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Full-Text Articles in Computer Engineering

Scalable Distributed Communication Architectures To Support Advanced Metering Infrastructure In Smart Grid, Jian Zhou, Rose Qingyang Hu, Yi Qian Sep 2012

Scalable Distributed Communication Architectures To Support Advanced Metering Infrastructure In Smart Grid, Jian Zhou, Rose Qingyang Hu, Yi Qian

Faculty Publications in Computer & Electronics Engineering (to 2015)

In this paper, we investigate the scalability of three communication architectures for advanced metering infrastructure (AMI) in smart grid. AMI in smart grid is a typical cyber-physical system (CPS) example, in which large amount of data from hundreds of thousands of smart meters are collected and processed through an AMI communication infrastructure. Scalability is one of the most important issues for the AMI deployment in smart grid. In this study, we introduce a new performance metric, accumulated bandwidth distance product (ABDP), to represent the total communication resource usages. For each distributed communication architecture, we formulate an optimization problem and obtain ...


Distributed And Centralized Iterative Detection Of Self-Encoded Spread Spectrum In Multi-Channel Communication, Liang Chi, Won Mee Jang, Lim Nguyen Jun 2012

Distributed And Centralized Iterative Detection Of Self-Encoded Spread Spectrum In Multi-Channel Communication, Liang Chi, Won Mee Jang, Lim Nguyen

Faculty Publications in Computer & Electronics Engineering (to 2015)

We propose self-encoded spread spectrum with two different iterative detection methods in multi-channel communication. The centralized iterative detection outperforms the iterative detection distributed over multiple channels. The results show that self-encoded spread spectrum with the centralized iterative detection is an excellent candidate for cognitive radio network.


Assurance Of Energy Efficiency And Data Security For Ecg Transmission In Basns, Tao Ma, Pradhumna Shrestha, Michael Hempel, Dongming Peng, Hamid Sharif, Hsiao-Hwa Chen Apr 2012

Assurance Of Energy Efficiency And Data Security For Ecg Transmission In Basns, Tao Ma, Pradhumna Shrestha, Michael Hempel, Dongming Peng, Hamid Sharif, Hsiao-Hwa Chen

Faculty Publications in Computer & Electronics Engineering (to 2015)

With the technological advancement in body area sensor networks (BASNs), low cost high quality electrocardiographic (ECG) diagnosis systems have become important equipment for healthcare service providers. However, energy consumption and data security with ECG systems in BASNs are still two major challenges to tackle. In this study, we investigate the properties of compressed ECG data for energy saving as an effort to devise a selective encryption mechanism and a two-rate unequal error protection (UEP) scheme. The proposed selective encryption mechanism provides a simple and yet effective security solution for an ECG sensor-based communication platform, where only one percent of data ...


Lte Phy Performance Analysis Under 3gpp Standards Parameters, Fahimeh Rezaei, Michael Hempel, Hamid Sharif Jan 2012

Lte Phy Performance Analysis Under 3gpp Standards Parameters, Fahimeh Rezaei, Michael Hempel, Hamid Sharif

Faculty Publications in Computer & Electronics Engineering (to 2015)

Long Term Evolution (LTE) has been introduced by 3GPP (3rd Generation Partnership Project) and is poised to dominate the 4th generation (4G) of mobile telecommunication networks. In this article, we present an in-depth analysis of the LTE physical layer’s characteristics and its performance. Our work is unique in providing a detailed performance study based on Release 8 of the 3GPP standard. Several works have discussed the LTE performance; however, most have been restricted to limited scenarios. Our work shows a more comprehensive investigation of the maximum data throughput under different conditions and scenarios. Our performance study includes TDD and ...


Quantitative Performance Analysis Of 3.65 Ghz Mobile Wimax, Pradhumna Shrestha, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Hamid Sharif Jan 2012

Quantitative Performance Analysis Of 3.65 Ghz Mobile Wimax, Pradhumna Shrestha, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Hamid Sharif

Faculty Publications in Computer & Electronics Engineering (to 2015)

3.65 GHz Mobile WiMAX spectrum is often a better commercial solution due to its attractive licensing requirements, in spite of the slightly lower coverage area. However, no significant performance data has been reported for 3.65 GHz equipment behavior. In this paper, we have presented an in depth analysis of a 3.65 GHz Mobile WiMAX solution. Our reported data can also contribute in performing link budget analyses and benchmarking similar equipment.


