Comparing Bluetooth Technology with Infrared - Coursework Example

Bluetooth Technology Bluetooth technology creates personal area networks (PAN) by allowing exchange of data from devices over short distances. It is a wireless protocol and exchange data from mobile and fixed devices. It transmits data by transmitting radio signals through a technology called as frequency hopping spread spectrum which breaks up the data being sent into chunks and then transmits these chunks of data at over about seventy nine frequencies. Bluetooth uses Gaussian Frequency Shift Keying (GFSK) modulation in its basic mode. GFSK is a frequency shift keying modulation that smoothes negative/positive frequency deviations using a Gaussian filter. The average number of bits or characters that can be transmitted per unit time by Bluetooth can reach up to a rate of 1Mb/s. Bluetooth exchanges information between devices through a globally unlicensed Industrial, Scientific, Medical (ISM) radio bands. It uses 2.4 GHz short range frequency of ISM. Bluetooth Special Interest Group(SIG) develop and license Bluetooth specifications. The SIG comprises of telecommunication, networking, computing and electronic companies (Newton, Harold). Bluetooth can transmit data between devices such as laptops, telephones, printers, digital cameras, mobile phones and video game consoles. It is a wireless protocol made for low power consumption and has short range which is based on low cost transceiver microchips in each device (Bluetooth SIG). The short ranges of Bluetooth are 1 meter, 10 meters and 100 meters and these ranges are power and class dependent. Class 1 of Bluetooth has a maximum permitted power of 100mW and approximate range of 100m; class 2 has a maximum permitted power of 2.5mW and approximate range of 10m; class 3 has a maximum permitted power of 1mW and approximate range of 1m (Newton, Harold). Bluetooth allows communication to be done among devices when they are in range. Because this system of communication uses radio waves, devices do not need to be in line of sight of each other for communication to take place. (Newton, Harold). In order for a device to be used by Bluetooth, it must be compatible with Bluetooth profiles. The most common use of Bluetooth includes wireless communication between handsets and mobile phones, wireless communication between computer input and output devices, file transfer between devices and OBEX, internet access of personal computers and communications in medical equipment. The technology of Bluetooth exists in many devices like Wi-Fi, telephones, and play stations and also in some high definition headsets and watches. This technology simplifies set up of services between devices. Devices with this technology can advertise all their services. It allows much of the security and permission configuration to be automated making its services easier for use as compared to other network types. A personal computer is required to have Bluetooth adapter in order to develop communication with other Bluetooth devices like mobile phones, keyboards and mice. Some laptops and personal computers have in built adapters while in others an external adapter is required. Through Bluetooth, multiple devices can communicate with a computer over one adapter. A Bluetooth enabled mobile phone allows it be communicated with many devices. The Open Mobile Terminal Platform has recently published a recommendation paper which recommends Bluetooth requirements in mobile phones which covers in car usage, printing and imaging. Bluetooth devices can transmit information like device names, list of services, device class and list of technical information on demand. Any Bluetooth device can undertake an inquiry to find other Bluetooth devices to connect to, and any Bluetooth device can usually respond to such inquires. However if a Bluetooth device that is trying to connect to another device knows the address of that other device than other devices always respond to the direct connection requests and transmit information mentioned above. Use of Bluetooth device services may require acceptance and pairing by the owner but the connection itself can be started by any device and held until the connection goes out of range. Some Bluetooth devices can connect to only one device at a time which prevents inquires from other devices appearing in until the Bluetooth device disconnect from one device. Every Bluetooth device has a 48 bit address but theses addresses usually do not appear in inquires, instead friendly Bluetooth names appear which can be set up by the users. The friendly name appears when another user scans for Bluetooth devices and services. Infrared Technology The Infrared Data Association (IrDA) defines a set of standard rules for data representation required to be exchange data over infrared light in personal areas of network. IrDA is used for short range date in free space optical communication. IrDA network interfaces which provide point of interconnection between public or private network and user terminal are used in mobile