Improve Communication Efficiency Research Articles

In-Network Aggregation for Vehicular <italic>Ad Hoc</italic> Networks

In-network aggregation mechanisms for vehicular ad hoc networks (VANETs) aim at improving communication efficiency by summarizing information that is exchanged between vehicles. Summaries are calculated, while data items are generated in and forwarded through the network. Due to its high bandwidth saving potential, aggregation is a vital building block for many of the applications envisioned in VANETs. At the same time, the specific environment of VANETs calls for novel approaches to aggregation, which address their challenging requirements. In this paper, we survey and structure this active research field. We propose a generic model to describe and classify the proposed approaches, and we identify future research challenges.

Communication-aware custom topology generation for VFI network-on-chip

The voltage-frequency island (VFI) design paradigm has strong potential for achieving high energy efficiency in emerging communication centric many-core system-on-chip (SoC) technology called network-on-chip (NoC). In VFI design, each core is allocated into a suitable domain with different voltage and frequency considering the required workload. Most VFI NoC studies have focused on regular topologies. However, today’s diversified applications demand custom NoC topologies to accommodate heterogeneous many-core architectures. In this paper, we propose a low-power custom topology generation method for constructing VFI NoCs, which embraces irregular topologies. The main objective of this work is to minimize energy consumption and communication resources, hence improving communication efficiency.

Communication-oriented performance optimisation during code generation from Simulink models

Increasing complexity of embedded systems brings a big challenge for designers to satisfy requirements for both high-performance and programmability. Automatic multi-threaded code generation facilitates MPSoC-based programming greatly. Apart from the savings on programming effort, system performance is also an important issue to be considered during code generation process. As thread communication is quite frequent in multi-threaded code, system performance will be improved by reducing communication cost. Communication pipeline technique applies distributed memory server for parallel execution between message passing and functional tasks, to reduce the cost caused by communication between different processors. The technique can be applied directly to communicating threads in acyclic topologies. To maximise its application, we also provide a solution to apply the technique to cyclic topologies with allocable delay units. Furthermore, we introduce a scheduling strategy for local threads to improve communication efficiency and processor usage. Experimental results demonstrate the performance improvements with the proposed techniques.

E-mail communication in the management of gastroenterology patients: a review.

E-mail correspondence between physicians and patients can be a useful tool to improve communication efficiency, provide economic and ecological benefits, improve therapeutic interventions and adherence, and enhance self-management. The model of self-management in chronic disease has become an integral component of North American and British medicine. From a practical standpoint, the use of e-mail between physicians and patients can complement the self-management model. E-mail communication has many benefits from both patient and physician perspectives. E-mail contact reduces the inefficiencies associated with telecommunications. Physicians are able to better document out-of-office patient encounters and provide access to specialist care for patients in remote locations. This use of e-mail has the potential to increase patient safety through physician approval of self-manager actions, including earlier initiation of needed treatments. Fewer clinic visits afford additional time for new consultations and sicker patients, reducing the overall burden on referral and wait times. The present article reviews some of the literature regarding physician-patient e-mail communication in the general ambulatory setting, in the context of chronic disease and with a specific focus on inflammatory bowel disease (IBD). The authors provide a framework for the use of e-mail communication in the IBD population, with emphasis on the concept of e-mail use. Also illustrated are the benefits and disadvantages, and examples of the e-mail contract as proposed by the Canadian Medical Protective Association. Examples of specific e-mail communication topics are provided for several IBD scenarios. Potential negative consequences of this mode of communication are also discussed.

A New Source Encoding Algorithm Based on Shannon Encoding

Source encoding algorithm has been widely concerned by the researchers, which aims to improve communication efficiency. In this paper, we put forward a new source encoding algorithm to decrease the redundancies between compiled code words in Shannon encoding. With the proposed algorithm, a code word is selected by considering whether the code is the prefix code of the other code words or not. The performance of the new encoding algorithm is investigated for both equal probability of source symbols and non-equal probability condition. Numerical results show that the proposed encoding algorithm can improve the encoding efficiency obviously, especially for the case of great probability differences between source symbols.

Asynchronous gaze-independent event-related potential-based brain–computer interface

