Network Transmission Rate Research Articles

Research on Passenger Information System Based on Train Security Detection Sensor Network

The existing train communication network transmission rate is low, large capacity Passenger Information System cannot be efficient and timely processing and transmission. As train security detection sensor network based on Ethernet which has high real-time, bandwidth and interoperability, good maintainability and expansibility, all information transmission and content updates in the PIS system will be centralized and distributed via train level security detection sensor network to all other cars using IP protocol, it will simple overall architecture, improve reliability, guarantee safety and reduce maintenance cost. This paper will mainly construct the PIS system architecture based on train security detection sensor network and simulate its network performance.

Application of Power Communication System in Wind Power Plant

The application of power communication system in the field of wind power mainly includes the overall system communication and local field communication. During the operation of wind farms, the total system requires that the electric power communication system should provide reliable rapid information channel, accuracy of transmission on a variety of digital business. This article will focus on the application of power communication system between the wind turbine and the booster station, which includes optical fiber communication, communication and leased public circuit, as well as the cable communication, wireless communication, microwave wireless communication. Finally, in the premise of various communications comparison, according to the actual situation of the wind power field, the network transmission rate and reliability should be considered to the requirements of power market.

Ethernet - based Mass Volume Train Security Detection Network

As the existing train communication network transmission rate is low, large capacity status and fault diagnosis data, the event log data, passenger information which are stored in different vehicles equipments, it is difficult to realize fault diagnosis and intelligent maintenance efficiently and timely. Based on the train level and vehicle level Ethernet network, this paper will focus on network construction technology and real-time performance of mass volume onboard security detection network. The research results will improve control and network function of train.

Large Volume Urban Train Security Detection Sensor Network Structure

There are large number of mechanical, electrical and auxiliary devices, and many sensors and intelligent nodes in urban train. The coupling relationship among onboard nodes becomes more and more complex, and various safety detection and information system demand train communication network higher performance. All of these variations need security detection sensor network which has high real-time, bandwidth and interoperability, good maintainability and expansibility. As the existing train communication network transmission rate is low, large capacity status and fault diagnosis data, the event log data, audio and video data which are stored in different vehicles equipments, and cannot be efficient and timely processing. So, it is difficult to realize the information transmission and processing, fault diagnosis and intelligent maintenance of train set. Based on the train level and vehicle level Ethernet network, this paper will focus on network construction technology of large volume onboard security detection sensor network. The research results will help to improve performance of urban train.

Development of a Network Adaptive H.264/AVC Medical Video Transmission System

Network high definition video applications such as video calls and videoconferences have been increasingly developed recent years. When congestions occur and network environment becomes unstable, the network applications have to deal with such issues like delay, packet loss and bandwidth constraints. In this paper, we describe a high definition H.264/AVC video transmission system with network adaptive function based on real-time transport protocol (RTP) and real-time transport control protocol (RTCP). The adaptive system is composed of three components: 1) transmission management (TM) which focuses on network state monitoring, bandwidth allocating and transmission rate control; 2) a feedback-based adaptive forward error correction (AFEC) scheme using Reed Solomon (RS) code; 3) adaptive video encoding (AVE) that adjusts the bitrate of video streaming according to the bandwidth constraint information offered by TM. In our paper, delay, packet loss and bandwidth constraints are generated by the network bottleneck and congestions. Hence, the main idea is to enhance the bitrate of video streaming adapt to the bandwidth constraints. In addition, we integrate AFEC with RTCP to feedback bandwidth status and make the adaptive video streaming more robust under packet loss environment. Here we call it interactive adaptive forward error correction (IAFEC). The test result shows IAFEC can be adaptive to strict bandwidth constraints and high packet loss rates.

