UPS: Universal Protocol Stack for emerging wireless networks

Recent devices developed for emerging wireless networks, such as 4G cellular networks, wireless mesh networks, and mobile ad hoc networks, support multiple communication substrates and require execution of multiple protocols within a layer, which cannot be supported efficiently by traditional, layered protocol stack approaches. While cross-layer approaches can be designed to support these new requirements, the lack of modularity makes cross-layer approaches inflexible and hence difficult to adapt for future devices and protocols. Thus, there is a need for a new protocol architecture to provide universal support for cross-layer interactions between layers, while also supporting multiple communication substrates and multiple protocols within a stack. In this paper, we propose Universal Protocol Stack (UPS), which provides such support in a modular way through packet-switching, information-sharing and memory management. To show that UPS is realizable with very low overhead and that it enables concurrent and independent execution of protocols of the same stack layer, first, we present a wireless sensor network test-bed evaluation, where UPS is implemented in TinyOS and installed on individual sensor motes. Two cross-layer routing protocols are implemented and evaluated with UPS and without UPS. We also implemented UPS in the OPNET simulator, where the IP (e.g., Routing Information Protocol (RIP)) and AODV routing protocols are executed concurrently to support networks with both static and mobile wireless nodes. Our implementation shows that the overhead incurred to implement UPS is very low, and little or no modification is required to adapt existing protocols to the UPS framework. Both studies also show the advantage of enabling concurrent protocol execution within a stack layer, improving the successful packet delivery ratio or the total number of packets sent for the investigated scenarios.     

无线传感器网络能耗分析与策略研究

无线传感器网络技术得到了广泛应用,但是该技术一直受能量的制约,因此能量始终是无线传感器网络的核心问题。通过对传感器节点结构与网络体系的分析,得出了传感器网络的能耗特性。为了延长无线传感器网络的生命周期,对传感器节点工作能耗与传感网络能耗做了具体研究,再从低功耗节点设计、网络协议及环境中能量补给三个方面总结出了一套有效的节能策略。     

A selective encryption and energy efficient clustering scheme for video streaming in wireless sensor networks

The past few years have witnessed increased interest in the potential use of wireless sensor networks (WSNs) in applications such as battlefield assistance, adversary intrusion detection, distributed signal processing, etc. In these applications, multimedia semantic information and video content are extremely sensitive to malicious attacks, including eavesdropping/intercepting of ongoing traffic, and manipulating/counterfeiting of the existing media flows. From a security standpoint, it is very important to transmit authentic and accurate data to surrounding sensor nodes and to the sink. However, securing sensor networks poses unique challenges because these tiny wireless devices are deployed in large numbers, usually in unattended environments, and are severely limited in their capabilities and resources like power, computational capacity, and memory. In this work, a secure and selective encryption framework is proposed so as to optimize network lifetime and video distortion for an energy constrained wireless video sensor network (WVSN).     

Energy awareness workflow model for wireless sensor nodes

Before the development of a large‐scale wireless sensor network (WSN) infrastructure, it is necessary to create a model to evaluate the lifespan of the infrastructure, the system performance and the cost so that the best design solution can be obtained. Energy consumption is an important factor that influences the lifespan of WSNs. One of the ways to extend the lifespan of WSNs is to design wireless sensor nodes with low power consumption. This involves component selection and the optimisation of hardware architecture, monitoring software system and protocols to satisfy the requirements of the particular applications. This paper proposes a comprehensive model to describe the workflow of a wireless sensor node. Parameter setup and energy consumption calculation are demonstrated through the model simulation. It provides a mathematical approach to dynamically evaluate the energy consumption of a sensor node. This will benefit the development of wireless sensor nodes based on microprocessors with limited computational capability. Therefore, the model can be applied in dynamic power management systems for wireless sensor nodes or in wireless communication protocols with energy awareness, in particular, for WSNs with self‐organisation. More importantly, the generalisation of the model may be employed as a standard paradigm for the development of wireless sensor node with energy awareness. Copyright © 2012 John Wiley & Sons, Ltd.     

