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Articles 1 - 12 of 12
Full-Text Articles in Physical Sciences and Mathematics
A Novel Scheduler For Concurrent Tx/Rx Wireless Mesh Networks With Weighted Links, Kwan-Wu Chin, Sieteng Soh, Chen Meng
A Novel Scheduler For Concurrent Tx/Rx Wireless Mesh Networks With Weighted Links, Kwan-Wu Chin, Sieteng Soh, Chen Meng
Faculty of Informatics - Papers (Archive)
This paper considers the NP-hard problem of scheduling weighted links in concurrent transmit/receive wireless mesh networks. The problem generalizes existing works to links with weight wij ≥ 1. We propose an O(|V|2) algorithm, where V is the set of routers, that is orders of magnitude faster than computationally intensive approaches that use the well-known Goemans-Williamson (GWA)'s maximum cut algorithm and also brute-force. Our algorithm generates schedules, on average, with at most 3% and 9% fewer links than the GWA and brute-force approaches respectively.
Characterising The Behaviour Of Ieee 802.11 Broadcast Transmissions In Ad Hoc Wireless Lans, Mehran Abolhasan, Farzad Safaei, Jerry Chun-Ping Wang, Daniel R. Franklin
Characterising The Behaviour Of Ieee 802.11 Broadcast Transmissions In Ad Hoc Wireless Lans, Mehran Abolhasan, Farzad Safaei, Jerry Chun-Ping Wang, Daniel R. Franklin
Faculty of Informatics - Papers (Archive)
This paper evaluates the performance of the IEEE 802.11 broadcast traffic under both saturation and nonsaturation conditions. The evaluation highlights some important characteristics of IEEE 802.11 broadcast traffic as compared to corresponding unicast traffic. Moreover, it underlines the inaccuracy of the broadcast saturation model proposed by Ma and Chen due to the absence of backoff counter freeze process when channel is busy. Computer simulations are used to validate the accuracy of the new model and demonstrate the importance of capturing the freezing of backoff counter in the analytical study of IEEE 802.11 broadcast.
An Energy-Aware Multilevel Clustering Algorithm For Wireless Sensor Networks, Xinfang Yan, Jiangtao Xi, Joe F. Chicharo, Yanguang Yu
An Energy-Aware Multilevel Clustering Algorithm For Wireless Sensor Networks, Xinfang Yan, Jiangtao Xi, Joe F. Chicharo, Yanguang Yu
Faculty of Informatics - Papers (Archive)
Clustering sensors nodes as the basic of routing is an efficient mechanism for prolonging the lifetime of wireless sensor networks. In this paper, the high-efficient multilevel clustering is abstracted as a root tree which has the performances of the minimal relay set and the maximal weight according to graph theory. A mathematical model for the clustering virtual backbone is built. Based on the model, an algorithm called energy-aware multilevel clustering (EAMC) is proposed. The EAMC can reduce the number of relays used for data transmission by minimizing the amount of the nodes in the root tree (that is cluster-head). Furthermore, …
Adaptive Self-Organisation Of Wireless Ad-Hoc Control Networks, Fazel Naghdy, Nathan Simiana
Adaptive Self-Organisation Of Wireless Ad-Hoc Control Networks, Fazel Naghdy, Nathan Simiana
Faculty of Informatics - Papers (Archive)
A novel concept called Wireless ad-hoc Control Networks (WACNets), exploring an ad-hoc approach to networked distributed control, has been under study for the last five years in the research group. Such systems represent a new stage in the evolution of distributed control and monitoring. The work carried out in developing an adaptive self-organisation algorithm for WACNet is reported. The algorithm deploys a distance measure technique while satisfying the rules and assumptions developed for WACNet framework. The effectiveness of the algorithm is verified through computer simulation under a number of given scenarios. The results obtained show that the algorithm effectively drives …
A Wireless Sensor Node Architecture Using Remote Power Charging, For Interaction Applications, Matthew D'Souza, Konstanty Bialkowski, Adam Postula, Montserrat B. Ros