Dynamic Reconfigurable Multi-Cell Battery: A Novel Approach To Improve Battery Performance, Song Ci, Jiucai Zhang, Hamid Sharif, Mahmoud Alahmad Jan 2012

Dynamic Reconfigurable Multi-Cell Battery: A Novel Approach To Improve Battery Performance, Song Ci, Jiucai Zhang, Hamid Sharif, Mahmoud Alahmad

Faculty Publications in Computer & Electronics Engineering (to 2015)

Many electronic systems such as robotics, battery powered electric vehicles, and mobile computing devices are powered by multi-cell battery with limited energy capacity. Therefore, maximizing the battery performance such as operating time, available capacity, and lifetime is one of the major battery design challenges. Traditional approaches such as dynamic power management to maximize the battery discharge performance have treated multi-cell battery as a pure passive component with a fixed configuration. Thus, the multi-cell battery performance is determined by the weakest battery cell, leading to a low utilization of battery energy. In this paper, we propose a novel multi-cell battery design ...


Impact Of Wireless Communication Delay On Load Sharing Among Distributed Generation Systems Through Smart Microgrids, Song Ci, Junjie Qian, Dalei Wu, Ali Keyhani Jan 2012

Impact Of Wireless Communication Delay On Load Sharing Among Distributed Generation Systems Through Smart Microgrids, Song Ci, Junjie Qian, Dalei Wu, Ali Keyhani

Faculty Publications in Computer & Electronics Engineering (to 2015)

Load sharing among distributed generation systems (DGS) is one of the most important topics in wireless-enabled smart microgrids, where a set of power inverters at different geographical locations work coordinately and collaboratively through wireless networks to meet the load requirement. Parallel power inverters operated in distributed generation systems rely on the underlying wireless communication channels to exchange power information among them for load sharing control. However, existing work in the area of load sharing has largely ignored the effect of wireless communication delay. Study has shown that the time-varying wireless communication delay may have a significant impact on the performance ...


An Adaptive Algorithm For Corrupted Images, Deborah D. Duran-Herrmann, Qilin Qi, Yaoqing Lamar Yang Jan 2012

An Adaptive Algorithm For Corrupted Images, Deborah D. Duran-Herrmann, Qilin Qi, Yaoqing Lamar Yang

Faculty Publications in Computer & Electronics Engineering (to 2015)

Noise is ever-present in communication channels and can produce devastating degradation to the images at the receiver end. In this paper, a novel approach to detecting different types of noise models in corrupted images is presented. Basically, it is a two-step process that has the ability to handle real-time applications due to its computational simplicity. The proposed algorithm handles error correction more efficiently in the second stage of processing, given a means to detect the type of noise present in the first stage. This algorithm will be verified and tested against existing methods on different noise models. Preliminary results show ...


Performance Analysis For Direction Of Arrival Estimating Algorithms, Pradhumna Shrestha, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Hamid Sharif Jan 2012

Performance Analysis For Direction Of Arrival Estimating Algorithms, Pradhumna Shrestha, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Hamid Sharif

Faculty Publications in Computer & Electronics Engineering (to 2015)

Smart antennas have emerged as one of the most promising directions in supporting maximum communication link throughput. In this paper, we have investigated the impact of smart antennas on a complex mobile network such as a railroad wireless communications system. The objective is to analyze the selection of a Direction-Of-Arrival (DOA) estimation algorithm which provides the maximum efficiency when deployed in our railroad testbeds for wireless vehicular communication. Our findings are discussed to provide an indepth understanding of how different algorithms should be selected to support efficient network operations.


Cross-Layer Optimized Coding Mode Selection For Wireless Video Communications, Yun Ye, Song Ci, Dalei Wu Jan 2012

Cross-Layer Optimized Coding Mode Selection For Wireless Video Communications, Yun Ye, Song Ci, Dalei Wu

Faculty Publications in Computer & Electronics Engineering (to 2015)

This paper proposed a coding mode selection method for video transmission over wireless networks. Unlike previous mode selection methods disregarding channel distortion or assuming constant packet loss rate (PLR), this method includes a cross-layer controller to collect both source and channel information. The mode selection process is formulated as a delay constrained distortion minimization problem. The three components in the resulting Lagrange cost function, namely distortion, Lagrange multiplier and packet delay, are estimated with online channel information feedback. Suboptimal coding decision and physical layer modulation and coding scheme (MCS) are determined by the controller for each packet. In our experiment ...