phones and laptops. In mobile phones and laptops IrDA is increasingly being replaced by Bluetooth. IrDA explicit set of requirements includes Infrared Physical Layer Specifications (IrPHY), Infrared Link Access Protocol (IrLAP), Infrared Link Management Protocol (IrLMP), Tiny Transport Protocol (Tiny TP), Infrared Communication Protocol (IrCOMM), Infrared Local Area Network (IrLAN) and Infrared Object Exchange (IrOBEX). The Physical Layer specification includes the range, angle, speed, modulation and infrared window of infrared device. The Infrared Link Access Protocol is IrDA specification which includes specifications like access control, establishing a reliable two way connection, discovering potential communication partners, distribution of Primary/Secondary roles of the device and negotiation of Parameters of Qos. The Link Management Protocol provide multiple logical channels, provide a list where service providers can list their services so that other infrared devices can access these services and it provides a system for changing Primary/Secondary devices. The Tiny Transport Protocol allows exchange of large messages by segmentation and reassembly process and it allows flow control by giving credits to logical channels. The Infrared Communication Protocol allows devices to be either parallel port or a serial port. The Infrared OBEX allows transfer of arbitrary data objects like vCalendars, business cards or applications to other devices. It is mandatory for an infrared device to have Tiny TP for IrOBEX to work. The Infrared Local Area Network allows infrared devices to be connected to local area networks through access point method, hosted method or peer to peer method. Infrared technology is used for exchange of information amongst palmtop computers and peripheral computers. IrDA devices use light emitting diodes which emit infra red light which is focused by a lens into a beam. The periodic waveform of the beam is varied i.e. the beam is switched on and off to encode the data. The beam receiver uses a silicon photodetector (photodiode) which converts the infrared light to an electric current. The receiver responds only to high frequency infrared signals and it filters out slowly changing ambient light to infrared radiation. Infrared technology is a good technology for indoor use in areas where there high population. Infrared radiation does not pass through walls so it does not interfere with other devices in other rooms. Remote controls use infrared radiation to command devices. Free space optical communication is a technology to exchange data between two points using light propagating in free space. This technology is mostly used in areas where installing optic fibers is impossible due to the heavy cost that incurs in burying optic fibers cables. Free space optical communication usually use infrared lasers which can develop communication link in urban areas with maximum speed of about 4 gigabits/s. Infrared radiation is used in optical fiber communication system. Optical fibers are long glass fibers that transmit infrared light along their length. They allow data to be traveled over long distances and at high data rates. Glass fibers are used instead of metal wires because lesser number of signals is lost and fibers are less affected by other electromagnetic interferences. Light is kept inside the fibers by total internal reflection fibers act like guides to the infrared light waves. Multi mode fibers are used for short distance communication between appliances that use high power transmission. Single mode fibers are used where communication links are to be developed longer than 600 yards. Joining optical fibers together is a complex task as compared to joining metal wires and cables. The ends of optic fibers are cleaved and then joined together either mechanically or are fused with an electric arc. Removable connections are made with the help of special connectors. The infra red spectrum that is used in optical communication is divided into several bands based on availability of light sources, absorbing and emitting materials and receivers. The different bands that are used include the following (Ramswami,Rajiv) Band Descriptor Wavelength range O band Original 1260-1360nm E band Extended 1360-1460nm S band Short wavelength 1460-1530nm C band Conventional 1530-1565nm L band Long wavelength 1565-1625nm U band Ultra long wavelength 1625-1675nm Comparison of Infrared Technology with Bluetooth Technology With different communication devices being produced everyday it is becoming more and more difficult to connect them. A system that comprises of variety of electronic devices and computers make use of variety of wires and cables in order to make connections. However cables and wires do not develop good connection between devices hence most systems are not used to their full extent. To simplify the problems wireless connection like Bluetooth and IrDA have been developed to improve upon the process of connections. Bluetooth is a type of automatic wireless communication system that has virtually