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The Vehicular Ad-hoc Networks includes high-density vehicles, communication access points, data collection and traffic load management. The nodes of these networks are relatively fast, thus accurate data transfer is a major challenge over time. As a result, routing in such networks can be taken as serious issue. To overcome this, an Optimal Geographic Cluster-based Scheduled Routing (OGCSR) protocol for VANET is proposed. It is divided into three stages, first, a multi-hop cluster formation is done using the Improved Chaotic Ant Swarm optimization method. Second, Cluster Head selection by measuring the optimal cluster member and third, searching for the nearby neighbours with Adaptive Neighbour Search algorithm and initiate data scheduling process to reduce the extra time of transmission of control packets. Finally, the performance of OGCSR is evaluated and compared with Cluster Based Life Time Routing, AODV for Conectivity in Vanet and Cluster Based Directional Routing Protocol protocols. As per the results analysis, with a constant speed of 40 kmph, the proposed routing protocol OGCSR gives 13.1% increase in packet delivery rate, 3.5% less delay and better throughput in a high density network. [ABSTRACT FROM AUTHOR]

Dynamic topology and power-controlled lightweight mobile devices usually affect the performance of wireless ad hoc networks and have always been a major focus of research. Data transmission between a source-destination pair is governed by different types of routing protocols like proactive, reactive, hybrid, geographical, etc. Reactive routing techniques are highly preferred due to on-demand source-based routing with limited space requirements. To get a stable route, the routing process should consider the link availability between the communicating nodes. If any two nodes along the route become unreachable, the communication could be interrupted. This could cause the receiver to lose data and experience longer delays. In this paper, we suggest a way to improve the existing DSR protocol. The focus is on choosing a stable route with less control overhead. During the route request phase, every participating node calculates its link availability time (LAT) for each adjacent link based on the current position of the neighbor and receiving signal strength. Links with lesser LATs than a threshold are not considered for route setup hence the flooding of control packets is reduced. Simulation has been performed over the basic DSR and proposed improvements over DSR in terms of control overhead, successful data transmission rate, and the number of route errors generated in the network. The findings show that previous knowledge of link availability during the routing phase aids in the discovery of more stable routes with lower control overhead, thereby promoting reliable data delivery and improving the overall network performance. [ABSTRACT FROM AUTHOR]

Nowadays, ocean networks gradually become increasingly important for communication among network entities such as maritime and sea-crossing users. However, ocean networks are highly dynamic because the communication links are composed of satellite and microwave links, which could be easily influenced by the environment such as local climate. Thus, network transmission in ocean networks faces great challenges, including low reliability and low efficiency. In this paper, we propose a smart ocean network architecture, where we use Software Defined Network (SDN) to perform unified management of the network, and Segment Routing (SR) to control data forwarding paths. In this way, we can control network flows and optimize network routing among diverse network entities in an ocean network. However, many Quality of Service (QoS) guaranteed applications in ocean networks, such as remote control, require lower delay. To guarantee the performance for such applications, we further propose QoS routing algorithms based on Fuzzy-Lagrange for the smart ocean networks architecture, where the optimization objective is to ensure service quality provided to users. According to experimental results, it is proved that, in comparison with the benchmark algorithms, the Fuzzy-Lagrange (FuzLag) algorithm proposed based on link fuzzification and Lagrangian Relaxation can improve the performance by 23% at most.

Summary: One of the infrastructure‐free networks is mobile ad hoc networks (MANETs) that are built with limited battery life using wireless mobile devices. This restricted battery capability in MANETs creates the necessity of considering the energy‐awareness constraint in designing them. As routing protocols, the major aim of MANETs is to create the energy awareness in the network; it improves the network's lifetime through effectively utilizing the available restricted energy. Moreover, it creates some limitations like the mobility constraint, wireless link's sensitivity to environmental impacts, and restricted transmission range and residual energy of nodes that causes rapid modifications in the network topology and frequent link failure. By taking those problems, this paper plans to develop a new multipath routing protocol, where the hybrid optimization algorithm with the integration of cuckoo search optimization (CSO) and butterfly optimization algorithm (BOA) is proposed and named sensory modality‐based cuckoo search butterfly optimization (SM‐CSBO) for determining the optimal path between the source and destination. The main goal is to select the path with better link quality and more stable links to guarantee reliable data transmission. The multi‐objective function is considered with the factors regarding distance, normalized energy, packet delivery ratio, and control overhead to develop an effective routing protocol in MANET. The proposed model of SM‐CSBO algorithm has superior than 5.8%, 30.4%, 36.7%, and 39.3%, correspondingly maximized than PSO, SFO, CSO, and SFO algorithms while considering the number of nodes as 150. The simulation outcomes proved that it enhances network performance when compared with the other traditional protocols. [ABSTRACT FROM AUTHOR]

