TinyOS Platform Research Articles

Scalable Downward Routing for Wireless Sensor Networks Actuation

In this paper, we study the downward routing for network control/actuation in large-scale and heterogeneous wireless sensor networks (WSNs). We propose the opportunistic source routing (OSR), a scalable and reliable downward routing protocol for WSNs. OSR introduces opportunistic routing into traditional source routing based on the parent set of a node’s upward routing in data collection, significantly addressing the drastic link dynamics in low-power and lossy WSNs. We devise a novel adaptive Bloom filter mechanism to effectively and efficiently encode the downward source-route in OSR, which enables a significant reduction of the length of source-route field in the packet header. OSR is scalable to very large-size WSN deployments, since each resource-constrained node in the network stores only the set of its direct children. We present an analytical scalability model and evaluate the performance of OSR via both the simulations and real-world testbed experiments, in comparison with the standard RPL (both storing mode and non-storing mode), ORPL, and the representative dissemination protocol Drip. Our results show that the OSR significantly outperforms RPL and ORPL in scalability and reliability. OSR also achieves significantly better energy efficiency compared with TinyRPL and Drip which are based on the same TinyOS platform as OSR implementation.

Accurate per-link loss tomography in dynamic sensor networks

Wireless Sensor Networks (WSNs) have been successfully applied in many application areas. Understanding the wireless link performance is very helpful for both protocol designers and network managers to improve the network performance and prolong the network lifetime. Loss tomography is a popular approach to infer the per-link loss ratios from end-to-end delivery ratios. Previous studies, however, are usually targeted for networks with static or slowly changing routing paths. In this work, we propose Dophy, a Dynamic loss tomography approach specifically designed for dynamic WSNs where each node dynamically selects the forwarding nodes towards the sink. The key idea of Dophy is based on an observation that most existing protocols use retransmissions to achieve high data delivery ratio. Dophy employs arithmetic encoding to encode the number of retransmissions along the paths compactly. Dophy incorporates two mechanisms to optimize its performance. First, Dophy intelligently reduces the size of the symbol set by aggregating the number of retransmissions, reducing the encoding overhead significantly. Second, Dophy periodically updates the probability model to minimize the overall transmission overhead. We implement Dophy on the TinyOS platform and evaluate its performance extensively using large-scale simulations. Results show that Dophy achieves both high encoding efficiency and high estimation accuracy. Comparative studies show that Dophy significantly outperforms traditional loss tomography approaches in terms of accuracy.

PD-MAC: Design and Implementation of Polling Distribution-MAC for Improving Energy Efficiency of Wireless Sensor Networks

Reducing the energy consumed by MAC layer in Wireless Sensor Networks (WSNs) can lead to major performance improvements. A number of previous scholars have focused on optimizing the energy usage in WSN through adjusting the wake-up intervals, duty cycles and polling intervals. Some of the protocols focusing on dynamically adjusting the duty-cycle or channel polling intervals based on the traffic arrival patterns include SCP-MAC, RIMAP, AS-MAC, MCAS-MAC, LAD and self-adaptive wakeup scheduling scheme. This paper aims at improving the energy efficiency of MAC protocols by studying the influence of using ‘polling interval distributions’ rather than ‘polling intervals’ for different traffic types. The influence of using deterministic and exponential polling interval distributions is illustrated by developing an asynchronous MAC protocol PD-MAC (Polling Distribution-MAC). Two types of traffic: deterministic and exponential has been used for evaluating the performance of PD-MAC. TinyOS platform for mica2 motes has been used for implementation. The impact of varying message generation intervals and polling intervals, over the delay and energy performance of PD-MAC has been studied. Results have revealed that PD-MAC with exponentially distributed polling intervals results in improved energy performance in contrast to PD-MAC with deterministic polling intervals. Similarly, PD-MAC with exponentially distributed polling intervals is shown to outperform established MAC protocol SCP-MAC. Hence, the major contribution of PD-MAC is to introduce an energy efficient MAC solution for WSN applications operating under different traffic patterns without the need of extensive memory usage or computational complexity.

