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The Marriage of Communications and Computing

Wireless Computing

Andrew Seybold

Imagine that you are in a meeting with your notebook computer open in front of you. Suddenly, the cursor begins to blink and a new e-mail message is displayed on the screen. Your computer isn't plugged into anything, your cellular phone is in your briefcase under the table, but you are receiving e-mail over the wireless network. How is this possible?

Over the past ten years, the communications and computer industries have developed new technology products that enable mobile workers to be more productive. As a result, our work force is able to spend more working hours in the field.

Today's mobile workers number some 45 million in the United States alone. They've gone from simple beepers to lightweight mobile phones; from 30-pound luggables to 5-ounce pocketable PCs. The devices are lighter and more powerful, but they're still separate devices with limited ability to work together to support the mobile worker's need to access their own e-mail, connect to their corporate information resources, and perhaps to send and receive faxes. Palmtops and mobile phones alone are no longer enough.

The merger of computing and communications

The computing and communications industries have been working together for the last five or six years to provide mobile workers with the same level of access to their computing data as they have to people via their mobile voice phones. Wireless networks originally developed for voice communications have been expanded to serve as wireless data pipes. Further, in more than a dozen countries including the United States, data-only wireless networks have been built and put into service.

Fortunately, the new wireless voice systems being implemented today are based on digital technologies, as are the existing data-only networks. In addition, most of the older analog wireless networks are being upgraded to digital. Digital networks are better suited to data, and most are capable of providing both voice and data communications.

With the recent success of palmtop and handheld computers, as well as the emergence of a new generation of still smaller and lighter mobile computers, there is renewed interest within the computing community for wireless data access. But implementing wireless data remains a complex and expensive proposition. Because the many wide-area networks and many different digital standards, computer vendors have been frustrated in their efforts to build wireless communications solutions into their mobile computers. Communications companies have had to find ways to enable their communications devices in the computing world. They've developed a number of solutions, each with it's own set of problems.

The communications industry has been trying to find a solution that would enable mobile computing devices to connect to their wireless networks. Computer companies have been trying to find a way to connect their devices to wireless networks. While they share the same goal, each industry has been focusing on its own technology without adequate consideration of the requirements of the other.

At Long Last: Bluetooth!

Eventually, companies from both industries decided that they needed to work together to find a common solution. They knew that there was a demand to merge mobile computing with mobile communications, and they understood the problems.

The result of their collaboration will be a technology code-named "Bluetooth." Rather than trying to design computers so they will work with any wireless interface card or modem on any frequency, using any one of a number of digital technologies, they decided to design a single, common radio that could be built into every mobile computer?

The computer and radio combination could then be optimized to minimize interference -- a task made easier for computer engineers with only one radio. And with a single-radio solution, computer vendors are no longer faced with having to make a network choice or supporting multiple networks.

The Bluetooth communications device is a small, low-powered radio on a microchip. It "talks" to other Bluetooth-enabled products, eliminating the need for cables or infrared beams to connect portable computers, cellular phones, printers, fax machines, etc. Bluetooth will make it possible to connect enabled devices on a one-to-one or one-to-many basis.

Since the chip supports both voice and data communications, applications will range from something as simple as replacing the cable between a mobile computer and cellular phone, to more complex connections involving multiple computers, and extending into hands-free voice communications for wireless phones in vehicles.

A "win" for the computer and communications industry

Bluetooth appears to be a "win" for the computer industry. Most computer manufacturers have been unable to determine which wide-area networks to support. Bluetooth eliminates the need for a wide-area network decision. This can be left to the makers of phones and modems and other wide-area network devices. As an added bonus, the inexpensive built-in radio makes it easy to quickly connect two or more Bluetooth equipped devices locally.

Computer manufacturers have known for some time that wireless communications will be important for mobile computers. The Bluetooth solution provides a short-range ad hoc network, enabling users to send and receive e-mail without a phone and synchronize their calendar and phone book automatically whenever the two devices detect each other's presence.

Bluetooth also appears to be a "win" for the communications industry. Communications companies will no longer have to build external cables and PC cards to connect mobile data devices to their wireless phones. Nor do they have to build wireless network cards for the mobile user to interface with company computers. A Bluetooth module built into the mobile phone or connected to the network will enable these devices to send and receive data to and from any Bluetooth-equipped mobile computer.