RPL (Routing Protocol) is the Quantum enabled Cloud-based Low-Power Wireless Personal Area Networks (6LoWPAN) routing protocol. Destination Oriented Directed Acyclic Graph (DODAG) information Solicitation (DIS) messages are received by a node in the RPL protocol to access the network. This function may be abused by a malicious node to transmit illegitimate DIS messages to neighbouring nodes to launch a DIS flooding attack. It is found that the DIS flooding attack raises the overhead of the network control packet, which greatly degrades the efficiency of the network. This further raises the network resource demand of the nodes. A defence scheme called DIS-mitigation in RPL is proposed to resolve this problem. The proposed system greatly mitigates the impact of the DIS flooding attack on the output of the network and also finds the nodes that produce the DIS flood attack effectively. The efficacy of the suggested scheme is related to the traditional RPL protocol and the current stable RPL mechanism. In both static and dynamic network conditions, the experimental findings demonstrate that the proposed model identifies and mitigates DIS flooding attacks rapidly and effectively, without introducing any major overhead to the nodes. • The 6LoWPAN network is actually used in many cloud applications. • Security of such a network from internal and outside threats is one of the key challenges currently for researchers. • In this paper we have also discussed the flood attack DIS which regularly transmits DIS control messages to neighbouring nodes from a malicious node. [ABSTRACT FROM AUTHOR]

The stationary hierarchical network faces considerable challenges from hotspots and faster network breakdowns, especially in smart monitoring applications. As a solution to this issue, mobile sinks were recommended since they are associated with huge and balanced ways to transfer data and energy across the network. Again, due to the mobile sink node advertisement around the network latency and the energy utilization overheads introduced across the network, ring routing reduces the control overhead while preserving the benefits of the mobile sink, thereby optimizing the energy and improving the network life span. Consequently, we suggested a novel, distributed advanced ring routing strategy, in this work, for the mobile wireless sensor network. Extensive simulations and performance evaluation, in comparison to previous distributed mobile approaches, reveal a 37% and 40% boost in the network throughput and end-to end delay, respectively. Additionally, the lifespan of a network is determined by the control overhead and energy demand. [ABSTRACT FROM AUTHOR]

Uneven clustering is an effective solution to solve the energy hole problem in multihop cognitive radio sensor networks (CRSNs). However, current literature leaves control overhead and multihop intercluster routing out of consideration and adopts constant weight coefficients for cluster radius calculation instead of reasonably setting their values according to specific network configurations. To solve the above problems, a distributed energy balance-oriented uneven clustering routing protocol (EBUCRP) is proposed in this article. First, by fully considering the energy consumption of control information exchange and data transmission, EBUCRP theoretically derives the optimal cluster radius of each unit within which distributed clusters are formed. Second, communication capability-based selection criteria are defined from joint energy and spectral efficiency perspectives to help select high-quality cluster heads and next-hop relays. In this case, the monitoring information can be transferred to the sink through efficient intracluster data aggregation and intercluster multihop forwarding. Third, EBUCRP strictly restricts the energy consumption of control information exchange during network operation. Simulation results show that EBUCRP gains obvious advantages over competing protocols in enhancing the lifetime and supervision capability of both single-hop and multihop CRSNs. [ABSTRACT FROM AUTHOR]

