Six hundred years ago, William of Occam admonished scholars to avoid multiple answers where one would suffice. But few heeded his advice. Physicists have been trying for decades to come up with a unified field theory that encompasses both gravity and electromagnetism. So far, they haven't had much luck. Now, telecom vendors have embarked on a quest for unified messaging -- a single in-box for voice mail, e-mail and faxes. Might they succeed where others have failed?

The long-promised convergence finally is happening. As voice, fax and video migrate to IP-based networks, accessing all types of messages from a single device becomes possible. Indeed, products are popping up all over the place that let users receive voice-mail messages on a notebook PC (as e-mail attachments), e-mail messages on a wireless phone (read via a text-to-synthesized speech server) or let subscribers manage all of their messages (regardless of format) from a personal Web page. Unified messaging is a natural byproduct of Internet-driven media convergence.

However, there isn't necessarily a market for something just because it is technically feasible. The often-cited benefits of unified messaging are convenience and efficiency. But whether subscribers have multiple in-boxes, each optimized for a specific medium, or one in-box that handles all media as best it can, may be just a "six of one, half dozen of the other" conundrum.

PulsePoint Communications (www.plpt.com), a developer of what it prefers to call "NextGen Messaging," believes the industry is placing too much emphasis on road warriors. The company divides the market into four segments: home office/consumer (1 to 4 people), small business (5 to 50), mid-size business (51 to 500), and enterprise (500+). As competition forces businesses to become leaner, flatter and more global, knowledge workers must find more productive solutions to communications overload.

Not that PulsePoint is averse to wireless communications -- the company has entered an agreement with Leap Wireless International to provide voice-mail and unified-messaging solutions for its networks.

SOFTWARE LIMITATIONSThe basic concept behind unified messaging isn't new. Telecom visionaries have long dreamed of a single phone number for voice, data and fax that works whether the user is in his home, office, or automobile -- or anywhere else. But this is easier said than done. Today, unified messaging systems must work with a hodgepodge of incompatible devices and formats. Voice messages can be delivered as WAV file attachments to e-mail messages, but not without some degradation of audio quality. E-mail messages may be converted to synthesized speech and read to the user over a telephone, but it is difficult to scan a long list of messages that way. The reason unified messaging hasn't taken off yet is that the convenience of a single in-box still is outweighed by the limitations of software that must struggle to translate content between speech, text and fax.

CHANGE COMINGAccording to Iperia, a developer of next-generation, IP-based, enhanced-service platforms and applications, that is about to change. On an IP-based network, all forms of content are just packets of bits. It doesn't matter whether subscribers play an 11kb/s voice-mail message over a wireless telephone or a PC equipped with a sound card (assuming the bits conform to a standard recognized by both media). However, until the migration is completed, it will be necessary to provide gateways between the new (IP-based) and legacy (public telephone) networks.

Thus, the ultimate benefit of unified messaging platforms is not the migration to a single mailbox but the ease with which enhanced services can be developed and introduced. Indeed, subscribers gain immediate access to new features the moment they attach voice mail to e-mail. For example, one can easily forward a voice-mail message to any number of recipients. And it is but a small step to develop an application that automatically pulls up records about the caller when the user opens a voice-mail attachment. Clearly, the need for enhanced services is why industry leaders also have jumped on the unified-messaging bandwagon.

TWO REASONSThe wireless industry is interested in unified messaging for two principal reasons. Unified messaging helps generate more wireless traffic. Road warriors and others who spend considerable time away from their desks can have all communications -- or at least alerts -- forwarded to their wireless handsets. Call Sciences' personal assistant acts like a personal secretary, contacting the user wherever he is at the moment, controlling availability, screening calls and rerouting voice calls, faxes and e-mail messages per the user's instructions. Unified messaging systems also permit the wireless handset user to originate e-mail and fax messages. Thanks to its speech-recognition capability, General Magic's Portico virtual assistant even will let the user create and read messages while operating hands-free during the commute to and from work.

Unified messaging platforms also can help wireless carriers create enhanced services. Some of these services may be used to help manage wireless subscriber accounts. For example, carriers could allow subscribers to access their account information in hands-free mode. But the biggest opportunity is for premium services such as news alerts and workgroup/family communications.

New standards such as voice extensible markup language and wireless markup language will make it easier to develop new applications. In the near future, your subscribers may be able to browse certain Web pages simply by talking and listening.

Today, carriers are best known for letting users make and receive calls when they are out and about. But as the recently announced strategic partnership between Sprint PCS and Internet portal Yahoo! suggests, wireless users soon may find themselves getting e-mail alerts, scheduling appointments and receiving a variety of Internet content on a push basis. Within two to three years, you may start to see digital cellular/PCS subscribers who use PDAs or portable PCs instead of phones.

Despite technical difficulties, there are compelling reasons to embrace unified messaging:

* Ensures quick access to anyone who spends considerable time away from his desk.

* Gives road warriors a variety of means for reaching others.

* Offers inconspicuous call screening.

* Keeps detailed, electronic records of all communications.

* Allows each user to communicate in his preferred medium.

* Enables customized message handling when the user is on vacation or otherwise unavailable.

* Permits more personal control of accessibility.

* Provides a platform for myriad enhanced services from alerting to Web chatting.