Reduce Transmission Delay Research Articles

A Joint Routing and MAC Protocol for Transmission Delay Reduction in Many-to-One Communication Paradigm for Wireless Sensor Networks

We propose a joint routing and medium access control (MAC) protocol, named as JRAM, for reducing transmission delays in a many-to-one communication paradigm for wireless sensor networks (WSNs). Due to the wide variety of WSN applications, there is a need for protocol solutions optimized for specific application classes. JRAM is proposed for WSNs deployed for monitoring multiple events in the same geographic region which require prompt detection and response. In existing contention-based synchronous MAC protocols designed for this, a node gets only one chance to succeed in data transmission scheduling per cycle, and a sink can also only receive data packets from at most one node in a cycle. Therefore, endto-end transmission delay (E2ETD) and packet delivery ratio (PDR) of these protocols drastically degrade with the increase in event occurrence rate (EOR). In contrast, JRAM proposes a novel approach to provide k (k > 1) chances to a node to succeed in data transmission scheduling in a cycle, and also allows a sink to receive data packets from k nodes in the same cycle. This is done, in JRAM, by partitioning the network nodes into k disjoint sets and then using a novel cycle structure. We evaluate JRAM through extensive NS-2.35 simulations and compare its performance with existing pipelined data collection (PDC), adaptive data collection (ADC), and CROPMAC protocols, for different types of traffic loads and traffic patterns. Results suggest that in case of high EOR, JRAM outperforms PDC, ADC and CROPMAC both in terms of the E2ETD and the PDR.

Coordinating robotic gaze using maximal octant difference election (MODE) visual features

In multi agent mobile robotic systems, coordinating the gaze of each autonomous robot without the use of predetermined gaze attractors requires the sharing of either a gaze vector together with knowledge of the location of each robotic or sharing of a visual description of what the gaze should be directed at. In the latter case, this should consist of the least amount of data possible to reduce transmission delay and processing requirements. Sharing a single unique visual feature is sufficient to direct gaze. Unfortunately, typical feature detection methods are tuned to detect many hundreds of features to maximize successful matches in corresponding images. This paper presents an alternate feature detection method that is tuned to select only a few, high quality features. Not only does this method achieve the accuracy of state of the art methods over the target range, it does so quicker and results in a significantly smaller amount of information that needs to be shared between agents for directing gaze to the same point of interest.

Multipath Routing Protocols in Wireless Sensor Networks: A Retrospective Review

Objectives: To review the basic principles of Multi-path Routing Protocols (MRPs) design and its performance metrics. To discuss the assortment of MRPs overview for Wireless Sensor Networks (WSNs) based on its arrangement and delivery. Methods/Statistical Analysis: The enhanced reliability, load balance and security promote the multi-path routing as an appropriate tool in the domain of Wireless Sensor Networks (WSNs). In order to obtain simultaneous data transfer with reduced delay period, critical review is made based on the performance metrics, taxonomy of MRPs, and qualitative comparison. Findings: From the discussions, it can be concluded that most of the protocols achieved better load balance with improved performance. Coding based MRPs can perform with better reliability when compared to other protocols. Application/Improvements: The survey of earlier reports led to the decisions that the energy-efficient, reduced transmission delay with multiple pairs is the details to be studied in the domain of MRPs.

Radio Resource Management for Ultra-Reliable and Low-Latency Communications

Supporting ultra-reliable and low-latency communications (URLLC) is one of the major goals in 5G communication systems. Previous studies focus on ensuring end-to-end delay requirement by reducing transmission delay and coding delay, and only consider reliability in data transmission. However, the reliability reflected by overall packet loss also includes other components such as queueing delay violation. Moreover, which tools are appropriate to design radio resource allocation under constraints on delay, reliability, and availability is not well understood. As a result, how to optimize resource allocation for URLLC is still unclear. In this article, we first discuss the delay and packet loss components in URLLC and the network availability for supporting the quality of service of users. Then we present tools for resource optimization in URLLC. Last, we summarize the major challenges related to resource management for URLLC, and perform a case study.