A Wireless Sensor Node Architecture Using Remote Power Charging, For Interaction Applications, Matthew D'Souza, Konstanty Bialkowski, Adam Postula, Montserrat B. Ros
Faculty of Informatics - Papers (Archive)
The wireless sensor node architecture proposed inthis paper is optimized for use in a wireless interactivepoint, listen and see system. In particular, we focus ondeveloping a wireless sensor node that can beremotely charged by harvesting microwave energy.The current system implementation allows a user toaccess information from a remote sensor via theirmobile computing device. These sensors are limited incomplexity due to the limited power available, and arecumbersome since manual intervention is required toreplace its batteries. We propose a system wherebattery powered wireless sensor nodes can berecharged by harvesting energy from a microwaveRadio Frequency (RF) signal source. The remotepower charging module of …
Ber-Delay Characteristics Analysis Of Ieee 802.15.4 Wireless Sensor Networks With Cooperative Mimo, Mohd Riduan Bin Ahmad, Eryk Dutkiewicz, Xiaojing Huang
Ber-Delay Characteristics Analysis Of Ieee 802.15.4 Wireless Sensor Networks With Cooperative Mimo, Mohd Riduan Bin Ahmad, Eryk Dutkiewicz, Xiaojing Huang
Faculty of Informatics - Papers (Archive)
This paper presents a study of the impact of transmission delay differences between co-operating nodes on bit error rate performance and energy consumption of wireless sensor networks. We consider a wireless sensor network using an Alamouti virtual MIMO (multiple-input multiple-output) configuration between collaborating nodes operating in quasi-static Rayleigh flat-fading channels. Our results show that above certain delay difference (in the range above 0.75Tb), the traditional non-cooperative approach is more energy-efficient than the cooperative strategy and that the transmission delay difference has the most significant on the transmission energy consumption in the delay range of below 0.75Tb.
Generic Scheduling Framework And Algorithm For Time-Varying Wireless Networks, Gengfa Fang, Yi Sun, Jihua Zhou, Jinglin Shi, Eryk Dutkiewicz
Generic Scheduling Framework And Algorithm For Time-Varying Wireless Networks, Gengfa Fang, Yi Sun, Jihua Zhou, Jinglin Shi, Eryk Dutkiewicz
Faculty of Informatics - Papers (Archive)
In this paper, the problem of scheduling multiple users sharing a time varying wireless channel is studied, in networks such as in 3G CDMA and IEEE 802.16. We propose a new generic wireless packet scheduling framework (WPSF), which takes into account not only the quality of service (QoS) requirements but also the wireless resource consumed. The framework is generic in the sense that it can be used with different resource constraints and QoS requirements depending on the traffic flow types. Subsequently, based on this framework a minimum rate and channel aware (MRCA) scheduling algorithm is presented. MRCA attempts to greedily …
Sava: A Novel Self-Adaptive Vertical Handoff Algorithm For Heterogeous Wireless Networks, Min Liu, Zhong-Cheng Li, Xiao-Bing Guo, Eryk Dutkiewicz, Ming-Hui Wang
Sava: A Novel Self-Adaptive Vertical Handoff Algorithm For Heterogeous Wireless Networks, Min Liu, Zhong-Cheng Li, Xiao-Bing Guo, Eryk Dutkiewicz, Ming-Hui Wang
Faculty of Informatics - Papers (Archive)
The next generation wireless networking (4G) is envisioned as a convergence of different wireless access technologies with diverse levels of performance. Vertical handoff (VHO) is the basic requirement for convergence of different access technologies and has received tremendous attention from the academia and industry all over the world. During the VHO procedure, handoff decision is the most important step that affects the normal working of communication. In this paper, we propose a novel vertical handoff decision algorithm, self- adaptive VHO algorithm (SAVA), and compare its performance with conventional algorithms. SAVA synthetically considers the long term movement region and short term …
Performance Evaluation Of Vertical Handoff Decision Algorithms In Heterogeneous Wireless Networks, Min Liu, Zhong-Cheng Li, Xiao-Bing Guo, Eryk Dutkiewicz, De-Kui Zhang
