This paper presents a novel data transmission protocol "SVFTP," which enables high-speed and error-free video data transmission over IP networks. A video transmission system based on SVFTP is also presented. While conventional protocols are designed for file transmission, SVFTP focuses on video data as a continuous media. In order to fit a flexible video transmission system, SVFTP achieves higher throughput on the long distance link as well as transmission interruption/resumption and progressive download and play back. In addition, a rate shaping mechanism for SVFTP is introduced in order to control greediness and burst traffic of multiple-TCP sessions. Laboratory and field transmission experiments show that SVFTP achieves high performance and functionality.

This paper presents a closed form expression of an exact average bit error rate (BER) for a time-division duplex (TDD) transmit diversity scheme employing maximal ratio combining (MRC) over time selective flat Rayleigh fading channels. In the proposed analysis, the feed back delay which degrades the BER performance is taken into account. The results are generally applicable to an arbitrary modulation scheme, as well as an arbitrary number of transmitting branches. To confirm the validity of the proposed analysis, the theoretical results are compared with the simulated ones.

In wideband code division multiaccess (W-CDMA) uplink, immediate accommodation of high data rate packet causes power control error and makes active users' signal quality deteriorate in a beginning of a frame. To avoid the deterioration, we propose a new radio resource management (RRM) which accommodates high data rate traffic gradually in several frames. The proposed RRM reduces the signal quality deterioration in the beginning of the frame. We also propose an effective power control scheme, where a power increase command is sent to all users before a new high data rate packet is transmitted. Simulation results show that joint utilization of the proposed two methods is effective to keep signal quality good for all users.

We demonstrated a vertically coupled microring resonator (VCMRR) filter as an Add/Drop wavelength filter. However, the accuracy of center wavelength was not sufficiently high for dense wavelength division multiplexing (DWDM) systems. Thus, a UV trimming technique using a SiN (n=2.01 at λ=1.55 µm) ring core was previously developed. Although a wide center wavelength trimming range of -12.1 nm and the long-term stability of center wavelength were realized, the core size required for single-mode propagation was too small for fabrication using a photolithography process. Therefore in this study, we introduced SiON as the microring core to relax the single-mode condition of core size. We discovered a large UV sensitivity of SiON film formed by a PECVD method, and a wide range UV trimming of microring resonator of -10.5 nm was demonstrated using this phenomenon.

System capacity of a wireless system can be improved greatly by using variable rate transmission. Assuming a low-rate and wide-coverage signaling-only wireless network, in this paper we evaluate, analytically and numerically, the extent of this improvement for various schemes with variable transmission rates. We considered log-normal shadowing as well as the effect of Rayleigh fading. Simulation results show close proximity with the analytical predictions.

L-convex functions are nonlinear discrete functions on integer points that are computationally tractable in optimization. In this paper, a discrete Hessian matrix and a local quadratic expansion are defined for L-convex functions. We characterize L-convex functions in terms of the discrete Hessian matrix and the local quadratic expansion.

A space-time RAKE (ST-RAKE) receiver with a blind interference-blocking (IB) pre-processor, termed as the IB-RAKE receiver, is proposed for spread spectrum communications systems. The design of the proposed architecture consists of three components. A blind IB transformer is first constructed based on the received data, and then applied on the undespread data for the suppression of strong interference. After despreading, optimal beamforming is then performed on the IB despread data to extract the signals of interest (SOIs) from the desired user. Finally, a RAKE receiver with a maximum ratio combining technique is employed to constructively collect all the SOI energies. Since strong interference has been removed in the first stage, the RAKE receiver combines only those SOIs plus negligible interference, leading to robustness against strong interference. Numerical results have shown that substantial improvement can be obtained from the proposed ST-RAKE receiver with the blind IB pre-processing scheme.

A test structure and method for two-dimensional analysis of fabrication process variation of MOSFET using a photoemission microscope are presented. Arrays of 2010 (=200) MOSFETs were successfully measured at a time and evaluated the fluctuation of their characteristics. The fluctuation of hot-carrier-induced photoemission intensity was larger as gate length becomes smaller. Although the intensity fluctuation of photoemission in the same MOSFET was within small range, the fluctuation all over the MOSFET array was relatively large and independent of the position in the array. An estimation method of the gate length fluctuation has been demonstrated with the photoemission intensity distribution analysis.

