ONLINE, May 2001
Copyright © 2001 Information Today, Inc.
Internet world is replete with buzzwords, trends, and rumors about the latest technologies coming to the fore. Ask anyone these days what the new darling of the Internet is, and they will tell you without a doubt that it's wireless technologies. Online journals, newsgroups, discussion forums, and print publications concerning the Internet are engaged in a furious exchange of opinions in which the pros and cons of various wireless data transmission protocols are alternately praised and reviled. One such protocol, simultaneously adored and despised, is Bluetooth (http://www.bluetooth.com).
According to Cahners In-Stat Group (http://www.instat.com) in its July 2000 report, "Bluetooth 2000: To Enable the Star Trek Generation," the manufacture of Bluetooth-enabled equipment will exceed one billion units by 2005, and the market will be worth some $5 billion. Frost & Sullivan (http://www.frost.com) is equally optimistic. It forecasts global shipments of Bluetooth-enabled products to reach over 11 million units in 2001 and predicts $2.5 billion in revenues.
The name itself is enough to start you wondering. When discussing the dry topic of data transmission protocols, we are used to throwing around terms such as TCP/IP, RIP, or PPP. Whether or not we can decipher the acronym, the terms have been used so often that most people have some idea of what we are talking about. But mention Bluetooth to the uninitiated and you're likely to be met with puzzled looks.
The Bluetooth standard is a complex conglomeration of protocols arranged in a protocol stack, which, when diagramed, somewhat resembles a Dagwood-style sandwich. To put it more simply, Bluetooth relies upon radio frequencies to transmit data, providing a universal bridge between devices on a network, or between devices from the outside and an existing network using a combination of circuit and packet-switching technologies. Bridges have the ability to link together different types of networks because a bridge delivers data based upon the MAC (Medium Access Control) address that is hard-coded into the network hardware by the factory that manufactures it, and it is unique for every device. This differs from other network devices, such as routers, that deliver network data based upon routable protocols such as TCP/IP. Because bridges operate at a lower level of the protocol stack, standards like Bluetooth can link unlike devices within a local network. The data is, like all network traffic, divided into packets. However, because Bluetooth is designed to work in the RF environmenta very noisy portion of the electromagnetic spectrumit employs the use of shorter packets for transmission, and combines this with fast frequency-hopping to ensure a fairly robust connection.
When a message is sent over a Bluetooth connection, each packet is transmitted on a different frequency within a range of 2.4-2.4835 gHz. After the first packet is transmitted, the Bluetooth controller hops to a different frequency before sending out the next packet. The determination of which frequency within the given range will be used to start packet transmission is semi-random and is controlled by the Bluetooth Radio portion of the protocol stack. This frequency remains fixed for the duration of each packet. However, once the initial transmission frequency is chosen for the first packet, the remaining frequencies are cycled through for each subsequent packet in a determined fashion. This is known as the phase.
Bluetooth can send data along four different channels simultaneously. Included is an asynchronous data channel (meaning packets are not sent out in pre-selected timeslots governed by the processor clock, but rather whenever there's an opportunity), and up to three simultaneous synchronous voice channels, or a combination channel, simultaneously supporting asynchronous data and synchronous voice. Each synchronous voice channel can support transfer rates of 64 kbps, and the asynchronous channel can support a bi-directional (two-way) asymmetric link of up to 721 kbps in either direction while permitting 57.6 kbps in the return direction.
So what does all of this have to do with libraries and information professionals? A lot, if the push to promote the standard is successful.
In Ken Varnum's insightful article entitled "Information at Your Fingertips: Porting Library Services to the PDA," appearing in the September/ October 2000 issue of ONLINE, he illustrates how Ford Motor Company's corporate library is taking the initiative in porting library services to handheld devices, such as the PDA. The article demonstrates precisely how the engaged and aware information professional is finding new avenues for reaching out to users. Varnum explains how the library has effectively employed a third-party software package to translate Web pages into PDA-friendly files that users can download and take along with them on trips away from the office. This technology allows users to view documents, check and respond to email messages, and even fill out online forms. The drawback, of course, is that the user must return to the office and interface the PDA with a PC in order to synchronize the devices and actually transmit the email, form, etc. The PDA itself is not connected online and does not allow for real-time operation.
Now, take that scenario and replace the old PDA with a new Bluetooth-enabled PDA. Then suppose traveling users find themselves at a hotel, airport, or library with a Bluetooth-enabled network connected to the Internet. Our users can now not only respond to email messages, but send them as well. They can conduct research and download updated documents. They can even use their PDAs to make phone calls. In short, the user has been given the type of information access that would have been unimaginable just a few years ago.
LEXIS-NEXIS has teamed up with a primary developer of the Bluetooth Standard and member of the Bluetooth SIG, Red-M, a subsidiary of the Dutch company Madge Networks, to launch m-news. With content from LEXIS-NEXIS, m-news will provide subscribers with email updates and hypertext links to stories located on the Red-M Web site that detail Bluetooth industry developments. Registration is required but the service is free (http://www.redm.com/aboutred/newsroom/content.asp?Article=21).
And if all of that sounds too good to be true, you may be right.
Another significant problem is that of interference. As Joe Wilcox, staff writer for CNET News.com notes in his September 15 article, "As Bluetooth Nibbles, Competition Lurks" (http://news.cnet.com/news/0-1003-200-2784702.html), the issue of frequency interference could potentially harm Bluetooth a great deal. Because Bluetooth uses the unlicensed radio portion of the electromagnetic spectrum, transmissions in that band must compete with industrial microwave ovens, stadium lights, garage door openers, cordless telephones, and virtually any wireless household appliance, even baby monitors. More detrimental to the long-term health of the Bluetooth standard, however, is its interference with two other wireless standards using the same 2.4 gHz band that are older and more established: that of the 802.11B and the HomeRF. While these standards lack the catchy name and media hype that Bluetooth currently enjoys, 802.11B allows portable electronic devices to connect to an existing network at distances up to 300 feet rather than the paltry 100 feet that limits Bluetooth. Additionally, HomeRF recently won a ruling from the FCC that allows it to expand its bandwidth to 5mHz (up from 1mHz), effectively increasing transmission speeds to 10 Mbps. While there is room for these standards to operate in a complementary fashion within a wireless network environment, another challenge rears its head: compatibility.
The bickering over who has control over various portions of the spectrum gets even uglier when dealing with the unlicensed portion that Bluetooth and other standards exploit. There is little that the FCC can do to regulate this area and still preserve the integrity of maintaining an open portion of bandwidth. To get around some of the interference problems, both HomeRF and Bluetooth use frequency-hopping. In contrast, the 802.11B standard has developed around a direct-sequence model in which only one frequency is used for transmission. The use of these two different methods introduces incompatibility between devices. A frequency-hopping Bluetooth device and a direct-sequence 802.11B device would not be able to communicate with each other.
Add to that the security problems inherent in the Bluetooth standard, and the outlook appears grim. There is a security layer within the specification for Bluetooth, but by all accounts, it is easily misunderstood and prone to confusion. As Wilcox reports, an analyst with Gartner, a leading Internet industry consulting firm states, "Bluetooth is a disaster waiting to happenÉthe specs cover (security), but unless you know what you're doing, it's possible to implement the spec in such a fashion (that) you aren't doing anything worthwhile."
Maryellen Mott Allen (firstname.lastname@example.org) is Instructor Librarian, University of South Florida Tampa Campus Library.
Comments? Email letters to the Editor at email@example.com.
Copyright © 2001, Information Today, Inc. All rights reserved.