In this study a gaze independent event related potential (ERP)-based brain computer interface (BCI) for communication purpose was combined with an asynchronous classifier endowed with dynamical stopping feature. The aim was to evaluate if and how the performance of such asynchronous system could be negatively affected in terms of communication efficiency and robustness to false positives during the intentional no-control state. The proposed system was validated with the participation of 9 healthy subjects. A comparison was performed between asynchronous and synchronous classification technique outputs while users were controlling the same gaze independent BCI interface. The performance of both classification techniques were assessed both off-line and on-line by means of the efficiency metric introduced by Bianchi et al. (2007). This latter metric allows to set a different misclassification cost for wrong classifications and abstentions. Robustness was evaluated as the rate of false positives occurring during voluntary no-control states. The asynchronous classifier did not exhibited significantly higher accuracy or lower error rate with respect to the synchronous classifier (accuracy: 74.66% versus 87.96%, error rate: 7.11% versus 12.04% respectively). However, the on-line and off-line analysis revealed that the communication efficiency was significantly improved (p<.05) with the asynchronous classification modality as compared with the synchronous. Furthermore, the asynchronous classifier proved to be robust to false positives during intentional no-control state which occur during the ongoing visual stimulation (less than 1 false positive every 6min). As such, the proposed ERP-BCI system which combines an asynchronous classifier with a gaze independent interface is a promising solution to be further explored in order to increase the general usability of ERP-based BCI systems designed for severely disabled people with an impairment of the voluntary control of eye movements. In fact, the asynchronous classifier can improve communication efficiency automatically adapting the number of stimulus repetitions to the current user's state and suspending the control if he/she does not intend to select an item.

Key Generation Protocol in IBC.

Identity Based Cryptography (IBC) is well known method in the field of security, however it has an inherent drawback of Key Escrow under which central key generation center is a sole issuing authority of private key and thus could misuse it. Our survey finds numerous solutions of key escrow; out of them secure key issuing protocol (SKIP) is most prominent. However, there are scopes for improving communication efficiency of this protocol. Thus, we propose an improved version of this protocol by employing clustering approach. With theoretical and empirical analysis, we demonstrate that the proposed approach indeed effectively reduces the communication overheads and improves efficiency of the original secure key issuing protocol.

차량간 인증 기반 메시지 집계 프로토콜 관리시스템 설계

본 논문에서는 차량 간의 메시지 전송 시에 차량 메시지를 인증함으로서 Sybil 공격에 의해 메시지가 위 변조되는 것을 막고, 동시에 전송 시에 빈번하게 발생하는 중복되는 차량 메시지를 집계하여 효율적인 통신을 제공하는 차량간 인증 기반 메시지 집계 프로토콜 관리시스템 설계를 제안한다. 이를 위하여 제안 시스템은 첫째, 세션 키 기반 로컬인증서인 SKLC(Session Key based Local Certificate)를 설계하고, 둘째, 중복되는 차량 메시지를 집계하는 MAP(Message Aggregation Protocol) 설계를 제안한다. 따라서 제안 시스템은 차량의 인증서를 확인할 때, 해시함수 연산으로 메시지 무결성을 검증하여 신뢰성이 높은 정보를 안전하게 제공할 뿐만 아니라, 연산 처리 시간을 줄여 통신 효율도 향상시킨다. This paper proposes the design of protocol management system for aggregationg messages based on certification between vehicles which not only prevents the messages between vehicles from being forged and altered by Sybil attack by authenticating the them, and but also provides the efficient communication by aggregating the redundant vehicle messages which frequently happens when communicating. For this, the proposed system proposes the SKLC(Session Key Local Certificate) design which is a local certificate based on a session key, and the MAP(Message Aggregation Protocol) design which aggregates the redundant vehicle messages. Therefore, when the proposed system checks the certificate of vehicle, it provides the reliable information securely by verifying the integrity of vehicle with a hash function operation, and improves communication efficiency by reducing the processing time.

A Communication Middleware with Unified Data Transmission Interface

In a Modern communication network, data exchange become a complex problem because there usually exists a various data formats due to the diversity and complexity of communication devices. In this paper, a communication middleware with unified data transmission interface is introduced, which acts as the abstract communication layer in the heterogeneous distributed private communication network. Devices within the network only need to interact with the middleware, instead of directly communicate with each other by various protocols and interfaces, which can reduce the complexity and diversity of the heterogeneous network. This article describes the structure and features of the middleware, and analyses the use of “buffer pool” in message sending and receiving process. The applications of this middleware can reduce the complexity of heterogeneous network interoperation, and improve communication efficiency.

An Adaptive Uplink Resource Allocation Scheme for LTE in Smart Grid

Data transmission is crucial for smart grid. Long Term Evolution (LTE) is considered to be a promising solution for smart grid communication because it uses a variety of new technologies to improve communication efficiency. Resource Blocks (RBs) allocation is applied to provide different levels of Quality-of-Service (QoS) in LTE. In this paper, we propose an Adaptive Wireless Resource Allocation (AWRA) scheme for the uplink of LTE-based cellular systems, which takes into account the user’s priority and fairness. According to QoS requirements, users are assigned three different priorities, so that AWRA performs flexible and efficient RBs allocation based on users’ priorities, thus satisfying a specific QoS requirement. Given Packet Loss Rate (PLR), a mathematical optimization framework is formulated for maximizing the total capacity. The proposed scheme allocates the RBs to the predefined user types with considering Signal Noise Ratio (SNR). An adaptive-scheduling scheme based on the delay time of the queues and the length of the queues is further introduced. Simulation results show that the proposed algorithm has better throughout and fairness than the conventional algorithms, it considerably reduce the data drop rate and satisfies the users’ QoS requirements of smart grid. 

