Here is the example:
Conception of wimax http://computer.howstuffworks.com/wimax1.htm
The real spec is http://ieee802.org/16/
Conception of wifi in local: /mnt/win/protocols/802.11tut.pdf
The real spec in local: /mnt/win/protocols/802.11.pdf
Conceptual is really good like talking about wimax
- There is the non-line-of-sight, WiFi sort of service, where a small antenna on your computer connects to the tower. In this mode, WiMAX uses a lower frequency range -- 2 GHz to 11 GHz (similar to WiFi). Lower-wavelength transmissions are not as easily disrupted by physical obstructions -- they are better able to diffract, or bend, around obstacles.
- There is line-of-sight service, where a fixed dish antenna points straight at the WiMAX tower from a rooftop or pole. The line-of-sight connection is stronger and more stable, so it's able to send a lot of data with fewer errors. Line-of-sight transmissions use higher frequencies, with ranges reaching a possible 66 GHz. At higher frequencies, there is less interference and lots more bandwidth
So when reading wimax 802.16 in section PHYSICAL LAYER there are 2 frequencies: 2 GHz to 11 GHz and 10-66 GHz you will understand right away why there are 2 frequencies it takes me a while to figure out if you read the conceptual you will know right away.
OR
VPN
Analogy: Each LAN is an Island
Imagine that you live on an island in a huge ocean. There are thousands of other islands all around you, some very close and others farther away. The normal way to travel is to take a ferry from your island to whichever island you wish to visit. Of course, traveling on a ferry means that you have almost no privacy. Anything you do can be seen by someone else.
This imply for everything including specs., coding... we need to understand the concept and specs it will easy to remember instead of learning by heart...