Objective Assessment of IP Video Calls with Asterisk

The paper deals with an objective assessment of IP video calls transmission over GSM and UMTS networks. Video transmission is affected by many factors in mobile network. Among these factors belong packet loss, latency and transmission rate of the mobile network. Network properties were simulated by Simena network simulator. Our team have developed a unique technique for finding defects in video appearing in video calls. This technique is built on modified Asterisk SW PBX with enabled video recording and playback functions. Transmitted video files are compared with original video file by means of size of transmitted video file and in-video-defects. We are using MSU VQMT software for finding in video defects; more precisely we are using VQM method for comparing two video sources.

Efficient Optical Resource Allocation and QoS Differentiation in Optical Burst Switching Networks Utilizing Hybrid WDM/OCDM

In this paper, a QoS differentiation framework is proposed for an optical burst switching (OBS) multiservice network. Furthermore, hybrid wavelength division multiplexing and optical code division multiplexing (WDM/OCDM) scheme is used to mitigate the blocking probability of OBS networks. In our study, the measurement criteria of QoS are the blocking probability, OBS network delay, transmission rate, and OCDM probability of error. In order to increase the bandwidth efficiency and control the multiplexing interference effect of OCDM, an advanced optical resource allocation strategy is introduced. The proposed strategy is also compared with a conventional strategy based on random allocation. The comparison shows the superiority of our technique. The blocking probability of the proposed WDM/OCDM-based OBS scheme is evaluated by utilizing both the generalized Engset model and 2-D Markov model. The effect of multiplexing interference is also investigated in computing the probabilities of error and outage. Additionally, an upper bound on the OBS network delay is derived by computing the expected values of burst assembly and burst transmission queuing delay. To proceed further, a four-class OBS network is numerically de- signed to explain the details of QoS differentiation framework and to highlight the advantages of the proposed scheme. Numerical results reveal that by using hybrid WDM/OCDM technique, the blocking probability of OBS networks is significantly reduced. Moreover, the probabilities of error and outage are reduced employing intelligent resource allocation.

Integrating field data and 3D simulation for tower crane activity monitoring and alarming

Abstract Visual monitoring and alarming is an effective way to avoid accidents and to increase the efficiency of project management in the construction industry. It is not feasible to use a camera in a remote monitoring and alarming system for a tower crane due to the low transmission rate of a wireless network. Instead of a camera-monitoring system, a data-driven remote monitoring and alarming system for tower cranes is developed, which integrates field data and 3D simulation. A smart Controller Area Network (CAN) Bus-based data acquisition and transmission system that conforms to standard IEEE 1451.2 is designed to improve the flexibility and quantity of information acquisition. A Module-Position-Attitude-Scale (MPAS) method for describing the parts of a tower crane is used, allowing the virtual crane to be built more easily through parameterization and modularization. A hierarchical architecture of the tower crane is analyzed, and then a robot-like kinematic model is deduced in which the virtual tower crane is driven by the parameters transmitted from the field sensors. The activities reconstruction process for the simulation is improved using the Event Triggering and Variation Computing (ETVC) method. An experience-based and practical alarming system is embedded into the virtual monitoring system. Finally, two application cases are implemented and popularized by users.

Improving DNS Security Using Active Firewalling with Network Probes

The security problems that outbreak network services today are increasing at a dramatic pace especially with the unceasing improvement of network transmission rates and the sheer amount of data exchanged. This translates not only more incidents but also new types of attacks with network incidents becoming more and more frequent. A significant part of the attacks occurs at Top Level Domains (TLDs) who have the assignment of ensuring the correct functioning of Domain Name System (DNS) zones. The proposed solution has been developed and tested at FCCN (Foundation for National Scientific Computing), the TLD manager for the .PT domain. The system consists of network sensors that monitor the network in real-time and can dynamically detect, prevent, or limit the scope of the attempted intrusions or other types of attacks to the DNS service, thus improving its global availability.