Model-based specification and validation of the dual-mode adaptive MAC protocol

Wireless sensor and actuator networks (WSANs) rely on MAC protocols to coordinate access to the wireless medium access and for managing the radio unit on each device. The dual-mode adaptive MAC (DMAMAC) protocol is a recently proposed protocol designed to reduce the energy consumption of the radio communication in WSANs. The DMAMAC protocol targets the industrial WSANs used for real-time process control. At its core, DMAMAC exploits the distinction between transient and steady of the controlled plant process to dynamically adapt the MAC superframe structure and thereby conserve energy. The switch between steady and transient mode of operation is a safety-critical part of the protocol. The contribution of this paper is to develop a rigorous specification of the DMAMAC protocol using timed automata and the supporting Uppaal software tool. The Uppaal tool is also used to verify key functional and real-time properties of the protocol. Finally, we have used execution sequences from the formal specification model to validate an OMNET simulation model used for performance evaluation of DMAMAC, and to validate a nesC implementation of the protocol on the TinyOS platform.

Adaptive Code Dissemination Based on Link Quality in Wireless Sensor Networks

Code dissemination is a main component of reprogramming which enables over-the-air software update in wireless sensor networks (WSNs). In this paper, we present an adaptive code dissemination based on link quality (ACODI), which aims to minimize energy consumption. Compared to prior works on code dissemination, ACODI has a variety of notable features. First, it dynamically adapts the payload size in terms of energy efficiency. Second, it provides very low-overhead link estimation method. Finally, it is gracefully integrated into Deluge, which is the de facto standard code dissemination protocol in WSNs, and implemented on the TinyOS platform with very small overhead in terms of computation and memory. Our experiments using TelosB motes in the indoor testbed show that ACODI outperforms Deluge-22 and Deluge-108, which are Deluge with a fixed payload size of 22 and 108 bytes, respectively, in terms of energy efficiency and completion time.

RPIDA: Recoverable Privacy-preserving Integrity-assured Data Aggregation Scheme for Wireless Sensor Networks

To address the contradiction between data aggregation and data security in wireless sensor networks, a Recoverable Privacy-preserving Integrity-assured Data Aggregation (RPIDA) scheme is proposed based on privacy homomorphism and aggregate message authentication code. The proposed scheme provides both end-to-end privacy and data integrity for data aggregation in WSNs. In our scheme, the base station can recover each sensing data collected by all sensors even if these data have been aggregated by aggregators, thus can verify the integrity of all sensing data. Besides, with these individual sensing data, base station is able to perform any further operations on them, which means RPIDA is not limited in types of aggregation functions. The security analysis indicates that our proposal is resilient against typical security attacks; besides, it can detect and locate the malicious nodes in a certain range. The performance analysis shows that the proposed scheme has remarkable advantage over other asymmetric schemes in terms of computation and communication overhead. In order to evaluate the performance and the feasibility of our proposal, the prototype implementation is presented based on the TinyOS platform. The experiment results demonstrate that RPIDA is feasible and efficient for resource-constrained sensor nodes.

Remote water quality monitoring in wide area

A wireless sensor network (WSN) with deployed field servers, which collect information on the water quality from a wide target area, is designed to detect water pollution in streams, rivers and coastal areas. The water pollution data, such as dissolved oxygen (DO), hydrogen ion exponent (pH), conductivity, turbidity, depth of water, and temperature, are transmitted between the field servers, and finally, to the base station (BS) in a self-organizing wireless sensor network using water quality sensor modules. A data averaging process is designed on the field servers to reduce the communication traffic and achieve consequential reliable data communication between the field servers and the BS in WSN. The measured sequential water quality data from the field servers are stored in a buffer for a fixed time duration and the stored water quality data are transmitted to the neighbor sensor node after performing the data averaging calculation at the node for data compression. A query-based flooding routing protocol is designed and used to transfer the measured water quality data efficiently. A query system is implemented using Java installed on a server PC connected serially via the RS-232 protocol to the BS. The sensor node is programmed using the nesC language on the TinyOS platform for small-scale WSN monitoring.

