A Short History of Telecommunications
This started with the switchboard where an operator received calls (originally generated by a hand generator on the telephone set) and then through a plug based system, manually interconnected or switched the call to the wanted destination. The destination was communicated orally by the caller to the switchboard operator.
The Strowger Switch
At some point in time in a little town in the US, it so happened that there were two morticians and the wife of one of the morticians was the local switch operator. So whenever a call came in for mortician services, the operator made sure that the call terminated to the family funeral parlor.This particular favoritism angered the other mortician, named Almon Strowger. Strowger thus took the initiative to design an automatic system that allowed mechanical call interconnection eventually rendering the manual switchboard obsolete. This system became know as the Strowger switch and was indeed the first mechanical telephone interconnection system and predecessor to the present circuit switched telephony system.
Stored Program Control (SPC)
The Strowger switch, also brought forth in a primitive way the concept of equal access.The Strowger switch eventually gave way to crossbar architectures and with the advent of computer systems, the stored program control system eventually replaced crossbar technologies.
Now the thing with stored program control (or SPC as its know in the industry) is that it was composed of segregated subsystems. You had a subsystem for SS7 signaling, a subsystem for voice interconnection (and by that time the common form of connection was through an aggregated (multiplexed) form of PCM (pulse code modulation)), a subsystem for supplementary services (such as call back, call waiting etc..), a subsystem for subscriber data, a subsystem for number translation/routing, a subsystem for operation and maintenance, and a whole other set of subsystems. All these subsystems where controlled/coordinated by a central control subsystem.
So the switch basically contained in a vertical sort of way whatever was needed to ensure proper call processing and communication with other switches and the human environment .
Typical SPC systems included the Ericsson AXE, the Alcatel System 12 (formerly ITT 1240) , the Motorola EMX, the Siemens EWSD, the Northern Telecom (Nortel) DMS, the Stromberg Carlsson DCO, the AT&T No. xx(eventually Lucent and now Alcatel-Lucent) and so forth.
Asian Telecom Suppliers
An interesting point is that Japanese manufacturers (for example Fujitsu and NEC) also became interested in the telecom game and started developing their own systems, but didn’t gain much headway in an industry that was dominated by European and American companies (as opposed to the success the Japanese have had in heavy industry (cars, steel) and electronics).Today, the Chinese (Huawei, ZTE) are experiencing tremendous success and have managed to change the rules of the game. Indeed, communication technology is no longer the prerogative of Europe and America.
The network consisted of a number of these switches, means to interconnect them (a transmission network initially PDH and then SDH) and synchronize them (a master clock that coordinated the local switch clocks) as well as a central (and many regional) operation centers for monitoring (and upgrading) the status of the switches and the network as a whole.
Telecom Deregulation, The FCC, and the Internet
Now in the eighties and nineties a number of factors started disrupting this Euro American haven. First of all, we had Judge Greene and deregulation which forced the breakup of AT&T and brought forth a system of regional bells and inter-exchange carriers injecting an embryonic form of competition into the bell system (Europe followed later in its own way). This, through equal access, increased the need for services and features at an attractive price.The market from an economics perspective was also proven to be price sensitive, and the first signs of commoditization started appearing in voice services.
In addition, new communications options coming in the form of mobile communication and companies (example Vodafone) that focused only on this form of communication. These companies started competing for customers and actually offered their services as replacement services to the traditional fixed line systems.
Thirdly, the democrats (the Clinton administration) shifted investment from military technologies to communication/information technologies (the information superhighway) and a host of new proprietary military technologies became available for mass industrial deployment (example: CDMA).
Entrepreneurship also grasped this new opportunity viewing the telecom market as virgin territory for their offering and started to convince the industry that IP was the way to go. The FCC had already provided the foundation for earlier on and the entrepreneurial spirit capitalized on this available foundation and the slow migration of the technology from the walled garden SS7 interconnection based concept to a more open architecture service based approach.
Needless to say, the telecom game will never be the same.