A General Attack Method For Steganography Removal Using Pseudo-Cfa Re-Interpolation, Pradhumna Shrestha, Michael Hempel, Tao Ma, Dongming Peng, Hamid Sharif Dec 2011

A General Attack Method For Steganography Removal Using Pseudo-Cfa Re-Interpolation, Pradhumna Shrestha, Michael Hempel, Tao Ma, Dongming Peng, Hamid Sharif

Faculty Publications in Computer & Electronics Engineering (to 2015)

Watermarking and steganography are two of the most researched topics in multimedia forensics. However, easy availability of tools and technology has made their misuse a serious concern. To counteract this development some effective tools are necessary to remove malicious steganography. In this work, we introduce a novel watermark attack method which can destroy hidden information embedded in images based on the principle of re-interpolation of Color Filter Array (CFA) artifacts. In digital cameras and scanners, CFA filters are used to acquire low-resolution physical color channel information and produce a high-quality image by subsequent interpolation. We propose to emulate a similar ...


A Cross-Layer Design For The Performance Improvement Of Real-Time Video Transmission Of Secondary Users Over Cognitive Radio Networks, Haiyan Luo, Song Ci, Dalei Wu Aug 2011

A Cross-Layer Design For The Performance Improvement Of Real-Time Video Transmission Of Secondary Users Over Cognitive Radio Networks, Haiyan Luo, Song Ci, Dalei Wu

Faculty Publications in Computer & Electronics Engineering (to 2015)

Cognitive radio (CR) has been proposed as a promising solution to improve connectivity, self-adaptability, and efficiency of spectrum usage. When used in video applications, user-perceived video quality experienced by secondary users is a very important performance metric to evaluate the effectiveness of CR technologies. However, most of the current research only considers spectrum utilization and effectiveness at medium access control (MAC) and physical layers, ignoring the system performance of the upper layers. Therefore, in this paper, we aim to improve the user experience of secondary users for wireless video services over CR networks. We propose a quality-driven cross-layer optimized system ...


Quantifying Performance Of Cooperative Diversity Using The Sampling Property Of A Delta Function, Won Mee Jang Jul 2011

Quantifying Performance Of Cooperative Diversity Using The Sampling Property Of A Delta Function, Won Mee Jang

Faculty Publications in Computer & Electronics Engineering (to 2015)

In this paper, we present a simple approach to evaluating the performance of amplify-and-forward cooperative diversity. The �-function can be asymptotically reduced to a delta (impulse) function. We extend the result to cooperative networks in fading channels. The proposed approach introduces a simple technique to evaluate the performance of complex networks by sampling.


Quantifying Performance In Fading Channels Using The Sampling Property Of A Delta Function, Won Mee Jang Mar 2011

Quantifying Performance In Fading Channels Using The Sampling Property Of A Delta Function, Won Mee Jang

Faculty Publications in Computer & Electronics Engineering (to 2015)

We apply the sampling property of a delta function to obtain the probability of error in fading channels. Our approach reduces the integration to a sampling. The sampling point is obtained in terms of fading parameters and the average signal-to-noise ratio (SNR) to provide the closed form solution of the performance.


A Simple Upper Bound Of The Gaussian �-Function With Closed-Form Error Bound, Won Mee Jang Feb 2011

A Simple Upper Bound Of The Gaussian �-Function With Closed-Form Error Bound, Won Mee Jang

Faculty Publications in Computer & Electronics Engineering (to 2015)

We present a simple upper bound of the Gaussian Q-function with its closed-form error bound. The proposed approximation can be applied to the evaluation of the average error probability of digital modulations with its error bound. Our bit error rate (BER) bound can be easily applied to fading channels.


Distributed Mimo Technologies In Cooperative Wireless Networks, Shichuan Ma, Yaoqing (Lamar) Yang, Hamid Sharif Jan 2011

Distributed Mimo Technologies In Cooperative Wireless Networks, Shichuan Ma, Yaoqing (Lamar) Yang, Hamid Sharif

Faculty Publications in Computer & Electronics Engineering (to 2015)

Multiple-input multiple-output techniques enhance wireless communications performance by taking advantage of spatial diversity. However, most traditional MIMO systems hardly achieve large spatial diversity because of limited terminal size. In this article, we present recent advances of the distributed MIMO technologies in cooperative wireless networks. We also compare and discuss various relay protocols and cooperative strategies. Our simulation results indicate that distributed MIMO systems can provide larger spatial diversity, and the data rate in cooperative networks can be significantly increased.


A Secure Data Aggregation And Dispatch Scheme For Home Area Networks In Smart Grid, Yun Ye, Yi Qian, Hamid Sharif Jan 2011

A Secure Data Aggregation And Dispatch Scheme For Home Area Networks In Smart Grid, Yun Ye, Yi Qian, Hamid Sharif

Faculty Publications in Computer & Electronics Engineering (to 2015)

Cyber security for smart grid communication systems is one of the most critical requirements need to be assured before smart grid can be operationally ready for the market. Privacy is one of a very important security services. The customer information privacy in smart grid need to be protected. Smart grid data privacy encompasses confidentiality and anonymity of the information extracted from smart devices and metering transmission in a smart grid communication system. In this paper, we consider a home area network as a basic reading data aggregation and dispatch unit in smart grid systems, and we propose a secure in-network ...


A Secure And Reliable In-Network Collaborative Communication Scheme For Advanced Metering Infrastructure In Smart Grid, Yun Ye, Yi Qian, Hamid Sharif Jan 2011

A Secure And Reliable In-Network Collaborative Communication Scheme For Advanced Metering Infrastructure In Smart Grid, Yun Ye, Yi Qian, Hamid Sharif

Faculty Publications in Computer & Electronics Engineering (to 2015)

We consider various security vulnerabilities of deploying Advanced Metering Infrastructure (AMI) in smart grid, and explore the issues related to confidentiality for customer privacy and customer behavior as well as message authentication for meter reading and control messages. There are only a very few research work on AMI authentications, and no work exists on confidentiality for user privacy and user behavior, from the best of our knowledge. In this paper, we propose an in-network collaborative scheme to provide secure and reliable AMI communications in smart grid, with smart meters interconnected through a multihop wireless network. In this approach, an AMI ...


A Study On Energy Efficient Multi-Tier Multi-Hop Wireless Sensor Networks For Freight-Train Monitoring, Puttipong Mahasukhon, Hamid Sharif, Michael Hempel, Ting Zhou, Tao Ma, Pradhumna Shrestha Jan 2011

A Study On Energy Efficient Multi-Tier Multi-Hop Wireless Sensor Networks For Freight-Train Monitoring, Puttipong Mahasukhon, Hamid Sharif, Michael Hempel, Ting Zhou, Tao Ma, Pradhumna Shrestha

Faculty Publications in Computer & Electronics Engineering (to 2015)

The North American freight railroad industry is trying to leverage wireless sensor networks (WSN) onboard railcars for advanced monitoring and alerting. In railroad environments, freight train WSNs exhibit a linear chain-like topology of significant length. Thus, existing wireless technologies such as the IEEE 802.15.4 communication protocol, based on a star topology, are unable to provide reliable service. The end-to-end communication between nodes generally relies on individual nodes communicating with their respective neighbors to carry the information over multiple hops and deliver it to the preferred destination. The routing performance and reliability significantly degrades with increasing number of hops ...


Battery-Aware Multimedia Coding Optimization By Dynamic Frequency Scaling, Jianxin Sun, Xueyi Wang, Song Ci Jan 2011

Battery-Aware Multimedia Coding Optimization By Dynamic Frequency Scaling, Jianxin Sun, Xueyi Wang, Song Ci

Faculty Publications in Computer & Electronics Engineering (to 2015)

Nowadays, multimedia application and video streaming have gained a great popularity because of the boasting development on mobile hardware, and battery driven devices have emerged with a tremendous speed. Due to the important issue of battery efficiency on mobile devices, many optimization algorithms have being proposed toward various of battery powered platforms and scenarios. Most of the provided solutions choose to aim at the minimization of energy usage under a given task scheduling by adjusting parameters reside in the processes of different schemes. However, the battery discharging characteristics and its instant output pattern are still ignored if the optimization is ...


