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10.4 Why Optical Layer Protection. The optical layer provides lightpaths for use by its client layers, such as the SONET, IP, or ATM layers. (Recall that the layers that use the services provided by the op- tical layer are called client layers of the optical layer.) We have seen that extensive protection mechanisms are available in the SONET layer, and...
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Figure 10.18 Comparison of (a) 1 + 1 0 M S and (b) 1 + 1 0 C h protection schemes.. This is perhaps the simplest optical layer protection scheme and is shown in Fig- ure 10.18(a). An alternative implementation uses optical amplifiers on each of the fibers and a passive combiner to combine both directions at the receiver.. This...
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5 8 0 NETWORK SURVIVABILITY. If the tables are inconsistent, routing pathologies, such as looping, can be present in the network with fairly high probabilities. For example, at the end of 1995, the likelihood of encountering a major routing pathology in the Internet was 3.3% [Pax97]. These pathologies can cause packets to be forwarded incorrectly in the network, but these...
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Access Networks. of the telecommunications network that runs from the service provider's facility to the home or business. Business users are big consumers of data services, many of which are delivered in the form of leased lines at various speeds ranging from 1.5 Mb/s to several gigabits per second. Today, homes get essentially two types of services: plain old telephone...
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Figure 11.5 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)...
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Compared to the HFC approach, FTTC has a higher initial cost, but provides bandwidth deeper in the network and may prove to be a better longer-term solution. Although FTTC refers to a simple broadcast TDM star PON architecture, we also explored several upgrade options of the PON approach that provide higher capacities by making clever use of wavelength division multiplexing...
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OTDM is illustrated in Figure 12.3. The interleaving can be done on a bit-by-bit basis as shown in Figure 12.3(a). Assuming the data is sent in the form of packets, it can also be done on a packet-by-packet basis, as shown in Figure 12.3(b). In both the bit-interleaved and the packet-interleaved case, framing pulses can be used. In the packet-interleaved...
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Figure 12.10 Block diagram of a soliton-trapping logical AND gate.. Figure 12.11 Illustration of the operation of a soliton-trapping logical AND gate. (b) Both pulses are present, undergo wavelength shifts due to the soliton-trapping phenomenon, and most of the energy from one pulse passes through to the filter output. Figure 12.12 The function of a synchronizer. (b) The two periodic...
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Figure 12.17 Example of a 2 x 2 routing node using a feedback delay line architecture.. for a common output port arrive simultaneously, one of them is switched to the output port while the others are switched to the recirculating buffers.. In the context of optical switches, the buffering is implemented using feedback. delay lines. In the feedback architecture of...
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process the header and set the switches to switch the burst through when it arrives, so that additional buffering is not needed for this purpose at the nodes.. Overall, burst switching is essentially a variation of PPS where packets have variable and fairly large sizes, and little or no buffering is used at the nodes. Like packet switching, one of...
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Assume that if ci = 1, switch i is set in the bar state, and if ci = 0, switch i is set in the cross state.. We have seen that many photonic packet-switching proposals use a lower-rate header compared to the payload. What size does the payload need to be?. This time is accounted for as an additional guard...
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Figure 13.1 A typical carrier backbone network based on SONET/SDH, showing SONET/SDH add/drop multiplexers (ADMs) and digital crossconnects (DCSs), along with optical line terminals (OLTs) and routers. (a) The network topology, which consists of interconnected rings in the backbone, with feeder metro rings. Figure 13.2 Bandwidth wasted when two rings built using ADMs share the same fiber route. The network...
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Figure 13.8 The future telecommunications network. (a) Network topology showing a meshed long-haul backbone with metro collector rings. A star configuration requires two disjoint fiber routes to be laid between each access node and the central office. In contrast, multiple access nodes can be combined on a single fiber ring, and additional nodes can be added to the ring as...
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Table 13.1 Traffic matrix for the long-haul mesh network case study. The fiber topology is shown in Figure 13.8(a). The traffic is shown in terms of the number of 10 Gb/s wavelengths between pairs of nodes in the upper-right triangle of this matrix.. 9 Kansas City. as ultra-long-haul (ULH) systems. We also look at the benefits of different types of...
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This is the primary application for most of the WDM networks deployed in metro networks today.. Because of the nature of the traffic and a large amount of passthrough traffic in these networks, a strong case can be made for deploying WDM rings with optical add/drop multiplexers instead of higher-speed TDM rings. Although spans are short, in many cases the...
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In Proceedings of National Fiber Optic Engineers Conference, 2000.. Doshi et al. Maeno et al. In Proceedings of National Fiber Optic. Engineers Conference, 2000.. Acronym Expansion. Bit error rate. Bidirectional line-switched ring. Constant bit rate Cross-gain modulation Cell loss priority. Dispersion-shifted fiber Digital subscriber loop. Dielectric thin film multicavity filter Dense wavelength division multiplexing Electro absorption. Erbium-doped fiber amplifier. Federal...
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Network node interface for the synchronous digital hierarchy (SDH).. Sub STM-0 network node interface for the synchronous digital hierarchy (SDH).. Synchronous digital hierarchy (SDH) management information model for the network element view. Vocabulary of terms for synchronous digital hierarchy (SDH) networks and equipment.. Characteristics of synchronous digital hierarchy (SDH) equipment functional blocks.. Synchronous digital hierarchy (SDH) management.. Architecture of transport...
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I N M A T H E M A T I C A L TERMS, chromatic dispersion arises because the propagation. As we will see, this is the velocity with which a pulse propagates through the fiber (in the absence of chromatic dispersion). Chromatic dispersion is also called group velocity dispersion.. If we were to launch a pure monochromatic wave...
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Figure E.1 The magnitude of the pulse envelope of the second-order soliton.. For an isotropic m e d i u m and an electric field polarized along one direction so that it has a single c o m p o n e n t E(r, t), this relationship can be written as follows:. O w i n g to certain...
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I N M A N Y P L A C E S in the book, we use random variables and random processes to model noise, polarization, and network traffic. Random Variables. The derivative of F x ( x ) is the probability density function d F x ( x. The expectation of a function g ( x ) is defined...