A Network Coding Based Rate Adaptive Protocol for Wireless Mesh Network

In this paper, TRANC-a transmission rate adaption network coding protocol for wireless mesh network is proposed. We investigate the interaction between network coding and transmission rate adaption in wireless mesh network. Traditional network coding schemes either assume a fixed transmission rate and do not consider the impact of using diverse rates on the performance of the network, which limits the performance of the wireless networks. each node makes the routing decision based on the link quality, making full use of the transmission capacity of idle nodes in the network, which effectively reduces the communication costs between nodes, as well as the probability of packet duplication. Simulations show that TRANC can effectively improve network throughput with a lower end to end delay.

Spatial Reuse Time-Division Multiple Access for Broadcast Ad Hoc Underwater Acoustic Communication Networks

Underwater acoustic communication (UWAC) is often the only viable solution to establish an ad hoc underwater communication network. The specific features of UWAC, arising from the physics of underwater acoustics, make the design of resource-efficient media access control (MAC) protocols important as well as challenging. In this paper, we tackle this task considering ad hoc UWAC networks that support high-traffic broadcast communication. To this end, we propose the application of the spatial reuse concept and the exploitation of direct sequence spread spectrum used at the UWAC physical layer to obtain a new hybrid spatial reuse time-division multiple-access (HSR-TDMA) protocol. By tracking the time-varying network topology, our protocol adaptively optimizes the set of active communication nodes and overcomes problems of UWAC networks such as the near-far problem, flickering, and formation of islands. Pertinent performance parameters, namely network availability, message reliability, and transmission rate, are analyzed for the proposed protocol. Evaluation of these analytical performance expressions demonstrates the significant advantages of HSR-TDMA over commonly used conventional TDMA for broadcast UWAC networks. We also report performance results for both the HSR-TDMA and the conventional TDMA protocol from a sea trial at the Haifa harbor, which corroborate the results obtained from the analysis.

Energy-efficient multipath routing in wireless sensor network considering wireless interference

Due to the energy and resource constraints of a wireless sensor node in a wireless sensor network (WSN), design of energy-efficient multipath routing protocols is a crucial concern for WSN applications. To provide high-quality monitoring information, many WSN applications require high-rate data transmission. Multipath routing protocols are often used to increase the network transmission rate and throughput. Although large-scale WSN can be supported by high bandwidth backbone network, the WSN remains the bottleneck due to resource constraints of wireless sensors and the effects of wireless interference. In this paper, we propose a multipath energy-efficient routing protocol for WSN that considers wireless interference. In the proposed routing protocol, nodes in the interference zone of the discovered path are marked and not allowed to take part in the subsequent routing process. In this way, the quality of wireless communication is improved because the effects of wireless interference can be reduced as much as possible. The network load is distributed on multiple paths instead of concentrating on only one path, and node energy cost is more balanced for the entire wireless network. The routing protocol is simulated in NS2 software. Simulation result shows that the proposed routing protocol achieves lower energy cost and longer network lifetime than that in the literature.

Joint congestion control and processor allocation for task scheduling in grid over OBS networks

This paper presents a task scheduling algorithm that fulfills the coordination of congestion control in conjunction with processor allocation in the grid over optical burst switching networks. Two requirement criteria, namely deadline and payment, are considered and formulated as a user utility maximization function. The optimization problem is decomposed into two parts: congestion control for network transmission rate adjustment and processor allocation for computational capacity adjustment. The parameters from the resource layer are abstracted and provided to a cross-layer optimizer to maximize user’s utility function. The effectiveness and performance of the algorithm are evaluated via simulations. Comparison with other algorithms shows the efficiency of the proposed algorithm.

