strength...all measured reception strength is consistently at quality 62/70 or higher at 15 feet distance from the OnHub.

I admit that I may very well have a malfunctioning device, new out-of-the-box for only two days...but given the number of reports of poor wifi performance with the RPi 3, I rather doubt that is the case.

I used a test methodology and tools that should be *easily* replicated by anyone with access to a simple Android phone, of virtually any manufacture or version of the OS. Don't take my word for it...test for yourself!

Rodney

EDIT: Added a final comparison graph that hopefully drives the point home more visually

rhester72
Posts: 7
Joined: Fri Apr 29, 2016 3:18 pm

Re: pi 3 wifi range

Tue May 03, 2016 5:17 pm

To my considerable surprise, my RPi 3 went down in an undervolt condition today, on the official CanaKit RPi 3 supply.

In the interest of fairness, I've ordered an official RPF supply today and will retest on arrival, in case that had an effect on the tests (I certainly can see how it could!).

Rodney

peletiah
Posts: 1
Joined: Wed Aug 03, 2016 8:55 pm

Re: pi 3 wifi range

Wed Aug 03, 2016 9:22 pm

Since I stumbled over this thread while searching for "wifi reception raspberry3", I would like to add my 2 cents.

I've been having trouble playing a 720p-file with Kodi from a local machine via the WLAN, despite that my router was just 4m away behind a thin wall. Since I couldn't solve it by changing Kodi's cache-settings, it dawned on me that it can't fill the buffer quickly enough due to bandwith issues.
My OpenWRT-router was showing an RX Rate below 20 Mbit/s for the Pi and when testing with bwm-ng while playing the movie, it barely scratched 800kB/s. Not enough to watch a 1 hour TV-show without rebuffering.

My pi3 was lying flat on a cupboard. I started moving it and that had a dramatic effect on the transfer rates, contrary to what rhester72 writes above.
Putting it vertically on it's wide edge already doubled the transfer rate.

I started an rsync of a large file from the other machine in the local network and started moving the pi3 around. I found an optimal position a little higher on the wall, vertically positioned with the HDMI and USB-port on the top and the LEDs on the right. At this position I get a consistent transfer rate of 2MB/s with peaks even over 3.2MB/s. That's quite enough to watch a 720p without buffering issues!

Toggling the power-setting didn't seem to have any effect. I didn't try rpi-update as some suggested, as I'm using OSMC, which doesn't seem to be supported.
Last edited by peletiah on Thu Aug 04, 2016 8:57 am, edited 2 times in total.

rhester72
Posts: 7
Joined: Fri Apr 29, 2016 3:18 pm

Re: pi 3 wifi range

Thu Aug 04, 2016 4:01 am

I completely forgot to follow up - in my case, doing nothing but swapping the aftermarket (high-wattage!) power supply with the official RPi one made a _world_ of difference...my transmission (which directly affects reception due to TCP ACK) quality went up quite dramatically, to such a degree that I got lost in testing and started happily watching a ton of content with Kodi and entirely forgot the point of the exercise was to measure wireless performance. :/

Long story short - for me, the power supply alone made all the difference. YMMV.

Rodney

skypickle
Posts: 5
Joined: Sat Oct 08, 2016 11:52 am

Re: pi 3 wifi range

Sat Oct 08, 2016 11:57 am

@energia
forgive my naïveté but i don't understand this:
This solved WiFi problems for me:
sudo iwconfig wlan0 power off
why does turning off wifi help wifi reception?

Pithagoros
Posts: 580
Joined: Wed Nov 12, 2014 8:16 pm

Re: pi 3 wifi range

Sat Oct 08, 2016 12:23 pm

skypickle wrote:@energia
forgive my naïveté but i don't understand this:
This solved WiFi problems for me:
sudo iwconfig wlan0 power off
why does turning off wifi help wifi reception?
I think this command turns off WiFi power management (the stuff that is supposed to reduce energy use), but doesn't turn off WiFi.

User avatar
Mikael70
Posts: 1
Joined: Wed Nov 27, 2019 10:13 am

Re: pi 3 wifi range

Wed Nov 27, 2019 10:57 am

MarkHaysHarris777 wrote:
Tue Mar 15, 2016 3:29 am
Just to post my 2 cents here (or is that tupence, or something else there, left pondia right pondia) cases and heat-sinks are an issue with the on-board wifi too. If you're overclocking and using metal heatsinks try using ceramic heatsinks. If you're using one of the classic metal cases find yourself a plastic case. And this last little tip is going to sound silly (like a propeller cap, or tinfoil helmet) but make yourself a foil lined back-board (manilla folder works well) and fold it --- then position it behind the RPI. Depending on where you place the foil back-board you can improve (or degrade) your wifi performance; experiment (YMWDV).
The more expensive option is to install range extenders throughout your home. We live in a multilevel colonial style and we get by with a range extender on each end of our home; both of them on the second level. If your location has lots of metal, brick, metal duct work, or steel | aluminum siding things can get screwy. Typically I try to place my RPIs in the same room as one of the range extenders :ugeek:
Thanks MarkHaysHarris777 for the tip with foil.

I replaced my Pi Zero with a secondhand Pi3. Distance to router 5.2m and one concreate wall.
Data reported by “sudo iwconfig wlan0”:

Pi3: LQ 61 -49dBm BR 72 Mb/s
Pi3 *: LQ 62 -48dBm BR 72 Mb/s alumnium foil
Pi3 **: LQ 68 -41dBm BR 72 Mb/s steel sheet
Pi zero: LQ 70 -40dBm

*90x60x0.1 aluminum foil 10mm behind (Backside of Pi)
*50x50x0.3mm steel 5mm behind (~centered behind antenna)

LQ: Link quality (I believe 70 is max for Pi?)
SL: Signal level dBm
BR: Bitrate Mb/s

Result:
Antenna of Pi Zero is better the Pi 3
Pi 3+ have the same type of antenna as Pi Zero so it should be better than Pi 3.
A sheet of steel behind Pi3 can improv signal strength with 6 dBm!

I got best reception with the Pi3 mounted vertically with power connector pointing down and component side of the motherboard facing the router.

Useful ssh commands:
watch -n 1 cat /proc/net/wireless
sudo iwconfig wlan0

Side note: Pi3 greatly improved print quality on my ender 2 compared with Pizero when printing at 50mm/s with complex structures. The same results as sprinting from SDcard.

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