The type of network used for communication among a laptop and smartphone using bluetooth is a

7.6.1 Personal Area Networks

A personal area network is a network concerned with the exchange of information in the vicinity of a person. Typically, these systems are wireless and involve the transmission of data between devices such as smartphones, personal computers, tablet computers, etc. The purpose of such a network is usually to allow either transmission of data or information between such devices or to server as the network that allows further up link to the Internet. Developments in the area of Personal Area Networks [PANs] are largely overseen by the IEEE 802.15 working group [18].

2.2 The Technology Trends

Ubiquitous computing comprises a broad and dynamic spectrum of technologies. Two of the most common placeholders for these devices are the personal technologies and smart environments.

Personal Area Network [PAN]: It is an interconnection of personal technology devices to communicate over a short distance, which is less than 33 feet or 10 meters or within the range of an individual person, typically using some form of wireless technologies. Some of these technologies are:

Bluetooth technology: The idea behind Bluetooth is to embed a low cost transceiver chip in each device, making it possible for wireless devices to be totally synchronized without the user having to initiate any operation. The chips would communicate over a previously unused radio frequency at up to 2 Mbps. The overall goal of Bluetooth might be stated as enabling ubiquitous connectivity between personal technology devices without the use of cabling as written in Mckeown [2003a].

High rate W-PANs: As per standard IEEE 802.15 TG3, launched in 2003, these technologies use higher power devices [8 dBm] than regular Bluetooth equipment [0 dBm] to transmit data at a rate of up to 55 Mbps and over a range of up to 55 m Ailisto et al [2003].

Low power W-PANs: As per standard IEEE 802.15 TG4, these technologies are particularly useful for handheld devices since energy consumption for data transmission purposes, and costs, are extremely low. The range of operation of up to 75 m is higher than current Bluetooth applications, but the data transfer rate is low [250 Kbps] Ailisto et al [2003].

BodyArea Network [BAN]: Wireless body area networks interlink various wearable computers and can connect them to outside networks and exchange digital information using the electrical conductivity of the human body as a data network. Advantages of BANs versus PANs are the short range and the resulting lower risk of tapping and interference, as well as low frequency operation, which leads to lower system complexity. Technologies used for wireless BANs include magnetic, capacitive, low-power far-field and infrared connections Raisinghani et al [2004].

Sensors and Actuators: Sensors are essential in capturing physical information from the real world. Different types of sensors are needed for different phenomena. These devices collect data about the real world and pass it on to the computing infrastructure for enabling decision-making. They can detect and measure mechanical phenomena of the user like movements, tilt angle, acceleration and direction. Actuators provide the output direction from the digital world to the real world. These devices allow a computing environment to affect changes in the real world.

Smart Tags: The smart tags contain microchips and wireless antennas that transmit data to any nearby receiver which is acting as a reader. Beyond just computing a price, the smart tags will enable companies to track a product all the way. New tags can recognize more than 268 million manufacturers, each with more than 1 million products. They use Radio frequency identification [RFID] system, which encompasses wireless identification through radio transmission.

12.6 Summary

Several WPAN are described in this chapter. Bluetooth consists of two versions—BR/EDR, which we refer to as legacy Bluetooth, and BLE. BR/EDR is used mostly for streaming data applications like wireless headphones and loudspeakers. BLE, with its four defined roles and device capabilities, serves control and monitoring functions as well as one-way beacons, where very low energy consumption for long battery life is a necessity. Both versions operate on world-wide 2.4 GHz unlicensed frequency channels using frequency hopping medium access. Problems and solutions for coexistence between Bluetooth and IEEE 802.11 devices are discussed.

The IEEE 802.15.4 standard and Zigbee implementations for personal area networks are designed for short-range network topologies and use in low cost, low power devices. Several frequency ranges and modulation techniques are defined to suit sub-1 GHz regulations in different countries and regions, in addition to operation on the 2.4 GHz band.

Other WPAN standards for specific application requirements are discussed. They include 6LoWPAN, Thread, WirelessHART, Z-Wave, DASH7, and ANT.

UWB is a WPAN technology that stands apart from the others from the point of view of operating frequencies, bandwidth, data rates and consequently its applications. Two signal generation techniques are explained—impulse radio and multiband OFDM. Due to spreading signal energy over a wide bandwidth, UWB does not interfere with narrow band communications over the same frequency range. Also, its wide bandwidth makes it particularly suitable for short range high precision wireless distance measurement.

Bluetooth [IEEE802.15.1 and .2]

Bluetooth is a personal area network [PAN] standard that is lower power than 802.11. It was originally specified to serve applications such as data transfer from personal computers to peripheral devices such as cell phones or personal digital assistants. Bluetooth uses a star network topology that supports up to seven remote nodes communicating with a single basestation. While some companies have built wireless sensors based on Bluetooth, they have not been met with wide acceptance due to limitations of the Bluetooth protocol including:

Relatively high power for a short transmission range.

Nodes take a long time to synchronize to network when returning from sleep mode, which increases average system power.

Low number of nodes per network [