scholarly journals Opportunistic and On-Demand Network Coding-Based Solutions for LPWAN Forwarding

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5792
Author(s):  
Dion Tanjung ◽  
Seunggyu Byeon ◽  
Junhwan Huh ◽  
Dong Hyun Kim ◽  
Jong Deok Kim
Keyword(s):  
Network Coding ◽  
Urban Areas ◽  
Network Capacity ◽  
Transmission Efficiency ◽  
Data Rate ◽  
Delivery Ratio ◽  
Compression Technique ◽  
On Demand ◽  
Fixed Path ◽  
Efficiency And Reliability

The single-hop star-of-stars topology in low-power and wide-area networks (LPWAN) exhibits reliability and substandard coverage issues, especially in urban areas where line-of-sight (LoS) communication is difficult to achieve. Moreover, LPWAN trade-off the data rate to achieve longer coverage, preventing other end-devices from using the time resource. Locating other gateways is uneconomical as it requires infrastructure, such as the internet and a power connection. In this study, we propose a forwarding scheme with a relay to increase LPWAN coverage and reliability while not degrading the network’s capacity. A relay tends to incur unnecessary forwarding that degrades the network capacity unless proper countermeasure is prepared. Our works, namely opportunistic and on-demand network coding (OODC), minimize unnecessary forwarding and make good use of multiple-receiving relays. Network coding is also applied in the relay for better transmission efficiency and reliability simultaneously. Because network coding occurs header overhead, we perform a header compression technique to counter it. According to our simulation result, our method shows better reliability than fixed path forwarding. In an adaptive data rate settings, the OODC achieves a 92% packet delivery ratio (PDR), whereas a fixed-path forwarding only achieves an 84% PDR.

scholarly journals Optimization of LoRaWAN Access control

2021 ◽  
Author(s):  
Hajer Tounsi ◽  
Norhane Benkahla ◽  
Ye-Qiong Song ◽  
Mounir Frikha
Keyword(s):  
Long Range ◽  
Duty Cycle ◽  
Network Capacity ◽  
Data Rate ◽  
Battery Life ◽  
Delivery Ratio ◽  
Area Network ◽  
Wide Area Network ◽  
Mobile Environment ◽  
Access Technique

Abstract Long Range Wide Area Network (LoRaWAN) enables flexible long-range communication with low power consumption which is suitable for IoT applications. LoRaWAN’s performance is due on the one hand to its spreading factor modulation allowing the spread out of communication between end-devices and gateways on different frequency channels and data rates. And on the other hand, to the ability to manage for each node its data rate and its transmission power thanks to the adaptive data rate (ADR) scheme in order to increase the overall network capacity and to maximize the battery life of end devices. However, because of the Aloha access technique adopted by LoRaWAN, the risk of using the same data rate on the same channel is not negligible. Despite the limitation of the duty cycle for each node, the risk of collision is high with the increase of the number of end devices which degrades the LoRaWAN’s performance. In this context, our paper proposes different approaches to improve the performance of LoRaWAN. The first contribution consists in improving the ADR technique to meet the characteristics of a mobile environment. The new mechanism proposed, called VHMM-based E-ADR, consists of adapting the data rate of the end-device according to its position. The second contribution consists in better managing the use of the duty cycle by proposing a dynamic sharing mechanism (Dynamic Duty-Cycle). The last contribution consists in proposing a deterministic access technique to replace Aloha. Our experimental study has shown that our proposals give better results in terms of Packet Delivery Ratio (PDR) and energy consumption than basic LoRaWAN in a mobile environment.

A Power Optimization Algorithm for Ad Hoc Networks with Variable Rate Control

2013 ◽  
Vol 470 ◽  
pp. 611-616
Author(s):  
Xuan Jie Ning ◽  
Hai Zhao ◽  
Mao Fan Yang ◽  
Dan Wu
Keyword(s):  
Ad Hoc Networks ◽  
Rate Control ◽  
Ad Hoc ◽  
Transmission Rate ◽  
Mac Protocol ◽  
Network Capacity ◽  
Data Rate ◽  
Medium Access ◽  
High Data ◽  
Hoc Networks

This paper is concerned with the capacity of ad hoc networks employing pure ALOHA medium access control (MAC) protocol under the effect of different transmission power levels and variable data rate control. The data rate of a certain link is related to the signal to interference plus noise ratio (SINR), and SINR is, in turn, related to the transmitted power and link distance. The increasing power conducts a high data rate, resulting in the high interference of networks. Consequently, the optimum power that yields maximum network throughput is a tradeoff between transmission rate and network interference. Mathematical model analysis for the ad hoc network capacity are presented in the paper. A revised expression to the approximate calculating of the capture probability in networks is proposed.

