A study of wireless technologies for IoT applications in terms of power consumption has been presented in this paper. The study focuses on the importance of using low power wireless techniques and modules in IoT appli...A study of wireless technologies for IoT applications in terms of power consumption has been presented in this paper. The study focuses on the importance of using low power wireless techniques and modules in IoT applications by introducing a comparative between different low power wireless communication techniques such as ZigBee, Low Power Wi-Fi, 6LowPAN, LPWA and their modules to conserve power and longing the life for the IoT network sensors. The approach of the study is in term of protocol used and the particular module that achieve that protocol. The candidate protocols are classified according to the range of connectivity between sensor nodes. For short ranges connectivity the candidate protocols are ZigBee, 6LoWPAN and low power Wi-Fi. For long connectivity the candidate is LoRaWAN protocol. The results of the study demonstrate that the choice of module for each protocol plays a vital role in battery life due to the difference of power consumption for each module/protocol. So, the evaluation of protocols with each other depends on the module used.展开更多
Sensor networks tend to support different traffic patterns since more and more emerging applications have diverse needs. We present MGRP, a Multi-Gradient Routing Protocol for wireless sensor networks, which is fully ...Sensor networks tend to support different traffic patterns since more and more emerging applications have diverse needs. We present MGRP, a Multi-Gradient Routing Protocol for wireless sensor networks, which is fully distributed and efficiently supports endto-end, one-to-many and many-to-one traffic patterns by effectively construct and maintain a gradient vector for each node. We further combine neighbor link estimation with routing information to reduce packet exchange on network dynamics and node failures. We have implemented MGRP on Tiny OS and evaluated its performance on real-world testbeds. The result shows MGRP achieves lower end-to-end packet delay in different traffic patterns compared to the state of the art routing protocols while still remains high packet delivery ratio.展开更多
The wireless application protocol （WAP） protocol is now the leading standard for information services on wireless terminals like digital mobile phones. By the use of WAP, wireless devices, like mobile phones, are po...The wireless application protocol （WAP） protocol is now the leading standard for information services on wireless terminals like digital mobile phones. By the use of WAP, wireless devices, like mobile phones, are possibly infected with virus and worms. Though up to now there is no such attack, as the usage of script languages increases, there is a chance of malicious code injection. This paper discusses the threats with current WAP protocol, and how changes in the protocol and the increase in its usage will enable entry of real viruses. Future threat scenarios are presented along with suggestions to avoid these problems.展开更多
Energy efficiency is the primary issue for the Medium Access Control(MAC)protocol in sensor networks.Adopting periodic sleep,adaptive listen,overhearing avoidance and message passing mechanisms,the Sensor Medium Acces...Energy efficiency is the primary issue for the Medium Access Control(MAC)protocol in sensor networks.Adopting periodic sleep,adaptive listen,overhearing avoidance and message passing mechanisms,the Sensor Medium Access Control(S-MAC)protocol improves energy efficiency and latency in the network.There are mainly two methods to enhance the S-MAC protocol:dynamic adjustment,and sending control and data packets under different transport conditions.For the wireless sensor network,it is not realistic to design one MAC protocol that meets all requirements of every aspect;however,it is possible to design corresponding protocols in accordance with different requirements by flexibly adopting different methods.展开更多
Medium access control( MAC) protocol of underwater acoustic communication network is a key technology for underwater acoustic networks( UANs). Most of the MAC protocols for wireless terrestrial communication networks ...Medium access control( MAC) protocol of underwater acoustic communication network is a key technology for underwater acoustic networks( UANs). Most of the MAC protocols for wireless terrestrial communication networks have been designed with negligible propagation delay. If it is deployed directly in an underwater environment,the UANs will perform inefficiently. In this paper,the characteristics of underwater acoustic channel are modeled and simulated by using the OPNET simulation tool,which are the speed of sound, propagation loss, and four sources for ambient noise: the turbulence,shipping,wind driven waves and thermal noise. The performance of pure Aloha( P-Aloha),carrier sense multiple access with collision avoidance( CSMA / CA) and multiple access collision avoidance for wireless local area network( MACAW) protocols in underwater acoustic channel environment are evaluated. The different performance of protocols in underwater environment is compared in the simulation.展开更多
Wireless sensor networks (WSNs) are important application for safety monitoring in underground coal mines, which are difficult to monitor due to natural conditions. Based on the characteristic of limited energy for WS...Wireless sensor networks (WSNs) are important application for safety monitoring in underground coal mines, which are difficult to monitor due to natural conditions. Based on the characteristic of limited energy for WSNs in confined underground area such as coal face and laneway, we presents an energy- efficient clustering routing protocol based on weight (ECRPW) to prolong the lifetime of networks. ECRPW takes into consideration the nodes' residual energy during the election process of cluster heads. The constraint of distance threshold is used to optimize cluster scheme. Furthermore, the protocol also sets up a routing tree based on cluster heads' weight. The results show that ECRPW had better perfor- mance in energy consumption, death ratio of node and network lifetime.展开更多
Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless...Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless links, some QoS mechanisms should be provided. We put forward a RTP/RSVP transmission scheme with DSR-specific payload and QoS parameters by modifying the present WAP protocol stack. The simulation result shows that this scheme will provide adequate network bandwidth to keep the real-time transport of DSR data over either wirelined or wireless channels.展开更多
To address the problems of the present Tera Hertz medium access control（MAC） protocols such as not updating the time slot requests numbers in time, unreasonable superframe structures and not merging time slot reques...To address the problems of the present Tera Hertz medium access control（MAC） protocols such as not updating the time slot requests numbers in time, unreasonable superframe structures and not merging time slot requests from the same pair of nodes, high throughput low delay medium access control（HLMAC）, a novel MAC protocol for Tera Hertz ultra-high data-rate wireless networks is proposed. It reduces the data access delay largely with a new superframe structure, from which nodes can get time slot allocation information immediately. The network throughput is also improved with the help of updating time slot requests number and merging time slot requests from the same pair of nodes. The theoretical analysis verifies the effectiveness of HLMAC, and the simulation results show that HLMAC improves the network throughput by 65.7% and decreases the access delay by 30%, as compared to energy and spectrum-aware medium access control（ES-MAC）.展开更多
Network coding mechanisms, such as COPE, can improve network throughput effectively in Wireless Mesh Networks（WMN）. While the Hybrid Wireless Mesh Protocol（HWMP） is suitable for WMN, its extension with COPE does n...Network coding mechanisms, such as COPE, can improve network throughput effectively in Wireless Mesh Networks（WMN）. While the Hybrid Wireless Mesh Protocol（HWMP） is suitable for WMN, its extension with COPE does not provide any added benefits; specifically, HWMP cannot establish paths with more coding opportunities. As a result, the advantages of network coding cannot be exploited sufficiently. This paper proposes improvements upon HWMP with a new, network Coding-Aware routing protocol（CAHWMP） for WMN. In the CAHWMP protocol, we propose a coding criterion based on data streams to devise an algorithm for actively detecting coding opportunities during path discovery. CAHWMP subsequently establishes paths using the codingaware routing metric, which can balance channel resource consumption and the gain due to sharing resources introduced by network coding. Simulation results show that CAHWMP can establish paths with more coding opportunities; as a result, it improves network performance such as network throughput.展开更多
文摘A study of wireless technologies for IoT applications in terms of power consumption has been presented in this paper. The study focuses on the importance of using low power wireless techniques and modules in IoT applications by introducing a comparative between different low power wireless communication techniques such as ZigBee, Low Power Wi-Fi, 6LowPAN, LPWA and their modules to conserve power and longing the life for the IoT network sensors. The approach of the study is in term of protocol used and the particular module that achieve that protocol. The candidate protocols are classified according to the range of connectivity between sensor nodes. For short ranges connectivity the candidate protocols are ZigBee, 6LoWPAN and low power Wi-Fi. For long connectivity the candidate is LoRaWAN protocol. The results of the study demonstrate that the choice of module for each protocol plays a vital role in battery life due to the difference of power consumption for each module/protocol. So, the evaluation of protocols with each other depends on the module used.
基金supported by National Key Technologies Research and Development Program of China under Grant No.2014BAH14F01National Science and Technology Major Project of China under Grant No.2012ZX03005007+1 种基金National NSF of China Grant No.61402372Fundamental Research Funds for the Central Universities Grant No.3102014JSJ0003
文摘Sensor networks tend to support different traffic patterns since more and more emerging applications have diverse needs. We present MGRP, a Multi-Gradient Routing Protocol for wireless sensor networks, which is fully distributed and efficiently supports endto-end, one-to-many and many-to-one traffic patterns by effectively construct and maintain a gradient vector for each node. We further combine neighbor link estimation with routing information to reduce packet exchange on network dynamics and node failures. We have implemented MGRP on Tiny OS and evaluated its performance on real-world testbeds. The result shows MGRP achieves lower end-to-end packet delay in different traffic patterns compared to the state of the art routing protocols while still remains high packet delivery ratio.
文摘The wireless application protocol （WAP） protocol is now the leading standard for information services on wireless terminals like digital mobile phones. By the use of WAP, wireless devices, like mobile phones, are possibly infected with virus and worms. Though up to now there is no such attack, as the usage of script languages increases, there is a chance of malicious code injection. This paper discusses the threats with current WAP protocol, and how changes in the protocol and the increase in its usage will enable entry of real viruses. Future threat scenarios are presented along with suggestions to avoid these problems.
基金the National Natural Science Foundation of China under Grant 60372107.