Comprehensive Optimization of Energy Consumption and Delay Performance for Green Communication in Internet of Things

Energy efficiency as well as fast data transmission is vital to green communications-based applications for Internet of Things (IoT). Wireless sensors, which constitute one of the important parts of IoT, adopt duty cycle operating mode to save energy. Although duty cycle operating mode will decrease the energy consumption of sensor nodes, it leads to a larger communication delay. In this paper, a utility-based adaptive duty cycle (UADC) routing algorithm is proposed to increase energy efficiency, reduce transmission delay, and keep long lifetime at the same time. First, UADC routing algorithm adopts a comprehensive performance evaluation function to evaluate the utility of choosing different relay nodes. Then it selects the node which maximizes the utility of the system to perform data relay. The utility function synthesizes comprehensive indexes like the reliability, energy consumption, and delay of the node. UADC routing algorithm adopts a high-duty cycle operating mode in the areas which have more remaining energy to decrease the delay. And a low-duty cycle operating mode in the energy-strained areas is adopted to ensure a long lifetime. The simulation results also prove the significant performances of our proposed algorithms.

Hypergraph-Based Wireless Distributed Storage Optimization for Cellular D2D Underlays

Distributed storage that leverages cellular device-to-device (D2D) underlay has attracted rising research interest due to its potential to offload cellular traffic, improve spectral efficiency and energy efficiency, and reduce transmission delay. This paper investigates the overall transmission cost minimization problem based on a content encoding strategy to download a new content item or repair a lost content item in D2D-based distributed storage systems while guaranteeing users’ quality of service. In addition to the optimization of the coding parameters, the cost minimization problem also considers the distribution of content items, the selection of content helpers for each content requester, and the spectrum reuse for establishing D2D links in between. Formulating a hypergraph-based three-dimensional matching problem among content helpers, requesters, and cellular user resources, we present a local search based algorithm with low complexity for optimization. Numerical results demonstrate the performance and the effectiveness of our proposed approach.

The Design of Fuzzy PID Controller for Networked Systems with Random Time Delay

In this paper, the nonlinear systems with time delay network control is discussed transmission delays and packet dropouts for networked control system with random time delay are analyzed. In this paper, online delay estimation method to obtain the delay value, the delay value is an input parameter of fuzzy adaptive PID controller, fuzzy PID temporal adjustment based on genetic algorithm and Particle swarm optimization algorithm to optimization objective function, three parameters of PID is adjusted Online in order to improve the system stability, through Matlab co-simulation tool True Time, the shows the fuzzy logic control system base on PSO algorithm promote reduce transmission delays and packet dropouts. The paper also shows the superiority of Fuzzy PID controllers over their traditional PID for NCS applications.

A Survey on Various Multipath Routing Protocols in Wireless Sensor Networks

There has been a huge development in the field of Wireless Sensor Networks (WSN) in the recent years. The development is mainly due to the availability of small size sensor cameras and microphones. Such devices capture the multimedia data from the environment and effectively transmit them. Wireless Multimedia Sensor Networks (WSMN) is also the current topic of discussion due to its application in various fields. In order to improve the channel utilization rate, reduce transmission delay and balance the transmission load in WMSN multipath routing is a promising solution. Multipath routing helps to transfer data simultaneously thus by reducing delay and congestion in WMSN. In this paper, various protocols and schemes are being discussed on multipath routing strategy which will identify the areas of further development for WMSN.

Coalition Formation for Cooperative Service-Based Message Sharing in Vehicular Ad Hoc Networks

Reliable message delivery is a challenging task in Vehicular Ad Hoc Networks (VANETs). Current literature on VANETs generalize all messages and use the same strategy to transmit them. In this paper, we model the cooperative service-based message sharing problem in VANETs as a coalition formation game among nodes. Nodes associate with a coalition based on the type of service-message they process. In the proposed model, service-messages are distinguished from one another by their types. Nodes process different types of service-messages and form a coalition based on the type of messages they process at that time. Some nodes within a coalition can work as a relay, which is modeled as a network formation game to select exactly one relay among a group of potential relay nodes to improve efficiency of the network in terms of improved packet reception rate and reducing transmission delay. The nodes form independent disjoint coalitions and tree structure is formed with the relay nodes within a coalition by using the proposed algorithm, COMES. Simulation results show that COMES, which allows nodes to form independent coalitions among themselves, improves the network performance in terms of incentive received by players by at least 40 percent compared to a non-cooperative function.

