Voice is only one piece in the communication puzzle. You might have just made a deal with a partner or client, but you still need to receive or send a quotation on email or fax; or voice communication being too expensive, you might decide to carry a lengthier dialogue on chat; or still, it might be necessary to discuss of a product prototype on video conferencing with several business partners.
On the other hand, you don’t use communication tools only in the office or at home – you do so while in the car, in the park, having lunch in a restaurant, and even in bed. Also, there is the fact that businesses are becoming more and more ‘virtual’, which means a business or its workers are not necessarily confined to one physical office or address; the business might be running with many decentralized elements, most of which exist only online.
Due to a lack of integration of all these services, the use of these different technologies is not optimized. As a result, while communication can be effective, it is far from being efficient, both technically and economically. Compare, for example, having separate services and hardware for phone, video conferencing, instant messaging, fax etc., and having all of these integrated into one same service and minimum hardware.
Unified communications (UC) is a new technological architecture whereby communication tools are integrated so that both businesses and individuals can manage all their communications in one entity instead of separately. In short, unified communications bridges the gap between VoIP and other computer-related communication technologies.
Presence represents the availability and willingness of a person to communicate. A simple example is the list of buddies you have in your instant messenger. When they are online (meaning they are available and willing to communicate), your instant messenger gives you an indication to that effect. Presence can also be enhanced to show where you are and how (since we are speaking about integrating many communication tools) you can be contacted. For example, if a buddy is not in her office or in front of her computer, there is no way your instant messenger can have you contact her unless other communication technologies are integrated, like pc-to-phone calling. With unified communications, you can know where your buddy is and how you can contact her… but of course, if she wants to share this information.
Even if your presence can be monitored and shared with unified communications, contacting you might still be impossible if your access point (an address, a number etc.) is not available or known. Now say you have five ways to be contacted (phone, email, paging… you name it), would people like to keep or know five different pieces of information to be able to contact you anytime they want? With unified communications, you will (as at now, ideally) have one access point (one number) through which people can contact you, whether they are using their computer’s instant messenger, their softphone, their IP phone, email etc.