文摘Energy efficiency is the primary issue for the Medium Access Control(MAC)protocol in sensor networks.Adopting periodic sleep,adaptive listen,overhearing avoidance and message passing mechanisms,the Sensor Medium Access Control(S-MAC)protocol improves energy efficiency and latency in the network.There are mainly two methods to enhance the S-MAC protocol:dynamic adjustment,and sending control and data packets under different transport conditions.For the wireless sensor network,it is not realistic to design one MAC protocol that meets all requirements of every aspect;however,it is possible to design corresponding protocols in accordance with different requirements by flexibly adopting different methods.
基金National Natural Science Foundations of China(Nos.60872073,6097501,and 51075068)the Doctoral Fund of Ministry of Education of China(No.20110092130004)the Research Foundation and Education Bureau of Anhui Province of China(No.KJ2009B137)
文摘Medium access control( MAC) protocol of underwater acoustic communication network is a key technology for underwater acoustic networks( UANs). Most of the MAC protocols for wireless terrestrial communication networks have been designed with negligible propagation delay. If it is deployed directly in an underwater environment,the UANs will perform inefficiently. In this paper,the characteristics of underwater acoustic channel are modeled and simulated by using the OPNET simulation tool,which are the speed of sound, propagation loss, and four sources for ambient noise: the turbulence,shipping,wind driven waves and thermal noise. The performance of pure Aloha( P-Aloha),carrier sense multiple access with collision avoidance( CSMA / CA) and multiple access collision avoidance for wireless local area network( MACAW) protocols in underwater acoustic channel environment are evaluated. The different performance of protocols in underwater environment is compared in the simulation.
基金supports provided by the National Natural Science Foundation of China (No.50904070)the China Postdoctoral Science Foundation (No.20100471009)+2 种基金the National High Technology Research and Development Program of China (Nos. 2008AA062200 and2007AA01Z180)the Key Project of Jiangsu (No. BG2007012)the Science Foundation of China University of Mining and Technology (No. OC080303)
文摘Wireless sensor networks (WSNs) are important application for safety monitoring in underground coal mines, which are difficult to monitor due to natural conditions. Based on the characteristic of limited energy for WSNs in confined underground area such as coal face and laneway, we presents an energy- efficient clustering routing protocol based on weight (ECRPW) to prolong the lifetime of networks. ECRPW takes into consideration the nodes' residual energy during the election process of cluster heads. The constraint of distance threshold is used to optimize cluster scheme. Furthermore, the protocol also sets up a routing tree based on cluster heads' weight. The results show that ECRPW had better perfor- mance in energy consumption, death ratio of node and network lifetime.
文摘Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless links, some QoS mechanisms should be provided. We put forward a RTP/RSVP transmission scheme with DSR-specific payload and QoS parameters by modifying the present WAP protocol stack. The simulation result shows that this scheme will provide adequate network bandwidth to keep the real-time transport of DSR data over either wirelined or wireless channels.
基金supported by the Project of Chongqing Municipal Education Commission(Kjzh11206)the Special Fund of Chongqing Key laboratory(CSTC)+2 种基金the National Natural Science Foundation of China(60972068)the Program for Changjiang Scholars and Innovative Research Team in University(IRT1299)and the Research Project of Fundamental and Frontier Science of Chongqing(cstc2015jcyjB X0085)
文摘To address the problems of the present Tera Hertz medium access control（MAC） protocols such as not updating the time slot requests numbers in time, unreasonable superframe structures and not merging time slot requests from the same pair of nodes, high throughput low delay medium access control（HLMAC）, a novel MAC protocol for Tera Hertz ultra-high data-rate wireless networks is proposed. It reduces the data access delay largely with a new superframe structure, from which nodes can get time slot allocation information immediately. The network throughput is also improved with the help of updating time slot requests number and merging time slot requests from the same pair of nodes. The theoretical analysis verifies the effectiveness of HLMAC, and the simulation results show that HLMAC improves the network throughput by 65.7% and decreases the access delay by 30%, as compared to energy and spectrum-aware medium access control（ES-MAC）.
基金supported by the National Natural Science Foundation of China (No. 61301110)
文摘Network coding mechanisms, such as COPE, can improve network throughput effectively in Wireless Mesh Networks（WMN）. While the Hybrid Wireless Mesh Protocol（HWMP） is suitable for WMN, its extension with COPE does not provide any added benefits; specifically, HWMP cannot establish paths with more coding opportunities. As a result, the advantages of network coding cannot be exploited sufficiently. This paper proposes improvements upon HWMP with a new, network Coding-Aware routing protocol（CAHWMP） for WMN. In the CAHWMP protocol, we propose a coding criterion based on data streams to devise an algorithm for actively detecting coding opportunities during path discovery. CAHWMP subsequently establishes paths using the codingaware routing metric, which can balance channel resource consumption and the gain due to sharing resources introduced by network coding. Simulation results show that CAHWMP can establish paths with more coding opportunities; as a result, it improves network performance such as network throughput.
