New Approach to Improvement and Measurement of the Performance of PHY Layer Links of WSN (original) (raw)

Performance of PHY layer links of WSN: Criterions and ways of improvement

2013 IEEE International Workshop on Measurements & Networking (M&N), 2013

The paper discusses difficulties in performance analysis of physical (PHY) layer of wireless sensor networks (WSN). There is shown that these difficulties can be removed by application, in the sensor nodes, of the properly designed analog transmitters that permits to develop a regular approach to optimization of communication links of PHY layer. The latter permits to define the upper boundaries of performance and to design top-quality links attaining these boundaries and transmitting the signals with minimal mean square error, bit rate equal to the capacity of the link, and maximal power-bandwidth efficiency. The resented results can be used for designing high quality and low cost PHY layer links for WSN with the star and cluster topology.

Performance analysis of wireless link quality in wireless sensor networks

5th International Conference on Computer Sciences and Convergence Information Technology, 2010

This paper aims to analyze wireless link quality like received signal strength indicator (RSSI) and link quality indicator (LQI) in IEEE 802.15.4 based wireless sensor networks. Our experiments are performed on Chipcon CC2420 radios, which comply with the IEEE 802.15.4. In order to measure the performance of LQI, RSSI and PRR in IEEE 802.15.4 based wireless sensor networks, the experiments were conducted by varying distances between transmitter and base-station and transmit power level. Our experimental results show that the PRR depends on some factors such as LQI and RSSI including the distance between transmitter and base-station and the location of each of the sensor nodes.

Effective-SNR estimation for wireless sensor network using Kalman filter

Ad Hoc Networks, 2013

In many Wireless Sensor Network (WSN) applications, the availability of a simple yet accurate estimation of the RF channel quality is vital. However, due to measurement noise and fading effects, it is usually estimated through probe or learning based methods, which result in high energy consumption or high overheads. We propose to make use of information redundancy among indicators provided by the IEEE 802.15.4 system to improve the estimation of the link quality. A Kalman filter based solution is used due to its ability to give an accurate estimate of the un-measurable states of a dynamic system subject to observation noise. In this paper we present an empirical study showing that an improved indicator, termed Effective-SNR, can be produced by combining Signal to Noise Ratio (SNR) and Link Quality Indicator (LQI) with minimal additional overhead. The estimation accuracy is further improved through the use of Kalman filtering techniques. Finally, experimental results demonstrate that the proposed algorithm can be implemented on resource constraints devices typical in WSNs.

Radio link quality estimation in wireless sensor networks

ACM Transactions on Sensor Networks, 2012

Radio link quality estimation in Wireless Sensor Networks (WSNs) has a fundamental impact on the network performance and also affects the design of higher-layer protocols. Therefore, for about a decade, it has been attracting a vast array of research works. Reported works on link quality estimation are typically based on different assumptions, consider different scenarios, and provide radically different (and sometimes contradictory) results. This article provides a comprehensive survey on related literature, covering the characteristics of low-power links, the fundamental concepts of link quality estimation in WSNs, a taxonomy of existing link quality estimators, and their performance analysis. To the best of our knowledge, this is the first survey tackling in detail link quality estimation in WSNs. We believe our efforts will serve as a reference to orient researchers and system designers in this area.

Radio link quality estimation in wireless sensor networks: a survey

2013

Radio link quality estimation in Wireless Sensor Networks (WSNs) has a fundamental impact on the network performance and affects as well the design of higher layer protocols. Therefore, since about a decade, it has been attracting a vast array of research works. Reported works on link quality estimation are typically based on different assumptions, consider different scenarios, and provide radically different (and sometimes contradictory) results. This paper provides a comprehensive survey on related literature, covering the characteristics of low-power links, the fundamental concepts of link quality estimation in WSNs, a taxonomy of existing link quality estimators, and their performance analysis. To the best of our knowledge, this is the first survey tackling in detail link quality estimation in WSNs. We believe our efforts will serve as a

Analyzing the Low Power Wireless Links for Wireless Sensor Networks

2010

There is now an increased understanding of the need for realistic link layer models in the wireless sensor networks. In this paper, we have used mathematical techniques from communication theory to model and analyze low power wireless links. Our work provides theoretical models for the link layer showing how Packet Reception Rate vary with Signal to Noise Ratio and distance for different modulation schemes and a comparison between MICA2 and TinyNode in terms of PRR.

Link layer measurements in sensor networks

2004

Key issues in wireless sensor networks such as data aggregation, localisation, MAC protocols and routing, all have to do with communication at some level. At a low level, these are influenced by the link layer performance between two nodes. The lack of accurate sensor network specific radio models, and the limited experimental data on actual link behaviour warrant additional investigation in this area. We present the results from extensive experiments, exploring several factors that are relevant for the link layer performance. These include (i) the effect of interference from simultaneous transmissions, which has not been looked into before, (ii) the degree of symmetry in the links between nodes, and (iii) the use of calibrated RSSI measurements. Finally, we present some guidelines on how to use the results for effective protocol design.

Analytical design of top power-bandwidth efficient transmitters for sensor nodes of WSN

2011

The paper presents new approach to designing high efficient adaptive transmitting units (TU) for the sensor nodes of wireless sensor nets (WSN). Particularity of the considered TU is lack of digitizing and coding units. The signals formed by the sensors are transmitted to the base station (BS) using pulse-amplitude modulator adaptively adjusted during the samples transmission. The BS computes estimates of the origin signal, as well as the adjusting controls transmitted to TU through the feedback channel. Transition to the analogue transmission in the channel “node-BS” simplifies the construction of TU and enables development of analytical methods permitting to design optimal TU capable to transmit the signals to BS with minimal MSE and bit-rate equal to the capacity of the channel. The signals emitted by optimal TU have the form of realizations of white Gaussian noise that increases information security of data-transmission. The results of research enable transition to the practical design of low energy and low cost optimal TU which ensure “ideal” power-bandwidth trade off, i.e. work at the Shannon boundary.

Real-time link quality estimation for industrial wireless sensor networks using dedicated nodes

Ad Hoc Networks, 2017

Adaptive mechanisms, such as dynamic channel allocation or adaptive routing, are used to deal with the variations in the link quality of Wireless Sensor Networks (WSN). In both cases, the first step is to estimate the link quality, so that the network nodes can decide if a channel or route change is needed. This paper proposes a Link Quality Estimator (LQE) for Industrial WSN, and a new type of node, the LQE node, that estimates the link quality in real-time, using the Received Signal Strength Indication (RSSI), and information obtained from received data packets. The proposed LQE is capable of capturing the effects of multipath, interference, and link asymmetry. Experiments were performed in a real industrial environment using IEEE 802.15.4 radios, and models were developed to allow the use of RSSI samples to proper estimate the link quality. A comparison was performed with a state-of-the-art LQE, the Opt-FLQE, and the results showed that the proposed estimator is more accurate and reactive for the type of environment in study. Different from other LQEs in literature, in the proposed LQE the sensor nodes do not need to send broadcast probe packets. Besides, using the LQE node, the other nodes of the WSN do not need to stop their operation to monitor the link quality.

The main effective parameters on wireless sensor network performance

Wireless Sensor Network (WSN) consists of a large number of sensor nodes to detect some physical phenomena. To design a WSN it is necessary to identify the major issues or the main metric parameters of WSN, which are network lifetime, data gathering, and security. These parameters effect on the overall performance of WSN. To enhance the performance of that network in this paper, we present a survey study of the methods and proposed algorithms that were used to overcome those issues. A number of challenges and research issues emerging from this survey study have been reported for further investigations.