Fast Program Codes Dissemination for Smart Wireless Software Defined Networks

In smart wireless software defined networks (WSDNs), sensor nodes are deployed in the monitored area to sense data. In order to increase the flexibility of WSDNs configuration, sensor nodes use programmable technology. Thus, programming and software engineering that integrate Internet of Things (IoT) lead to a smart world. Due to the large capacity of program codes and the limited energy of wireless network, only a subset of nodes is selected to spread program codes, and the remaining nodes are in sleep status to save energy. In this paper, a fast program codes dissemination (FPCD) scheme for smart wireless software defined networking is proposed; many nodes in the area far from the sink will be selected to spread program codes; those areas have much energy left, while the area near the sink chooses less number of active nodes to spread program codes to save energy. Thus, FPCD scheme can reduce delay for spreading program codes while retaining network lifetime. The theoretical analysis and experimental results show that our approach can reduce transmission delay by 10.76%–105.791% while retaining network lifetime compares with previous broadcast schemes.

New Investigations of Aggressive Packet Combining Scheme to Reduce Transmission Delay and Three States Markov Model Using Multiple Routes to Increase Throughput

New Investigations of Aggressive Packet Combining Scheme to Reduce Transmission Delay and Three States Markov Model Using Multiple Routes to Increase Throughput

CADMA: collision-avoidance directional medium access for vehicular ad hoc networks

Quick and accurate message transmission is an important research topic for vehicular ad hoc networks (VANET). Most studies assume that the periodic broadcast of beacon frames between vehicles increases the safety of the driver. In particular, there has been a lot of research into broadcasting based on carrier sense multiple access with collision avoidance (CSMA/CA) algorithms for medium access. However, the CSMA/CA algorithm is not an optimum technique for the VANET system, due to the transfer delay that occurs in inducing frequent collisions on transmission signals. In this paper, we propose a collision-avoidance directional medium access (CADMA) protocol and infrastructure-utilized clustering method for VANET to support reliable data transfer. In the proposed scheme, the CADMA protocol uses non-competitive transmission methods and cluster heads (CHs) to manage access by allocating the nodes resources. In addition, the roadside unit (RSU) helps with the clustering process. The simulation results indicate that the CADMA can reduce transmission delays and the collision rate of the broadcasting signal, and have shown that the CADMA can be effectively utilized for the VANET systems.

MANET환경에서 Interrupt Message와 Backup path 기법에 기반한 AODV의 성능개선

MANET 환경에서 빈번한 경로 단절은 반복된 경로 탐색으로 인해 제어 패킷 오버헤드와 패킷 손실을 증가시킨다. AODV-I는 event driven방식을 이용하여 주기적인 Hello 메시지를 제거함으로써 AODV의 성능을 개선하였다. Hello 메시지와 달리 각 이벤트마다 전송되는 인터럽트 메시지는 이웃노드의 상태를 알 수 있어 링크 단절을 탐지 및 예측도 할 수 있다. 따라서 AODV-I의 성능은 각 인터럽트 메시지 종류에 따라 처리 절차를 추가함으로써 더욱 개선될 수 있고, 또한 AODV의 단일경로로 인한 문제를 백업 경로기법을 추가하여 개선하는 것도 가능하다. 본 연구에서는 경로 탐색 수와 전송 지연을 줄이기 위해 개선된 백업 경로방식과 인터럽트 메시지 방식을 결합한 AODV-IB를 제안한다. AODV-IB는 각 인터럽트 메시지마다 링크 단절 예측과 탐지에 대한 처리 절차를 추가하여 AODV-I를 개선한다. 또한 추가적인 제어 패킷 없이 지연을 최소화하도록 개선한 백업 경로 방식도 구현한다. QualNet 5.0을 사용하여 구현한 시뮬레이션 결과는 AODV-I에 비해 제안하는 AODV-IB가 더 좋은 성능을 나타낸다. In MANET, frequent route breaks lead to repeated route discovery process and this increases control packet overhead and packet drop. AODV-I improves performance of AODV by using the event driven approach which removes periodic Hello message. Unlike the Hello message, Interrupt message which is sent for each event can detect and predict the link failure because it allows node to know the status of the neighbor node. From this characteristics of Interrupt message, performance of AODV-I can be further improved by adding a processing procedures for each type of Interrupt message and it is also possible to improve AODV-I by adding the Backup path scheme because it originally has problems due to a single path of AODV. In this paper, we propose AODV-IB that combines improved Backup path scheme and Interrupt message approach of AODV-I in order to reduce transmission delay and the number of route discoveries. AODV-IB improves AODV-I by adding proper processing procedures for the link failure prediction and detection for each Interrupt message. We also implement improved Backup path strategy in AODV-IB by minimizing delay without additional Control packet. Simulation results, using the simulator QualNet 5.0, indicate that proposed AODV-IB performs better than AODV-I.