Routing is one of the most challenging task in mobile ad hoc networks. Several works have been proposed to address this challenge. Majority numbers of researchers have introduced the routing protocols based on minimize resource consumption but still research needs improvement to design the efficient routing protocols which control the node movement. Proper use of location information and dynamically adjustment of intermediate nodes' retransmission adopted by a number of algorithms contribute to a reduction in the number of retransmissions and consequently reduce control overhead and resource consumption, but this feat was achieved at a price on network reachability. In this paper, an overview of analytical, network, and simulation model used in the design of routing mechanisms wherever possible is presented. This review paper classifies routing protocols into three categories named as route discovery, QoS (Quality of Service), and route maintenance with their relative performance. This paper also compares routing mechanisms against routing efficiency, reliability, packet delay, packet delivery ratio, control overheads, and QoS. This paper reviewed some current literatures that were proposed to improve the reliable, resource consumption, scalable, and QoS based routing mechanisms. This article also highlights the performance demands required of these protocols to assist researcher in MANET resource conservation as a good starting point for developing efficient routing algorithm. [ABSTRACT FROM AUTHOR]

In a multi-controller software-defined networking (SDN) architecture, solving the controller placement problem (CPP) has a direct effect on the generated control overhead in the network. We aim to minimize the control overhead exchanged in the network, especially in software-defined multihop wireless networks (SDMWN), i.e., a network that is built on multihop communications using a wireless medium. We solve this problem both optimally, using a nonlinear optimization model, and via a heuristic algorithm. The proposed heuristic approach is based on the genetic algorithm (GA). The objective of both the proposed optimization problem and the proposed GA algorithm is to find a given number of controllers, controller placements and assignments of controllers to devices while minimizing the generated control overhead in the network. Our results show the impact of different metrics, including the number of controllers, the arrival rate of new flows and the capacity limit of wireless links on the control overhead and the average number of controller-device and inter-controller hops. In addition, our results demonstrate that the GA-based heuristic approach can derive the same optimal solution for a small network with much less computational overhead, and can solve larger networks in a short period of time, making it feasible for non-trivial network sizes. [ABSTRACT FROM AUTHOR]

MANET is an infrastructure-less, fixed topology less, multi-hop and bandwidth constraint wireless network. In MANET optimized control message broadcasting through an efficient routing can results in bandwidth utilization and efficient data transmission with minimum numbers of hops. An efficient routing technique using a broadcast network, designed by existing minimum cost spanning tree (MCST) is also unable to provide all-nodes-to-all shortest route and also have issues about data transmission efficiency. In this article, our broadcast network design approaches can provide a solution for optimized control message broadcast and data transmission efficiency by considering Kruskalś MCST based broadcast network as a base network. Initially, we consider high-frequency links (HF-Link) to be added in the base network by considering the Dijkstra algorithm. Secondly, the broadcast network is designed by including those links with the neighbors who have at least a fixed number of neighbors (CF-Link) and finally, only those links are added with the base network which gives a shorter path to all other nodes (ST-Link) in the network. Using Omnet++ we have compared individual broadcast network design with the base network and observe that a slight increment in control overhead in existing based techniques could increase data efficiency significantly through a given suboptimal path.

With the widespread use of IoT applications and the increasing trend in the number of connected smart devices, the concept of routing has become very challenging. In this regard, the IPv6 Routing Protocol for Low-power and Lossy Networks (PRL) was standardized to be adopted in IoT networks. Nevertheless, while mobile IoT domains have gained significant popularity in recent years, since RPL was fundamentally designed for stationary IoT applications, it could not well adjust with the dynamic fluctuations in mobile applications. While there have been a number of studies on tuning RPL for mobile IoT applications, but still there is a high demand for more efforts to reach a standard version of this protocol for such applications. Accordingly, in this survey, we try to conduct a precise and comprehensive experimental study on the impact of various mobility models on the performance of a mobility-aware RPL to help this process. In this regard, a complete and scrutinized survey of the mobility models has been presented to be able to fairly justify and compare the outcome results. A significant set of evaluations has been conducted via precise IoT simulation tools to monitor and compare the performance of the network and its IoT devices in mobile RPL-based IoT applications under the presence of different mobility models from different perspectives including power consumption, reliability, latency, and control packet overhead. This will pave the way for researchers in both academia and industry to be able to compare the impact of various mobility models on the functionality of RPL, and consequently to design and implement application-specific and even a standard version of this protocol, which is capable of being employed in mobile IoT applications.

