High-speed Data Transport Research Articles

Performance Evaluation of a 4 × 20-Gbps OFDM-Based FSO Link Incorporating Hybrid W-MDM Techniques

Free space optics (FSO) has been recognized as a crucial technique to meet the high-bandwidth requirements in future wireless information transmission links. It provides a feasible solution to the last-mile bottleneck problem due to its merits that include high-speed data transportation and secure and low-latency networks. Due to these merits, FSO is a reliable technology for future health-care and biomedical services like the transmission of biomedical sensor signals. But the main limiting factor in the data transmission employing FSO links is adverse atmospheric weather conditions. This research work reports the designing and simulative evaluation of the performance of a high-speed orthogonal frequency division multiplexing–based free space optics link by incorporating wavelength division multiplexing of two independent frequency channels (193.1 THz and 193.2 THz) along with mode division multiplexing of distinct spatial laser Hermite–Gaussian modes (HG01 and HG03). Four independent 20-Gbps quadrature amplitude-modulated data signals are transported simultaneously under different atmospheric weather conditions using the proposed link. Also, the link performance has been investigated for an increasing beam divergence angle.

Application Analysis of TD-SCDMA & Wi-Fi Inter-Working Solution for Coal Mine Industry

The coverage and capacity of high speed data service in coal mine hot spots is not sufficient in present TD-SCDMA communication system. This paper proposes a TD-SCDMA & Wi-Fi network interworking solution , utilizing the high speed data transport of Wi-Fi network on the foundation of TD-SCDMA system. The results show that the solution is feasible and effective .

Receiving Buffer Adaptation for High-Speed Data Transfer

New applications based on cloud computing, such as data synchronization for large chain departmental stores and bank transaction records, require very high-speed data transport. Although a number of high-bandwidth networks have been built, existing transport protocols or their variants over such networks cannot fully exploit the network bandwidth. Our experiments show that the fixed-size application level buffer employed in the receiver side is a major cause of this deficiency. A buffer that is either too small or too large impairs the transfer performance. Due to the varied natures of network conditions and of real-time packet processing (i.e., consuming) speed at the receiver, it is important to ensure that the buffer size is dynamically adjusted according to the perceived execution situation during runtime. In this paper, we propose Rada, a dynamic receiving buffer adaptation scheme for high-speed data transfer. Rada employs an exponential moving average aided scheme to quantify the data arrival rate and consumption rate in the buffer. Based on these two rates, we develop a linear aggressive increase conservative decrease scheme to adjust the buffer size dynamically. Moreover, a weighted mean function is employed to make the adjustment adaptive to the available memory in the receiver. Theoretical analysis is provided to demonstrate the rationale and parameter bounds of Rada. The performance of Rada is also theoretically compared with potential alternatives. We implement Rada in a Linux platform and extensively evaluate its performance in a variety of scenarios. Experimental results conform to the theoretical results, and show that Rada outperforms the static buffer scheme in terms of throughput, memory footprint, and fairness.

Design and Realization of the Dynamic Magnetic Measurement System for Soft Magnetic Material

A dynamic magnetic measurement system for soft magnetic material based on virtual instrument technology is presented. High frequency AC excitation power supply is adopted to drive soft magnetic material. High speed data transport system composed by FPGA chip ALTERA EP1C12Q240C8N and USB microcontroller Cypress CY7C68013A. The problem of phase-shift of hardware integrator which is difficult to control is solved by digital integration. LabVIEW with powerful data processing capabilities is used to simplifies the hardware structure and improve the testing accuracy and automation level of measurement. The paper also points out problems of digital integration and gives a solution.

An Overview of High-speed Packet Data Transport in CDMA Systems

Rapid growth of data services in wireless communication systems requires an efficient means for high speed data transport. Modern CDMA systems have evolved to support this need. This paper presents an overview of the key techniques for improving high speed data transport in the following standards: 1xEV-DO (IS-856 Rev A), 1xEV-DV (cdma2000 Rev D), and HSDPA & EUL (WCDMA FDD Release 6). The emphasis is on identifying the common themes for high speed data transport in all these systems: adaptive modulation and coding, incremental redundancy and hybrid ARQ, smart scheduling to exploit channel variations, limited downlink macro-diversity aided by fast sector switching, and the use of shared channels to improve perceived latency.

Moving and Utilizing Film Images as Data in a Real-World Video Facility

This paper presents an alternative use for standard video pipelines and transport layers. It suggests taking advantage of SMPTE 292M serial digital video connections for high-speed data transport within a traditional video environment, and the subsequent use, storage, and transfer with non-traditional platforms. A new transport medium for film data images is introduced. The proposal includes information on how data images can be viewed, stored, and processed, and how standard video connections can move the data transparently. The format is described as a video-compliant data structure with variable resolutions and aspect ratios. Existing installations are described as application examples.

