ERCIM News No.37 - April 1999

The last 15 years saw the development of the Internet, and more generally of data services. I usually try to explain this development by quoting two strong forces, Moore’s law and Metcalfe’s law. As predicted by Moore’s law, the power of microprocessors has been regularly doubling about every 18 months for the past 25 years, the trend continues, computers are becoming much more powerful and affordable, and will pervade many more places. The networking effect often referred to as Metcalfe's law states that the value of a computer network grows as the square of the number of connected elements. This law resonates with one of the principles of the Internet, the trend to connect all computers on earth to a single network, and may well largely explain the success of the Net. In any case, we observe that data transmission already accounts for more volume than voice transmission, and grows much faster.

Today’s telecommunication network have been designed to transmit voice, with data as an add-on service. But, at the current growth rate, in a few years, voice will only represent a small fraction of the global traffic. It will then not make sense to maintain a voice network, and we will see an inversion of the current situation: voice will run as an application within network primarily designed for data.

Next Generation Networks represent the convergence of multiple independent networks including voice, video and data into a single, unified, broadband network.

The broadband network is built using optical fibers, waveband digital multiplexing, ATM switches or IP routers. Cable modems or digital subscriber loops can provide high speed access to home. Voice gateways can be integrated in these modems. They provide a classic telephony interface to the residential user, but send the voice signals as packet over the data infrastructure. Network-based servers, the Call Agents, manage the establishment of phone calls. Other servers will manage the gateways to the existing phone network, including the translation between ATM or IP call set-up and the native signalling procedures of the phone network (SS7).Everything is designed to be ‘transparent’, at least in the first phase: the users will keep the same telephone handset, dial the same numbers, benefit from the same services such as call waiting or caller identification. There are already several such networks being planned, or built, in the United States and in Canada.

The deployment is motivated both by short term economies and by long term strategies. First, next generation networks can be deployed for a fraction of the cost of classic networks built of telephony switches and digital multiplexes. New entrants such as Level3 Communications or Qwest can thus compete without having to replicate the huge investments of the existing carriers. But, more important, the next generation networks are designed for the future. They will not only enable telephony and high speed access to the Web, e-mail and electronic commerce, but they will allow a next generation of applications.

My team at Bellcore, now Telcordia Technologies, has been working on the architecture of these new networks, designing for example the ‘Media Gateway Control Protocol’ that will be used by the Call Agents. But this is only the beginning of a new adventure. There are many new services that the ERCIM laboratories will help us invent!