January 1998

BY STEVE COPLAND AND HENRY TEBINKA

When development of the USB (Universal Serial Bus) specification began some three years ago, computer telephony was ballyhooed as the next great killer application driving the need for an outsidethebox plug-and-play peripheral subsystem for PCs.

Given several recent announcements of plans for USB telephones, computer telephony adapters, CTI software packages, and other products, the USB market appears to be on the verge of moving into its next logical phase where applications will be deployed. In fact, the steady climb in USB-equipped PC shipments these days indicates that user interest and acceptance of USB has accelerated. According to the market research firm Dataquest, approximately 53 million USB-based PCs will be shipped this year. In addition, the recent introduction of user-ready USB telephony products demonstrates the firm commitment of telecommunications, computer, and component suppliers to the USB marketplace. The time is ripe for a blossoming of USB telephony applications.

USB: A TELEPHONY ENABLER
The architects of USB envisioned a simple means for connecting peripherals, such as telephones and other communications equipment to PCs. No more would printers connect only to printer ports, keyboards to keyboard connectors, and so forth. No more would users be asked to perform the daunting task of opening up their PCs, installing add-in boards, and reconfiguring their systems. USB was designed to solve all of these problems. USB aims to eliminate the confusing array of strange connectors that clutters the back of every PC in favor of a single, standard USB connector. And it doesn’t matter which port a device is connected to. The operating system is smart enough to distinguish one peripheral device (a telephone) from another (a printer). The operating system will sense the types of peripherals that have been connected to the PC via USB and allocate the needed facilities accordingly. Drivers will be provided automatically and no software reconfiguration will be required of the user.

From an architectural standpoint, USB creates a tiered star topology capable of connecting as many as 127 peripherals to a PC (Figure 1). The USB hubs which connect each tier to its next higher neighbor can be embedded in any sort of device, like a PC keyboard, monitor, printer, or even telephone.

Although USB’s overall bandwidth of 12 Mbps supports the low- to mediumspeed peripherals usually found on the typical PC user’s desktop, it was never intended for bandwidth-hungry applications such as broadband video conferencing or high-speed LAN connections. USB complements other technologies such as 1394 Firewire (which can communicate at speeds in excess of 200 Mbps) that have been proposed for high-speed computer input/output (I/O) peripherals.

USB is the first industry standard intended from its very inception to fully enable computer telephony applications. With this technology, both analog and digital telephones and telephone systems can be easily connected to PCs without specialized add-in cards. USB uses Enhanced Time Division Multiplexing (eTDM) for highspeed digital trunk interfaces including ISDN PRI, T1, or E1 lines. Realistically, look for end-user USB products to first come out supporting ISDN BRI, standard analog interfaces and potentially even cable modem and xDSL network interfaces. The fact that USB supports both asynchronous and isochronous communications is critical to computer telephony applications. Isochronous communication transmissions receive guaranteed bandwidth over a USB link and, without such a dedicated communications channel, everyday applications like simple conversations would not be possible over USB.

USB, as a desktop-centric technology, is certainly effective at bridging the chasm between user-and-PC and user-andtelephone. The result is a seamless continuum among user, PC, and telephone. But if this continuum extends only to the frontiers of the desktop, its usefulness is decidedly limited. The very immediate needs of a user at his desk are certainly of paramount importance in the circumscribed realm of each individual, but behind and beyond the desktop, other infrastructure technologies are cropping up that complement USB and provide the next several levels of functionality needed by an entire enterprise to widen and extend the reach of computer telephony.

THE SOFT SIDE OF USB
Aside from hardware implementation issues, USB presents a number of software challenges as well. illustrates the software architecture that comes into play in the development and use of USB-based computer telephony applications.

For USB to provide transparent out-sidethe-box plug-and-play for PC peripheral equipment, the PC’s operating system must be able to sense the type of device being connected and automatically activate software device drivers that will allow the PC to interact with the device. The USB specification defines several device categories, like the Human Input Device Class, the Communication Device Class and others.

Based on the generic types of devices described in the USB specification, generic device drivers can be developed and embedded in the operating system (OS). Beyond the OS’s generic drivers, vendor-specific drivers can be used to optimize the performance of particular peripherals. In addition, Microsoft’s latest operating environment features an abstraction layer for telecommunications and communications applications. The Telephony Application Programming Interface (TAPI) is really a set of complementary application programming interfaces (APIs) that ease the development of computer telephony software. Inserting an abstraction layer in the operating environment frees software developers from having to develop and support different versions of computer telephony applications for each hardware device or platform.

