We have been talking mainly about Voice over Internet Protocol (VoIP) technology. However, Digitcom's network will include a number of other facets. From the press release:
"The Digitcom Network will offer users high-quality voice- and fax-over-IP, and global voice messaging. Products planned include enterprise- level ''Intranet'' IP phone service, video conferencing and multimedia transmission for customers."
For those who are not all that knowledgeable about the technology (we are all learning), the simple explanation is this. For all of you techies out there, please ignore this tutorial, or feel free to correct it if it is wrong.
Telephone conversation goes out over wires, over microwaves, over glass fibers, over satellite links, and over any other media that can carry signals. This is no different than radio or TV signals. The challenge in telephony is not sending out the signal but figuring out where it came from and where it is supposed to go, which is called switching. Traditional switches have evolved over many years, include a hybrid of a number of technologies, and are classified together into what is called the Public Switched Telephone Networks (PSTN).
The problem with early switches was that a telephone call would hog a line and keep it until the party hung up the phone. Eventually, the technology advanced, many calls could be placed over the same line, and the lines themselves could be switched between calls, but this made the switches very complex, inefficient, and costly. With the advent of computers, data as well as voice had to be sent over PSTN, which made for even more challenges. Data transmissions could really hog lines because they were slow to transmit, and if even one bit was lost the data set could be worthless.
This led to a new switching paradigm, called packet switching. This combined advances in switching technology with advances in computer technology. To transmit large amounts of data long distances, instead of sending it in traditional ways, and risk losing part of it and tying up phone lines, it was broken up into small packets. Each packet contained not only a piece of the data to be transmitted, but also information on where it belonged in the large data set, where it came from, and where it was going. This packet would go out to the nearest switch, and the switch would read the information from the packet and send it to another switch, hopefully closer to its eventual destination. Even if a packet was lost on the way, it could be retransmitted easily. Eventually all the packets got to where they were supposed to get, would be recombined, and the data was there. This method was applied initially to the Department of Defense's Arpanet, which eventually was turned loose and became the internet. Thus the name Internet Packet (IP) protocols.
As computers got faster, and networks larger, the idea was born that if data could be sent this way, why not voice? All that needed to be done was to turn the voice into data (digitize it) and treat it like any other packet. The problem was (is) that voice is very rich in information, and the data size to send even a small amount of voice is huge. That is why compression is needed for what is called Voice over Internet Protocols (VoIP). Digitcom uses as much as 43:1 voice compression in their gateways, for example. The trick is to compress without losing a lot of quality.
Now, since voice can be sent over IP packets, why not send anything else as well, as long as it can be digitized? Faxes (simple), video (hard), multimedia (harder). In fact, why not integrate computer data transmissions with telephone, video, fax, and any other communications into one system? That is, IMHO, the ultimate goal of this type of technology, but today there is not enough bandwidth to accomplish this on a large scale. But maybe this can begin on a smaller scale, like within a company's local comm networks (an "intranet"), which is why the Digitcom press release mentions "Products planned include enterprise- level ''Intranet'' IP phone service, video conferencing and multimedia transmission for customers."
The last piece of the puzzle is to ensure there is a robust enough network around to send all this data through. Digitcom can not just put in gateways and expect that the lines will be there when needed, at no cost. So what they are doing is to lease dedicated high speed lines. That is why the press release talks about "Scheduled installations will make use of a dedicated 1.5Mbps T1 circuit, with the U.S. termination gateway housed on a Northern Telecom DSM-250 phone switch."
Disclaimer: The above is just my take on the technology and how Digitcom is applying it. There is nothing in this technology that is peculiar to Digitcom, other than they are moving very quickly into this hot sector with state-of-the-art equipment and lucrative market penetration. Any of you techies out there feel free to correct anything I have that is wrong. |