无线传感器网络多业务仿真平台的实现方案

在无线传感器网络中,由于传感器节点的能源十分有限,节能是设计的首要因素。然而,无线传感器网络的多业务在现实生活应用中对QoS(服务质量)都有不同的需求,这就使得WSN网络的QoS研究成为了专家学者们的主要研究方向。在WSN网络拓扑结构和业务类型的研究基础上,使用网络模拟器(Network Simulator Version 2,NS2)来搭建基于多业务共存的星型以及对等结构两种WSN网络仿真平台,建立多种业务流量模型,实现以无线传感器网络协议、流量模型、拓扑为基础的功能模块化设计;并对无线传感器网络关键性能进行了仿真模拟,实现延时、吞吐量、能耗等关键性能的分析。     

Improving Low-Energy Adaptive Clustering Hierarchy Architectures with Sleep Mode for Wireless Sensor Networks

A wireless sensor network (WSN) is composed of sensor nodes whose energy is battery-powered. Therefore, the energy is limited. This paper aims to improve the energy efficiency of sensor nodes in order to extend the lifetime of WSNs. In this paper, we propose four new hierarchical clustering topology architectures: random cluster head and sub-cluster head (RCHSCH), random cluster head and max energy sub-cluster head (RCHMESCH), random cluster head and sub-cluster head with sleep mode (RCHSCHSM) and random cluster head and max energy sub-cluster head with sleep mode (RCHMESCHSM). Our proposed architectures involve three-layers and are based on low-energy adaptive clustering hierarchy (LEACH) architecture. Notably, RCHSCH can improve upon cluster head death within the LEACH architecture. In addition, we develop a sleep mode for sensor nodes based on correlations among sensor data within sub-clusters in RCHSCHSM. Thus, we can reduce the energy consumption of the sensor node and increase energy efficiency. From the simulation results, our proposed RCHSCH, RCHMESCH, RCHSCHSM and RCHMESCHSM architectures perform better than the LEACH architecture in terms of initial node death, the number of nodes alive and total residual energy. Furthermore, we find the performance of RCHMESCHSM architecture to be optimal in the set of all available architectures.     

Implementing a hardware-embedded reactive agents platform based on a service-oriented architecture over heterogeneous wireless sensor networks

Wireless Sensor Networks (WSNs) represent a key technology for collecting important information from different sources in context-aware environments. Unfortunately, integrating devices from different architectures or wireless technologies into a single sensor network is not an easy task for designers and developers. In this sense, distributed architectures, such as service-oriented architectures and multi-agent systems, can facilitate the integration of heterogeneous sensor networks. In addition, the sensors’ capabilities can be expanded by means of intelligent agents that change their behavior dynamically. This paper presents the Hardware-Embedded Reactive Agents (HERA) platform. HERA is based on Services laYers over Light PHysical devices (SYLPH), a distributed platform which integrates a service-oriented approach into heterogeneous WSNs. As SYLPH, HERA can be executed over multiple devices independently of their wireless technology, their architecture or the programming language they use. However, HERA goes one step ahead of SYLPH and adds reactive agents to the platform and also a reasoning mechanism that provides HERA Agents with Case-Based Planning features that allow solving problems considering past experiences. Unlike other approaches, HERA allows developing applications where reactive agents are directly embedded into heterogeneous wireless sensor nodes with reduced computational resources.     

