Multimode modems cut phone bills, facilitate document conferencing, and enable "visual" interactive voice response
Andy Reinhardt
In a small office, where you're trying to keep costs to a minimum, having to install two or more separate phone lines for voice, data, and fax calls seems wasteful. A new class of multimode modems solves this problem with an added benefit: Not only can you share a single line among multiple uses, but you can do so concurrently. The only other way to accomplish the same thing is via ISDN, which still isn't available in many areas and costs more than analog phone service.
The most obvious use for multimode modems is conferencing, where two or more users view and discuss documents at the same time. But there are dozens of other potential uses, including vis
ual voice-response systems and information access, product support, show-and-tell remote presentations, multimedia messaging, and business-card exchange. Many of these applications are especially tempting to mobile users, telecommuters, and owners of home-based businesses.
The simplest, least expensive, and likely most widely installed solution will be a new class of switching modems built using the VoiceView technology from Radish Communications Systems (Boulder, CO). VoiceView runs across conventional phone lines and equipment, sharing a line, for instance, between a phone call and a file transfer by switching quickly from voice mode to data mode and back again. Radish has licensed VoiceView to major modem manufacturers (representing roughly 85 percent of the market, Radish says) and software companies, including Microsoft, in a bid to establish it as the baseline standard. The cost of adding VoiceView support to modem firmware is so low (Radish charges only a one-time fee, not a royalty) that analys
t Harry Newton, president of Computer Telephony Expo (New York, NY) expects 60 to 70 percent of all new modems sold by the end of 1995 to include support for mode switching.
Radish isn't the only game in town, however. AT&T Paradyne (Largo, FL) and Multi-Tech (Mounds View, MN) make modems that let you combine voice and data on a single line simultaneously, rather than switching between the two modes. (
See the photo
.) These cost more money--on the order of $500--and they use proprietary (and different) modulation schemes, which means that you have to have the same modem on both sides of the line. But through an agreement with Radish, AT&T will also support VoiceView, so if an AT&T simultaneous voice/data modem calls a Radish-type modem, the AT&T device can "fall back" into a switching mode.
Another option comes from Spectrum Signal Processing (Burnaby, BC), which specializes in products based on DSPs (digital signal processors). Spectrum has already staked out a position in
computer/telephony boards (the Envoy II fax/modem) and multimedia (SoundChoice32) and has recently introduced the OfficeF/X, a fax/modem/sound card with software for unified inbox, Internet mail, and call management.
In early 1995, Spectrum plans to go a step further, adding support for simultaneous voice and data, first on a 14.4-Kbps "soft" modem and later in a 28.8-Kbps implementation. For the time being, Spectrum's solution will be proprietary, but the company hopes to include Radish-compatible switching and is also working with other players on standards for simultaneous voice and data.
In a sense, all these schemes are in a race against time, because what they provide for customers can be done better and faster by ISDN digital telephony. ISDN's 2B+D basic rate provides two 64-Kbps voice/data channels and a 16-Kbps data channel, for a net bandwidth of more than four times that of a V.34 modem. But Radish, AT&T Paradyne, Spectrum, and others are counting on the current conventional wisdom th
at says it will be years before digital telephony is ubiquitous--not just ISDN service but also compatible phones and other devices on customer premises.
The Baseline
By positioning its technology as the least common denominator, Radish hopes that users will soon be able to assume the presence of VoiceView modems on the other end of the line. To that end, Microsoft plans to build support for VoiceView into Windows 95. Developers will start to count on an installed base and write new programs that take advantage of multimode communications. "VoiceView is an arbitrator," says Paul Davoust, vice president of marketing at Radish. "It's the fundamental glue in computer-telephony integration."
Whether
switched or simultaneous
, the basic benefit of multimode modems is that you can talk and exchange data during a single phone call. You could discuss a project with a colleague, transfer a spreadsheet file, view the spreadsheet together while discussing its num
bers, fax over a mock-up for the packaging design, and so on, all while using one live phone line.
Document conferencing programs from Intel (ProShare), Crosswise (Face to Face), Future Labs (TalkShow), and DataBeam (FarSite) are obvious candidates for multimode modems, because by definition they involve two users discussing and viewing data at the same time. None of these packages now supports voice directly; to the contrary, they require that you use two phone lines, one for the voice call and another for the modem to exchange data. Moreover, the two calls must be placed separately, and you accrue twice the service charges. By contrast, riding on top of a multimode modem lets you initiate a single call and share the service cost among uses. Most document conferencing programs will be able to support multimode modems with little or no modification.
One conferencing package, ShareVision PC3000 from Creative Labs (Milpitas, CA), was designed from the very beginning to support simultaneous audio,
video, and data communication. In fact, the bundled hardware and software package includes a proprietary 28.8-Kbps multimode modem that compresses audio and video (using a scheme called Vector Adaptive Transfer Processing) and multiplexes it with data across a single line. Creative has not commented on whether it plans to move toward a standards-based modem.
Trade-Offs
The switched and simultaneous solutions have opposing strengths and weaknesses. Radish boasts of its ability to work transparently on nearly any phone infrastructure (i.e., analog or digital PBXes, Centrex, and so on). But with switching modems, conversation ceases during data transfers. The duration of the gaps in speech depends on the size of the file transfer or fax. However, both voice and data communication occur at their normal rates: standard-quality audio and 9600-bps or faster (depending on the modem) data.
The AT&T and Multi-Tech modems share bandwidth among uses; this means that conversation by it
self happens at a normal rate, but when you talk and exchange data at the same time, data transfer occurs at a maximum of 4800 bps and speech quality is degraded. The unusual modulation schemes used in these devices can also pose problems when running over certain digital phone switches or IVR (interactive voice response) systems.
