SONET
The transport network for broadband services will be SONET (synchronous optical network), a set of international standards for transmission over fiber-based networks at speeds of 51.84 mbps (above T3) to a shopping 13 gigabytes per second. its importance lies with the fact that SONET will allow networks to use equipment from different vendors due to its “mid-span meet”-an information model and messages sets for making translations among equipment.