A cluster-based power-efficient MAC scheme for event-driven sensing applications

In developing an architecture for wireless sensor networks (WSNs) that is extensible to hundreds of thousands of heterogeneous nodes, fundamental advances in energy efficient communication protocols must occur. In this paper, we first propose an energy-efficient and robust intra-cluster communication bit-map assisted (BMA) MAC protocol for large-scale cluster-based WSNs and then derive energy models for BMA, conventional TDMA, and energy efficient TDMA (E-TDMA) using two different approaches. We use simulation to validate these analytical models. BMA is intended for event-driven sensing applications, that is, sensor nodes forward data to the cluster head only if significant events are observed. It has low complexity and utilizes a dynamic scheduling scheme. Clustering is a promising distributing technique used in large-scale WSNs, and when combined with an appropriate MAC scheme, high energy efficiency can be achieved. The results indicate that BMA can improve the performance of wireless sensor networks by reducing energy expenditure and packet latency. The performance of BMA as an intra-cluster MAC scheme relative to E-TDMA depends on the sensor node traffic offer load and several other key system parameters. For most sensor-based applications, the values of these parameters can be constrained such that BMA provides enhanced performance.     

Signaling alternatives in a wireless ATM network

The world of wireless telecommunications is rapidly changing. The capabilities of wireless networks are improving at a steady pace. This paper presents two possible protocols for implementing mobility for wireless users in an asynchronous transfer mode (ATM) network. The vision of the authors is of one “wireless ATM telecommunications network” that is capable of supporting a variety of today's applications with room to grow for advanced applications of the future. We first visit database architectures that can support mobility in a wireless ATM network. We then discuss one of two signaling architecture alternatives, the “overlay signaling”, for overlay support of mobile users in the ATM-based wireless telecommunications network. “Overlay signaling” aims at minimizing the modification needed to the existing ATM protocols. We then describe a native “migratory signaling” approach that further integrates wireless and wireline users into one global wireless ATM network at the expense of requiring some modifications to the existing ATM protocols. A performance analysis of the proposed signaling architecture alternatives is also presented. We conclude by pointing out some challenges in merging ATM with wireless telecommunications     

Energy efficiency of dense wireless sensor networks: to cooperate or not to cooperate

Decentralized detection in a network of wireless sensor nodes involves the fusion of information about a phenomenon of interest (PoI) from geographically dispersed nodes. In this paper, we investigate the problem of binary decentralized detection in a dense and randomly deployed wireless sensor network (WSN), whereby the communication channels between the nodes and the fusion center are bandwidth-constrained. We consider a scenario in which sensor observations, conditioned on the alternate hypothesis, are independent but not identically distributed across the sensor nodes. We compare two different fusion architectures, namely, the parallel fusion architecture (PFA) and the cooperative fusion architecture (CFA), for such bandwidth-constrained WSNs, where each sensor node is restricted to send a I-bit information to the fusion center. For each architecture, we derive expression for the probability of decision error at the fusion center. We propose a consensus flooding protocol for CFA and analyze its average energy consumption. We analyze the effects of PoI intensity, realistic link models, consensus flooding protocol, and network connectivity on the system reliability and average energy consumption for both fusion architectures. We demonstrate that a trade-off exists among spatial diversity gain, average energy consumption, delivery ratio of the consensus flooding protocol, network connectivity, node density, and Poll intensity in CFA. We then provide insight into the design of cooperative WSNs     

Survey on the design of underwater sensor nodes

Underwater wireless sensor networks are networks composed of various underwater sensor nodes (USNs) that are able to communicate with each other. The vast majority of Earth’s surface is composed of water, which makes such networks a very interesting research topic and enables a variety of applications, i.e, from oil monitoring to real time water pollution control. The design of USNs is paramount to the network’s operation. In comparison to terrestrial wireless sensor nodes, USNs are more expensive, larger, and present greater energy consumption, due to the harsh conditions of the aquatic environment. This leads to different challenges that need to be addressed in the design of the node, including processing, communications, energy management, data sensing, and storage. This survey aids in the development of underwater sensor nodes, and underwater applications. We present a general architecture of USNs and discuss the basic functions that must be accomplished by each unit. We also present a comprehensive study of all elements that compose a sensor node, including microcontrollers, memories, sensors, and batteries. In doing so, we highlight which aspects should be of pivotal importance in the design of a USN and how they affect communication protocols and applications. We believe that this survey can facilitate and guide development of future UWSN applications and protocols.     

