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Unit 4: Wireless Networks Types and PAN Technologies

electrical conductivity coming out of human body. This linkup information exchange can take Notes
place even between two people who are carrying digital assistance devices while they are shaking
hands. In this process of hand shake, an electric field is generated around people, and they emit
Pico amps. These emissions complete the circuit and hence an exchange of information takes
place. This information exchange includes the transfer of personal data such as email address,
phone numbers etc.

The purpose of PDAs is to make the use of electric field around human beings. Mobile phones
(smart phones only), palmtops and even pagers serve this purpose. Wireless digital devices work
twenty four hours a day and seven days a week. This enables you to stay in communication circle
always.

Notes PAN (Personal Area Network) network has enabled the transfer of data within the
small geographical areas with the help of many small and portable carrying devices.

4.2.1 IEEE 802.15

Wireless PAN technologies utilize both radio frequencies and infrared light, depending on the
application. The IEEE 802.15 standards working group focuses on the development of standards
for wireless PANs and coordinates with other standards, such as 802.11 wireless LANs.
The 802.15 standards working group contains the following elements:

z z 802.15.1? This working group, Task Group 1, defines a wireless PAN standard based on
Bluetooth v1.1 specifications, which uses frequency hopping spread spectrum (FHSS) and
operates at up to 1 Mbps. The 802.15 group published 802.11.1 in June of 2002, and it is
meant to serve as a resource for developers of Bluetooth devices.
z z 802.15.2? The group responsible for this standard, Task Group 2, is defining recommended
practices to facilitate the coexistence of 802.15 and 802.11 networks. An issue is that both
networks operate in the same 2.4 GHz frequency band, making coordination between
operations necessary. The group is quantifying the interference and proposing methods to
counter the interference.
z z 802.15.3? This is Task Group 3, which is drafting a new standard for higher-rate wireless
PANs. Data rates include 11, 22, 33, 44, and 55 Mbps. Combined with these higher data
rates, quality of service (QoS) mechanisms make this standard good for satisfying needs for
multimedia applications. This group is also focusing on lower cost and power requirements.
A draft of the 802.15.3 standard is now available for purchase.
z z 802.15.4? This group, Task Group 4, is investigating the definition of a standard with low
data rates that leads to extremely low-power consumption for small devices where it’s not
practical to change batteries within months or years. For example, sensors, smart badges,
and home automation systems are candidates for this technology. Data rates include 20, 40,
and 250 kbps. A draft of the 802.15.4 standard is now available for purchase.

4.2.2 Bluetooth

The introduction of Bluetooth in 1998 was the result of several companies, including Ericsson,
IBM, Intel, Nokia, and Toshiba, working together to create a solution for wireless access among
computing devices. Bluetooth, which is a specification and not a standard, is ideal for small
devices with short-range, low-power, and inexpensive radio links. This makes Bluetooth a good
solution for connecting small devices within range of a person in a small working area. That’s
why the 802.15 chose Bluetooth as the basis of the 802.15.1 standard.

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