analyzing sociotechnical networks a spectrum perspective

... 161 variable optical attenuator (VOA), 213 Vernier effect, 231 vertical cavity surface-emitting lasers (VCSELs), 173-174 advantages, 173 drawbacks, 173 tunable, 180-181 two-dimensional array, ... Spanke architecture, 205-206 illustrated, 206 nonblocking, 205 Trang 7Spanke-Bene~ architecture, 207 spatial dilation, 305 drawbacks, 305 illustrated, 306 spatial reuse, 551,555 spatial walk-off ... 324-325 scrambling, 241 advantage of, 241 SONET standard, 274 SDH networks, 12, 278, 364 basic signal rate, 367 channel layer, 543 extra traffic support, 546 high-reliability services, 366 management

Ngày tải lên: 02/07/2014, 12:21

... affordable for many applications where the data rates are low and distances are short This is the case in many data communi- cations applications (see Chapter 6) and in some access networks (Chapter ... integrated on a single substrate This is the main motivation for the development of arrayed lasers such as the DFB laser arrays that we discussed earlier Moreover, an arrayed laser can be used as a ... desired wavelength) These lasers can all be grown on a single substrate in the form of an array Four- and eight-wavelength laser arrays have been fabricated in research laboratories, but have not

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... is an attractive alternative to lithium niobate modulators because it can be fabricated using the same material and techniques used to fabricate semiconductor lasers This allows an EA modulator ... packaging cost In fact, transmitter packages that include a laser, external modulator, and wavelength stabilization circuits are becoming commercially available for use in WDM systems External ... undesirable effects, particularly chirp Several types of external modulators are commercially available and are increasingly being integrated with the laser itself inside a single package Trang

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... multiplicative gain and denoted by Gm The multiplicative gain of an APD can be made quite large and even infinite a condition called avalanche breakdown However, a large value of Gm is also accompanied ... wavelengths for a number of semiconductor materials In l_xGaxAs is a ternary compound semiconductor material where a fraction 1 - x of the Ga atoms in GaAs are replaced by In atoms In l-xGaxAsyPl_y ... is a quaternary compound semiconductor material where, in addition, a fraction 1 - y of the As atoms are replaced by P atoms By varying x and y, the band gap energies and cutoff wavelengths can

Ngày tải lên: 02/07/2014, 12:21

... which means that these mirrors can be manufac- tured and packaged as arrays Moreover, the mirrors can be fabricated using fairly standard semiconductor manufacturing processes These mirrors are deflected ... technologies available today Larger switches can be realized by cascading small bulk mechanical switches, as we saw in Section 3.7.1, but there are better ways of realizing larger port count switches, as ... large switches as a measure of the switch cost W h a t makes the Spanke architecture attractive is that, in many cases, a 1 x n optical switch can be built using a single switch element and does not

Ngày tải lên: 02/07/2014, 12:21

... streams The basic unit of this serial approach is a crossbar fabricated as a single IC Today, 64 x 64 crossbar ICs operating at 2.5 Gb/s line rates are commercially available The practical considerations ... nonlinear effect in a semiconductor optical amplifier (SOA) This approach works over a wide range of signal and probe wavelengths, as long as they are within the amplifier gain bandwidth, which is about ... beginning to be available Typically a large electronic switch uses a multistage design, and in many cases, the Clos approach is the preferred approach as it provides a strict-sense nonblocking architecture

Ngày tải lên: 02/07/2014, 12:21

... data or is complementary The advantage of this approach over CGM is that much less signal power is required to achieve a large phase shift compared to a large gain shift In fact, a low signal ... receivers are both available today Large-scale MEMS-based optical switches for use in wavelength crossconnects are now emerging as commercial devices, and a variety of technologies are avail- able ... between a fixed-input waveguide and any two successive arrayed waveguides is a constant Assume that the length of the arc on which the arrayed waveguides are located is much smaller than the diameter

Ngày tải lên: 02/07/2014, 12:21

... M.-C Amann and J Buus Tunable Laser Diodes Artech House, Boston, 1998 [AD93] G.P Agrawal and N K Dutta Semiconductor Lasers Kluwer Academic Press, Boston, 1993 [Agr95] G.P Agrawal Nonlinear Fiber ... Grubb et al High power 1.48/~m cascaded Raman laser in germanosilicate fibers In Optical Amplifiers and Applications, page 197, 1995 [Gui98] C Guillemot et al Transparent optical packet switching: ... Takahashi, K Oda, and H Toba Impact of crosstalk in an arrayed-waveguide multiplexer on n • n optical interconnection IEEE/OSA JLT/JSA C Special Issue on Multiwavelength Optical Technology and

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... modulation, and both digital and analog modulation techniques can be employed The figure shows an example where the microwave car- rier is amplitude modulated by a binary digital data signal The ... such signals at high bit rates Another potential advantage of multilevel modulation is that the signaling rate on the channel is lower than the data rate For example, a 16-level modulation scheme ... worst-case DC imbalance is 10% [Bur86] mapping of the data stream into another data stream before it is transmitted on the link At the transmitter, a scrambler takes the incoming bits and does an

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... diagram shown in Figure 4.6(b) Such a diagram is called an eye diagram because of its resemblance to the shape of the human eye An eye diagram can be easily generated experimentally using an ... following mathematical formulation The photocurrent for a i bit is a sample of a Gaussian random variable with mean I1 and variance or1 (and similarly for the 0 bit as well) The receiver must look at ... the APD by 7~APD, and the average avalanche multiplication gain by Gm, the average photocurrent is given by [ - 7~APDP Gm~P, and the shot noise current at the APD output has variance The quantity

Ngày tải lên: 02/07/2014, 12:21

... see that Ramaswami and Sivarajan have reorganized and updated their outstanding 1998 traversal of this fascinating and important field and have done so in a way that accurately portrays what is ... Wittmann and Martina Zitterbart MPLS: Technology and Applications Bruce Davie and Yakov Rekhter High-Performance Communication Networks, 2e Jean Walrand and Pravin Varaiya Computer Networks: A Systems ... trademarks In all instances in which Morgan Kaufmann Publishers is aware of a claim, the product names appear in initial capital or all capital letters Readers, however, should contact the appropriate...