A cross-layer approach to timely responsive transmission under collection tree topology in wireless sensor network

Collection tree protocol CTP provides a link quality-based routing schema for wireless sensor networks WSNs with a collection tree topology, under which the link quality is measured by throughput rather than transmission latency. Yet it is not appropriate for the applications that need to transmit packets in a timely manner. Furthermore, implementation of timely responsive service in WSNs demands real-time supports from both routing and transport control layer. In this paper, we propose a cross-layer approach in which the packets with transmission deadlines are routed via an average transmission time ATT protocol and the congestion control is imposed through a performance-differentiated packet dropping policy. Simulation experiments on the TinyOS platform show that ATT protocol outperforms CTP by reducing the transmission delay up to 17.7%, while maintains a slightly better transmission reliability measured by the packet loss rate. The proposed cross-layer approach presents a promising core feature of framework in delivering real-time service in WSNs.

Link Quality Aware Code Dissemination in Wireless Sensor Networks

Wireless reprogramming is a crucial technique for software deployment in wireless sensor networks (WSNs). Code dissemination is a basic building block to enable wireless reprogramming. We present ECD, an Efficient Code Dissemination protocol leveraging 1-hop link quality information based on the TinyOS platform. Compared to prior works, ECD has three salient features. First, it supports dynamically configurable packet sizes. By increasing the packet size for high PHY rate radios, it significantly improves the transmission efficiency. Second, it employs an accurate sender selection algorithm to mitigate transmission collisions and transmissions over poor links. Third, it employs a simple impact-based backoff timer design to shorten the time spent in coordinating multiple eligible senders so that the largest impact sender is most likely to transmit. We implement ECD based on TinyOS and evaluate its performance extensively via testbed experiments and simulations. Results show that ECD outperforms state-of-the-art protocols, Deluge and MNP, in terms of completion time and data traffic (e.g., about 20 percent less traffic and 20-30 percent shorter completion time compared to Deluge).

Integrity and Privacy Preserving Secure Data Aggregation in Wireless Sensor Networks

Data aggregation based on in-network processing is useful in improving the communications overhead in Wireless Sensor Networks (WSNs) by reducing the overall number of packets communicated to the base station. However, due to the fusion of data items sourced at different nodes into a single one, the security of the aggregated data as well as that of the aggregating node, demands critical investigation. This paper observes that though there have been substantial numbers of research attempts recently in proposing techniques for secure data aggregation, there is still a need for a coherent, integrated framework for secure data aggregation. It proposes such an integrated framework for secure data aggregation in this paper. The proposed framework implements a secure data aggregation protocol, offering the attributes viz. confidentiality, privacy, authentication, robustness, as well as data integrity using a defined data aggregation topology. In addition to that, the proposed framework is based on a zero configuration protocol that supports a generation of a defined aggregation topology and a key exchange procedure. This work supports the framework with detailed security analysis and performance evaluation on TinyOS platform using TOSSIM as the base simulator. Through humble observations, this is an unique attempt that integrates the support for security features, topology generation and key management in a single, secure data aggregation protocol; substantiating the proposal with elaborate experimental evaluation, too.

Performance Analysis of MAC Schemes in Wireless Sensor Networks

Wireless sensor networks have become an important area of research in recent years. A sensor network can be a network infrastructure consisting of elements that are nothing but some sensing devices which perform communication and computation along with the sensing of real world phenomenon. The data collected by these elements are sent to an administrator located at a base station who can react to specific situations by analyzing the data. Thus data collection is an important activity performed by a sensor network. To facilitate the smooth and faster collection of data, various channel access schemes are available in literature. Among these schemes TDMA (Time Division Multiple Access), CDMA (Code Division Multiple Access) and FDMA (Frequency Division Multiple Access) are the most basic as well as the most important ones. This paper analyzes the performance of these schemes in wireless sensor networks by considering a data collection scenario with a set of performance metrics. The TDMA scheme has been implemented using an adaptive timeslot assignment mechanism. The experimentations are conducted in TinyOS platform using Crossbow TelosB motes. The performance done in this paper will be helpful in choosing an optimal protocol based on these schemes for deployment of a network as well as for developing a new medium access protocol,