Reliable and energy aware query-driven routing protocol for wireless sensor networks

Wireless sensor networks become very attractive in the research community, due to their applications in diverse fields such as military tracking, civilian applications and medical research, and more generally in systems of systems. Routing is an important issue in wireless sensor networks due to the use of computationally and resource limited sensor nodes. Any routing protocol designed for use in wireless sensor networks should be energy efficient and should increase the network lifetime. In this paper, we propose an efficient and highly reliable query-driven routing protocol for wireless sensor networks. Our protocol provides the best theoretical energy aware routes to reach any node in the network and routes the request and reply packets with a lightweight overhead. We perform an overall evaluation of our protocol through simulations with comparison to other routing protocols. The results demonstrate the efficiency of our protocol in terms of energy consumption, load balancing of routes, and network lifetime.     

无线移动传感器网络自适应体系结构的设计

随着无线网络技术的日益成熟及其对小型、微型移动设备的支持,无线移动传感器网络已经逐渐成为一个研究的热点。主要讨论了为无线移动传感器网络设计的一个自适应的体系结构。在该体系结构中,使用了一个区域和核心路由节点相结合的多层结构的方法来增加无线移动网络的信息传输能力、可扩充性和可靠性,并降低网络的能耗,这样就可以适应无线移动网络的高度动态性和移动性。     

Multi-channel support for DMAC in WSNs

Currently most wireless sensor network applications assume the presence of single-channel medium access control (MAC) protocols. However, lower sensing range result in dense networks, single-channel MAC protocols may be inadequate due to higher demand for the limited bandwidth. In this paper we proposed a method of multi-channel support for DMAC in Wireless sensor networks (WSNs). The channel assignment method is based on local information of nodes. Our multi-channel DMAC protocol implement channel distribution before message collecting from source nodes to sink node and made broadcasting possible in DMAC. Analysis and simulation result displays this multi-channel protocol obviously decreases the latency without increasing energy consumption.     

Routing in mobile wireless sensor network: a survey

The Mobile Wireless Sensor Network (MWSN) is an emerging technology with significant applications. The MWSN allows the sensor nodes to move freely and they are able to communicate with each other without the need for a fixed infrastructure. These networks are capable of out-performing static wireless sensor networks as they tend to increase the network lifetime, reduce the power consumption, provide more channel capacity and perform better targeting. Usually routing process in a mobile network is very complex and it becomes even more complicated in MWSN as the sensor nodes are low power, cost effective mobile devices with minimum resources. Recent research works have led to the design of many efficient routing protocols for MWSN but still there are many unresolved problems like retaining the network connectivity, reducing the energy cost, maintaining adequate sensing coverage etc. This paper addresses the various issues in routing and presents the state of the art routing protocols in MWSN. The routing protocols are categorized based on their network structure, state of information, energy efficiency and mobility. The classification presented here summarizes the main features of many published proposals in the literature for efficient routing in MWSN and also gives an insight into the enhancements that can be done to improve the existing routing protocols.     

REACA: An Efficient Protocol Architecture for Large Scale Sensor Networks

The emergence of wireless sensor networks has imposed many challenges on network design such as severe energy constraints, limited bandwidth and computing capabilities. This kind of networks necessitates network protocol architectures that are robust, energy-efficient, scalable, and easy for deployment. This paper proposes a robust energy-aware clustering architecture (REACA) for large-scale wireless sensor networks. We analyze the performance of the REACA network in terms of quality-of-service, asymptotic throughput capacity, and power consumption. In particular, we study how the throughput capacity scales with the number of nodes and the number of clusters. We show that by exploiting traffic locality, clustering can achieve performance improvement both in capacity and in power consumption over general-purpose ad hoc networks. We also explore the fundamental trade-off between throughput capacity and power consumption for single-hop and multi-hop routing schemes in cluster-based networks. The protocol architecture and performance analysis developed in this paper provide useful insights for practical design and deployment of large-scale wireless sensor network.     

