The Interconnected Home - Getting Wired for the Digital Era - Part 1

A (Very) Brief History of Communications to the Home

We are experiencing a revolution in communication and control systems that is changing the way we live.

For a long time there were two major systems of distributed electrical wiring coming into homes: power and telephone, and oh yes, one minor system - cable TV. The revolution developed slowly at first. In the years after World War II, however the technology of communication and control started to accelerate. A major turning point was the invention of the transistor during the early post-war years, followed by the first integrated circuit in 1958. These two developments made the world of modern technology possible. They enabled extremely complex devices to be compressed into a tiny volume. These solid state chips became the foundation of a revolution in electronic communication and control.

The laws governing telecommunications eventually had to be changed to keep up with this technological revolution. Electric power and telephone companies had been granted monopolies by the government in order to maintain uniformity in the delivery of these fundamental services. This system of monopolies began to weaken in 1984 when a Federal judge issued a decree ordering the breakup of the telephone monopoly held by AT&T and its local Bell telephone subsidiaries. The next big step came when congress passed the Telecommunications Act of 1996. This law removed many of the rules that prohibited players from one part of the telecommunications industry, like telephone, from providing services in other sectors, like cable TV. Once all of these companies were free to compete, the applications for new technology multiplied at an incredible rate. Telecommunications was allowed to become a means of transmitting video and data in addition to voice.

At the same time that solid state integrated circuits were revolutionizing communications, they enabled the growth of powerful computers in very small sizes. Personal size computers that could fit on someone's desktop reached the market in the early 1980s. Since systems were becoming available to transmit data over a pair of wires it was natural to enable these computers to exchange information with each other. In the 1980s at about the time Personal Computers (PCs) first hit the market, work was begun on developing a communication standard to enable computers to understand each other. There were several competing systems but the winner, which is pretty universally accepted today, was Ethernet. The first Ethernet connections between computers were run on coaxial cable. As the numbers of computers linked on a single network (Local Area Network) grew, coax became cumbersome and expensive. However many buildings had plenty of excess installed unshielded twisted pair telephone cable, so unshielded twisted pair cable (UTP) was chosen to be the standard cable for connecting computers in a network. This was the birth of what we now know as the 10BASE-T UTP Ethernet standard and the start of the category rating system, the first being category 3.

Another important development that was going on at the same time was the birth of programmable logic controllers (PLCs) for controlling and getting information about manufacturing processes. They were developed in response to a specification issued by General Motors in 1968. These days most factories that manufacture large numbers of products use automatic systems based on PLCs. By the way you can see a little bit of history, in that PLCs were originally called PCs (programmable controllers), but the personal computer revolution far outstripped them so they had to change their name.


The next key step, and one that is still continuing, is convergence. It probably started on the factory floor. There were often separate PLCs controlling each process station, so to really automate the system, PLCs had to communicate with each other. They also had to communicate with programmable devices such as temperature and motor speed controllers. At first, most manufacturers used proprietary systems, but that was a limiting factor. In order to be able to use devices made by different manufacturers, it made sense to develop open systems of communication based on a shared publicly available standard. Since Ethernet was already being used in offices, it was often chosen for communication among manufacturing systems. Using Ethernet also meant that the operations on the shop floor could send data to management in real time.

The Coming Residential Revolution

The kinds of integration that have become commonplace in commercial settings, factories, educational and health care facilities, have so far not made a big impact on residential systems-but they will. The only question is when. What will drive home networking is the coming of Smart Television. Many new TVs can now be directly connected to the Internet. This can be done by connecting an Ethernet cable to a modem or router. If there are UTP Ethernet cables in the home, a network can be set up to provide content to the TV from an Ethernet enabled home theater system, Blu-ray player, audio device, game box, and of course from your laptop. Online content such as movies, video, music as well as standard TV shows can be delivered directly "on demand" and in high definition from such services as Netflix, Amazon, Hulu, Youtube and Pandora. There are even some TVs already on the market that can directly surf the Web. Once you've set up a home network to link all of these entertainment devices, it would be a simple and logical next step to save energy and improve life safety, by connecting temperature control, lighting, fire alarms, intrusion detection and access control to the same network. And all of these systems could be monitored and controlled by any computer in your home, as long as it is connected to the network.

The Wired Home

The best choice for such a home network is a wired system that can reliably carry all of the required data for this networking and carry it at speeds high enough so that all of the connected devices operate smoothly. The key to moving these signals about the home is an Ethernet network using category rated unshielded twisted pair (UTP) cabling.

See Part 2 for a technical discussion of Ethernet and UTP cable.