SENSORLock: a lightweight key management scheme for wireless sensor networks

ABSTRACTSecurity in wireless sensor networks demands an efficient key management scheme. As sensors typically operate unattended, it becomes quite important to ensure security to cryptographic keys stored in their memories. In this scenario, the development of lightweight encryption mechanisms is a challenge because of sensor‐constrained resources. In this work, we present a mechanism tailored to sensor networks calledSENSORLockapplying it to a specific case. Our main contribution is to propose, analyze, and demonstrate the feasibility ofSENSORLockfor secure symmetric key distribution solving the stored key exposure problem. Analytical results demonstrate that this approach increases the system's security against the tampering of sensor nodes. Additionally, the mechanism is evaluated using simulation and practical experiments, using the TinyOS platform. Simulation results reveal that this scheme introduces very low processing overhead, in the order of nanoseconds, and an estimated power consumption quite similar to existing approaches. Besides, practical experiments indicate that the scheme can be deployed by off‐the‐shelf sensors, such as MicaZ and TelosB. Copyright © 2013 John Wiley & Sons, Ltd.

플러딩 라우팅 프로토콜을 이용한 WSN 기반의 연안 환경 모니터링 시스템

The rapid water pollution in stream, river, lake and sea in recent years raises an urgent need for continuous monitoring and policymaking to conserve the global clean environment. In particular, the increasing water pollution in coastal marine areas adds to the importance of the environmental monitoring systems. In this paper, the mobile server is designed to gathers information of the water quality at coastal areas. The obtained data by the server is transmitted from field servers to the base station via multi-hop communication in wireless sensor network. The information collected includes dissolved oxygen(DO), hydrogen ion exponent(pH), temperature, etc. By the information provided the real-time monitoring of water quality at the coastal marine area. In addition, wireless sensor network-based flooding routing protocol was designed and used to transfer the measured water quality information efficiently. Telosb sensor node is programmed using nesC language in TinyOS platform for small scale wireless sensor network monitoring from a remote server.

Compressed data-stream protocol: an energy-efficient compressed data-stream protocol for wireless sensor networks

In this study, the authors present an energy-efficient data compression protocol for data collection in wireless sensor networks (WSNs). WSNs are essentially constrained by motes’ limited battery power and networks bandwidth. The authors focus on data compression algorithms and protocol development to effectively support data compression for data gathering in WSNs. Their design of compressed data-stream protocol (CDP) is generic in the sense that other lossless or lossy compression algorithms can be easily ‘plugged’ into the proposed protocol system without any changes to the rest of the CDP. This design intends to support various different WSN applications where users may prefer more specific compression algorithms, tailored to the sensing data characteristics in question, to their general algorithm. CDP is not only able to significantly reduce energy consumptions of data gathering in multi-hop WSNs, but also able to reduce sensor network traffic and thus avoid congestion accordingly. The proposed CDP is implemented on the tinyOS platform using the nesC programming language. To evaluate their work, the authors conduct simulations via TOSSIM and PowerTOSSIM-z with real-world sensor data. The results demonstrate the significance of CDP.

6PANview: A network monitoring system for the “Internet of Things”

We present network monitoring architecture and the implementation of 6PANview, a network monitoring system which we developed to oversee the health of a 6LoWPAN based WSN from the Internet. At the core, 6PANview uses well known standard Internet monitoring and diagnostic tools such as ping, traceroute, SNMP. We implemented a memory efficient and power conscious snmp agent on the TinyOS platform and defined an enterprise MIB for WSN monitoring. 6PANview provides transparent snmp proxy model which incorporates snmp OID compression techniques. Other 6PANview features include, alert threshold definitions, reverse traceroute, time series online plots, and so on. 6PANview provides JAVA/WEB based administration console for configuring, displaying various monitoring statistics, and troubleshooting. The 6PANview prototype has been tested in a 6LoWPAN/RPL WSN lab setup. As per our knowledge 6PANview is one among the first open standards based network health monitoring systems for 6LoWPAN/RPL based WSNs.