Clustered Zigbee networks with data fusion: Characterization and performance analysis

In this paper, we analyze the performance of clustered Zigbee wireless sensor networks (WSNs) with data fusion. Performance indicators at both physical (probability of decision error) and network (network transmission rate, throughput, aggregate throughput, delay, and network lifetime) layers are considered. Data fusion is carried out at the access point (AP) and, in clustered configurations, also at the clusterheads, which act as intermediate fusion centers (FCs). The goal of this paper is to shed light on the joint impact of topology and data fusion on the network performance. The presented results, mainly obtained through Opnet-based simulations, show clearly that the operational point of a Zigbee WSN with data fusion lies over a characteristic multi-dimensional surface, whose shape remains the same regardless of the number of nodes in the network. The existence of this peculiar surface highlights fundamental performance trade-offs in Zigbee networks.

A Wireless Video Transmission Scheme Based on MAC-independent Opportunistic Routing & Encoding Protocol

It is a tremendous challenge to transmit real-time video streams over wireless sensor network because of the poor wireless communication conditions and the high requirements of video transmission. The opportunistic routing protocol can take advantage of the broadcast nature of wireless communication and can improve transfer throughput significantly. But the bigger size of transmission unit also increases the end-to-end delay at the same time. In order to overcome this problem and improve the real-time video transmission quality in wireless video sensor network, we propose a source adaptive frame discard algorithm for MAC-independent Opportunistic Routing & Encoding (MORE) Protocol in this paper. In our approach, the historical transmission delay is recorded to estimate current network transmission rate. Based on the video deadline, frames predicted to be delayed are discarded adaptively in the source node to get better overall video quality. In some practice application scenarios, there are usually need to deliver multiple video streams over multi-hop wireless network. It can’t work effectively with the originally MORE protocol in such scenarios. Furthermore, we modify the MORE protocol and design an adaptive scheme to support multiple video streams over multi-hop wireless video sensor network in this paper. The simulation results show that our algorithm can reduce frame loss rate and improve video quality significantly.

Information-Constrained Resource Allocation in Multicamera Wireless Surveillance Networks

Real-time multiuser multimedia applications, such as surveillance or monitoring using multiple cameras, have recently started to be deployed over flexible and low-cost multihop wireless networks. In such multimedia systems, the various sources (cameras) share the limited network resources and collaboratively forward the captured video streams to a remote central monitor. However, existing resource allocation schemes often ignore the dynamic application-layer video and network characteristics by focusing on the steady-state or worst-case operating conditions. This may result in inefficient allocation of the network resources. In this paper, we focus on determining whether the resource allocation for wireless video surveillance systems should be performed based on steady-state or worst-case operating conditions, or whether perpetual adaptation to the dynamically changing source and network conditions is desirable. We analyze three different types of solutions that have different information requirements: a centralized optimization approach, a decentralized game-theoretic approach (which guarantees a stable allocation), and a distributed greedy approach (which perpetually adapts allocation based on the local information exchanged among the neighboring nodes). We compare these three approaches using the following four metrics: 1) the total video quality; 2) the computational complexity; 3) the required control information overhead; and 4) the timely adaptation to the network and source variation. We show that in a static network, the game theoretic resource allocation is only better than the distributed greedy approach when the network transmission rates are high. In a dynamic network, the distributed greedy approach can outperform the other two approaches significantly in terms of video quality (peak signal-to-noise ratio). This shows that resource allocation solutions for multicamera wireless surveillance networks need to explicitly consider both the dynamic source characteristics and network conditions, rather than always relying on stable, but predetermined, allocations.

