N-GEN Communications Web-based Seminars ©NGCS

Seminar - An Overview of Communications Technologies

Module 4 - ATM Technology                                                                                                                      Slide 7 of 46 _________________                                                                                  __________

                                            Why ATM Technology was Developed 

                                     Broadband Networks Developed on Ad hoc Basis

                                     Carriers Realizing Importance of Migrating Private
                                        Networks to Public Networks

                                     Corporations Faced with High-Bandwidth Applications

                                     Carriers Needed a Technology to Carry Information
                                           within SONET / SDH

_________________                                                                                  __________

ATM technology development was the telephone companies initiative. SONET technology standards were maturing in the late 80s. SONET technology was making inroads into the telephone companies toll network. At the same time many private broadband networks were set up to meet individual corporations communications needs. The telephone companies main business was voice communications and data was a secondary business on overlay networks. The telephone companies looked for a way to attract the private broadband network market to their public broadband network. What carriers needed was a technology that would allow the customer to set up a connection to any location for multi-media applications on demand which could be transported over SONET networks. ATM was developed as a result of defining and standardizing a transmission mechanism based on narrowband ISDN for the broadband services.

CCITT selected ATM to transport information within SONET/SDH and Broadband ISDN (B-ISDN). A compromise was reached between North American and European carriers on the ATM cell size.