scholarly journals Implementation and evaluation of a 2.4 GHz multi-hop WSN: LoS, NLoS, different floors, and outdoor-to-indoor communications

Author(s):  
Vasin Chaoboworn ◽  
Yoschanin Sasiwat ◽  
Dujdow Buranapanichkit ◽  
Hiroshi Saito ◽  
Apidet Booranawong

In this paper, the communication reliability of a 2.4 GHz multi-hop wireless sensor network (WSN) in various test scenarios is evaluated through experiments. First, we implement an autonomous communication procedure for a multi-hop WSN on Tmote sky sensor nodes; 2.4 GHz, an IEEE 802.15.4 standard. Here, all nodes including a transmitter node (Tx), forwarder nodes (Fw), and a base station node (BS) can automatically work for transmitting and receiving data. The experiments have been tested in different scenarios including: i) in a room, ii) line-of-sight (LoS) communications on the 2nd floor of a building, iii) LoS and non-line-of-sight (NLoS) communications on the 1st floor to the 2nd floor, iv) LoS and NLoS communications from outdoor to the 1st and the 2nd floors of the building. The experimental results demonstrate that the communication reliability indicated by the packet delivery ratio (PDR) can vary from 99.89% in the case of i) to 14.40% in the case of iv), respectively. Here, the experiments reveal that multi-hop wireless commutations for outdoor to indoor with different floors and NLoS largely affect the PDR results, where the PDR more decreases from the best case (i.e., the case of a)) by 85.49%. Our research methodology and findings can be useful for users and researchers to carefully consider and deploy an efficient 2.4 GHz multi-hop WSN in their works, since different WSN applications require different communication reliability level.

2016 ◽  
Vol 26 (03) ◽  
pp. 1750043 ◽  
Author(s):  
Ching-Han Chen ◽  
Ming-Yi Lin ◽  
Wen-Hung Lin

Wireless sensor networks (WSNs) represent a promising solution in the fields of the Internet of Things (IoT) and machine-to-machine networks for smart home applications. However, to feasibly deploy wireless sensor devices in a smart home environment, four key requirements must be satisfied: stability, compatibility, reliability routing, and performance and power balance. In this study, we focus on the unreliability problem of the IEEE 802.15.4 WSN medium access control (MAC), which is caused by the contention-based MAC protocol used for channel access. This problem results in a low packet delivery ratio, particularly in a smart home network with only a few sensor nodes. In this paper, we first propose a lightweight WSN protocol for a smart home or an intelligent building, thus replacing the IEEE 802.15.4 protocol, which is highly complex and has a low packet delivery ratio. Subsequently, we describe the development of a discrete event system model for the WSN by using a GRAFCET and propose a development platform based on a reconfigurable FPGA for reducing fabrication cost and time. Finally, a prototype WSN controller ASIC chip without an extra CPU and with our proposed lightweight MAC was developed and tested. It enhanced the packet delivery ratio by up to 100%.


Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 466 ◽  
Author(s):  
Farhan Masud ◽  
Abdul Abdullah ◽  
Ayman Altameem ◽  
Gaddafi Abdul-Salaam ◽  
Farkhana Muchtar

This paper proposes an improved Traffic Class Prioritization based Carrier Sense Multiple Access/Collision Avoidance (TCP-CSMA/CA) scheme for prioritized channel access to heterogenous-natured Bio-Medical Sensor Nodes (BMSNs) for IEEE 802.15.4 Medium Access Control (MAC) in intra-Wireless Body Area Networks (WBANs). The main advantage of the scheme is to provide prioritized channel access to heterogeneous-natured BMSNs of different traffic classes with reduced packet delivery delay, packet loss, and energy consumption, and improved throughput and packet delivery ratio (PDR). The prioritized channel access is achieved by assigning a distinct, minimized and prioritized backoff period range to each traffic class in every backoff during contention. In TCP-CSMA/CA, the BMSNs are distributed among four traffic classes based on the existing patient’s data classification. The Backoff Exponent (BE) starts from 1 to remove the repetition of the backoff period range in the third, fourth, and fifth backoffs. Five moderately designed backoff period ranges are proposed to assign a distinct, minimized, and prioritized backoff period range to each traffic class in every backoff during contention. A comprehensive verification using NS-2 was carried out to determine the performance of the TCP-CSMA/CA in terms of packet delivery delay, throughput, PDR, packet loss ratio (PLR) and energy consumption. The results prove that the proposed TCP-CSMA/CA scheme performs better than the IEEE 802.15.4 based PLA-MAC, eMC-MAC, and PG-MAC as it achieves a 47% decrease in the packet delivery delay and a 63% increase in the PDR.