The quality of Spectrum's MWave-based solution depends on the underlying soft modem. In a 14.4-Kbps version, 13 Kbps is allotted to voice (8-bit digitized voice, sampled at 16 KHz and compressed using GSM (Global Standard for Mobile communications [the pan-European digital cellular standard]) encoding, leaving only 1400 bps for a trickle of data communication during conversation. But during minute breaks in speech, data speed surges to 14.4 Kbps. In the planned 28.8-Kbps product, voice traffic will stay at 13 Kbps, and data speeds will vary from roughly 15.8 to 28.8 Kbps. Short of ISDN, this will be the fastest way to do simultaneous voice and data. The OfficeF/X board lists
for $349, so the street price for the enhanced version probably won't be much higher.
Smorgasbord
Most people are so accustomed to using a phone while working on their PCs that it never occurs to them how the two devices could be integrated. Aside from file transfer and document conferencing, multimode modems permit a variety of remote-access applications.
For instance, if you had a caller I.D. service (with or without the capability to associate incoming numbers with entries in a database) and a multimode modem fronting your voice-mail system, you could implement a visual inbox that would let you call your voice mail from a PC (locally or from the road), see the numbers (or names) of the people who had called you, and select in any order the messages you wanted to hear. Or, if you implemented a unified "multimedia" inbox, you could make a single call to a message server that would relay your voice mail, E-mail, and faxes at one fell swoop or would let you receive multimed
ia messages containing both voice and images.
Voice and data together will facilitate remote presentations, in which you talk somebody through a Harvard Graphics slide show, show someone real estate listings with maps and photos, or view and discuss a medical image. It could also be a boon for customer support, because a technician could, during a single call, talk to a user, perform remote diagnostics, assume remote control of a troubled system, and capture files and screens. When the presentation or support call is finished, the participants could exchange business cards in the background by clicking on an icon (this would rely, of course, on the emergence of a standard for representing electronic cards).
Perhaps the greatest and most underappreciated application for multimode modems is as an enhancement to traditional IVR systems, for applications ranging from banking to shopping to order entry. Given that multimode modems can "query" the capabilities of devices on the other end of the line,
information-services providers can set up their IVR systems to be audio-only if a caller just has a phone or to switch into a visual mode if a caller is using a multimode modem. In the latter case, service providers can enrich their offerings with text, graphics, and images, as well as provide customers with visual confirmation of transactions. Users will be able to select options visually, instead of having to listen to long lists of spoken menu choices.
Davoust argues that supporting textual and graphical interfaces via conventional phone lines, using a standardized protocol, will let service providers differentiate themselves from their competition. "This will make it possible for people to get value-added phone services from call centers," he says. Thus, a customer with a multimode modem, dialing into a ticket agency, might be able to choose a seat visually, whereas a traditional voice customer would have to rely on the luck of the draw. Radish is so convinced of the business opportunity for intera
ctive "service applications" such as these that it believes the "person-to-provider" market will precede and initially outpace that for "person-to-person" mixed-mode communications.
Radish is selling tools for developing Unix- and OS/2-based VoiceView servers in conjunction with Dialogic, which has a 65 to 70 percent market share of call-processing boards with four or fewer ports, according to Nancy Jamison, a senior analyst with Dataquest (San Jose, CA). The pairing of Radish and Dialogic is especially promising for small businesses looking for an inexpensive way to jump into interactive merchandising and customer relations. With a single server, you could set up a purely voice-based service and, driven from the same underlying databases and menus, an interactive on-line service. A customer could then use the service visually or through voice menus, depending on the device he or she was dialing in on.
Smooth Sailing
Despite Radish's effort to establish a baseline standard
, users may not be willing to settle for switching voice and data when solutions such as the Spectrum 28.8-Kbps modem arrive on the market. Barry Jinks, president of Spectrum, argues that although his firm's product is similar in concept to the simultaneous voice/data products from AT&T Paradyne and Multi-Tech, it benefits from being based on a DSP and, thus, being upgradable via software. As for Radish, Jinks contends that switching solutions aren't feasible for some applications, such as "telegaming," where two users in remote locations collaborate on a video game, because the sound and images have to be synchronized.
Spectrum, too, could enjoy only a limited window of opportunity if ISDN becomes more widely available throughout the U.S. and the world. Sharing less than 30 Kbps of bandwidth between a voice channel and simple data transfers is a reasonable solution. But as soon as you introduce multimedia data types--24-bit color, animations, digital audio, and especially video--the requirements skyro
cket. Even basic-rate ISDN isn't a fat enough pipe for sending video clips from your home office to a client across the country.
Applications for MultiMode Modems
-- Document conferencing
-- File transfer or fax during conversation
-- Remote presentations
-- Product support with remote access
-- Visual voice mail
-- Multimedia messaging
-- Enhanced voice-response systems
illustration_link (28 Kbytes)
Two new types of modems let you combine voice and data on a single line. Switched devices modulate data over a carrier and then alternate the full modem bandwidth between that signal and a normal voice channel. Simultaneous devices digitize voice and merge it with a data signal and then modulate the synthesized bit stream over a single carrier, in effect sharing the modem's bandwidth
between the two sources. Both types typically come with software that supports file transfer during voice phone calls, and many include (or support) whiteboarding packages for sharing and marking up documents while discussing them.
photo_link (19 Kbytes)
The AT&T DataPort 2001 Multimedia Communicator modem carries both digitized voice and computer data simultaneously over the same carrier, allowing you to talk and swap documents with somebody on the other end of the phone at the same time. The technology is proprietary, so you need at least two DataPort 2001s, but AT&T has agreed to support the Radish Communications VoiceView modem-switching protocol.
Andy Reinhardt is BYTE's West Coast bureau chief. You can contact him on the Internet or BIX at
areinhardt@bix.com
.
Doing It All on One Line