Learning Aided Digital Image Compression Technique for Medical Application

2016 ◽  
pp. 400-422
Author(s):  
Kandarpa Kumar Sarma
Keyword(s):  
Image Compression ◽  
Digital Image ◽  
Signal To Noise Ratio ◽  
Medical Application ◽  
Learning Systems ◽  
Signal To Noise ◽  
Compression Technique ◽  
Compressed Images ◽  
Digital Image Compression ◽  
Efficiency And Reliability

The explosive growths in data exchanges have necessitated the development of new methods of image compression including use of learning based techniques. The learning based systems aids proper compression and retrieval of the image segments. Learning systems like. Artificial Neural Networks (ANN) have established their efficiency and reliability in achieving image compression. In this work, two approaches to use ANNs in Feed Forward (FF) form and another based on Self Organizing Feature Map (SOFM) is proposed for digital image compression. The image to be compressed is first decomposed into smaller blocks and passed to FFANN and SOFM networks for generation of codebooks. The compressed images are reconstructed using a composite block formed by a FFANN and a Discrete Cosine Transform (DCT) based compression-decompression system. Mean Square Error (MSE), Compression ratio (CR) and Peak Signal-to-Noise Ratio (PSNR) are used to evaluate the performance of the system.

Multipath Extension of the ZigBee Tree Routing in Cluster-Tree Wireless Sensor Networks

2012 ◽  
Vol 4 (2) ◽  
pp. 30-48 ◽  
Author(s):  
Zahia Bidai ◽  
Moufida Maimour ◽  
Hafid Haffaf
Keyword(s):  
Sensor Networks ◽  
Low Cost ◽  
Multipath Routing ◽  
Data Rate ◽  
Delivery Ratio ◽  
Personal Area Networks ◽  
Wireless Multimedia ◽  
Wireless Personal Area Networks ◽  
Cluster Tree ◽  
Tree Routing

Wireless Multimedia Sensor Networks (WMSNs) are one of the most challenging applications of WSN. They require large amounts of data to be transmitted with high reporting rates which consume an order of magnitude of resources, such as storage, computation, bandwidth, and energy. On the other hand, the ZigBee standard was originally specified for low data rate, low power consumption, and low cost wireless personal area networks (WPANs), making it suitable to WSN. However, handling high data rate applications, such as video surveillance in WPANs, is a challenge. Simultaneous multipath routing is one solution to increase the available bandwidth in a ZigBee network. In this paper, we proposed Z-MHTR (ZigBee Multipath Hierarchical Tree Routing), a node disjoint multipath routing extension of the ZigBee tree routing protocol in cluster-tree WSNs. Extensive simulations were performed and showed that the propsed multipath routing enhances application performance in terms of packet delivery ratio, end to end delay, and network lifetime even under heavy data rates.

scholarly journals Data Publish/Subscribe with Network Coding in DTN

2016 ◽  
Vol 12 (06) ◽  
pp. 51
Author(s):  
Xia Yi ◽  
Deng Guanghong
Keyword(s):  
Network Coding ◽  
Ant Colony Algorithm ◽  
Random Network ◽  
Large Data ◽  
Network Capacity ◽  
Delay Tolerant Network ◽  
Delivery Performance ◽  
Coding Method ◽  
Delay Tolerant ◽  
Working Out

A data Publish/Subscribe method with network coding (DPS-NC) used in delay tolerant network is proposed. Based on the publish/subscribe mechanism, the topic data were encoded and transmit with random network coding method, which can take full advantage of the network capacity to multicast. At the same time, for working out the problem of large data redundancy and vast invalid de-liveries in the network coding broadcast process, a packet routing scheme based on ant colony algorithm was brought. In the end, some simulation experiments are carried out and results show that the DPS-NC method can get better delivery performance.

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