Sensors are regarded as significant components of electronic devices. The sensor nodes deployed with limited resources, such as the power of battery inserted in the sensor nodes. So the lifetime of wireless sensor networks(WSNs) can be increased by using the energy of the sensor nodes in an efficient way. A major part of energy is consumed during the communication of data. Also, the growing demand for usage of wireless sensors applications in different aspects makes the quality-of-service(QoS) to be one of the paramount issues in wireless sensors applications. QoS guarantee in WSNs is difficult and more challenging due to the fact that the sensors have limited resources and the various applications running over these networks have different constraints in their nature and requirements. The packet delivery ratio(PDR) is a major factor of QoS. To achieve high QoS the packet delivery ratio should be maximum. The energy-efficient unequal clustering routing protocol (EEUCR) is evaluated and results show that it enhances the packet delivery ratio(PDR) and a lifetime of WSNs. In this protocol, the area of the network is divided into a number of rings of unequal size and each ring is further divided into a number of clusters. Rings nearer to the base station(BS) have smaller area and area of rings keeps on increasing as the distance from BS increases for balanced energy consumption. The nodes with heterogeneous energy are deployed in the network. Nodes nearer to the base station have higher energy as compared to farther nodes. Static clustering is used but cluster heads(CHs) are not fixed and are elected on the basis of remaining energy. This helps to increase lifetime of EEUCR. PDR of EEUCR is improved because multiple rings help to find better route which further aids to ensure safe reception of packets at the destination. Simulation results are compared with existing protocols and show that this algorithm gives better results.


Author(s):  
Amit Grover Et al.

Wireless Sensor Networks (WSNs) comprised of battery operated sensor nodes that collect data from their neighbor nodes and transmit the aggregated information to the sink node or the Base Station (BS). This may result in congestion near the BS and leads to a bottleneck situation in the network. In this paper, an extensive study of earlier reported diverse congestion techniques explicitly diverse Algorithm based - and Layer based-congestion techniques is carried out. Accordingly, a recommendation is drawn based upon their performance comparison. Furthermore, a demonstration is carried out for contemporary earlier reported strategies such as Pro-AODV, CC-AODV, EDAPR, ED-AODV and PCC-AODV by evaluating delay, packet delivery ratio (PDR) and packet loss ratio (PLR). Accordingly, a recommended congestion strategy is suggested depending upon the comparison of the demonstrated schemes.


Author(s):  
Pere Tuset-Peiró ◽  
Ferran Adelantado ◽  
Xavier Vilajosana ◽  
Ruan Delgado Gomes

The IEEE 802.15.4-2015 standard includes the SUN (Smart Utility Networks) modulations, i.e., SUN-FSK, SUN-OQPSK and SUN-OFDM, which provide long range communications and allow to trade data rate, occupied bandwidth and reliability. However, given the constraints of low-power devices and the challenges of the wireless channel, communication reliability cannot still meet the PDR (Packet Delivery Ratio) requirements of industrial applications, i.e., PDR>99%. Hence, in this paper we evaluate the benefits of improving communication reliability by combining packet transmissions with modulation diversity using multiple IEEE 802.15.4g SUN modulations. The results derived from a real-world deployment show that going from 1 to 3 packet transmissions with the same SUN modulation can increase PDR from 85.0/84.6/71.3% to 94.2/94.1/86.0% using SUN-FSK, SUN-OQPSK and SUN-OFDM, respectively. Combining the same number of packet transmissions with modulation diversity allows to further increase the average PDR to 97.1%, indicating its potential as a tool to help meeting the reliability requirements of industrial applications.


2021 ◽  
Vol 11 (4) ◽  
pp. 1362
Author(s):  
Kohei Tomita ◽  
Nobuyoshi Komuro

This paper proposes a Duty-Cycle (DC) control method in order to improve the Packet Delivery Ratio (PDR) for IEEE 802.15.4-compliant heterogeneous Wireless Sensor Networks (WSNs). The proposed method controls the DC so that the buffer occupancy of sensor nodes is less than 1 and assigns DC to each sub-network (sub-network means a network consisting of a router node and its subordinate nodes). In order to use the appropriate DC of each sub-network to obtain the high PDR, this paper gives analytical expressions of the buffer occupancy. The simulation results show that the proposed method achieves a reasonable delay and energy consumption while maintaining high PDR.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Zafar Iqbal ◽  
Heung-No Lee ◽  
Saeid Nooshabadi

