Optical Access Networks

The economics of fiber to the home revisited

“…This burst mode requirement potentially adds hundreds of dollars of extra cost to the transceiver in the customer premises equipment (CPE). In addition, since no regeneration of the user's signals is performed in a PON (unlike the situation in an AON, in which the switch effectively regenerates all the user's upstream traffic), the receiver in the MAN node must be able to adjust its gain setting dynamically so as to provide equivalent signal-to-noise reception for different users, who are at different distances from the MAN node and whose signals, therefore, suffer differing levels of attenuation [5]. This requirement for a burst mode receiver in the MAN node again increases the cost of the network, though the extra cost is shared among all downstream users.…”

“…Finally, a source of power must be provided for an AON. For an excellent review of the respective merits and historical evolution of different optical access technologies, see [5].…”

Fiber to the Home Using a PON Infrastructure

“…For clarity, we will separate our discussion to first consider the various multiple-access methods for dealing with the upstream traffic (subscribers to CO) [8]. These schemes can be generally categorized as time-division multiple access (TDMA), wavelengthdivision multiple access (WDMA), subcarrier-division multiple access (SCMA), and code-division multiple access (CDMA).…”

“…This FTTP architecture is referred to as a PON that allows many customers to share a singlefeeder fiber running to the CO. At the CO, the feeder fiber terminates at the optical line terminal (OLT) that manages the communications to the multiple subscribers. At the remote subscriber location, the drop fiber terminates at an optical network termination (ONT) that converts the optical signal to electrical signals for use by various devices such as phones, computers, TVs, etc., [8].…”

Whatever happened to fiber-to-the-home?

“…The major power penalty caused by the OOK injection scheme in [3] was that the upstream traffic suffered from severe crosstalk with the downstream data, particularly when the extinction ratio of downstream traffic was high. The use of DPSK alleviates this problem to a large extent due to the constant intensity properly of the injected signal.…”