Improving WiFi Speed in Apartments and Suburban Homes

ByJohn Wuethrich

Improving WiFi Speed in Apartments and Suburban Homes

This time there really is one simple trick to improving wifi throughput and latency (what most call speed). No im not leading you on! ill get into the how in a moment. there are a few additional steps to further improve your wifi experience but first lets look at the factors that can make wifi suck in urban and suburban housing.

Did you manually configure your wifi ap when you set it up? tell the wizard:

“fuck off i got this?

Do you know exactly how the physical layer of wifi operates? when I say layer are you thinking ogre or osi model? if you thought green and animated… you should probably keep reading. 

The OSI Onion Model

Here is a link for those that care to learn what the osi model to networking is. For the intent in the article title we dont need a full lesson. Conceptually though:

have you ever wondered how Ethernet and wifi are obviously two different things but it seems transparent on most networks? along the same lines how can all these different internet and networking things like Cable(cattv), DSL, 3g and 4g cellular all use an ip address and deliver the same experiance? well any type of networking is divided into chunks and stacked chunk on chunk until (if intended) this is the end result. WUT?!

Chunk list:

5. Session layer
4. Transport layer
3. Network layer
2. Data link layer[
1. Physical layer

Ip addresses? they happen on chunk 3. This allows things like DSL, Cable, and Cellular Modems to all speak different respective languages to the next thing down the line but deliver the same network to the customer. Its also why wifi and ethernet can be so different but the computer plugged into the access point via that fat phone plug (rj45) can share its printer and or folders with your laptop on wifi. ‘all the complexity of radio signaling vs signaling in a cable, its being handled by the manufactures hardware driver and the OS you happen to be using gets to just speak layer 3 and up to it. For any given standard a designer wishes to implement (wifi, ethernet modem) or coder wishes to enable an os for…

there is a related set of rules decided by a company/org/working group. the “protocol” for say speaking wifi radio signals or sending power over ethernet wires to have data come out the other end. Some of these rules matter to your daily experiance with the tech and can hurt you and your neighbors (as far as speed/watching netflix with out buffering is concerned) 

Wifi Phy (that not a Stutter)

There is one key thing you need to know about layer 1 and or 2 of wifi. Assuming you understand that a two way radio is running the show (think walkie talkie/frs radio) the driver/firmware on the wifi hardware is in control of the talk button. Every time you request data, it keys the mic and says hey give me the link this guy, gal or Apache helicopter just requested. it lets go of talk and listens for the start of a frame (which is a structure around a packet) clearly as the user you are hoping the access point keys its walkie and gets you that page you requested asap. Its the same but automatic for things like netflicks and youtube, you rarely have more than a few seconds to min worth of that video downloaded, the “stream” gives you just enough to hopfully view with out pause depending on the app/source/site/your settings you might get to keep what youve already watched or for intelectual property reasons it might be a strict limit of x seconds stored on your box for reverse or forward buffer.

ok so wheres the problem? well if you’ve used a walkie talkie you know you can only talk or listen not both at once. Wifi’s radio control layer has a strict rule for all devices. 

LISTEN BEFORE TALK (transmit) 
IF Channel Clear (no one else is talking) —-> TALK
ELSE —> Wait random time (in ms) Repeat (including random wait)

From this we can derive that

most streaming and or live video feeds(like your front door security cam) streaming video (netflix) and to a lower extent audio streaming is greedy when it comes to other users hoping to do much more than browse the web on your access point. 

the more devices connected to an ap and doing anything from auto update, web browsing to streaming or backups; more wifi clients/devices the more frequent the random wait time is going on whether you know it or not. There are a lot of things between the server storing the netflix title you have binged the last 12 hrs and your modem/wifi ap that can introduce delays as well but in even a small apartment building your most frequent cause is likely your neighbor. wait but they are on their access point?!




It's The Freakin FCC

actually its scarcity of bandwith 

The FCC happens to control which frequencies are set aside for what applications. Term time:

Band: A set of continuous frequencies assigned to a purpose.
 this is how we denote chunks of radio spectrum 

In north america the 2.4Ghz Wifi Band is given the set of frequencies between the 2401MHz and 2484 MHz.

its actually called ISM band. but is used by 802.11b, 802.11G 802.11n and 802.11ax (wifi 6) 

Channel: Are you a human? do you prefer rememering/comunicating/writing 2437 or ch 4? human memory and need for actually occupying more than one frequency at any moment creates the concept of a channel. The first table to the right list the channels “center frequency” wifi channels occupy 20mhz per channel on default settings. Theres mathmatical laws/theorms behind how many hz you need to send data at a desired speed but I think we are probably deep enough at the moment. 

ok great numbers so what? problem is that a standard width wifi channel is 20MHz and the frequency given for a channel sits in the center. North American Channels (actually more accurately everyone gets these, this is just all North America gets for 2.4ghz wifi (its actually part of what the FCC calls the 2.4ghz ISM band) 

add 10 to say, ch 1s freqency. see the issue? 

1, 6, and 11 are the only 2.4ghz channels that dont overlap.

Wifi Channels by Center Frequency  (North American Subset)

 

1 2412 
2 2417 
3 2422 
4 2427 
5 2432 
6 2437 
7 2442 
8 2447 
9 2452 
10 2457 
11 2462

Freq Range of each Wifi Ch.

12401 – 2423
22406 – 2428
32411 – 2433
42411 – 2433
52416 – 2438
62421 – 2443
72426 – 2448
82431 – 2453
92436 – 2458
102441 – 2463
112446 – 2468
  

Physics To The Rescue, Kinda....

