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:


JSR Notes:

Firstly, here's the link to the St. Julian's page, which has a bit of good stuff and links.


WiFi is "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, such as 450 Mbps.

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.

Mobility/reachability (coverage) - Limited to the range of the router's transmitter. 35 meters indoor and 100 meters outdoor for 802.11g. (802.11b. n is double these values.)

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:

Microwave transmissions of large amounts of data around a large geographic region. So this could replace or be an alternative option for developing countries for service provider Internet access (instead of wires - cable, DSL T1 fiber optic.) Note that the frequency range of WiMAX is different than the microwave reception the International School of Prague (ISP) gets from its Internet Service Provider (ISP) - what we have is one direct connection, whereas WiMAX is a technology intended for broad distribution of signal.

WiMAX is very much still a dream for the future in many places. It's interesting to note that our tech guys next door have never even heard of it - there are no examples of it in the Czech Republic. It really is something that would be more for a developing country or a region in the world where there is no existing infrastructure for Internet distribution. In this way it could 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.

- 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.

Mobility/reachability (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.



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, but refer to the following ranges of mobile Internet service presently provided by O2 in the Czech Republic:

Mobile Internet:
GPRS ("General Packet Radio Service")/EDGE- up to 236 Kbps

3G - up to 14.4 Mbps
HSPA+ ("High Speed Packet Access") - up to 42 Mbps
LTE ("Long Term Evolution")- up to 75 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 are quite often "outrageous".

1 GB per month limit on plan == 300 Kc
Yet 300 Kc/MB when roaming to UK and 252 Kc/MB when roaming to Turkey

Mobility/reachability (coverage) - varies by location, with urban areas generally better served with faster access than rural areas.

Take a look at O2's coverage map for the Czech Republic.

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.



We can include here 4G, since for most places around the world, it is not yet the present.


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!

Never-the-less, in the near future, the following uses will require this much transmission speed:

4G is to arrive in the Czech Republic in 2015.

Even now in a couple of countries, there is 4GLTE, which is up to 600 Mbps!!


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.)