36.5 IEEE 802.1X

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IEEE 802.1x standards-based wireless LANs have become very popular in recent years. IEEE 802.11b and IEEE 802.15.3 are for personal/home area networks. The details of these standards are discussed in Chapter 17 "Local Area Networks" where all the IEEE Standards for LANs and PANs are covered. While deploying these networks, base stations need to be installed strategically to avoid interference because these networks are interference prone when installed in apartments.

Note

IEEE 802.11b and IEEE 802.15.3 are the IEEE standards for Personal/Home Area Networks.

Summary

Personal area networks and home area networks are receiving a lot of attention. The objective of PAN and HAN is to interconnect various devices used in offices, homes, and even in cars using wireless technology. The important technologies for achieving this objective are Bluetooth, HomeRF, IrDA, and IEEE 802.1x. These technologies are reviewed in this chapter.

Bluetooth enables creation of ad hoc spontaneous networks using wireless technology. A group of devices form a piconet. Each piconet will have a master and up to seven active slaves. Communication is in the 2.4GHz band using frequency hopping. Point-to-point and point-to-multipoint communication can be done between the master and the slaves. Both connection-oriented and connectionless services are supported for voice and data applications. Necessary security is built into this technology through encryption as well as frequency hopping. Bluetooth is gaining popularity, and devices such as PCs, laptops, palmtops, mobile phones, speakers, microphones, and headphones are being Bluetooth enabled. The range of Bluetooth is about 10 meters but can be extended to 100 meters with higher transmission power.

HomeRF is another wireless technology to interconnect up to 127 devices within a radius of about 150 feet. HomeRF systems also operate in the 2.4GHz band using frequency hopping with data rates support up to 10Mbps.

Infrared as the medium to interconnect devices has the main attraction of low cost. Devices such as palmtops, mobile phones, desktops, and laptops are being provided with infrared port for exchanging data within a range of about one meter.

In addition to providing wireless connectivity between devices, these technologies provide the capability for creating ad hoc networks wherein two or more devices spontaneously form a network when they come close to one another.

References

C. Bisdikian. "An Overview of the Bluetooth Wireless Technology". IEEE Communications Magazine, Vol. 39, No. 11, December 2001. This paper gives an excellent overview of Bluetooth.
B. Rose. "Home Networks: A Standards Perspective". IEEE Communications Magazine, Vol. 39, No. 11, December 2001. This paper gives the details of various standards for home networking.
J. Karaoguz. "High Rate Personal Area Networks". IEEE Communications Magazine, Vol. 39, No. 11, December 2001. This paper gives the details of the various personal area network technologies.
Dreamtech Software Team. WAP, Bluetooth and 3G Programming. Hungry Minds Inc., 2001. This book contains the theory of Bluetooth and also the source code for developing applications using Ericsson's Bluetooth development kit.
http://www.anywhereyougo.com Provides information on wireless technologies and resources for developers.
http://www.bluetooth.com Official site of Bluetooth special interest group.
http://www.comtec.sigma.se Web site of Sigma Comtec AB, Sweden, distributor of Ericsson's Bluetooth application toolkit.
http://www.cstack.com Bluetooth site by engineers for engineers.
http://www.homerf.org Web site for HomeRF standards and products.
http://www-124.ibm.com/developerworks/projects/ IBM's web resources for developers. Bluehoc 2.0, a network simulator, can be downloaded from this site.
http://standards.ieee.org You can obtain the IEEE standards on local area networks and personal area networks form this site.
http://www.irda.org IrDA Web site.
http://www.lucent.com/micro/bluetooth Bluetooth information area of Lucent Technologies.
http://www.motorola.com/bluetooth Motorola's Bluetooth resources.
http://www.nokia.com/bluetooth/index.html Nokia's Bluetooth resources.
http://www.semiconductors.philips.com/bluetooth Philips' Bluetooth resources.

Questions

Compared to wired LANs, what are the advantages of PANs with reference to ad hoc networking and spontaneous networking?
Explain the Blutooth protocol architecture.
Explain the salient features of HomeRF technology.
What are the important features and limitations of infrared communication systems?
Compare the various PAN technologies.
Explain the service discovery protocol with an example.

Exercises

1.	Carry out a comparison of different technologies used for personal/home area networking. The comparison can be based on the data rates, security features, number of devices supported, and cost.
2.	SyncML is a markup language developed to synchronize data between two devices (for example, between desktop and palmtop). Study SyncML and prepare a technical report.
3.	Study how wireless networks can be simulated on a LAN. Study the Bluehoc development kit.
4.	Write a technical paper on WAP over Bluetooth and its applications.

Answers

1.	For PANs, Bluetooth and IEEE 802.11 are the most popular technologies.
2.	You can get information about SyncML from http://www.syncml.org and also from http://www.symbian.com, http://www.nokia.com, http://www.ibm.com, http://www.motorola.com, and http://www.ericsson.com.
3.	You can obtain the Bluehoc Development Kit from http://www-124.ibm.com/developerworks/opensource/bluehoc.
4.	Bluetooth provides the radio link between various devices that form a network when they are close to one another. This radio link can be used to transfer WAP applications. Consider the following example: At a railway station, a WAP server can be installed that provides the latest information about the train arrivals/departures and the platform numbers. This WAP server can be Bluetooth enabled. When a Bluetooth-enabled mobile device comes near this WAP server, automatically the server can send the details of the train information to the mobile device over the Bluetooth link. This is known as WAP Kiosk.

Projects

Using a Bluetooth development kit, develop software for a chat application between two PCs using Bluetooth as the wireless link.
Simulate a wireless personal area network on a LAN using IBM's Bluehoc.
Develop a WAP server that can be installed at a railway station. This server has to periodically broadcast information about the details of trains (train number, platform number, and the departure/arrival time) over a Bluetooth link. Whenever any mobile phone goes near this WAP server, automatically the information has to be sent to the mobile device by the WAP server. Use a WAP toolkit to test the application.
Home appliances such as air conditioner and VCD player can be controlled from a mobile phone if the appliance and mobile phone are Bluetooth enabled. Write the software for this type of remote control. You can simulate the control functions for the air conditioner (switch on/off, temperature, fan on/off) on a PC, and another PC can be used for simulating the mobile phone. The link between the two PCs can be either Bluetooth or an RS232 link.

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