Performance Evaluation Of Vertical Handoff Decision Algorithms In Heterogeneous Wireless Networks, Min Liu, Zhong-Cheng Li, Xiao-Bing Guo, Eryk Dutkiewicz, De-Kui Zhang
Faculty of Informatics - Papers (Archive)
In recent years, many research works have focused on vertical handoff (VHO) decision algorithms. However, evaluation scenarios in different papers are often quite different and there is no consensus on how to evaluate performance of VHO algorithms. In this paper, we address this important issue by proposing an approach for systematic and thorough performance evaluation of VHO algorithms. Firstly we define the evaluation criteria for VHO with two metrics: matching ratio and average ping-pong number. Subsequently we analyze the general movement characteristics of mobile hosts and identify a set of novel performance evaluation models for VHO algorithms. Equipped with these …
A Generalized Algorithm For The Generation Of Correlated Rayleigh Fading Envelopes In Wireless Channels, Le Chung Tran, Tadeusz A. Wysocki, Alfred Mertins, Jennifer R. Seberry
A Generalized Algorithm For The Generation Of Correlated Rayleigh Fading Envelopes In Wireless Channels, Le Chung Tran, Tadeusz A. Wysocki, Alfred Mertins, Jennifer R. Seberry
Faculty of Informatics - Papers (Archive)
Although generation of correlated Rayleigh fading envelopes has been intensively considered in the literature, all conventional methods have their own shortcomings, which seriously impede their applicability. In this paper, a very general, straightforward algorithm for the generation of an arbitrary number of Rayleigh envelopes with any desired, equal or unequal power, in wireless channels either with or without Doppler frequency shifts, is proposed. The proposed algorithm can be applied to the case of spatial correlation, such as with multiple antennas in Multiple Input Multiple Output (MIMO) systems, or spectral correlation between the random processes like in Orthogonal Frequency Division …
An Efficient Certified E-Mail Scheme Suitable For Wireless Mobile Environments, Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng
An Efficient Certified E-Mail Scheme Suitable For Wireless Mobile Environments, Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng
Faculty of Informatics - Papers (Archive)
As security enhanced systems for standard e-mail, certified e-mail schemes guarantee the fair exchange of a digital message with the corresponding receipt between two mistrusted parties. That is, the intended receiver gets the e-mail content if and only if the e-mail sender obtains an irrefutable receipt issued by the receiver, which could be used to prove that the message has been delivered to the receiver. A number of such protocols have been proposed in recent years. However, most of them are not suitable for mobile networks, since many intricate cryptographic primitives are involved so that considerable overheads are introduced. In …
Background Radio Frequency Interference Measurements For Wireless Devices In The Electricity Supply Industry, D A. Robinson, Tadeusz A. Wysocki, Victor W. Smith, Keni Popovski
Background Radio Frequency Interference Measurements For Wireless Devices In The Electricity Supply Industry, D A. Robinson, Tadeusz A. Wysocki, Victor W. Smith, Keni Popovski
Faculty of Informatics - Papers (Archive)
Incorporation of radio controller units into heavy equipment used in the electricity industry provides numerous advantages including: improved electrical isolation between plant and operator, ability to incorporate an additional remote operator, and reductions in vehicle wiring and hydraulic hoses for equipment control. However, secure operation of vehicles and plant incorporating radio control rely on establishing suitable levels of immunity to possible radio frequency interference. Interference levels in close proximity to high voltage power lines are of special concern to the electricity industry. This paper reports on a preliminary investigation into quantifying the levels of background radio interference at such locations …