Many developers have already introduced TAPI-compliant computer telephony applications enabling users to perform many cumbersome telephone operations, like initiating conference calls or managing multiple calls at once from the virtual desktop of their PCs. Many in the development community are eager for the release of TAPI 3.0, which is expected to be a robust set of facilities for computer telephony including speech, data, and video call control, phone control, media routing, and the much anticipated Internet telephony capabilities.

APPLICATIONS
The hardware and software pieces required for USB-based computer telephony applications are finally coming together, albeit more slowly than some in the development community might prefer. The key developers of USB have maintained their commitment to the technology throughout its nascent stages. As a result, several new CTI products and systems have recently emerged.

Most of the new USB products being introduced now have targeted the consumer, small office/home office (SOHO), and single-site/work group market segment, but expectations are that USB-based CTI applications will spread to mainstream enterprisewide systems as the market progresses and as enterprise infrastructures are put in place. In addition, USB technology allows for the efficient use of the telephone in conjunction with voice input or speech recognition applications. A telephone — the voice handling form factor that consumers are most familiar with and, therefore, most comfortable with — can become the device for voice input into the PC. Voice commands can be input and speech recognition programs launched from the phone. USB not only enables the sharing of data between PCs and phones, it also enables the most efficient use of existing voice technology as well.

EMBRACING USB IN BUSINESS
For larger businesses, singlesite operations like a branch sales office, or even a workgroup or department within a larger organization, new USBready adapters for small to medium-size business telephone systems have been announced. USB adapters avoid the often nerve-wracking problem of installing add-in boards into a PC and reconfiguring a system. A USB CTI adapter can provide a simple way to implement computer telephony applications (like desktop messaging, for example) without running afoul of technical complications.

Adapters are a very costeffective way for businesses with phone systems to quickly take advantage of new CTI applications running on PCs equipped with USB. In addition, not all users on a PBX system will want or need to implement CTI applications immediately. Adapters give the organization’s communications or IT manager the ability to deploy computer telephony where it is needed and when it is needed.

With a USB adapter and an enabling application running on the connected PC, users have at their disposal many sophisticated call control and management functions like automated dialing, graphical handling of call hold/unhold and answer, point-and-click icons for call transfers, forwards, and donotdisturb states, call screening functionality, and Calling Line ID. Functions that previously may have been difficult for some users to handle are now quite simple. Initiating conference calls, for example, is as easy as dragging the several call icons into the conference field in the application window. The system will also store a great deal of information, such as call duration, last callers, and a call log with complete details.

CONCLUSION
USB is a much needed building block, but it will certainly not be the final word on computer telephony. Enterprise-wide computer telephony applications are receiving their own set of enabling technologies. So, will USB live up to its potential? Ultimately, that decision will be in the hands of the end user. But if the early signs of consumer interest and growth potential are any indicators, the time is truly ripe for the blossoming of USB.

Steve Copeland is product manager of consumer products CTI and Henry Tebinka is product manager of Norstar desktop CTI for Nortel, Inc.(Northern Telcom). Nortel works with customers worldwide to design, build, and integrate digital networks — for information, entertainment, education, and business. For more information on Nortel’s products and services, visit the company’s Web site at www.nortel.com

One new USB product directed toward the consumer/Centrex/ telecommuter end of the market is a two-line analog telephone from Nortel that connects to a PC via USB. The Nortel Meridian 9617 USB Telephone ships with a TAPI 2.1-compliant service provider and a new version of the Nortel Personal Call Manager (PCM) application. (Version 1.0 of PCM was reviewed in the September 1997 issue of CTI magazine and received an “Editors’ Choice Platinum Award.”)

When the PC is turned off, the USB telephone functions as a normal, standalone analog phone. When the PC is powered up, the USB connection allows the telephone to take advantage of the PC’s graphical user interface (GUI), processing power, and information storage capacity. The PC and telephone can work together to manage calls and handle many of the esoteric functions of telephony — like placing and receiving calls — by simply clicking or dragging and dropping icons on the PC desktop.

Since the telephone is usually the “always-on” device while an individual’s PC is often turned off, the USB telephone can store information which will eventually be processed by the PC. For example, call logs and directories can be maintained by the telephone when the PC is turned off. Once the PC is powered-up, Personal Call Manager will automatically inspect the call logs and directories on the telephone and upload any changed information to the PC’s database. What’s more, the feature keys on the USB telephone can be configured to launch applications on the PC, acting as an input device for the computer, just as a keyboard or mouse does. For example, instead of programming a speed dial key to call a friend, program it to launch your favorite computer game.

