The Telecommunications Network in Software

Creating QR Code JIS X 0510 in Software The Telecommunications Network

Prior to 1984, most of the network was owned by AT&T through its local Bell operating telephone companies A layered hierarchy of office connections was designed around a five-level architecture Each of these layers was designed around the concept of call completion The offices were connected together with wires of various types called trunks These trunks can be twisted pairs of wire, coaxial cables (like the CATV wire), radio (such as microwave), or fiber optics As the convergence of voice and data networks continues, we see a revisitation to the older technologies as well as the new ones Fiber is still the preferred medium from a carrier s perspective However, microwave radio is making a comeback in our telecommunications systems, linking door-to-door private line services Carrying voice, data, video, and high-speed Internet access is a natural for a microwave system Lightbased systems, however, are limited in their use by telephone companies It has been user demand that has brought infrared light and now SONET-based infrared systems in place Recently, the introduction of an unguided light introduced by Lucent Technologies operates at speeds up to 24 Gbps with a promised speed of up to 10 Gbps by end of 2000 This offers the connectivity to almost anyone who can afford the system, because the right of way is no longer an issue

The Network Hierarchy (Post-1984)

After 1984, ownership of the network took a dramatic turn AT&T separated itself from the Bell Operating Companies (BOCs), opening the door for more competition and new ventures Equal access became a reality and users were no longer frustrated in their attempts to open their telecommunications networks to competition

The US public-switched network is the largest and the best in the world Over the years, the network has penetrated to even the most remote locations around the country The primary call-carrying capacity in the US is done through the public-switched network Because this is the environment AT&T and the BOCs built, we still refer to it as the Bell System However, as we ve already seen, significant changes have taken place to change that environment The public network enables access to the end office, connects through the long-distance network, and delivers to the end This makes the cycle complete Many companies use the switched network exclusively, while others have created variations depending on need, finances, and size The network is dynamic enough, however, to pass the call along longer routes through the hierarchy to complete the call in the first attempt wherever possible

The network-numbering plan was designed to enable a quick and discreet connection to any telephone in the country The North American Numbering Plan , as it is called, works on a series of 10 numbers As progress occurs, the use of Local Number Portability (LNP) and Intelligent Networks (IN) enables the competitors to break in and offer new services to the consumer Note that there have been some changes in this numbering plan When it originally was formulated, the telephone numbers were divided into three sets of sequences The area codes were set to designate high-volume usage and enabled some number recognition tied to a state boundary With the convergence in full swing, the numbering plan became a bottleneck Now with the use of LNP, the Numbering Plan will completely become obsolete as we know it No longer will we recognize the number by an area code and correlate it to a specific geographic area LNP will make the number a fully portable entity Moreover, 10-digit dialing in the age of convergence becomes the norm because of the multitude of area codes that will reside in a state