Optical Access
Definition
The access network is that portion of a public switched network that connects POPs or COs to individual subscribers. More simply, it is the last link in a network between the customer premises and the first point of connection to the network infrastructure - a point of presence (POP) or central office (CO). In the past, the access network connections have consisted predominantly of passive, twisted-pair copper wires.
The bandwidth available in the access network has lagged behind that provided within local area networks (LANs) and in the upper echelons of the network (in metropolitan and core networks, for example), where concentration factors and economies of scale have allowed optical fiber to substantially increase bandwidth capacity. Now, optical access, which enables data to be transmitted at a speed of up to several gigabits per second (Gbps), is available to increasing portions of the access network.
This bandwidth availability opens up new architectural possibilities for provisioning high-bandwidth services. With the access network as a bandwidth bottleneck, it is necessary to place some sort of processing equipment at the customer premises to manage or control the amount of data transmitted over an access connection. Once the bottleneck is opened, new opportunities present themselves - such as the option of carrying larger quantities of data across an access link to be routed, switched, or processed in some other way at a POP or CO. |
