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3.1.14

Describe the characteristics of wireless networks.

 

Teaching Note:

Include: WiFi; Worldwide Interoperability for Microwave Access (WiMAX); 3G mobile; future networks.

S/E, INT Connectivity between different locations.

 

Sample Question:

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JSR Notes:

WiFi

WiFi is short for "wireless fidelity", a standard of wireless communication using radio waves based on the IEEE 802.11 standard. A WLAN (Wireless Local Area Network) sets up Internet and other wireless services for computers and mobile devices within the range of its "hot spot" coverage.

Speed - Generally fast because pumped through a LAN, so depends on the speed of the LAN - usually the maximum is in the hundreds of Mbps. Theoretical and actual speeds always differ, with the widely available 802.11n being: theoretical upper limit, 600 Mbps and actual upper limit, 100 Mbps. But 802.11ac can get even higher, and after school, I currently can get up to 150 Mbps in the classroom.

Use - Used by individuals, groups and organizations to set up local wireless networks (WiFi "hot-spots").

For which devices - computers, laptops, mobile phones and tablets, and cameras (to post pictures automatically on-line).

Cost - no additional Internet costs, since supplied via the LAN, only cost of wifi router.

Range (coverage) - Limited to the range of the router's transmitter. Typically it is 32 meters indoor and 100 meters outdoor for 802.11g. Though with directional antennas and point-to-point transmisstion this can be extended to many kilometers.

Ease of use - has to be set up by user.

Compatibility: standard around the world (various versions of the IEEE 802.11 family of standard).

 

 

WiMAX - Worldwide Interoperability for Microwave Access:

WiMax is a wireless technology for the broad distribution of large numbers of microwave transmissions around a large geographic region. It was designed to make high quality, long range data and voice communications affordable. This was intended to replace or be an alternative option in developing countries for service providers to provide Internet access (instead of wires - cable, DSL T1 fiber optic.) Note that the frequency range of WiMAX is different than that used in a traditional point-to-point directed microwave transmission between tranmitter and receiver; WiMAX is a technology intended for broad distribution of signal, not just from one place to another. Though, like all microvave, there still needs to be a line of sight between transmitter and receiver, so tall microwave towers are a key part of the system.

WiMAX is very much still a dream for the future in many places. But the intent is for a developing country or a region in the world where there is no existing infrastructure for Internet distribution to jump staight to broadband capabilities. In this way it can be considered a "leap-frog" technology, in which developing countries actually get better technology than developed, since the developing countries can "leap" right to the future technology without having to build it on top of legacy infrastructure.

The list of present WiMAX Deployments includes mainly developing countries, though the US has a bunch, and Canada has several serving isolated communities and regions in the North.

Here is a good overall summary of WiMAX from Wikipedia:

WiMAX is sometimes referred to as "Wi-Fi on steroids"and can be used for a number of applications including broadband connections, cellular backhaul, hotspots, etc. It is similar to Wi-Fi, but it can enable usage at much greater distances.

Microwave transmission tower for a WiMAX system


Speed
- 30 to 40 Mbps, so slower than WiFi and 3G.
(Though can actually be up to 1 Gbps for fixed stations; i.e. wireless, but from one fixed tower to one fixed receiver, like how we get our (non-WiMAX) microwave Internet reception at the school.)

Use - to provide Internet access to regions without existing infrastructure (so ideal for developing countries and isolated regions)

For which devices - both computers and mobile devices, depending on how deployed.

Cost - Expensive to set up, but less so than setting up entire DSL or cable or fiber optic networks from scratch.

Range (coverage) - up to 50 km.

Ease of use - no different than other wireless option

Compatibility- adheres to a worldwide standard for wireless networks (specifically, IEEE 802-16) so compatibility equally as good as other technologies adhering to other IEEE 802 standards.

 

3G:

Third generation of mobile telecommunication technology. (So includes software and hardware protocols to certain standards, most notably maximum speed of data transfer.)

Speed - standard 3G is in the range of 1 Mbps to 15 Mbps.

Use - for mobile Internet access uses such as:

For which devices - phones & mobile devices

Cost - Very much variable. Depends on if part of plan, or per quantity downloaded, as with many "roaming" plans. Roaming charges can be quite high.

Coverage - varies by location, with urban areas generally better served with faster access than rural areas.

Ease of use - very easy; in fact, no set up at all required.

Compatibility - Depends on device and provider, but what is most convenient is when you are able to switch between standards - i.e. can it switch back to 2G when out of range of 3G.

 

 

4G

Speed - 4G is defined as providing 100 Mbps (as compared to 144 Kbps for 2G and around 10 Mbps for 3G)

So with 4G, a phone with present-day storage of 64 GB would be filled up in about 20 minutes of 100 Mbps download!

Here is the 4G Internet service presently provided by TrueMove in Thailand early 2018:

Use - A variety of bandwidth hogs benefit from 4G:

For which devices - All mobile devices

Cost - Cheap in Thailand (see above)

Coverage - Here is the coverage of DTAC in and around Bangkok in early 2018:

From sensorly.com

Ease of use - High, like 3G.

Compatability - High, since can switch back to 3G and 2G on the fly.

 

4G LTE ("4th Generation Long Term Evolution")

Now in many countries, with speeds up to and beyond 600 Mbps!!

Compatibility - Compatible with a vast array of devices.

AIS, DTAC, and TrueMove all offer 4G LTE in Thailand.

 

Future:

Also for the future, here's a wild prediction on my part: 5G! And guess what, it will:


Other Wireless Technologies
not mentioned in the Teaching Note, but of which you should at least be aware:

Bluetooth - short-range, used with both phones and laptops, what is used for hands free phoning

Infrared - older wireless technology, still used in some devices today.
- short range, line of sight transmission (so you would see two people holding their phones up to each other, for example, to assure transmission.)

 

Various Related Links: