by Brian on 3/10/2010
I was doing some quick reading about the technology that makes Porter Airlines‘ airplanes, the Bombardier Q400, quiet. It sounds like someone did a lot of research to make the technology work. Essentially it works like this:
- Noise is caused by air being displaced by the spinning of the propeller, which in turn hits the cabin and causes it to vibrate.
- A microphone captures the noise and sends information about it to a computer, which also knows the speed of the propellers.
- The computer does computations on this data, and then send this information to a device called an Active Tuned Vibration Absorbers (ATVAs) mounted on the fuselage frames.
- The ATVA produces counter vibrations which our out of phase of the original vibrations, which reduces the noise and vibrartions of the aircraft.
You can find more information, as well as some diagrams of this technology on Bombardier’s website. The noise suppression system was developed by Ultra Electronics based in the UK.
by Brian on 3/9/2010
Today I decided to upgrade to Shaw Extreme, and after I’ve upgraded I noticed my connection was not any faster. It’s easy to assume this is because Shaw throttles their services–isn’t it great how they advertise, speeds up to 15Mbps–but I decided to investigate further. The first test I did was run a speed test using Speedtest.net on my laptop using the wireless connection. I was getting maybe 1.5 Mbps at most. Then I tried plugging my laptop directly into the cable modem and I was able to get speeds close to 15Mbps. Testing your connection by plugging your computer directly into the cable or DSL modem is always the first test you should do.
Next I tried plugging my laptop into my router and turned off my wifi connection. Doing this I was able to get 5Mbps. Then I checked to see if there was a firmware update for my router, and it turns out Linksys released a firmware update in early February. So I downloaded and installed the update and my connection improved to 13Mbps. I checked my wifi connection and I was getting about 5Mbps.
So I checked my wifi settings, and I tried changing the wireless channel, that did not seem to make a lot of difference for me, but for those of you who have not already changed your wifi channel, do this immediately! Have you noticed that there can easily at minimum be 6 or 7 wifi connections in your neighbourhood all using the same default channel?
For added security I have been using MAC address filtering, in addition to WPA. I decided to see what would happen if I turned off MAC address filtering and sure enough, my speeds improved to about 13Mbps over wifi.
So the point of this exercise is to show you that often the bottleneck in your network is not the connection itself, but quite possible a device such as a router or switch, or even a bad network cable.
