802.11ac Wi-Fi Router Testing: Interference And Workloads

[ceomrman2]

I'm looking for suggestions and having a bit of trouble interpreting how these results apply to my use case.
I have a big old tri-level duplex in a crowded neighborhood. The wireless router is on the second floor, near the front of the house. I need to reach 70 feet to the back patio, where people use their cell phones for games and music streaming. I need to reach up 20 feet to stream video to tablets in bedrooms, plus I need to reach down fifteen feet to the other living room for 1080p streaming to their TV. There are perhaps a dozen simultaneous devices, all supporting lots of different wireless standards. The neighbors have loads of their own WiFi networks. So I gather it’s pretty challenging.
My Asus rt-ac56u is getting crushed. Sometimes it can reach the back patio, but it often drops connections or stalls out. It can stream HD well over a short distance, but range and reliability under load is a real problem. It often bogs down to a crawl, requiring a reboot that may or may not help.
Which of these routers do you think would be most likely to show a meaningful improvement? Are there tests a relative moron can run that would yield insightful results? I like max speeds and all that, but reliability and decent-enough throughput at range for many devices in a busy environment is way more important to me. Maybe I should use a bridging setup or something? Maybe a three-antenna beast can handle it well?

 

[jacobian]

Get a free wireless analysis tool like Acrylic-free. Put it on a laptop, walk around and study the connectivity to your own networks, as well as the interference from neighbors networks. It could be really telling if it should something like your wifi channels clashing with somebody else's strong signal.

The next thing you should try is add a second access point if you can run an Ethernet wire between your access points. That could really help with bringing a stronger signal to a different floor. You can also try to interconnect the access points by the means of powerline adapters, but those can be quite slow, often slower than wifi at longish distances. The newer AV2-standard powerline devices work a lot better than the older ones.

The problem of poor wifi range is ages old. First, when we're talking about true longish distances, the 2.4GHz band works better. Sure, a single stream of a 20MHz-wide 2.4GHz channel is theoretically five times slower than each stream of a 80MHz-wide 5GHz channel when you stand near the router, but 5GHz connections become very weak and slow with distance. At 30ft or more, the 2.4GHz clients have better connectivity to the router than those still using 5GHz band. If you're on a different floor from the router, then 2.4GHz is going to work almost certainly better, unless your device is more or less right above or below the router.

Channel selection: For 2.4GHz band you (and everyone else) should use only channels 1,6, and 11. These are the only non-overlapping channels. For the 5GHz band, use the upper four channels 149 though 161, because the FCC regulations allow those channel to have much stronger signal than others.

Regarding the access point, try to buy a second generation access point (e.g. something that came into the market last year or later). The newer AC access points and routers have better antennas, better CPUs, etc, and generally benefit from the knowledge accumulated over the 2-3 years since 802.11ac has gone mainstream.

 

[Solandri]

To me, MU-MIMO and Tri-Band routers sound more like an up-selling pitch through a bunch of hacks, rather a genuine improvement over an ordinary dual-band AC1750 class router. The reality is that everyone's wireless performance is limited by client hardware, and this means a two stream 2x2 802.11ac for most mid to high-end clients, and 3x3 for the very high end clients, like Apple's MacBoo Pro, very few others, or external USB. Neither tri-band nor MU-MIMO is going to change that limitation.

I worked with phased array sonars (whose math is identical to phased array radars). Conceptually, MU-MIMO is the same thing, just with fewer independent transducers. The benefits are very real.

The primary determinant for wireless throughput is signal to noise ratio (SNR). Analyzing the received signal spatially like phased array radar or MU-MIMO lets you increase SNR by mathematically combining it in a way where noise coming from a different direction cancels itself out (partially) while signal from the desired source is unaffected. It is not a marketing gimmick or a hack. It is very real.

And in fact, MU-MIMO will be a pretty useless technology for some time to come, because you need MU-MIMO clients, which mostly exist on a drawing board right now.

I haven't looked into how the current MU-MIMO implementations are designed, but only one side needs to have it for it to be effective. As long as the router can make a good guess as to the client's location, it can use the technology to increase both received and transmitted signal strength.