The enhanced Mobile Broadband (eMBB) and ultra-Reliable Low Latency Communications (uRLLC) are the two main scenarios of $5^{th}$ generation (5G) mobile communication system networks. There is an obvious difference in service requirements between different scenarios. When multi-scenario services coexist in the 5G networks, exploring optimized resource scheduling and allocation strategies become a critical issue. The 5G New Radio (NR) and numerology technologies have been standardized, which lay the foundation for flexible frame structure and adaptive scheduling. In this paper, we propose the self-adaptive flexible transmission time interval (TTI) scheduling (SAFE-TS) strategy in the eMBB and uRLLC coexistence scenario. Machine learning (ML) is applied to achieve flexible TTI scheduling. Moreover, we design the random forest-based ensemble TTI decision algorithm (RF-ETDA) to accomplish the TTI selection for each service. Compared with the existing ML methods, the proposed algorithm has a performance improvement in selecting TTI, especially for the uRLLC services. Then, the TTI selection results will be the basis of system resource scheduling and allocation. The simulation results prove that the proposed SAFE-TS effectively reduce the delay and packet loss rate of the uRLLC services while guaranteeing the eMBB requirements. Therefore, it is highly recommended that flexible TTI scheduling should be applied in the construction of the 5G networks to achieve superior network performances.

In this article, we propose a model-based characterization of energy consumption in a software-defined wireless sensor network (SD-WSN) architecture in an effort to examine the implications for network performance when making the WSN reprogrammable. The proposed model consists of breaking down all key functions involved in the correct functioning of an SD-WSN, namely; neighbor discovery, neighbor advertisement, network configuration, and data collection. The model is analyzed from a multihop network perspective. We consider two static SD-WSN scenarios to examine scalability, and one scenario to assess the performance implications in a pseudo-dynamic SD-WSN. Extensive simulation results are presented regarding the control overhead introduced, the percentage of alive nodes and remaining energy, and the impacts on network lifetime. We show that the accumulated control overhead is inversely proportional to the interaction period with the controller, whereas the remaining energy and the network lifetime are directly proportional to this parameter. Results show that the control overhead, for static SD-WSNs, can take up to 10%–29% of the total data flowing to the controller for the large SD-WSN and 6–19% for the small SD-WSN. For a pseudo-dynamic network, the control overhead can take up to two-thirds of the total data sent to the controller, and the network lifetime was reduced by up to 80% compared with the static scenarios. [ABSTRACT FROM AUTHOR]

Software-Defined Networking (SDN) has been largely used in wired networks to separate the control plane and the data plane and enable users to programmatically change the networking capabilities. This investigation focused on understanding how SDN concepts could be applied in a networked embedded systems environment where the nodes have limited capabilities and the wireless links have limited bandwidth. The goals were to realize the benefits of SDN while maintaining the network's topology and connectivity. A SDN controller was implemented on BeagleBone Black Board and interfaced with a networked embedded system via a SINK node. The approach was validated through simulations and experiments based on a physical testbed in multiple scenarios. In the future, the design can be extended to a fully capable Wireless-SDN system for use in a variety of applications such as Healthcare Systems, Internet of Things and Advanced Manufacturing Systems. [ABSTRACT FROM AUTHOR]

In wireless sensor networks (WSNs), providing source node with sink position is an essential principle for geographic routing protocols. Previous works have only focused on the problem of sink localization in a 2-D sensing field while that of 3-D WSNs has received little attention. Providing sink location service with low control overhead and energy consumption is a challenging issue in 3-D WSNs area. In this paper, we propose a unital design based sink location service (UDSL) for WSNs. In this scheme, sink location announcement (SLA) and sink location query (SLQ) packets are forwarded along two paths or blocks. The node located at the intersection of the two paths sends the sink position to the source. In the proposed method, SLA and SLQ messages are constructed using unital design blocks. For this purpose, a mapping from unital design to sink location service has been proposed. However, this basic mapping does not guarantee an intersection of paths,therefore, we propose an enhanced UDSL providing 100% probability of intersection. In order to analyze the proposed scheme's performance, extensive WSNs simulations and experiments have been conducted. The results indicate that UDSL provides reasonable performance in terms of hop counts, path length, and energy consumption for providing sink location service.