Free Classification of Canadian and American Emergency Management Map Symbol Standards

Emergency management in transnational contexts can be a challenging endeavour. Cultural and language differences among multiple countries can hinder the exchange of information during dynamic emergency response. With increasing international threats and the explosion of near real-time data availability, the emergency response process has become mired in complex communication practices. Maps have the potential to provide an intuitive medium for communication and means for establishing situation awareness during emergency events. The development of map symbol standards is one method for improving communication efficiency. This paper evaluates how the design of two national emergency management map symbol sets (American ANSI and Canadian EMS) influences map-readers’ conception of represented information.

Fermat Point Based Joint Routing in Dual-Aggregation-Points Inter-Backup M2M Communications

Machine-to-machine (M2M) communications can be widely used in military probing, disasters monitoring, etc., where have rigorous environment and require reliable communications. In order to provide enough reliability, M2M subnet can be deployed with two inter-backup aggregation points. This paper proposed a novel routing algorithm named Fermat Point based Joint Routing (FPJR) for such dual-aggregation-points inter-backup M2M Communications. Taking nodes on Fermat Points as route anchors, FPJR forms joint routes which can decrease energy cost and improve communication efficiency greatly. Further, considering the probability is quite little that there is exactly a node deployed on an appointed Fermat Point, we proposed a new terminology ‘ -Fermat Region’, which denotes the circle area with the Fermat Point as center and as radius. Based on -Fermat Region and through the FPJR interaction protocol, FPJR can act not only separately but also as the aid of other routing algorithms, without any compatibility problem. The simulation results show that FPJR can greatly decrease packet lost ratio, energy cost and packet delay.

Buffer Pocketing and Pre-Checking on Buffer Utilization

Problem statement: In this study, the paper proposes the development of Effective Buffer Utilization on Adaptive Router with Buffer Pocketing and Pre-Buffer Checking Technique. Network-on-Chip could be prepared more capable by tricky faster routers. By using improved buffers, superior number of ports and channels, adaptive routing, all of which acquire key of overheads in hardware costs. Approach: This technique will improve communication efficiency without increasing the buffer size with support of input buffer space feedback controller in an input channel. A Buffer-Pocketing system enables the input channels to use the unused buffer from another channel at runtime that have not enough buffer space to utilize as per the input flits. The current buffer status in a router could be updated on each cycle of data flits transmitted to buffer space controller with the help of Router Monitor Sensor (RMS). Results: Implementation results of the proposed design for a 64-bit 4 input-buffer router show a reduction of the average packet transmission latency and an increase of the average transmission flits. The results show that the proposed design can reduce the cycles required for transmitting a fixed number of packets, when compared to that without buffer stealing. Conclusion: The study confirmed that the pre-buffer checking and feedback collecting from the router design take the place of the original design in terms of both throughput and latency. Thus, BS is more robust in handling hardware overhead ratio.

Visualization system for field monitoring data and its effectiveness

Abstract As an integral part of modern civil engineering systems, automated monitoring systems provide quantitative monitoring data for disaster-prevention, as references for future designs, and for forensics working at the site of an engineering disaster, among other possibilities. Most of these applications, however, require integration of the environment, sensor-deployment, and the monitoring data to realize the data's potential. This work proposes a visualization system that integrates monitoring information systems, three-dimensional digital field models, interactive computer graphics, and visualization techniques for the visualization of monitoring data along with field models. Testing of the developed system with undergraduate construction engineering majors showed a consistent improvement in efficiency of about 50% in the interpretation of monitoring data using the developed visualization versus conventional 2D maps and bar charts. The system enables users to interpret monitoring data effectively and intuitively, reduces misinterpretation, improves communication efficiency, and facilitates efficient decisions that are supported by the collected monitoring data.

Evaluation of a Hands-Free Communication Device in an Acute Care Setting

Quality medical care hinges on healthcare providers being able to communicate effectively and efficiently. In this study, we examine if healthcare providers' perceptions of the performance of a wireless communication device are consistent with what it is claimed the technology can offer, namely, improved patient safety and quality of care. We used a mixed-methods design where we collected data from a single medical unit. During the qualitative component of the study, we conducted face-to-face interviews to explore healthcare team members' perceptions of the impact of a wireless communication device on their day-to-day patient care activities. Three major improvements were identified from the interview data: more direct and effective communication, improved work efficiency, and enhanced continuity of patient care. The quantitative component consisted of a questionnaire constructed from the major themes extracted from the interviews. Many of the healthcare team members reported that the wireless communication device improved their communication and allowed them to complete their work more efficiently. In addition, the questionnaire findings suggest that both improved communication and work efficiency are correlated with perceptions of improved quality of patient care. Based on the results of this study, this wireless communication device does live up to its aims of enhancing communication, staff efficiency, and improving perceived patient safety.