We implemented all-fiber delay line using linearly chirped fiber Bragg gratings (CFBG), which can be applicable for reflectometry or optical coherence tomography (OCT). Compared with the previously reported delay lines, the proposed fiber-based optical delay line has in principle novel advantages such as automatic dispersion cancellations without additional treatment and a gain in optical delay that is dependent on parameters of used CFBGs. Dispersion compensation in optical delay line (ODL), which is the indispensable problem in bulk optics based ODL, is demonstrated in fiber by using two identical but reversely ordered CFBGs. Amplified variable optical delay of around 2.5 mm can be obtained by applying small physical stretching of one of CFBGs in the proposed scheme. The operational principles of the all-fiber variable optical delay line, which are based on the distributed reflection characteristic of a CFBG employed, are described. Especially properties such as in-line automatic dispersion cancellation and amplified optical delay under strain are dealt. To demonstrate the properties of the proposed scheme, which is theoretical consequences under assumptions, an all-fiber optical delay line have been implemented using fiber optic components such as fiber couplers and fiber circulators. With the implanted ODL, the group delay and amplified optical delay length was measured with/without strain. The wavelength independent group delay measured within reflection bandwidth of the CFBG has proved the property of automatic dispersion cancellations in the proposed fiber delay line. Optical delay length of 2.5 mm was obtained when we apply small physical stretching to the CFBG by 100 µm and this is expressed by the amplification factor of 25. Amplification factor 25, which is less than theoretical value of 34 due to slipping of fiber in the fiber holder, shows that the proposed scheme can provide large optical delay with applying small physical stretching to the CFBG. We measure slide glass thickness to check the performance of the fiber delay line and the good agreement in measured and physical thickness of slide glass (1 mm thick) validates the potential of proposed delay line in the applications of optical reflectometry and OCT. We also discuss the problem and the solution to improve the performance.

We describe a transmission system having a data rate of 160 Gbit/s based on the RZ-DPSK modulation format. The 160 Gbit/s single-polarization signal is generated by optical time division multiplexing technology using the base rate of 40 Gbit/s. The setup is explained and results are given with a special focus on the stability issue of the transmission system. The pulse source, the optical gate for demultiplexing, the clock recovery and the balanced photo-detector are based on semiconductor components. We present long-term bit error measurements (10 hours) over two different long-haul fiber links. The first link comprises 3106 km standard single mode fiber and uses a PMD mitigation scheme. The other link consists of 4 dispersion managed 80 km fiber spans without the need for an additional PMD compensation. Using EDFA amplification solely and also no FEC, error-free operation was achieved over several hours, only limited by slow drift effects in the laboratory system.

A new inductance extraction technique of spiral inductor from measurement fixture is presented. We propose a scalable expression of parasitic inductance for interconnects, and design consideration of test structure accommodating spiral inductor. The simple expression includes mutual inductance between the interconnects with high accuracy. The formula matches a commercial field solver inductance values within 1.4%. The layout of the test structure to reduce magnetic coupling between the spiral and the interconnects allows us to extract the intrinsic inductance of spiral more accurately. The proposed technique requires neither special fixture used for measurement-based method nor skilled worker for precise extraction with the analytical technique used.

In the next-generation networks, ultra high-speed data transmission will become necessary to support a variety of advanced point-to-point and multipoint multimedia services with stringent quality-of-service (QoS) constraints. Such a requirement desires the realization of optical WDM networks. Researches on multicast in optical WDM networks have become active for the purpose of efficient use of wavelength resources. Since multiple channels are more likely to share the same links in WDM multicast, effective routing and wavelength assignment (RWA) technology becomes very important. The introduction of the wavelength conversion technology leads to more efficient use of wavelength resources. This technology, however, has problems to be solved, and the number of wavelength converters will be restricted in the network. In this paper, we propose an effective WDM multicast design method on condition that wavelength converters on each switching node are restricted, which consists of three separate steps: routing, wavelength converter allocation, and wavelength assignment. In our proposal, preferentially available waveband is classified according to the scale of multicast group. Assuming that the number of wavelength converters on each switching node is limited, we evaluate its performance from a viewpoint of the call blocking probability.

This paper proposes an extension field named TypeII AOPF. This extension field adopts TypeII optimal normal basis, cyclic vector multiplication algorithm, and Itoh-Tsujii inversion algorithm. The calculation costs for a multiplication and inversion in this field is clearly given with the extension degree. For example, the arithmetic operations in TypeII AOPF Fp5 is about 20% faster than those in OEF Fp5. Then, since CVMA is suitable for parallel processing, we show that TypeII AOPF is superior to AOPF as to parallel processing and then show that a multiplication in TypeII AOPF becomes about twice faster by parallelizing the CVMA computation in TypeII AOPF.