A large fraction of the microprocessor energy is consumed by the data movement in the system. One of the reasons is the inefficiency in the conventional cache design. Cache blocks larger than a word are used in conventional caches to exploit spatial locality. However, many applications only use a small part of a cache block before its eviction. Transferring and storing unused data wastes bandwidth, energy, and limited cache space. Prior work on fine-grained caches can reduce data access and storage granularity to reduce the amount of unused data. However, small data blocks typically require greater metadata and control overhead. Sharing the common bits among tags of fine-grained blocks can reduce the metadata overhead but the constraints on which fine-grained blocks can share tag bits can cause fragmentation. This work proposes scrabble, a fine-grained cache that can merge multiple non-contiguous fine-grained blocks into a variable size merged block. The length of the shared tag is maximized to reduce the metadata overhead. The space utilization is improved by supporting merged blocks with variable size. The control overhead can be reduced by moving the merged block together from memory to the last level cache. For applications with poor spatial locality, Scrabble cache can achieve more than 40 percent of performance improvement. Even for application with good spatial locality, the speedup is still more than 7 percent. In general, for an evaluated set of benchmarks, Scrabble cache achieves an average of 2.41× effective capacity over the baseline cache with the same cache capacity which leads to a 16.7 percent performance improvement and an 11 percent on-chip energy reduction. As compared to a state-of-the-art fine-grained cache, Scrabble cache achieves a 1.25× effective capacity, a 7.9 percent speedup, and a 5.8 percent on-chip energy reduction. [ABSTRACT FROM AUTHOR]

In the growing world of technology, use of WSN is increasing at an exponential rate in many real time applications such as security, monitoring, tracking, management, learning etc. The most critical challenge in networks is energy consumption; any method used has to be energy efficient. One of the most used approach for reducing the energy consumption and improvement of performance is clustering. In this paper, clustering based new routing algorithm for WSNs using Bio-inspired energy efficient clustering protocol (BeeCup) has been implemented. IBeeCup method has been proposed which is an extension of BeeCup method that finds shortest path. The location information is determined by RSSI. This approach takes an advantage of biologically inspired computation which improves the performance of network. [ABSTRACT FROM AUTHOR]

During the last two decades, there has been a tremendous growth in the use of MANETs, not only due to the development of the technology but also due to their high flexibility. MANETs have challenges and limitations and among the major challenge is the routing process because of high dynamic topology and distributed nature. This is the main reason for quick depletion of network resources. Thus, there is a need to develop a routing protocol to fulfill various application requirements and enhance routing paths according to the topology change. In this paper, two protocols are proposed in order to optimally utilize the constrained network resources and reliably detect high-quality links. They are Hybrid Geo-cast Routing (HGR) protocol and Prediction Residual Lifetime of the Link mechanism (PRLL). The optimal and adaptive HGR protocol utilizes geographical location information to limit search area during route discovery process by including only promising search paths to minimize control overhead. Meanwhile, adaptive PRLL uses signal strength to predicate residual lifetime of the link in order to minimize link breakage, error control packets, and reduce packet drop and end to end delay. The experimental results show that the proposed HGR protocol is able to reduce up to 46.67% control overhead. Meanwhile, the proposed adaptive PRLL protocol improved packet delivery ratio by 26%. [ABSTRACT FROM AUTHOR]

The foremost challenge in designing Wireless Sensor Networks (WSNs) is careful node placement. Sensor Node placement is a one of the powerful optimization technique for accomplishing the anticipated goals. This paper focuses on categories of node deployment in WSN. The paper highlights various problems and identifies the different objectives in sensor node deployment. The paper proposes a novel node deployment strategy based on Quasi- random method of low-discrepancy sequences to increase the lifetime and the coverage of the network. The aim of the paper is to study how the node deployment affects the different QoS parameters such as packet delivery ratio, average energy consumption, delay, etc. with various multi-objective routing algorithms WSN. To validate the proposal simulation, results are presented in this paper. The paper concludes with the future outlook. [ABSTRACT FROM AUTHOR]

Coarse-grained reconfigurable architectures (CGRAs) can provide extremely energy-efficient acceleration for applications that are rich in arithmetic operations such as digital signal processing and multimedia applications. Since those applications are often naturally represented by stream graphs, it is very compelling to develop optimization strategies for stream graphs on CGRAs. One unique property of stream graphs is that they contain many kernels or loops, which creates both advantages and challenges when it comes to mapping them to CGRAs. This paper addresses two main problems with it, namely, many-buffer problem and control overhead problem, and presents our results of optimizing the execution of stream graphs for CGRAs including our low-cost architecture extensions. Our evaluation results demonstrate that our software and hardware optimizations can help generate highly efficient mapping of stream applications to CGRAs, with 3.4\boldsymbol \times speedup on average at the application level over CPU-only execution, which is significant. [ABSTRACT FROM PUBLISHER]