Comparative Study of Radio Models for data Gathering in Wireless Sensor Network

Sensor Network (WSN) consists of irreplaceable nodes which are equipped with limited energy resources. Necessity of power consumption becomes a prior importance for various pervasive and ubiquitous applications. For realistic computation of energy in accordance with available motes like Micaz, Telos, Mica2, a discrete radio model exist. In this paper we have incorporated a discrete radio model over popular data gathering algorithm. We have formulated a data sheet, which relates details of power required to transmit data packets over range of distance that includes Lognormal Shadowing model for acquiring the required received signal strength. Range of distance is the key factor for energy consumption, which justifies the reduction of power levels to a limited count. We have disseminated the power transmission into specific band with respect to distance. Our paper shows the variation of node deployment over Network lifetime, which produces a significant alteration from sparse to dense network. We have conducted a comparison of Network lifetime and Mean energy consumption for chain based, shortest-hop and load balanced energy aware routing protocols. We have conducted a comparative study of the proposed method in TinyOS platform while running the simulation in TOSSIM.

국지기상 모니터링용 필드서버를 위한 플러딩 라우팅 프로토콜의 구현

A field server was developed by using ubiquitous sensor network technology to monitor the abrupt weather variation in local or mountain area. The data transmissions between deployed field servers in local terrain are very important technology in disaster prevention monitoring system. Weather related information such as temperature, humidity, illumination, atmospheric pressure, dew point and meteorological data are collected from the designated field at a regular interval. The received information from the multiple sensors located at the sensor field is used flooding routing protocol transmission techniques and the sensing data is transferred to gateway through multi-hop method. Telosb sensor node are programmed by nesC language in TinyOS platform to monitor the weather parameters of the local terrain.

A scalable distributed dynamic address allocation protocol for ad-hoc networks

Dynamic address allocation is an essential part in effective configuration and maintenance of a mobile ad-hoc network (MANET). In this paper, we present a new distributed dynamic address allocation protocol minimizing address allocation latency and communication overhead. Through analytic evaluation and experimental measurements, we show that scalability and faster recovery from failures can be achieved by dynamic address allocation. The dynamic address assignment protocol presented here requires a low memory footprint while supporting unicast, broadcast and multicast communication. A performance analysis of the proposed address allocation protocol is given in terms of address allocation latency and communication overhead. Node and Network mobility is addressed from the point of dynamic address management. The dynamic address allocation protocol is implemented on a TinyOS platform over a cluster tree network.

SPINE: a domain‐specific framework for rapid prototyping of WBSN applications

AbstractWireless body sensor networks (WBSNs) enable a broad range of applications for continuous and real‐time health monitoring and medical assistance. Programming WBSN applications is a complex task especially due to the limitation of resources of typical hardware platforms and to the lack of suitable software abstractions. In this paper, SPINE (signal processing in‐node environment), a domain‐specific framework for rapid prototyping of WBSN applications, which is lightweight and flexible enough to be easily customized to fit particular application‐specific needs, is presented. The architecture of SPINE has two main components: one implemented on the node coordinating the WBSN and one on the nodes with sensors. The former is based on a Java application, which allows to configure and manage the network and implements the classification functions that are too heavy to be implemented on the sensor nodes. The latter supports sensing, computing and data transmission operations through a set of libraries, protocols and utility functions that are currently implemented for TinyOS platforms. SPINE allows evaluating different architectural choices and deciding how to distribute signal processing and classification functions over the nodes of the network. Finally, this paper describes an activity monitoring application and presents the benefits of using the SPINE framework. Copyright © 2010 John Wiley & Sons, Ltd.

Development of a low-cost multifunctional wireless impedance sensor node

In this paper, a low cost, low power but multifunctional wireless sensor node is presented for the impedance-based SHM using piezoelectric sensors. Firstly, a miniaturized impedance measuring chip device is utilized for low cost and low power structural excitation/sensing. Then, structural damage detection/sensor self-diagnosis algorithms are embedded on the on-board microcontroller. This sensor node uses the power harvested from the solar energy to measure and analyze the impedance data. Simultaneously it monitors temperature on the structure near the piezoelectric sensor and battery power consumption. The wireless sensor node is based on the TinyOS platform for operation, and users can take MATLAB interface for the control of the sensor node through serial communication. In order to validate the performance of this multifunctional wireless impedance sensor node, a series of experimental studies have been carried out for detecting loose bolts and crack damages on lab-scale steel structural members as well as on real steel bridge and building structures. It has been found that the proposed sensor nodes can be effectively used for local wireless health monitoring of structural components and for constructing a low-cost and multifunctional SHM system as place and forget wireless sensors.