This isnt as bad as it seems at first. If you could graphicly plot power vs the bandwidth of a single channel. The highest power is a spike at the middle while twoards either end of the channels 20mhz alotment, power levels are significantly lower at any instance. Something Called the Inverse Square Law governs power at a physical distance. it says if you double the distance between you and a source of em/rf energy, you end up with 1/4th of the power. So this saves the day a lot of the time, because in a subraban house with any yard at all, you start to get distances where even trying to connect to your access point from the neighors might not work. The issue is anything “talking” with in your wifi channel, will stop your access point and device from doing what you bought them for. 

if anyone is old enough to remember 802.11b , ever have that issue where someone poping popcorn kicks you off battle.net? your microwave also uses 2.4ghz radiation and 802.11b was notorious for hearing them as speakers and not talking. also microwave oven generate it with a magnetron not a transistor, the former is a high power (LOUD) but Crude device and im not sure how much was improved microwave sheilding vs improved wifi front ends(noise rejection and weak signal detection/prefrence over noise) but actually using 2.4ghz for data with consumer affordable hardware was in its infancy in the 802.11b days. that all compounded for a bad time, but i digress. 

Lets recap:

 

your access point picks a channel or you tell it one in manual setup, all your devices and your access point talk on that channel.

Listen before talk is an unbreakable wifi rule.

Other speakers with in your channels 20mhz range (be it your neighbor on a overlaping ch, your neighbor on the same channel, microwave, radar, bluetooth, ET phoning home) Triggers a random wait (stand off) before listening again to see if we can talk.

Only Wifi Channels 1, 6, and 11 have no overlap (can talk all day and the next one on that list wont be bothered even at close proximity*)

The Edges of a channel wont travel as far as the center frequency due to inverse square law and power level at any instance in time being lower towards the edge of ch.

standard wifi channels on 2.4ghz are 20mhz wide but some wifi access points and flavors (bgnax) allow double wide channels with the marketing promoise of higher throughput. in theory yes more bandwidth = more bits per second but… listen before talk gets in the way and you can end up slowing down your network and everyone around you. which makes a great segway to practical use of what we just covered.

How can we apply this for teh l33t wifiz?

Download a Wifi Spectrum Analyzer 

I cant predict your surroundings, but this app or one like it can scan and then display the situation. (see screenshot on the right) you can use any similar. I just like how this one formats/displays the relative info/great presentation and ui. if anyone knows better drop it in the comments section!

Improving WiFi Speed in Apartments and Suburban Homes 1

here is the output mine produces

Im in a rather dense(in more ways than one) apartment complex

Pick The Channel Least Occupied

note that in the picture above the y-axis corresponds to signal strength relative to where ever you happen to be standing when you run the program.  

least occupied for me right now would probably be channel 6.

  • Find the biggest hole or space with fewest overlapping other networks on the output of the app.
  • manually set your access point to use this channel.
  • check again in a week.
    • a lot of routers periodically scan and use a rule/logic list to try to pick the least used channel as well. aka you might find in a week that the auto in your neighbors unit is waging war

Turn Down The Power!

  1. Turn your access point power down and play around until its at the lowest level it sustains a connection (from the furthest room/corner in your unit/house)
    1. remember inverse square? the extra distance to the next unit will help drop the rest. 
    2. as your neighbor if they would like a free tuneup, maybe show the pic from the app (step 1) while summarizing 
    3. remember, most people never touch the settings. In theory a poorly written access point control program evaluates for maybe 2 days after it first comes online/hard reset and tunes itself to only need enough power to reach the furthest client it saw in that time. It probably does this by mesuring signal strength plus other things like packets sent but not acknowledged (your laptop might see the neighbors overlap but ap doesnt…hence it has to sit silent) well if the same was true for their laptop… having your devices maxed on power potentially causes their routers auto to bump its power and everyone loses.
      1. you obviously cant force everyone to comply here but in general turning yours down is a good step and might accomplish turning theirs down automatically. sadly most aps come with a preset wpa2 key these days… but in the case the neighbors running an unsecured wifi there are things like default passwords listed by manufacture.
  2. walking around your unit and rescanning with the app can probably help idenitify which network name is in what direction. considering or ignoring local regulations such as firecode, s

Use only 20MHz Channels

if your analizer output looks anything like mine, setting wide channels is only going to hurt your throughput and everyone else around you. If you can identify a neighbor who is offending, consider a door knock and explaining some of this. 

if your spectrum graph looks like mine and you are currently using 40mhz channels on 2.4 ghz, this is probably the single biggest change you can make to up your throughput and decrease latency!

Consider Sheilding

something as thin as tinfoil on a wall, ceiling or under a carpet can block 2.4 Ghz radiation quite effectively. The wall behind where ever your access point sits might make a significant difference. If your laptop in the other room still hears another ap on the same channel but the sheild behind your AP keeps it from hearing that ap… your next bit of netflix is still likely to be sent from ap to laptop. 

above like  1000mhz (1ghz things like tree leaves and water drops start causing issues. ever wonder why your dish network/direct tv drops in heavy rain or snow? cable offices downlink via dish too but they will usually use a automated controller and several dishes spread a bit, it increases the odds that one dish always has the signal/ makes it rare a cable network feed drops in heavy weather but it does sometimes happen)

random fact: that hexagonal mesh on the front of a microwave door… also used over the cockpit windscreens in air force one. 

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