Cooperation among sensors in a wireless sensor network, deployed for industrial monitoring in an indoor scenario, is a topic of interest in the smart factory and smart city research. The indoor wireless communication channel is very harsh and the observations of all the sensors cannot be sent reliably to the base station. Failure to transmit correct sensing results to the base station may result in false alarms or missed detection of events. Therefore, we propose a cooperation scheme for the wireless sensors to send the data reliably to the base station. Our aim is to increase the reliability of the received information, reduce the probability of error, lower the overall power consumption, and keep the latency to an acceptable low level. We propose a reliability factor feedback algorithm to adjust the weight of unreliable sensors in the decision-making process. The proposed scheme is analyzed based on its latency, power consumption, and packet delivery ratio. Our results show significant improvement in the reliability of the received data, improved packet delivery, and reduced false alarm ratio for full repetition and cluster head-based cooperation. The power consumption and latency in data transmission are also kept to an acceptable low level.


Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3884 ◽  
Author(s):  
Hongxian Tian ◽  
Mary Weitnauer ◽  
Gedeon Nyengele

We study the placement of gateways in a low-power wide-area sensor network, when the gateways perform interference cancellation and when the model of the residual error of interference cancellation is proportional to the power of the packet being canceled. For the case of two sensor nodes sending packets that collide, by which we mean overlap in time, we deduce a symmetric two-crescent region wherein a gateway can decode both collided packets. For a large network of many sensors and multiple gateways, we propose two greedy algorithms to optimize the locations of the gateways. Simulation results show that the gateway placements by our algorithms achieve lower average contention, which means higher packet delivery ratio in the same conditions, than when gateways are naively placed, for several area distributions of sensors.


2021 ◽  
Author(s):  
Jenice Prabu A ◽  
Hevin Rajesh D

Abstract In Wireless sensor network, the major issues are security and energy consumption. There may be several numbers of malicious nodes present in sensor networks. Several techniques have been proposed by the researchers to identify these malicious nodes. WSNs contain many sensor nodes that sense their environment and also transmit their data via multi-hop communication schemes to the base station. These sensor nodes provides power supply using battery and the energy consumption of these batteries must be low. Securing the data is to avoid attacks on these nodes and data communication. The aggregation of data helps to minimize the amount of messages transmitted within the network and thus reduces overall network energy consumption. Moreover, the base station may distinguish the encrypted and aggregated data based on the encryption keys during the decryption of the aggregated data. In this paper, two aspects of the problem is concerned, we investigate the efficiency of data aggregation: first, how to develop cluster-based routing algorithms to achieve the lowest energy consumption for aggregating data, and second, security issues in wsn. By using Network simulator2 (NS2) this scheme is simulated. In the proposed scheme, energy consumption, packet delivery ratio and throughput is analyzed. The proposed clustering, routing, and protection protocol based on the MCSDA algorithm shows significant improvement over the state-of - the-art protocol.


2020 ◽  
Vol 3 (2) ◽  
pp. 128-139
Author(s):  
I Gusti Made Ngurah Desnanjaya ◽  
Mohammad Dwi Alfian

Wireless Sensor Network is a wireless network technology that includes sensor nodes and embedded systems. WSN has several advantages: it is cheaper for large-scale applications, can withstand extreme environments, and data transmission is relatively more stable. One of the WSN devices is nRF24L01+. Within the specifications given, the maximum communication distance is 1.1 km. However, the most effective distance for transmitting data in line of sight and non-line of sight is still unknown. Therefore, testing and analysis are needed so that the nRF24L01+ device can be used optimally for communication and data transmission. Through testing analysis on nRF24L01+ line of sight, Kuta beach location in Bali and non-line of sight on the STMIK STIKOM Indonesia campus. The effective communication distance of the nRF24L01+ module in line of sight is between 1 and 1000 meters. The distance of 1000 meters is the limit of the effective distance for sending data, and the packet loss rate is less than 15% which is included in the medium category. Meanwhile, in the non-line of sight, the effective distance of the nRF24L01+ communication module is 20 meters, and the packet loss is close to 15%, which is a moderate level limit. With the analysis module, nRF24L01+ can be a reference in determining the effective distance on WSN nRF24L01+ in determining remote control equipment data communication.


Sign in / Sign up

Export Citation Format

Share Document