Among recent trends in Quality of Service (QoS) provisioning in the Internet is the Differentiated Services Architecture, termed DiffServ. The successful deployment of Diffserv to provide a premium QoS guarantees to network traffic requires an effective admission control mechanism, which needs to be scalable and relatively simple to implement. In this paper we present a QoS network framework with novel and effective measurement-based resource management and admission control mechanisms. The mechanism is based on the characteristics of measured arrival and departure traffic. Those characteristics are captured via a passive monitoring. We implement the mechanism at the edge routers of a DiffServ Domain. The admission control mechanism is only executed at the edge routers and doesn't require any signaling between inner routers. The mechanism does not depend on the underlying network topology or any specifications of the cross traffic present in the domain. Therefore the mechanism is scalable. In addition, the proposed approach does not require any traffic policing mechanism at the entrance of the network. This approach can provide the statistical QoS guarantees to a variety of service classes within a DiffServ domain. We show that the proposed framework can provide a high degree of network resource sharing among multiple traffic classes while satisfying their QoS requirements. To evaluate the effectiveness of the proposed framework, we perform a set of simulations on a number of bursty video traffic sources.

By using multiple transmit antennas, wireless systems have a large capacity in time-varying multipath fading channels. Space-time block code (STBC), space-frequency block code (SFBC), and space-time-frequency (STF) block code are well-known techniques in transmitter diversity schemes. While the SFBC (or the STF block coded) system gives full diversity at frequency-nonselective channels, it breaks down when used in a frequency-selective environment. This is because the SFBC (or the STF block code) scheme disregards frequency selectivity of the channel by assuming that channel frequency responses (CFRs) at adjacent subcarriers are the same. In this paper, we propose efficient channel estimation and symbol decoding methods, which consider the difference between CFRs at the adjacent subcarriers of the SFBC (or the STF block coded) orthogonal frequency division multiplexing (OFDM) system in multipath fading channels. The proposed method gives initial channel information by designing a simple training symbol, and the CFRs at all the subcarriers and the differences between the CFRs are easily calculated by using an interpolation method or a discrete Fourier transform (DFT) operation.

Performing a musical session via networks requires real-time interaction. There exists, however, the problem of delay between the network nodes, which causes musical sessions become an impediment. To overcome this problem, we have proposed a new protocol for musical session called Mutual Anticipated Session (M.A.S.), which is a type of ensemble that controls appropriate timing of sounds. In the M.A.S, one player's performance precedes the other players', thus this performance is called a "precedent musical performance," and we call a time lapse between the players' performance as "precedent time." In the current M.A.S, it is assumed that the tempo during the performance is constant. In such a case, however, players' requirements to perform more expressively or more emotionally by varying the tempo are sacrificed. Thus, in this paper, enhancement of function that accommodates changes of the tempo by predicting tendency of it is realized. Finally we evaluate the enhancement both by system performance test and by task performance of subject experiments.

We report the empirically obtained conditions for the fusion splicing with photonic crystal fibers (PCF) having large mode areas. By controlling the arc-power and the arc-time of a conventional electric-arc fusion splicer, the splicing loss between two PCFs could be lowered down to 0.2 dB in average. For the splicing PCF with a conventional single mode fiber (SMF), the loss was increased due to the modal field mismatch, but still below 0.45 dB in average. The tensile strength was weakened by the splicing from 2.83 GPa down to 1.04 GPa for the PCF-PCF case and 0.89 GPa for the PCF-SMF one.

This paper investigates a relationship between inkdot and one-pebble for two-dimensional finite automata (2-fa's). Especially we show that (1) alternating inkdot 2-fa's are more powerful than nondeterministic one-pebble 2-fa's, and (2) there is a set accepted by an alternating inkdot 2-fa, but not accepted by any alternating one-pebble 2-fa with only universal states.

This paper presents an analysis of the cavity length modulation of a Z-cut quartz etalon equipped with a weight for Laser Diode (LD) wavelength lockers. The electro-optic effect, piezoelectric effect and photo-elastic effect are considered, and the mechanical movement of the etalon with a weight is analyzed by using a mechanical circuit. Approximate equations that clearly explain the mechanical force, mechanical resonance frequency, and Q factor of the mechanical resonance are obtained. The mechanism for improving the modulation efficiency by placing a weight is clarified. We also compare the analysis with experimental results, and show that most of the experimental values are in accord with the calculated values.

The rapid growth of multimedia applications has increased interest in the compression of video data. This paper presents a new method for improving the compression ratio of video data, which can be easily used in a multilayer environment for error resilience applications as well. Data of four luminance blocks in a macroblock are processed and arranged in such a way that important macroblock data is compressed in one block(A), while the rest of the three remaining data blocks(H,V,D) are given difference values in the horizontal, vertical and diagonal directions. This results in a reduced bitstream size because of the low-valued data present in the three blocks(H,V,D), giving better compression at low bitrates. In an error resilient environment, the important data block in a macroblock is transmitted in a secure channel while the remaining three blocks with difference data are sent via a lossy channel. If error occurs in the lossy channel, picture can still be reconstructed with reasonably good quality using only the block data that is transmitted in the secure channel.