Data link layer of selective repeat protocol based on quantum teleportation

In this paper we study the quantum selective repeat protocol of data link layer based on quantum teleportation. When two sites are communicating in the physical layer, the sender divides a series of qubits intom frames by adding auxiliary qubits. After continuously transmitting m quantum frames, the receiver judges whether he receives the correct quantum frame according to the classical information provided by the sender. If the receiver receives the correct quantum frames, he returns confirmed frames using the quantum channel. If the correct quantum frames are not received, the receiver does not return denial frames. The sender judges quantum frames which he must resend according to the received confirm frames in setting time. Because the sender resends only the quantum frames which are lost or mistaken, this protocol reduces the transmission delay and improves communication efficiency. In the entire course of communications, the classical channel is used only to transmit the survey information, thus its burden is reduced.

Adaptive Forwarding Delay Control for VANET Data Aggregation

In-network data aggregation is a useful technique to reduce redundant data and to improve communication efficiency. Traditional data aggregation schemes for wireless sensor networks usually rely on a fixed routing structure to ensure data can be aggregated at certain sensor nodes. However, they cannot be applied in highly mobile vehicular environments. In this paper, we propose an adaptive forwarding delay control scheme, namely Catch-Up, which dynamically changes the forwarding speed of nearby reports so that they have a better chance to meet each other and be aggregated together. The Catch-Up scheme is designed based on a distributed learning algorithm. Each vehicle learns from local observations and chooses a delay based on learning results. The simulation results demonstrate that our scheme can efficiently reduce the number of redundant reports and achieve a good trade-off between delay and communication overhead.

Simulation and Comparison of Channel Estimation Based on Block-type Pilot Frequency in OFDM System

Abstract Orthogonal Frequency Division Multiplexing (OFDM) splits a high-speed data stream into a number of lower-speed data streams that are transmitted simultaneously over a number of subcarriers. The capability of resistance of intersymbol interference and bandwidth efficiency are improved, and multipath fading is effectively combated. In order to improve communication efficiency and communication quality, it is necessary to make a dynamic estimation of the current characteristics of the channel. In OFDM system, the technology of channel estimation based on the pilot frequency of block-type distribution is that pilot signal is inserted at regular intervals of time on the transmitting terminal, and on the receiving terminal extract pilot signal from the received data stream, and according to that the channel characteristics are estimated at the period of time. Three common methods of channel estimation based on pilot frequency: MMSE estimation, LS estimation and SVD estimation are discussed with comparison in OFDM system. Through the simulation of matlab, three channel estimation methods and their characteristics are analyzed and compared. The results show that the performance of MMSE estimation is far better than that of the LS estimation, but MMSE estimation has high computational complexity. The performance and computational complexity of SVD estimation are ranged between that of the MMSE estimation and LS estimation.

Matching sender and receiver: poikilothermy and frequency tuning in a tree cricket

Animals communicate in non-ideal and noisy conditions. The primary method they use to improve communication efficiency is sender-receiver matching: the receiver's sensory mechanism filters the impinging signal based on the expected signal. In the context of acoustic communication in crickets, such a match is made in the frequency domain. The males broadcast a mate attraction signal, the calling song, in a narrow frequency band centred on the carrier frequency (CF), and the females are most sensitive to sound close to this frequency. In tree crickets, however, the CF changes with temperature. The mechanisms used by female tree crickets to accommodate this change in CF were investigated at the behavioural and biomechanical level. At the behavioural level, female tree crickets were broadly tuned and responded equally to CFs produced within the naturally occurring range of temperatures (18 to 27°C). To allow such a broad response, however, the transduction mechanisms that convert sound into mechanical and then neural signals must also have a broad response. The tympana of the female tree crickets exhibited a frequency response that was even broader than suggested by the behaviour. Their tympana vibrate with equal amplitude to frequencies spanning nearly an order of magnitude. Such a flat frequency response is unusual in biological systems and cannot be modelled as a simple mechanical system. This feature of the tree cricket auditory system not only has interesting implications for mate choice and species isolation but may also prove exciting for bio-mimetic applications such as the design of miniature low frequency microphones.

Distributed Memory Service Modeling in Multi-Processor Design

Distributed Memory Service is integrated in Simulink-based multiprocessor design flow to improve communication efficiency comparing to Global FIFO(GFIFO) method.In Motion-JPEG case study,DMS made the percentage cost on communication of total execution time decreased by 50%,and the execution time decreased by 30% for decoding 10 frames,comparing with GFIFO.This integration makes more opportunities in design exploration to improve the performance of Simulink-based multiprocessor design flow.