BY DOMINIC CONSTANTINO

There is no doubt that USB will become the standard in home, office, and in mobile personal computers, the only question is when. As we shift from technology and development of the USB specifications, we must focus on the benefits that USB will bring to consumers. As the easytouse cable and connection for your computer, USB is commonly known as “Plug-n-Play outside the box.” Unfortunately, this oversimplified definition is just that — simple — and as such, does not get a lot of people excited. Sure, I can easily install a new peripheral and my PC will tell me what device I am using. I can also easily install my new devices anywhere on my desktop using a new USB hub device or connect through my new USB keyboard, but there is much more to USB than this.

IN THE FUTURE, MORE FOR LESS
The last thing people want to do is to spend more on a new technology. USB truly gives the consumer more for less. We will see USB digital speakers with an overall less cost and improved quality than today’s offerings. We will see scanners that are lighter, less expensive, and easier to use than what is available today. We will witness the advent of new computer telephony solutions that are impossible to implement with currently available technology. We will also see an explosion of digital video cameras for desktop video conferencing. These new technologies are what USB is all about, giving the consumer more for less.

DESKTOP VIDEO CONFERENCING
Desktop video conferencing brings communications to an entirely new level, and bringing quality, affordable video conferencing to the desktop is what end users are demanding. The ability to converse with scores of people as opposed to a small group in a conference room environment is one of the factors driving video conferencing to the desktop. According to a recent report by Frost & Sullivan, the desktop video conferencing market is expected to boom as applications increase on all major communications levels in business, health care, education and government. By 1998, the market is expected to be $1.65 billion (enduser value), and is projected to grow at a compound annual rate of 45.7 percent to $7.09 billion through the year 2002.

The last 12 months has seen rapid advances effect the video conferencing industry. New technologies, including compression algorithm techniques, communications and conferencing standards, microprocessor advances, broadly available featurerich software, and USB are quickly changing the face of this industry.

COMPRESSION/DECOMPRESSION
One of the core technologies impacting video conferencing is the codec. The name comes from the compressing and decompressing of video data. There are three main technologies in modern video compression: Interframe coding, DCT transformation, and Entropy coding.

Interframe Coding allows you to remove redundancy between frames. It also does motion compensation that tracks when an object moves.

DCT Transformation allows you to convert 8x8 regions of an original picture to a much small number of coefficients to encode.

Entropy Coding uses techniques such as Huffman coding to compress data to the smallest amount of bits possible.

Each of these techniques can be used alone or in combination to compress data.

FIRST THE SOFTWARE, THEN THE INPUT DEVICE
Video conferencing software, such as Microsoft’s NetMeeting 2.0, and others, has become widely available as of late. Incorporating standards, such as H.323, into the video conferencing software has also solved the issue of compatibility. Now that we have the software needed to do video conferencing, what we need is the input device.

That input device is a digital video camera using USB technology. Using a digital camera eliminates costly and hard to install capture cards that analog cameras require, and USB provides a high-performance solution. At 12 Mbps, the USB connection is much faster that any parallel or serial connection which is less than 1 Mbps. USB also uses less host processor utilization, which allows your CPU to continue serving other applications. USB is easy to install, affordable, and reliable, and helps provide a quality video conferencing solution.

CONCLUSION
“Now is the time for desktop video conferencing.” If you are a part of the teleconferencing world, you have heard this statement at every trade show for the last five years. USB is the ingredient that will finally turn this statement into reality. According to a release from Forward Concepts, “The market for desktop video conferencing is poised to take off, fueled by the continuing declines in cost, improvements in quality, and the need for business solutions configured as personal computer add-on devices. Desktop video conferencing is expected to grow 40 percent, from $360 million in 1997 to $600 million in 1998.” The only way to get there is through the USB.

Dominic Costantino is director of sales and marketing at Xirlink. Xirlink is known for several products, but has become one of the world’s leading suppliers in the highly competitive Video CD market. Xirlink’s VCD solution includes a complete family of highperformance control boards, Karaoke modules, and complete Video CD players. The company produces highly integrated solutions for the consumer electronics and personal computer industries. For more information, visit the company’s Web site at www.xirlink.com