Wireless
Brett Lee
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Below are topics having to do with:

	Infrared,
	Bluetooth
	802.11,
	802.11a,
	802.11b,
	802.11e,
	802.11g


Not necessarily in that order...

				Signal
		Modulation	Rate	Freq	Distance

Bluetooth	FHSS			2.4	10 meters
802.11		FHSS		2	2.4
802.11a		OFDM		54	5.7		
802.11b		DSSS		11	2.4
802.11g		OFDM		54	2.4


Bluetooth
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From: http://www22.verizon.com/about/community/learningcenter/articles/displayarticle1/0,1727,1006z1,00.html

Most of the time, a network or communications method either works in one direction at a time, called asynchronous communication, or in both directions simultaneously, called synchronous communication. A speakerphone that lets you either listen or talk, but not both, is an example of asynchronous communication, while a regular telephone handset is a synchronous device. Because Bluetooth is designed to work in a number of different circumstances, it can be either synchronous or asynchronous. The cordless telephone is an example of a use that will call for a synchronous, or two-way, link, and Bluetooth can send data at more than 64,000 bits per second in a synchronous link -- a rate high enough to support several human voice conversations. If a particular use calls for an asynchronous link -- connecting to a computer modem, for example -- Bluetooth can transmit up to 721 Kilo bits per second in one direction, with 57.6 Kbps in the other. If the use calls for the same speed in both directions, a link with 432.6 Kbps capacity in each direction can be made. 

Computer manufacturers are planning to include Bluetooth in a number of products. Cellphone and entertainment product designers are also making plans for the standard because Bluetooth includes three voice channels in each piconet. Since Bluetooth doesn't require a physical adapter, manufacturers are planning cellular modems, headsets and other devices that tie telephone and data together. 



Details
Here are some details from The Bluetooth Specification:


The devices in a piconet share a common communication data channel. The channel has a total capacity of 1 Megabit/second. Headers and handshaking information consume about 20 percent of this capacity. 
In the United States and Europe, the frequency range is 2,400 to 2,483.5 MHz, with 79 1-MHz RF channels. In practice, the range is 2,402 MHz to 2,480 MHz. In Japan the frequency range is 2,472 to 2,497MHz with 23 1-Mhz RF channels. 
A data channel hops randomly 1,600 times per second between the 79 (or 23) RF channels. 
Each channel is divided into time slots 625 microseconds long. 
A piconet has a master and up to seven slaves. The master transmits in even time slots, slaves in odd time slots. 
Packets can be up to five time slots wide. 
Data in a packet can be up to 2,745 bits in length. 
There are currently two types of data transfer between devices: SCO (synchronous connection oriented) and ACL (asynch connection-less) links. 
ln a piconet there can be up to three SCO links of 64,000 bits per second each. To avoid timing and collision problems, the SCO links use reserved slots set up by the master. 
Masters can support up to 3 SCO links with 1, 2 or 3 slaves. 
Slots not reserved for SCO links can be used for ACL links. 
One master and slave can have a single ACL link. 
ACL is point-to-point (master to one slave) or broadcast to all the slaves. 
ACL slaves can only transmit when requested by master. 


1.  802.11b

Commonly known as Wi-Fi, 802.11b is the 




2.  802.11a

3.  802.11e

4.  802.11g