SE 4C03 Winter 2005 Bluetooth Wireless Network Technology Researcher: Daren Tan Shen Hau Last Revised: April 4, 2005
Bluetooth As everyone will ask, what is Bluetooth? Bluetooth is a new technology that uses short range radio frequency to communicate between devices. This technology is supposed to help simplify the communication between all devices such as between Internet devices or between cell phone devices. In this research, I will first talk about how Bluetooth wireless works, then discuss its advantages and disadvantages, briefly talks about it security issue, about the future of the technology and lastly a conclusion for it. How does Bluetooth wireless works? Bluetooth devices need four things in order for it to function properly; they are a radio frequency for receiving and transmitting data, a module with a baseband microprocessor, memory, and an interface to the host device. And for any devices to qualify as a Bluetooth device, they must satisfy the following seven protocols: 1. Radio Protocol it serves as the digital signal-processing component of the system. It works similarly as other wireless technologies of today. Bluetooth will transmit data over a radio frequency in the form of bits. It uses Gaussian Frequency Shift Keying (GFSK) as its modulation method. Then another Bluetooth device will try to pick the bits that are currently over the air. 2. Baseband Protocol it manages physical channels and links. The physical channel makes the transmission rapidly hops among the available channels by dividing the transactions into dedicated time slots each for the Master and the Slave. The links which Bluetooth can make are Asynchronous Connection Less (ACL) data link and Synchronous Connection Oriented (SCO) voice links. 3. LMP Protocol which is link manager protocol, it controls the link setup, authentication, configuration and other low level protocols. It establishes all the connections for all Bluetooth devices and help them communication among each other using this protocol. 4. HCI Protocol stands for host control interface. It provides a command interface to the baseband controller and link manager or one would say it provides a uniform method of accessing the Bluetooth baseband capabilities. 5. L2CAP Protocol stands for logical link control and adaptation layer protocol, a processor which gives connectionless data services to higher level protocols using protocol multiplexing capability, segmentation and reassembly operation, and group abstractions. 6. RFCOMM Protocol this protocol is a simple transport protocol, but it can allow Bluetooth devices to have up to 60 simultaneous connections. 7. SDP Protocol stands for service discovery protocol, uses a request/response model where the transaction have only one request protocol data unit and one response protocol data unit. With all these protocols together, it will form a Bluetooth device. As it is really hard to get all these to work together, that is why Bluetooth is not yet compatible to all devices known. Why Bluetooth? Many people believe that there is a future for Bluetooth technology. With devices moving towards wireless and a lot of people trying to blend into the wireless world, they 1
will believe that Bluetooth will be able to compete with other wireless technologies such as WiFi and over take technologies such as Infrared Data Association (IrDA). A brief comparison table can be found on Table 1 on the next page. Compare to a few years ago, not many people would know what Bluetooth is, but in today s world, most of them are using it in devices such as cellular phones and computers. It is slowly being use in today s technologies. Most devices that use Bluetooth are Internet Bridge, wireless headset, and automatic synchronization. Internet Bridge is a useful and timesaving feature in the use of mobile phones, which Bluetooth is ideal for, is rapidly increasing. Wireless headset, another Bluetooth device, allows users to use his or her mobile phone even when the mobile phone is being kept in the briefcase. This will help the user keep their hands free for other important tasks such as driving a car. Another use of Bluetooth is automatic synchronization, it can help the user synchronize his or her calendars and address books. Technology Bluetooth WiFi Infrared Ideal Application Cable Replacement Ad Hoc PAN High speed LAN Range (m) 10-100 100+ 1 Data Rate (Mbps) <1 11 16 Cost 10 45 10 TABLE 1 Technologies comparison table Device Sunchronization data transfer Advantages and Disadvantages As every technology has its own advantages and disadvantages, here are some advantages that all wireless technologies have. The advantages that a wireless technology such as Bluetooth are o they eliminates the problem of having wires and cables connecting between both stationary and mobile devices o they can facilitates both data and voice communication for short distance, making it an economic wireless solution o offers the possibility of ad hoc networks and also delivers the synchronizations between all personal devices o it has a global technology specification of an universal radio interface in 2.5GHz ISM frequency band o no setup is needed as it is always turn on in the background o the actual radio device is an inexpensive device o it contain techniques for avoiding and dealing with interference, they include transmitting weak signals and using frequency hopping o it is a low power consumption device The disadvantages that Bluetooth has comparing with other wireless devices such as WiFi are as follows o it does not have the best security o it has a really short range of communication o it is not compatible in all devices o it may interfere with other devices that may be using the same frequency, such as cordless phone or other wireless technologies that uses the same radio frequency 2
o it is still a new technology which may not be as popular as other wireless technologies As stated in the disadvantages, it is yet a new technology currently being implemented on daily devices, it might still have some disadvantages on it, but in the years to come, there might be newer versions of Bluetooth which will overcome those disadvantages and work towards their main advantage which is inexpensive. Bluetooth Wireless Security As security is concern, it is one of the major problems that a wireless technology has. For someone to breach a non-wireless technology, they need to tap into the actual line to see the flow of bits, but for them to breach into a wireless technology, all they need to do is be in the range of the transmission. In order for Bluetooth is keep their transmitted data secure, they have their own security which consists of the following four essential parts; authentication, data integrity, nonrepudiation, and confidentiality. Authentication part here will make sure that the transmissions and messages are being authenticated and then the recipient can only receive specific categories of the information only. Data integrity part will make sure that the information being transmitted is still unchanged from its source. Nonrepudiation part will make sure that the sender will be notified that the information or data had been delivered. Lastly the confidentiality part is to make sure that the information being transmitted can only be seen or read by certain authorized personals only. This is how Bluetooth ensure its security; a device will first have to do the authentication by using personal identification number (PIN), they both have to have the same PIN in order for the connection to exist. When a connection is being setup between the two devices, and encryption of the data may be used to allow both devices to communicate securely. Bluetooth Wireless Future Although Bluetooth has not played a major roll on current technologies, but it is climbing towards that goal step by step as many people are starting to see the importance and benefits of using Bluetooth technologies in wireless network. Recently, a newer version of Bluetooth (Version 1.2) came out with improvements in both security and capabilities. A lot of companies are starting to do research on its technology and try to bring its benefits towards applications of wireless technology. In the near future, people might be using Bluetooth access points to create large ad hoc network for the use of offices and home. Conclusion Bluetooth wireless technology are becoming more advance since the born of its technology. There is no doubt that it will keep on expand until it takes over the wireless technology of the others with its major price advantage. And also since there are not many developments being done in the case of wireless USB that I have been heard, so Bluetooth can now be said to have monopolized the wireless network on short range and its low power technology. It is only a matter of time before it becomes a technology as popular as current WiFi technology. 3
References 1. Curt Franklin, How Bluetooth Works, http://electronics.howstuffworks.com/bluetooth.htm 2. No Author, Bluetooth-Future, http://wiki.media-culture.org.au/index.php/bluetooth_-_future 3. No Author, Wireless Networking, http://www.jr.com/templates/guides/wireless.tem 4. Justin Blasdel, The Future of Bluetooth Technology, http://faculty.mckendree.edu/kian_pokorny/course_pages/csi490/bluetooth.pdf 5. No Author, Bluetooth Tutorial Specifications, http://www.palowireless.com/infotooth/tutorial.asp 6. Riku Mettala, Bluetooth Protocol Architecture, https://www.bluetooth.org/foundry/sitecontent/document/protocol_architecture 4