Optical Networks: A Practical Perspective - Part 64. This book describes a revolution within a revolution, the opening up of the capacity of the now-familiar optical fiber to carry more messages, handle a wider variety of transmission types, and provide improved reliabilities and ease of use. In many places where fiber has been installed simply as a better form of copper, even the gigabit capacities that result have not proved adequate to keep up with the demand. The inborn human voracity for more and more bandwidth, plus the growing realization that there are other flexibilities to be had by imaginative use of the fiber, have led people. | 600 Access Networks Central office Cabinet Home Passive optical network PON FTTCab FTTC FTTB FTTB FTTH Figure Different types of fiber access networks based on how close the fiber gets to the end user. In many cases the remote node may be located at the central office itself. The ONUs terminate the fiber signal and the links between the ONUs and the NIUs are copper based. be thought of as fiber to the curb FTTC or fiber to the building FTTB . Typically in FTTC the fiber is within about 100 m of the end user. In this case there is an additional distribution network from the ONUs to the NIUs. With the fiber to the cabinet FTTCab approach the fiber is terminated in a cabinet in the neighborhood and is within about 1 km of the end user. To make the FTTC architecture viable the network from the CO to the ONU is typically a passive optical network PON . The remote node is a simple passive device such as an optical star coupler and it may sometimes be colocated in the central office itself rather than in the field. Although many different architectural alternatives can be used for FTTC the term FTTC is usually used to describe a version where the signals are broadcast from the central office to the ONUs and the ONUs share a common total bandwidth in time division multiplexed fashion. In the context of FTTC the feeder network is the portion of the network between the central office and the remote node and the distribution network is between the remote node and the ONUs. We will see that a variety of different types of architectures can be realized by using different types of sources at the central office combined with different types of remote nodes. Practically speaking it is quite expensive today to transmit analog video signals over an all-fiber infrastructure this may necessitate an analog hybrid fiber coax overlay that carries the analog video signals. The FTTC architecture is sometimes also called baseband modulated fiber coax bus BMFCB or switched digital video