Multi-tier heterogeneous networks have become an essential constituent for next-generation cellular networks. Meanwhile, energy efficiency (EE) has been considered a critical design criterion along with the traditional spectral efficiency (SE) metric. In this context, we study power and spectrum allocation for a two-tier phantom cellular network. The optimization framework includes both EE and SE. We consider densely deployed phantom cellular networks and model the EE optimization problem considering the inevitable interference in this setup and imperfect channel estimation impairments. To this end, we propose three resource allocation strategies aiming at optimizing this network EE performance metric. Furthermore, we investigate the effect of changing some system parameters on the performance of these strategies, such as phantom cells resource units share, number of deployed phantom cells within a macro cell, number of pilots, and the phantom cells transmission power budget. It is found that increasing the number of pilots will deteriorate the EE performance of the whole setup, while increasing phantom cells transmission power budget will not affect the EE of the whole setup significantly. In addition, we observed that it is always useful to allocate most of the network resource units to the phantom cells tier. [ABSTRACT FROM PUBLISHER]

The millimeter-wave (mmWave) frequencies have attracted considerable attention for fifth generation (5G) cellular communication as they offer orders of magnitude greater bandwidth than current systems. However, the medium access control (MAC) layer may need to be significantly redesigned to support the highly directional transmissions, and the demand for ultra-low latencies and high peak rates expected in mmWave communication. To address these challenges, we present a novel mmWave MAC layer frame structure with a number of enhancements, including flexible, highly granular transmission times, dynamic control signal locations, extended messaging, and the ability to efficiently multiplex directional control signals. Analytic formulas are derived for the utilization and control overhead as a function of control periodicity, number of users, traffic statistics, signal-to-noise ratio, and antenna gains. Importantly, the analysis can incorporate various front-end MIMO capability assumptions—a critical feature of mmWave. Under realistic system and traffic assumptions, the analysis reveals that the proposed flexible frame structure design offers significant benefits over designs with fixed frame structures similar to current 4G long-term evolution. It is also shown that the fully digital beamforming architectures offer significantly lower overhead compared with analog and hybrid beamforming under equivalent power budgets. [ABSTRACT FROM PUBLISHER]

In mobile ad hoc network, nodes co-operatively form a network independent of any fixed base station infrastructure. Every node in a mobile ad-hoc network can function as a router and forwards the data packets to the other nodes. Multicasting plays an important role whenever group communications are required. Most of the existing multicast routing protocols in mobile ad hoc networks consider only one source in a multicast group and become inefficient when the protocol is extended to multi-source multicasting. In this paper, we propose a unicast forwarded multi-source multicast routing protocol, for ad hoc networks which is having more than one source in a group. Here, the sources of the group also act as a receiver for other sources in that group. The proposed routing method is a cluster based one and avoids the flooding or broadcasting of control packets to form routing structure. On executing source joining and receiver joining procedures, a complete path for multicast data transfer was established. As the join request control packets are forwarded only through cluster-heads and junction nodes, lower amount of control overhead is incurred. Simulation result shows that the proposed protocol maintains the delivery ratio with reduced control overhead and utilizes the bandwidth efficiently.

Black hole attack refers an attack by single or more number of malicious nodes which forcibly captures the route from source to destination by sending reply with largest sequence number and smallest hop count. In this paper, a novel technique using Localized Secure Architecture for MANET (LSAM) routing protocol is proposed to detect and prevent co-operative black hole attack. Security Monitoring Nodes (SMNs) would be activated only if the threshold value is exceeded. If malicious nodes are detected, other SMNs in its proximity area are intimated to isolate the malicious nodes. Network simulator tool is implemented to analyze the network performance of different scenarios with various number of nodes. Packet delivery ratio (PDR), routing overhead, control overhead, packet drop rate, throughput and end-to-end delay (EED) are the factors taken into consideration for performance analysis and it is shown that the proposed protocol is more secured and efficient. PDR is been increased by 27 % in the presence of 40 % misbehaving nodes, while it increases the percentage of overhead on proposed routing protocol from 1 to 4 %. EED is greatly reduced from 0.9 to 0.3 % in LSAM. [ABSTRACT FROM AUTHOR]