Consistency-Aware Zone Mapping and Client Assignment in Multi-Server Distributed Virtual Environments

In Distributed Virtual Environments (DVEs), the primary task is to maintain a consistent view of the virtual world among all users. Multi-server architecture has been shown to have good scalability to support a large population of users in DVEs. In the zone-based Multi-server Distributed Virtual Environment (MSDVE), zone mapping and client assignment are two key issues in the design of an efficient and scalable MSDVE. Most of the existing work on the zone mapping and client assignment issues in MSDVE aims to either balance workload among servers, reduce inter-server communication, and/or reduce transmission delay. In this paper, we study the zone mapping and client assignment issues from a new perspective aiming to reduce the inconsistency of a DVE. Using the time-space inconsistency metric, we formally formulate the problem as a mix integer programming problem. The zone mapping and client assignment strategy is proposed which consists of a centralized algorithm for initialization and a distributed adaptive tuning algorithm for running system. Extensive experiments were conducted both by simulation and real system for evaluating the performance of the proposed solutions and results are reported in the paper.

WBAN 환경에서 패턴 보정을 통한 임의접근구간 최적 할당 방법

WBAN (Wireless Body Area Network)은 센서 노드를 신체에 삽입 또는 부착하여 생체 신호를 지속적으로 모니터링하기 위해 사용하는 네트워크이다. 특히 의료서비스에서 사용하는 센서 노드는 교체가 어렵기 때문에 배터리 전력 소비가 적어야하며, 지속적으로 생체 신호를 모니터링하기 위해서는 데이터의 높은 전송률과 짧은 전송지연 시간을 보장해야 한다. 본 논문에선는 액티브 노드 개수를 추정하여 슈퍼프레임 내 임의접근구간의 길이와 센서 노드의 데이터 전송확률을 동적 할당함으로써 전송지연시간과 에너지 소모량을 감소시키고 안정적인 처리량을 보장하는 알고리즘을 제안한다. 추정한 액티브 노드 수는 이전 슈퍼프레임의 채널상태에만 의존하기 때문에 잘못 추정될 가능성이 있다. 따라서 액티브 노드 개수를 추정하여 패턴을 정의한다. 그리고 슈퍼프레임의 임의접근구간 길이와 전송확률을 결정하기 위해 정의된 패턴을 이용하여 추정한 액티브 노드 개수를 보정한다. 제안하는 알고리즘의 성능을 평가하기 위해 Matlab을 통해 WBAN과 동일한 환경을 구성하였다. 실험 결과, IEEE 802.15.6 표준의 Slotted ALOHA 방식과 비교한 결과 처리량은 향상되고 전송지연시간과 에너지 소모량은 줄어드는 것을 확인하였다.

Asynchronous decentralized event-triggered control

In this paper we propose an approach to the implementation of controllers with decentralized strategies triggering controller updates. We consider set-ups with a central node in charge of the computation of the control commands, and a set of not co-located sensors providing measurements to the controller node. The solution we propose does not require measurements from the sensors to be synchronized in time. The sensors in our proposal provide measurements in an aperiodic way triggered by local conditions. Furthermore, in the proposed implementation (most of) the communication between nodes requires only the exchange of one bit of information (per controller update), which could aid in reducing transmission delays and as a secondary effect result in fewer transmissions being triggered.

Energy Efficient and Reliable ARQ Scheme (E $$^2$$ 2 R-ACK) for Mission Critical M2M/IoT Services

Wireless sensor networks (WSNs) are the main infrastructure for machine to machine (M2M) and Internet of thing (IoT). Since various sophisticated M2M/IoT services have their own quality-of-service (QoS) requirements, reliable data transmission in WSNs is becoming more important. However, WSNs have strict constraints on resources due to the crowded wireless frequency, which results in high collision probability. Therefore a more efficient data delivering scheme that minimizes both the transmission delay and energy consumption is required. This paper proposes energy efficient and reliable data transmission ARQ scheme, called energy efficient and reliable ACK (E $$^2$$ R-ACK), to minimize transmission delay and energy consumption at the same time. The proposed scheme has three aspects of advantages compared to the legacy ARQ schemes such as ACK, NACK and implicit-ACK (I-ACK). It consumes smaller energy than ACK, has smaller transmission delay than NACK, and prevents the duplicated retransmission problem of I-ACK. In addition, resource considered reliability (RCR) is suggested to quantify the improvement of the proposed scheme, and mathematical analysis of the transmission delay and energy consumption are also presented. The simulation results show that the E $$^2$$ R-ACK scheme achieves high RCR by significantly reducing transmission delay and energy consumption.