recreated the meaning of connection because of the services it offers and because of its excellent features. Bluetooth has improved on the standard method of connecting as almost anything can be connected on a single system. Computers, headsets, cell phones and keyboards can be connected through the automatic wireless system of Bluetooth. IrDA a wireless type of infrared technology used for communication developed by Infrared Data Association. IrDA specifically used infra red light as a medium for communication; Bluetooth devices however specifically use radio waves as a medium of communication IrDA specifies and defines software and hardware protocols just like Bluetooth special interest group (SIG) for wireless communication which is to promote interoperable application. Although both Bluetooth and IrDA are wireless but both technologies use different segments of electromagnetic spectrum with signal propagation characteristics that are quite different from each other. Since infrared devices use non visible light rays the infrared light is easily blocked by obstacles like doors, walls and people. The wavelength of signal used by Bluetooth technology is about 12.5 cm and has an associated frequency of about 2.4 GHz which is about three times greater in magnitude than IrDA. At this wavelength the radio frequency used by Bluetooth technology can penetrate obstacles like doors and walls. Although recently there have been advances in infrared technology which has enabled more diffuse transmission, much of the IrDA devices still use narrowly focused beam which requires that the two equipments involved in IrDA communication to be in line with and point at each other. The radio frequency transmission however, radiate in some patters usually in spherical pattern around a radio antenna, so that any two Bluetooth equipment can communicate which are in range can communicate with each other whether or not they are aligned with each other. In fact, the second device which is communicating with the first device might not be visible at all to the user of the first device as the second device could be in an another room behind the walls and doors or it could be on some other floor of the same building. Initially the data rates of IrDA were about 115 kilobits per second but these have been enhanced to 1 Mbps which are comparable to data rates of first Bluetooth radios (Miller, pp3). IrDA can today achieve data rates of about 4Mbps with even higher data rates have been proposed and being implemented. Bluetooth wireless communication occurs at a raw data of about 1Mbps with higher speeds being investigated (Miller, pp3). Using the standard 0dBm the Bluetooth wireless communication can effectively reach a range of about 10meters. With a power amplification of about 20dBm, a Bluetooth communication range of about 100 meters can be reached. As already mentioned earlier IrDA communication range is about 1 m and generally two devices are required to point at each other to establish a connection. Bluetooth and IrDA wireless technology are made for low cost and low power consumption. As compared to other radio frequency technologies used for communication, Bluetooth devices use very little power and it expected to have low module costs in the future. But IrDA devices use less power as compared to power used by Bluetooth devices. This is because radio frequency transceivers require more power than infrared transceivers. Also the Bluetooth radio modules are more expensive than IrDA hardware because of the maturity and large number of activities that are done to make IrDA available for use. The brief discussion proves that IrDA technology is favorable as compared to Bluetooth technology in terms of cost, data rate and power. But Bluetooth is more convenient sort of technology because it allows users to have connection with other Bluetooth devices without worrying much about alignment and line of sight requirement as in IrDA communications. Bluetooth technology illustrates new design parameter for wireless personal areas of network: unconscious application of communications technology has enabled enhanced device usability(Miller pp3). For this aspect of wireless areas of network radio frequency technologies are well suited and Bluetooth wireless technology is ideal choice for wireless personal areas of network because they provide greater device usability. Both objective and subjective reasons influence the choice of wireless technology that is used for a particular application. Works Cited. 1.Newton, Harold. Newton's telecom dictionary. New York: Flatiron Publishing 2007 2."How Bluetooth Technology Works". Bluetooth SIG. http://www.bluetooth.com/Bluetooth/Technology/Works/. Retrieved on 2008-02-01. 3. Ramaswami, Rajiv "Optical Fiber Communication: From Transmission to Networking" May 2002 IEEE. http://ieeexplore.ieee.org/iel5/35/21724/01006983.pdf Retrieved on 2006-10-18 4. Miller, Brent. "IrDA And Bluetooth Wireless Communication Compared". Nov 30 2001http://www.informit.com/articles/article.aspxp=24265&seqNum=3 Read More