Zhenquan Qin

A balanced energy consumption sleep scheduling algorithm in wireless sensor networks

Network lifetime is one of the most critical issues for wireless sensor networks (WSNs) since most sensors are equipped with non-rechargeable batteries with limited energy. To prolong the lifetime of a WSN, one common approach is to dynamically schedule sensors active/sleep cycles (i.e., duty cycles) with sleep scheduling algorithm. In this paper, we propose a new sleep scheduling algorithm, named EC-CKN (Energy Consumed uniformly-Connected K-Neighborhood) algorithm, to prolong the network lifetime. The algorithm EC-CKN, which takes the nodes residual energy information as the parameter to decide whether a node to be active or sleep, not only can achieve the k-connected neighborhoods problem, but also can assure the k awake neighbor nodes have more residual energy than other neighbor nodes at the current epoch. Based on the algorithm EC-CKN, we can obtain the state transition probability at the nth epoch, and upper bound and lower bound of the network lifetime by Markov chain and Markov decision chain.

A dynamic channel assignment strategy based on cross-layer design for wireless mesh networks

In wireless mesh networks (WMNs), if nonoverlapped channels or partially overlapped channels are used properly, the throughput can be improved drastically. However, the number of nonoverlapped channels is limited in wireless communication standards. An effective channel assignment algorithm for a WMN is necessary to increase the utilization rate of space and nonoverlapped channels. Static channel assignment algorithms can improve network throughput, but their accuracies are not satisfactory in common scenarios. Dynamic channel assignment algorithms can allocate channels according to the status of adjacent links in WMNs. A dynamic channel assignment algorithm needs cross-layer design to get the information of routing. A routing-information-aware channel assignment algorithm based on a cross-layer design is proposed, which is named R-CA. The proposed method can dynamically allocate channels for wireless nodes when they need communication and release channels after data transmission. In R-CA, limited channel resources can be used efficiently by more wireless nodes, and hence the communication throughput can be improved. Simulation results show that our channel allocation strategy can effectively ensure and enhance the network throughput and packet delivery rate in WMNs. Copyright ©u20092012 John Wiley & Sons, Ltd.

A Game Theoretic Resource Allocation Model Based on Extended Second Price Sealed Auction in Grid Computing

In resource-limited environment, grid users compete for limited resources, and how to guarantee tasks’ victorious probabilities is one of the most primary issues that a resource scheduling model cares. In order to guarantee higher task’s victorious probabilities in grid resources scheduling situations, a novel model, namely ESPSA (Extended Second Price Sealed Auction), is proposed. The ESPSA model introduces an analyst entity, and designs analyst’s prediction algorithm based on Hidden Markov Model (HMM). In ESPSA model, grid resources are sold through second price sealed auction. Moreover, to achieve high victorious probabilities, the user brokers who are qualified to participate in the auctions will predict other players’ bids and then carry out the most beneficial bids. The ESPSA model is simulated based on GridSim toolkit. Simulation results show that the ESPSA model assures a higher victorious probability and superior to other traditional algorithms. Moreover, we analyze the existence of Nash equilibrium based on simulation results, thus, any participant who changes its strategy unilaterally could not make the results better.

A Geographic Routing Algorithm in Duty-Cycled Sensor Networks with Mobile Sinks

In this paper, we focus on achieving better energy conservation for geographic routing algorithms in duty-cycled WSNs when there is a mobile sink. We simplify the problem as a topology coverage one, and propose a multi-metric geographic algorithm (MMGR) which uses multi-metric candidates (MMCs) for geographic routing. The analysis and extensive simulation results show that MMGR can achieve better energy conservations than McTPGF, while retaining good performance of end-to-end delay and hop counts.

R-CA: A Routing-Based Dynamic Channel Assignment Algorithm in Wireless Mesh Networks

Even though channel assignment has been studied for years, most IEEE 802.11-based multi-hop wireless networks such as WSN, WMN, MANET are limited by channel interference. Properly assigning orthogonal channels to wireless links can improve the throughput of multi-hop network. To solve the dynamic channel assignment problem, a routing-based channel assignment algorithm R-CA is proposed. R-CA can allocate channels for wireless nodes when they need communication and free channels after data transmission. Limited channel resources can be taken advantage of by more wireless nodes. Simulations are done and the results show that this channel allocation strategy can effectively ensure and enhance the network throughput and packet delivery rate.

An Experimental Study of BATMAN Performance in a Campus Deployment of Wireless Mesh Networks

Based on a fundamental understanding of a high-quality routing protocol called Better Approach To Mobile Ad-hoc Networking or BATMAN, we provide an experimental study of its performance considering a representative set of meaningful measures with a real Wireless Mesh Network (WMN) test bed deploying in our campus. Analysis and experiments results show that BATMAN is not only an efficient and stable routing protocol, but also can satisfy the requirements of multimedia communication in mesh networks.

Poster: a green solution for intelligent metropolitan heating system with uSDcard

In this poster, we present the architecture, design, and the preliminary simulation results of a system for Metropolitan Heating, via intelligent temperature monitoring. The system consists of several Crossbow TelosB-compatible motes, a Nokia uSDCard, and a smart phone. The motes are used to collect indoor temperature data, which is further relayed to the smart phones uSD interface. The uSDCard connects the phone with IEEE 802.15.4/ZigBee compatible devices. We use the smart phone as the sink terminal because it has a rich set of user interfaces and can access to different kinds of networks, such as GPRS and 3G. In real scenes, our system can reduce the reading fluctuation, and ultimately save the energy consumed for heating company, achieving a better living condition in the houses.

Research and simulation of transport protocols optimization on wireless multi-hop networks

It will encounter problems when traditional transport protocols are applied in wireless multi-hop networks (WMNs). Stream Control Transmission Protocol (SCTP) has the potential to be an alternative transport protocol that may be able to better satisfy the requirements of WMNs than traditional protocols, TCP and UDP. In this paper, we analyze and simulate the impact of some factors on the performance of transport protocols on WMNs. (e.g., hops, CWmin, packet size and maximum window of TCP, chunk size of SCTP). Moreover, via extensive simulations of four transport protocols (TCP, SCTP, UDP and DCCP) in competition scenarios, we analyze the relationship between network performance (e.g., throughput) and network factors. And we propose optimization methods with proper values of factors. The results of simulations also can be used as the foundation of further studies on transport protocols on WMNs.

A green solution for intelligent metropolitan heating system with uSDCards

In this paper1, we present the architecture, design, and simulation of an intelligent system for Temperature Monitoring used in metropolitan heating. The system consists of several TelosB-compatible motes, a Nokia uSDCard, and a smart phone. We use TelosB Motes to collect temperature data, and to transport the data to the smart phone. The uSDCard, as the middle layer, connects the smart phone with the ZigBee compatible devices. The smart phone, as the terminal, processes data and manages the TelosB Motes. We use the smart phone as the final terminal because it has a rich set of user interfaces and has access to various kinds of networks, allowing our system to be extended more easily and more user-friendly. In real scenes, our system can reduce the temperature reading fluctuation, and ultimately save the energy consumption for heating companies, providing a better living environment for indoor users.

A Fast Handoff Mechanism with Pre-scanning for Wireless Mesh Networks

With the development of real-time business, the original traditional WMN has been difficult to satisfy the needs of the real-time business. This article is in support of this delay sensitive type under the background of real-time application business in WMN. This improved mechanism is proposing an pre-scanning algorithm focusing on the higher delay in WMN link layer scanning which based on traditional WMN link layer switching mechanism.