wireless technologies

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1)Discuss four different types of wireless technologies

IEEE 802.11 - WLAN/Wi-Fi

Wireless LAN (WLAN, also known as Wi-Fi) is a set of low tier, terrestrial, network
technologies for data communication.

IEEE 802.15.1 ?Bluetooth

The IEEE 802.15.1 standard [3] is the basis for the Bluetooth wireless communication
technology.

IEEE 802.15.4 ?ZigBee

ZigBee is a low tier, ad hoc, terrestrial, wireless standard in some ways similar
to Bluetooth.

IEEE 802.15.6

IEEE 802.15.6 is a bit elusive, but some of the available information points to
some kind of wireless Body Area Network (BAN

2) Describe the characteristics and properties of each signal type, and how each can be used.

IEEE 802.11 - WLAN/Wi-Fi

The WLAN standards operates on the 2.4 GHz and 5 GHz Industrial, Science and Medical (ISM) frequency bands. It is specified by the IEEE 802.11 standard [2] and it comes in many different
variations like IEEE 802.11a/b/g/n. The application of WLAN has been most visible in the consumer market where most portable computers support at least one of the variations.

IEEE 802.15.1 ?Bluetooth

Bluetooth is a low tier, ad hoc, terrestrial, wireless standard for short range communication. It is designed for small and low cost devices with low power consumption. The technology operates with three different classes of devices: Class 1, class 2 and class 3 where the range is about 100 meters, 10 meters and 1 meter respectively. Wireless LAN operates in the same 2.4 GHz
frequency band as Bluetooth, but the two technologies use different signaling methods which should prevent interference.

IEEE 802.15.4 ?ZigBee

The IEEE 802.15.4 standard [4] is commonly known as ZigBee, but ZigBee has some features in addition to those of 802.15.4. It operates in the 868 MHz, 915 MHz and 2.4 GHz ISM bands.

IEEE 802.15.6

It is possible that it is meant to be the WBAN Study Group Medical Body Area Networks (SG-MBAN), but that group have not yet released any standards. SG-MBAN's meeting minutes
from their meeting in Montreal, May 2007 [5] indicates that the group name
has not been clarified as one of their members asked if the group title will be
15.5x or 15.6 without getting an answer. This could explain why no standard
has been released and little information about the specification could be found.
According to their meeting minutes from San Fransisco, July 2007 [6] and the
Montreal meeting minutes, the frequency band has not yet been clarified.
A paper by S. Maharj [7] from the University of KwaZulu-Natal is the only
reference of frequency and throughput on 802.15.6 I have been able to find. The
paper says that 802.15.6 will cover the terahertz range and it will use T-rays
which has properties of both light and radio. It also explains that the theoretical
maximum data rate will be in the order of several gigabit. Unfortunately the
information from this paper does not correspond with what I have read from the
meeting minutes of SG-MBAN. However, this is the only concrete information
I could locate.

3) Include a table or matrix that compares properties of the four signal types

Modes of operation:

Wireless networks can have to distinct modes of operation:
 Ad hoc
 Infrastructured

Infrastructured wireless networks usually have some kind of base station which acts as a central node which connects the wireless terminals. The base station is usually provided in order to enable access to the Internet, an intranet or other wireless networks. Most of the time the base stations have a fixed location, but certain mobile base stations also exist. The disadvantage
over ad hoc networks is that the base station is a central point of failure. If it stops working none of the wireless terminals can communicate with each other.

Ad hoc networks can be formed "on the fly?without the help of a base station. Self organization is the key to forming an ad hoc network because initially there is no central node to talk to. In ad hoc networks the wireless terminals may communicate directly with each other while terminals in infrastructured networks have to use the base station to relay their messages. The different standards have different capabilities when it comes to these two modes of operation.

Table 1 contains an overview of which standards support which modes.

Frequency, data rate and range

The standards described ...