Lifetime analysis of wireless sensor nodes in different smart grid environments

Wireless sensor networks (WSNs) can help the realization of low-cost power grid automation systems where multi-functional sensor nodes can be used to monitor the critical parameters of smart grid components. The WSN-based smart grid applications include but not limited to load control, power system monitoring and control, fault diagnostics, power fraud detection, demand response, and distribution automation. However, the design and implementation of WSNs are constrained by energy resources. Sensor nodes have limited battery energy supply and accordingly, power aware communication protocols have been developed in order to address the energy consumption and prolong their lifetime. In this paper, the lifetime of wireless sensor nodes has been analyzed under different smart grid radio propagation environments, such as 500 kV substation, main power control room, and underground network transformer vaults. In particular, the effects of smart grid channel characteristics and radio parameters, such as path loss, shadowing, frame length and distance, on a wireless sensor node lifetime have been evaluated. Overall, the main objective of this paper is to help network designers quantifying the impact of the smart grid propagation environment and sensor radio characteristics on node lifetime in harsh smart grid environments.     

An Improved Pillar K-Means Based Protocol for Privacy-Preserving Location Monitoring in Wireless Sensor Network

A number of tiny sensor nodes are strategically placed in and around the human body to obtain physiological information. The sensor nodes are connected to a coordinator or a data collector to form a wireless body area network (WBAN). WBAN consists of variety of medical and non-medical applications with aggregate data rate requirement ranging from few bytes per second to 10 Mbps. These applications are having relatively different energy saving, reliability and quality of service (QoS) requirements. For example, emergency medical data are highly erratic but should be transferred with high reliability and minimum delay, whereas electrocardiogram and electroencephalogram applications are constant bit rate traffic which need to be transferred with moderate reliability. Additionally, non-medical applications include variable bit rate traffic and their jitter and delay requirements must also be met. On the above, a sensor node should spend minimum energy and conserve power to increase its life time in the network. The existing media access control (MAC) protocols present in various short and medium range wireless technologies such as 802.11 and 802.15.4 have been designed for specific purposes, and therefore, do not fulfill the diverse performance requirements across all WBAN applications. In this paper, we propose a poll-based MAC protocol, PMAC for WBAN, which can meet such diversified functional requirements of various WBAN applications. In particular, we introduce few concepts in polling based channel access mechanism to make an energy efficient and QoS aware MAC protocol. The design has been validated by obtaining the performance of proposed PMAC protocol through simulation.     

Energy-aware wireless microsensor networks

This article describes architectural and algorithmic approaches that designers can use to enhance the energy awareness of wireless sensor networks. The article starts off with an analysis of the power consumption characteristics of typical sensor node architectures and identifies the various factors that affect system lifetime. We then present a suite of techniques that perform aggressive energy optimization while targeting all stages of sensor network design, from individual nodes to the entire network. Maximizing network lifetime requires the use of a well-structured design methodology, which enables energy-aware design and operation of all aspects of the sensor network, from the underlying hardware platform to the application software and network protocols. Adopting such a holistic approach ensures that energy awareness is incorporated not only into individual sensor nodes but also into groups of communicating nodes and the entire sensor network. By following an energy-aware design methodology based on techniques such as in this article, designers can enhance network lifetime by orders of magnitude     

无线移动传感器网络自适应体系结构的设计

随着无线网络技术的日益成熟及其对小型、微型移动设备的支持，无线移动传感器网络已经逐渐成为一个研究的热点。主要讨论了为无线移动传感器网络设计的一个自适应的体系结构。在该体系结构中，使用了一个区域和核心路由节点相结合的多层结构的方法来增加无线移动网络的信息传输能力、可扩充性和可靠性，并降低网络的能耗，这样就可以适应无线移动网络的高度动态性和移动性。