The "compelling" reasons for incorporating Bluetooth are to wirelessly connect mobile computers to cellular phones, and to establish small workgroups quickly and easily. As the number of Bluetooth-equipped devices grows, so will their uses. Printers, fax machines, LANs, and more will be able to communicate with each other.

I expect to see most other two-way wireless devices equipped with Bluetooth, including: cellular phones, two-way pagers, and wireless data-only terminals. I also expect to see many computer companies build add-in and add-on modules to enable existing wireless and computing combinations.

Bluetooth is a universal solution to what has been a perplexing connectivity problem. I am really excited about this technology and what it will mean to mobile computing and communications. To me, Bluetooth represents a no-brainer concept at a reasonable price. I believe that any computer or communications vendor building mobile devices or accessories should embrace this concept and these products ¡ immediately if not sooner!

Bluetooth has been designed to solve a number of connectivity problems experienced by mobile workers and consumers. And it does so in a simple, neat package that is inexpensive--the OEM only pays for the cost of the module.

Bluetooth was well conceived, and I believe that it will be well received. I will certainly encourage all of my clients to make Bluetooth a part of their strategy as they move forward. My only disappointment is that I have to wait until mid-1999 before I can have a Bluetooth-enabled set of mobile computing and communications devices.
 

A Look at Bluetooth

The Bluetooth wireless technology will use one of the available unlicensed, yet virtually worldwide radio bands--2.4 GHz--and it can support both voice and data. Everything needed to be Bluetooth-capable will be contained in a module that will cost between $15 and $20 at first. Driven by volume, the cost should drop to about $5 by 2001.

The low-power radio module can and will be built into mobile computers, mobile phones, printers, fax machines, and network connection points. While its primary focus is to be the wireless connection between mobile computers and/or between computers and wireless network devices such as cellular phones, Bluetooth supports data speeds of up to 721 Kbps (including a 56 Kbps back channel) as well as three voice channels.

Bluetooth is a collaborative effort between communications and computing companies. Ericsson and Nokia independently were working on similar radio concepts. They understood the need for a partner on the computer side and each approached Intel with the idea. Intel quickly grasped the importance of the concept and has been instrumental in driving the concept to reality. The initial group working on Bluetooth also includes IBM, Toshiba, Motorola, and Palm (3Com).

Bluetooth has been designed to operate in a multi-user environment. Devices can be enabled to communicate with each other by the computer or communications device end user. Up to eight users or devices can make up a "piconet" and ten piconets can co-exist in the same coverage range. Since each link is encoded and protected against both eavesdropping and interference, Bluetooth can be considered a secure short-range wireless network.

The balance of the specifications are as follows*:

Frequency Band: 2.4 GHz (unlicensed ISM Band) 
Transmitter Power: 1 milliWatt (0 dBm) 
Technology: Spread Spectrum Hybrid Direct sequence and frequency hopping 
Maximum Voice Channels: 3 per piconet 
Maximum Data Channels: 7 per piconet 
Data speed: 721 Kbps per piconet 
Expected System Range: 10 meters (40 feet) 
Number of Devices Supported: 8 per piconet, 10 piconets in coverage area1 
Security: Yes, link layer 
Power Requirement: 2.7 volts 
Power Consumption: 30 uA sleep, 60 uA hold, 300 uA standby 
8-30 mA transmitting 
Module size: 0.5 square inches 
Interference: Bluetooth minimizes potential interference by employing fast frequency hopping 1600 times a second. 

*Features currently planned are subject to change without any notice. Actual features may vary.
1 Graceful degradation of the symbol rate for more than 10 piconets in a given coverage area.

 Seybold gray ABOUT THE AUTHOR
  Andrew Seybold heads a computer and communications industry consulting and newsletter company, and publishes the well-respected Andrew Seybold's Outlook on Communications and Computing. He has an extensive radio communications and computer background, is recognized as one of the top analysts in these fields, and is a founder and President of the Portable Computing and Communications Association (PCCA). Andrew Seybold's Outlook can be reached at 408-338-7701, fax 408-338-7806, e-mail: lseybold@outlook.com

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