상호연결망 폴디드 하이퍼-스타 연결망 FHS(2n,n)의 고장 지름

고장 지름은 상호연결망의 통신 능률과 신뢰도를 평가하는 중요한 척도 중의 하나이다. 이형옥 외 4인[Folded 하이퍼-스타 그래프의 병렬 경로, 한국정보처리학회논문지, Vol.6, No.7, pp.1756-1769, 1999]은 폴디드 하이퍼-스타 FHS(2n,n)의 노드 중복 없는 경로를 제안하였고, FHS(2n,n)의 고장 지름이 2n-1 이하임을 증명하였다. 본 논문에서는 폴디드 하이퍼-스타 FHS(2n,n)의 개선된 노드 중복 없는 경로를 제안한다. 그리고 FHS(2n,n)의 광역 지름이 dist(U,V)+4이고, 고장 지름이 n+2 이하임을 증명한다. The fault diameter is one of the important measures for transmission rate and reliability of interconnection network. H.-O. Lee et al.[Parallel paths in folded hyper-star graph, Journal of KIPS, Vol.6, No.7, pp.1756-1769, 1999] suggested the node-disjoint paths of FHS (2n,n), and proved that the fault diameter of FHS(2n,n) is less than 2n-1. In this paper, we suggest an advanced node-disjoint paths of FHS(2n,n). We also prove that the wide diameter of FHS(2n,n) is dist(U,V)+4, and the fault diameter of FHS(2n,n) is less than n+2.

Joint Design of Network Coding and Transmission Rate Selection for Multihop Wireless Networks

Network coding has the potential to greatly improve the throughput of wireless networks. In the current proposals for wireless network coding, network nodes transmit packets at a fixed transmission rate. It is notable, however, that by dynamically selecting the rate, we can effectively improve the node transmission efficiency. In this paper, we study the application of a rate-adaptive transmission mechanism in network-coding-based multihop wireless networks. In such networks, whether a coding solution is satisfactory or not depends not only on the number of involved native packets but on the packet loss probabilities of its intended next hops and its transmission time as well, both of which depend on the transmission rate. Therefore, we aim to jointly design the coding operation and rate selection to maximize the transmission efficiency. Specifically, we first describe and mathematically formulate the optimal packet coding and rate-selection problem. Then, we prove the NP-completeness of this optimization problem. Finally, we propose an efficient algorithm for finding good combinations of the coding solution and the transmission rate. Simulation results demonstrate that compared with the rate-fixed transmission, the rate-adaptive transmission based on our algorithm can significantly improve the node transmission efficiency.

Hybrid Packet-Pheromone-Based Probabilistic Routing for Mobile Ad Hoc Networks

Ad-Hoc networks are collections of mobile nodes communicating using wireless media without any fixed infrastructure. Minimal configuration and quick deployment make Ad-Hoc networks suitable for emergency situations like natural disasters or military conflicts. The current Ad-Hoc networks can only support either high mobility or high transmission rate at a time because they employ static approaches in their routing schemes. However, due to the continuous expansion of the Ad-Hoc network size, node-mobility and transmission rate, the development of new adaptive and dynamic routing schemes has become crucial. In this paper we propose a new routing scheme to support high transmission rates and high node-mobility simultaneously in a big Ad-Hoc network, by combining a new proposed packet-pheromone-based approach with the Hint Based Probabilistic Protocol (HBPP) for congestion avoidance with dynamic path selection in packet forwarding process. Because of using the available feedback information, the proposed algorithm does not introduce any additional overhead. The extensive simulation-based analysis conducted in this paper indicates that the proposed algorithm offers small packet-latency and achieves a significantly higher delivery probability in comparison with the available Hint-Based Probabilistic Protocol (HBPP).

The peregrine high‐performance RPC system

AbstractThe Peregrine RPC system provides performance very close to the optimum allowed by the hardware limits, while still supporting the complete RPC model. Implemented on an Ethernet network of Sun‐3/60 workstations, a null RPC between two user‐level threads executing on separate machines requires 573μs. This time compares well with the fastest network RPC times reported in the literature, ranging from about 1100 to 2600 μs, and is only 309 μs above the measured hardware latency for transmitting the call and result packets in our environment. For large multi‐packet RPC calls, the Peregrine user‐level data transfer rate reaches 8.9 Mbit/s, approaching the Ethernet's 10 Mbit/s network transmission rate. Between two user‐level threads on the same machine, a null RPC requires 149 μs. This paper identifies some of the key performance optimizations used in Peregrine, and quantitatively assesses their benefits.