An ad hoc wireless network consists of mobile networks which create an underlying architecture for communication without the help of traditional fixed-position routers. There are different protocols for handling the routing in the mobile environment. Routing protocols used in fixed infrastructure networks cannot be efficiently used for mobile ad-hoc networks (MANET), so it requires different protocols. The node moves at different speeds in an independent random form, connected by any number of wireless links, where each node is ready to pass or forward both data and control traffic unrelated to its own use ahead (routing) to other nodes in a flexible interdependence of wireless communication in between. In contrast to infrastructure wireless networks, where the communication between network nodes is take place by a special node known as an access point. It is also, in contrast to wired networks in which the routing task is performed by special and specific devices called routers and switches. In this paper, we consider fuzzy inference system, an attempt has been made to present a model using fuzzy logic approach to evaluate and compare three routing protocols i.e. AODV, DSDV and DSR using effective factor of the number of nodes based on 3 outputs of control overhead, delay and PDR (totally fuzzy system with 4 outputs) in order to select one of these two routing protocols properly under different conditions and based on need and goal. To show efficiency and truth of fuzzy system, three protocols have been evaluated equally using NS-2 simulator and attempt has been made to prove efficiency of the designed fuzzy system by comparing results of simulation of fuzzy system and NS-2 software. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we replace the periodic transmission of control information by transmissions that depend on local network conditions. As a case study, we consider the proactive link state routing protocol OLSR running in a wireless network without infrastructure. Each node maintains a time series on its betweenness, a metric widely used in social network analysis. We interpret an anomaly in a node’s time series as a change in its role and use it to trigger the transmission of link state. In order to ensure throughput does not degrade by the use of dated information, we use a keep-alive timer whose interval takes into account other local conditions including the node speed, packet arrival rate, and number of flows served. We also measure the number of local link breaks and use it to trigger the transmission of neighbour information. ns-2 simulations comparing our proposed A +-OLSR to OLSR, A-OLSR, and Adaptive OLSR show a statistically significant increase in throughput and a decrease in control overhead. Our evaluation also considers packet losses and the use of CRAWDAD wireless traces to drive node movement. [Copyright &y& Elsevier]

The industries are presently exploring the use of wired and wireless systems for control, automation, and monitoring. The primary benefit of wireless technology is that it reduces the installation cost, in both money and labor terms, as companies already have a significant investment in wiring. The research article presents the work on the analysis of Mobile Ad Hoc Network (MANET) in a wireless real-time communication medium for a Networked Control System (NCS), and determining whether the simulated behavior is significant for a plant or not. The behavior of the MANET is analyzed for Ad-hoc on-demand distance vector routing (AODV) that maintenances communication among 150 nodes for NCS. The simulation is carried out in Network Simulator (NS2) software with different nodes cluster to estimate the network throughput, end-to-end delay, packet delivery ratio (PDR), and control overhead. The benefit of MANET is that it has a fixed topology, which permits flexibility since mobile devices may be used to construct ad-hoc networks anywhere, scalability because more nodes can be added to the network, and minimal operating expenses in that no original infrastructure needs to be developed. AODV routing is a flat routing system that does not require central routing nodes. As the network grows in size, the network can be scaled to meet the network design and configuration requirements. AODV is flexible to support different configurations and topological nodes in dynamic networks because of its versatility. The advantage of such network simulation and routing behavior provides the future direction for the researchers who are working towards the embedded hardware solutions for NCS, as the hardware complexity depends on the delay, throughput, and PDR., Competing Interests: The authors declare no conflict of interest., (© 2022 The Authors.)