Numerical analysis of some basic fluid communication models via parallel block methods

In this work we propose a general method for the solution of some basic delayed feedback schemes used in long haul, high speed data transport. In such cases, simple batch Poisson models do not describe packet delays well, while the propagation delay is now becoming a major factor. Two basic virtual circuit networks of balanced form are examined; the single-hop network which aggregates many virtual circuits in parallel, and the multi-hop virtual circuit network having M nodes in tandem. Using well known adaptive algorithms to dynamically adjust the window size, the above networks are presented as linear systems of some delay differential equations in which the rate of transmission and the queue occupancy are modelled as fluids. Although these systems are locally unstable (in a Liapounov sense), we identify the appropriate scale for the parameters so that the systems will perform near their optimal theoretical values for a wide range of speeds. In addition, we propose a general method for their numerical solution which in reality are large and complex. The approach is based on parallel block methods that are used to solve the systems of the ordinary differential equations in which the original systems of the delay differential equations have been transformed. The basic theory underlying the parallel block methods is developed and numerical stability of low order is deduced.

Low-power chip interconnection by dynamic termination

A low-power dynamic termination scheme is proposed and demonstrated as a way to reduce power dissipation for high-speed data transport. In this scheme, the transmission lines are terminated only if the signals change. The gate of a switching MOS transistor connected to a termination resistor is driven by differentiating the transmission signal with a resistor and a capacitor. The power dissipation of the terminating resistor can be reduced to 1/5 in the conventional determination scheme, and overshoot can be reduced to 1/5 that in the open scheme. This scheme is promising for use with palm-top equipment, facilitating high-speed low power operation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Frame relay and SMDS services on a common ATM-based platform

The evolution to broadband networking in the world market has started, enabled by the evolution of the transmission infrastructure and new switching techniques. The market is being driven by the high-speed requirements imposed by the unprecedented penetration of LAN technology and associated high-speed applications as well as the integration of voice, data, image and video requirements. The rapid deployment of more reliable, often fiber-based, facilities migrating to the Synchronous Digital Hierarchy (SDH) and the introduction of switching techniques such as Frame Relay and Asynchronous Transfer Mode (ATM) make possible the introduction of networking capabilities to satisfy emerging requirements. Frame Relay services rely on a stream-lined protocol implementation that makes advantage of end-to-end error control strategies to simplify network processing and enable higher throughput and lower delay. Frame Relay services are being targeted at the 64 Kbps to E1 range. The Asynchronous Transfer Mode (ATM) has been accepted as the transport mechanism for the future Broadband Integrated Services Digital Network (B-ISDN). Metropolitan Area Networks (MANs), based on IEEE 802.6 ATM principles, represent the first commercial application of ATM technology. An early MAN service is the Switched Multimegabit Data Service (SMDS) 1 which has been specified to provide efficient high-speed data transport in the E1 to 34 Mbps range with future extensions to incorporate isochronous transport for the addition of constant-bit rate services such as voice and video services. Similar to SMDS, Connectionless Broadband Networking Services (CBDS) are being defined by ETSI for the European Market with input from the European SMDS Interest Group (ESIG). This paper presents an ATM-based architectural approach, as implemented in At&T's Broadband Networking System 2000 (BNS-2000), to provide Frame Relay as well as SMDS services on the sam platform. The BNS-2000 represents a growable and modular architecture that has been built to comply with international standards such as ANSI, CCITT and ETSI to support the emerging needs of the market.

Alloys of aluminum and zinc

The evolution to broadband networking in the world market has started, enabled by the evolution of the transmission infrastructure and new switching techniques. The market is being driven by the high-speed requirements imposed by the unprecedented penetration of LAN technology and associated high-speed applications as well as the integration of voice, data, image and video requirements. The rapid deployment of more reliable, often fiber-based, facilities migrating to the Synchronous Digital Hierarchy (SDH) and the introduction of switching techniques such as Frame Relay and Asynchronous Transfer Mode (ATM) make possible the introduction of networking capabilities to satisfy emerging requirements.Frame Relay services rely on a stream-lined protocol implementation that makes advantage of end-to-end error control strategies to simplify network processing and enable higher throughput and lower delay. Frame Relay services are being targeted at the 64 Kbps to E1 range. The Asynchronous Transfer Mode (ATM) has been accepted as the transport mechanism for the future Broadband Integrated Services Digital Network (B-ISDN). Metropolitan Area Networks (MANs), based on IEEE 802.6 ATM principles, represent the first commercial application of ATM technology. An early MAN service is the Switched Multimegabit Data Service (SMDS)1 which has been specified to provide efficient high-speed data transport in the E1 to 34 Mbps range with future extensions to incorporate isochronous transport for the addition of constant-bit rate services such as voice and video services. Similar to SMDS, Connectionless Broadband Networking Services (CBDS) are being defined by ETSI for the European Market with input from the European SMDS Interest Group (ESIG).This paper presents an ATM-based architectural approach, as implemented in At&T's Broadband Networking System 2000 (BNS-2000), to provide Frame Relay as well as SMDS services on the sam platform. The BNS-2000 represents a growable and modular architecture that has been built to comply with international standards such as ANSI, CCITT and ETSI to support the emerging needs of the market.