Ngày tải lên: 02/07/2014, 12:21

... fascinating in itself based on a medium with thousands of gigabits of capacity yet so small as to be almost invisible, transmitters no larger than a grain of salt, amplifiers that amplify vast ... authors have captured what is going on and what is going to be going on in this field in a completely up-to-date treatment unavailable elsewhere I learned a lot from reading it and expect that ... optical networking would be a roaring success or disappear into the annals of "whatever happened to " stories of technology that had once sounded great on paper, but that had somehow never panned...

Ngày tải lên: 02/07/2014, 12:21

... a large amount of new material, and removed some material that is not as relevant to practical optical networks We have also updated the references and added some new problems The major changes ... also computing the detailed mesh network design example, Tapan Kumar Nayak for computing the lightpath topology design example, Parthasarathi Palai for simulating the EDFA gain curves, and Rajeev ... Johnstone, Alan Repech, George Stewart, Suresh Subramaniam, Eric Verillow, and Martin Zirngibl In addition, we would like to acknowledge Bijan Raahemi, Jim Refi, Krishna Thyagarajan, and Mark R Wilson...

Ngày tải lên: 02/07/2014, 12:21

... provides a "pipe" with a certain amount of bandwidth to the layer above it The physical layer may be optical, wireless, or coaxial or twisted-pair cable The next layer above is the data link layer, ... (virtual circuits) and is capable of providing a variety of quality-of-service guarantees Packets in ATM are called cells and are of fixed length (53 bytes) ATM is being used by many carriers as a ... take in N data streams, each of B b/s, and multiplex them into a single fiber with a total aggregate rate of NB b/s high-speed streams are transmitted over a fiber As we will see in Chapters and...

Ngày tải lên: 02/07/2014, 12:21

... specified, and the service may accept data at any bit rate and any protocol format within these limits It may also be able to carry analog data Transparency in the network provides several advantages An ... frequency spacing A f and the wavelength spacing A) ~ as r Af ) ~A) ~ This relationship is accurate as long as the wavelength (or frequency) spacing is small compared to the actual channel wavelength ... physical layer is a complex task with a variety of parameters to be taken into consideration For this reason, it is very difficult to build and operate a network that can support analog as well as...

Ngày tải lên: 02/07/2014, 12:21

... transmission has been all about how to transmit data at the highest capacity over the longest possible distance and is remarkable for its rapid progress What is equally remarkable is the fact that researchers ... commercially viable EDFAs spurred the deployment of a completely new generation of systems A major advantage of EDFAs is that they are capable of amplifying signals at many wavelengths simultaneously ... distributed-feedback (DFB) laser A DFB laser is an example of a single-longitudinal mode (SLM) laser An SLM laser emits a narrow single-wavelength signal in a single spectral line, in contrast to MLM lasers...

Ngày tải lên: 02/07/2014, 12:21

... frontiers has focused on (1) transmitting terabits-per-second aggregate traffic across transoceanic distances with individual channel data rates at 10 or 20 Gb/s [Cai01, Bak01, VPM01], or 40 Gb/s channel ... [HSS98] A. M Hill, A A M Saleh, and K Sato, editors IEEE JSAC" Special Issue on High-Capacity Optical Transport Networks, volume 16, Sept 1998 [Ish83] H Ishio Japanese field trials and applications ... optical networks in this chapter: first-generation networks and second-generation networks First-generation networks use optical fiber as a replacement for copper cable to get higher capacities...

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... different propagation speeds for different modes has an analog in the geometrical optics approach We can think of a "mode" as one possible path that a guided ray can take Since the path lengths are different, ... wave theory approach The wave theory is more general and is applicable for all values of the fiber radius The ray theory is an approximation that holds when the optical wavelength is much smaller ... the wave number, the propagation constant is kn Thus for a wave propagating purely in the core, the propagation constant is knl, and for a wave propagating only in the cladding, the propagation...

Ngày tải lên: 02/07/2014, 12:21

... main loss mechanisms in an optical fiber are material absorption and Rayleigh scattering Material absorption includes absorption by silica as well as the impurities in the fiber The material absorption ... orthogonally polarized Since the wave equations are linear, any linear combination of these two linearly polarized fields is also a solution and thus a fundamental mode The state of polarization (SOP) ... optical fiber is its core, which has a circular cross section The propagation of light in waveguides can be analyzed in a fashion similar to that of propagation in optical fiber In the ray theory...

Ngày tải lên: 02/07/2014, 12:21

... have a chromatic dispersion of at most 3.3 ps/nm-km in the 1.55 #m wavelength range and typically zero dispersion at 1550 nm A large fraction of the installed base in Japan is DSE Recall that ... shows the same pulse after it has propagated a distance of only 0.4T2/j,821 along the fiber The amount of broadening can be seen to be about the same as that of the unchirped Gaussian pulse, but ... convenient to use an effective cross-sectional a r e a A e (see Figure 2.15), related to the actual area A and the cross-sectional distribution of the fundamental mode F(r, 0), as [fr fo Ae - IF(r,...

Ngày tải lên: 02/07/2014, 12:21