Path routing and protocol selection are the primary strategies to design any wireless network. In Mobile Adhoc Network (MANET) the selected protocol should have best in terms of data delivery and data integrity. Hence the performance analysis of the protocols is the major step before selecting a particular protocol. In this paper, the performance analysis is carried out on Adhoc On-demand Distance Vector (AODV), Dynamic Source Routing (DSR), Optimized Link State Routing (OLSR) and Destination Sequenced Distance Vector (DSDV) protocols using NS2 simulator. The delay, throughput, control overhead and packet delivery ratio are the four common measures used for the comparison of the performance of above protocols. [ABSTRACT FROM AUTHOR]

Mobile Ad Hoc Networks are comprised of mobile devices communicating via their wireless interfaces and their topology is continuously changing. During communication process between mobile devices or nodes, control-messages transfer occurs among the nodes and the communication process requires significant number of processing cycles in devices. Processing cycles and control messages consume bandwidth and processing resources. Since bandwidth and resource are at a premium, routing protocols should not send more than the optimal number of control messages they need for operation, and algorithms need to be designed for small processing and control overheads. In this paper 'Clustered Optimized AODV' routing protocol, based on the clustered network, is proposed to minimize the control-message overhead and two algorithms are proposed for clustering the network: 'Centroid Clustering Algorithm' and 'Greedy 3-hop Clustering Algorithm'. [ABSTRACT FROM AUTHOR]

In general, link-adaptive schemes, such as adaptive modulation and coding (AMC) and hybrid automatic repeat re- quest (HARQ), enhance system capacity in time-varying wireless channels. For these link-adaptive schemes to be applied, resources have to be adaptively and dynamically allocated every frame. Thus, the system needs control messages to send information to users about dynamic resource allocation. Such information includes user ID, resource position, level of modulation, and coding and automatic repeat request (ARQ) information. However, the transmission of these resource-allocation messages causes control overhead. In this paper, we introduce a scheme that applies AMC to the transmission of resource-allocation messages and analyze its performance in systems that support truncated ARQ, such as link-layer ARQ and HARQ. In addition, we show that using AMC to transmit control messages is a good way to reduce control overhead; in particular, it is very effective when the number of users per frame is large, as in voice over Internet Protocol (VoIP) services. [ABSTRACT FROM AUTHOR]

Precoding with block diagonalization (BD) is an attractive technique for approaching the sum capacity in the multiuser multiple-input multiple-output (MIMO) broadcast channel. Unfortunately, BD requires either global channel state information at every receiver or an additional training phase, which demands additional control overhead and additional system planning. In this paper we propose a new multiuser MIMO algorithm that combines BD with vector perturbation (VP). The proposed algorithm avoids the second training phase, reduces each user is receiver complexity thanks to pre-equalization with VP at the transmitter, and has comparable diversity performance to BD with maximum likelihood decoding algorithm. A bound on the achievable sum rate for the proposed technique is derived and used to show that BD with VP approaches the achievable sum rate of BD with water-filling. Numerical simulations confirm that the proposed technique provides better bit error rate and diversity performance than BD with a zero-forcing receiver as well as BD with zero-forcing precoding. [ABSTRACT FROM PUBLISHER]

It is well-known that MIMO links in slow fading channels can benefit significantly through rate and power adaptations when there is knowledge of channel state information at the transmitter (CSIT). However, practical MIMO transmitter can only support finite combinations of the channel encoding rates and modulation constellation levels due to the finite number of bits allocated in the control overhead (embedded in the packet transmission). In this paper, we shall address various practical MIMO adaptation design issues associated with discrete transmission modes. We propose a systematic design framework to address the MIMO adaptation design based on information theoretical framework. The design problem is cast into an optimization problem similar to the classical vector quantization problem with a modified distortion measure. As an illustration, we apply the design framework to a 2 times 2 MIMO link and compare the goodput performance with the optimal performance predicted by the theory. We found that the goodput performance of the MIMO link predicted by the theoretical framework matches the actual performance closely [ABSTRACT FROM PUBLISHER]

In this paper, we present a performance model of optical burst switching (OBS) that can explain the degradation of OBS throughput performance when the control packet processing time increases. We then use the proposed performance model to investigate three feasible methods to improve OBS performance without significantly increasing the implementation complexity: addition of simple fiber delay lines (FDLs), random extra offset time, and window-based channel scheduling (WBS). Additional FDLs can eliminate the negative impact caused by the variation of the offset time between control packets and data bursts. The random extra offset time approach does not require any additional hardware and computational capability in the nodes. If higher computational capability is available, WBS in general can provide better throughput improvement than that of random extra offset time when FDLs are used in the nodes to compensate the processing time. Simulation results show that a combination of the proposed methods can significantly improve OBS performance. [ABSTRACT FROM PUBLISHER]