Distributed Scheduling in MIMO Empowered Cognitive Radio Ad Hoc Networks

Two fast growing technologies, MIMO and cognitive radio (CR), can both effectively combat the transmission interference among links and thus increase the network throughput. MIMO exploits spatial degree of freedom (DoF) through spatial multiplexing and interference cancellation within the same frequency channel, while CR exploits all available frequency channels for transmissions. We consider an ad hoc network where each node is equipped with an array of cognitive radios. A radio can tune to a different channel and transmit independently, or transmit together with other radios on the same channel using MIMO mode. Additionally, different frequency and spatial channels could have different conditions. There is a big challenge for nodes to distributively coordinate in selecting a transmission channel and/or a spatial DoF taking advantage of this unprecedented flexibility and diversity of channels for a higher network performance. In this work, we mathematically model the opportunities and constraints for such a network with the objective of maximizing the weighted network throughput. We propose a centralized algorithm as our comparison benchmark, and a distributed algorithm to flexibly assign spectrum channel or spatial DoF exploiting the multiuser diversity, channel diversity and spatial diversity for a higher performance in a practical network. The algorithm further supports different transmission priorities, reduces transmission delay and ensures fair transmissions among nodes by providing all nodes with certain transmission probability. The performance of our algorithms are studied through extensive simulations and the results demonstrate that our algorithm is very effective and can significantly increase the network throughput while reducing the delay.

이동 에드혹 네트워크에서 다중전송률전송에 기반한 다중경로 라우팅 기법

이동 에드혹 네트워크에서는 소스 노드로 부터 목적지 노드까지 데이터 전달을 위해 멀티 홉 전송방식을 사용하며 이때 전송경로를 설정하는 라우팅 기법이 중요한 기술적 이슈가 된다. 각 노드들의 위치 변경 및 채널환경의 변화에 따라 노드들 사이의 무선링크가 불안정해 질 수 있으며 이는 링크에러를 증가시키게 된다. 이와 같은 문제를 해결하기 위해 다중경로 라우팅기법이 제안되었다. 다중경로 라우팅은 데이터를 분산 전송하여 특정 링크에서의 혼잡을 줄이고 데이터의 전송효율을 증가시킬 수 있다. 그러나 다중경로 라우팅에서 각각의 경로는 서로 간섭을 야기할 수 있으며 이는 네트워크의 성능을 크게 저하시킬 수 있다. 본 논문에서는 이동 에드혹 네트워크에 적용가능한 다중경로 라우팅기법을 제안하다. 제안된 방식에서는 노드의 위치정보 없이도 경로 간 간섭을 회피할 수 있도록 설계되었다. 시뮬레이션을 통해 제안된 다중경로 라우팅 기법이 전송지연과 에러를 크게 감소시킬 수 있음을 확인하였다. In a mobile ad hoc networks, multi-hop transmission is used to transfer data from source node to destination node and the routing protocol is the one of the important technical issues. The links between nodes can be unstable due to the changes of node location and channel conditions, and it can induce link error. To solve this problem, multipath routing was proposed. Multipath routing can reduce the data congestion and increase data throughput. In the multipath routing, however, each path can be interfered by the other path, and it can aggravate network performance. In this paper, we propose the multipath routing technique in the multi-rate MANET. The proposed multipath routing can avoid interference without the knowledge of node location. Simulation results show that the proposed multipath routing can reduce transmission delay and error.

An Improved Method for Maintenance Scheme of an Inter-Zone Route

In ad hoc networks, the maintenance scheme of an inter-zone route in ZRP (Zone Routing Protocol) makes ZRP take less reliability, more transmission delay and more routing overheads. Aiming at the problem above, BSRZRP (Backup Segment Routes based Zone Routing Protocol) was proposed. In BSRZRP, an inter-zone route was repaired by using backup segment routes as much as possible when an inter-zone route-link opened. This improved method is favor to improve protocol reliability and reduce transmission delay and routing overheads of protocol.