Impact Of Channel Estimation Errors On Effectiveness Of Eigenvector-Based Jamming For Physical Layer Security In Wireless Networks, James M. Taylor, Michael Hempel, Hamid Sharif, Shichuan Ma, Yaoqing Lamar Yang Jan 2011

Impact Of Channel Estimation Errors On Effectiveness Of Eigenvector-Based Jamming For Physical Layer Security In Wireless Networks, James M. Taylor, Michael Hempel, Hamid Sharif, Shichuan Ma, Yaoqing Lamar Yang

Faculty Publications in Computer & Electronics Engineering (to 2015)

In this paper, we present our study of an Eigenvector-based artificial noise-based jamming technique developed to provide increased wireless physical layer security in transmit-receive diversity systems and analyze the impact of channel estimation errors on system performance. Our simulation results showed that with knowledge of perfect channel state information, the technique provided secrecy capacity of approximately 7 bits/s/Hz for a normalized transmit power of 25 dB for a variety of transmit, receive, and eavesdropper configurations. We also describe a novel method to simulate generalized channel state information estimation errors. While other publications neglect the impact of these estimation ...


Priority Preemption For Real-Time Application Qos Guarantees In Cooperative Vehicular Networks, Ting Zhou, Hamid Sharif, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Pradhumna Shrestha Jan 2011

Priority Preemption For Real-Time Application Qos Guarantees In Cooperative Vehicular Networks, Ting Zhou, Hamid Sharif, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Pradhumna Shrestha

Faculty Publications in Computer & Electronics Engineering (to 2015)

Inter-vehicle and roadside-to-vehicle communications can contribute to a safer and more efficient driving experience by providing time-sensitive and location-aware information. However, its performance suffers from vehicle mobility, intermittent user connectivity, and wireless channel unreliability. In this paper, we propose a novel cross-layer optimization approach based on our Adaptive Distributed Cooperative Medium Access Control (ADC-MAC) protocol to guarantee the quality-of-service (QoS) of real-time applications. Markov chain based theoretical analysis show that our proposed priority preemption approach can improve the quality of a real-time application by guaranteeing its bandwidth and reducing its transmission latency.


Power Controlled Multirate Multimedia Transmission In Self-Encoded Spread Spectrum Over Dynamic Fading Channels, Liang Chi, Poomathi Duraisamy, Won Mee Jang, Lim Nguyen Jan 2011

Power Controlled Multirate Multimedia Transmission In Self-Encoded Spread Spectrum Over Dynamic Fading Channels, Liang Chi, Poomathi Duraisamy, Won Mee Jang, Lim Nguyen

Faculty Publications in Computer & Electronics Engineering (to 2015)

In this paper, we propose to apply power control to self-encoded spread spectrum (SESS) in multirate and multimedia applications. The transmitter employs power control to to combat dynamic channel fading and the receiver employs decorrelation to reduce interference from multiple applications. We show that iterative detection can significantly improve the system performance. The proposed approach also improves the power efficiency which is essential in battery-driven communications such as mobile cellular systems.


Self-Encoded Spread Spectrum For Multirate Multimedia Communication In Multipath Channel, Liang Chi, Won Mee Jang, Lim Nguyen Jan 2011

Self-Encoded Spread Spectrum For Multirate Multimedia Communication In Multipath Channel, Liang Chi, Won Mee Jang, Lim Nguyen

Faculty Publications in Computer & Electronics Engineering (to 2015)

In this paper, we propose the self-encoded spread spectrum (SESS) with multirate multimedia communication in multipath channel. In multirate multimedia SESS system, each application has their own transmission bit rate. The signal is transmitted through multipath channels each with different channel gain and time delay. We view the main path as the signal resource and other paths as interference. At the receiver side, decorrelation scheme is employed for the main path combined signal not only to reduce the crosstalk between different applications, but also to provide a better estimation for the despreading sequence in the main path. Interference cancellation(IC ...


Low-Complexity Image Coder/Decoder With An Approaching-Entropy Quad-Tree Search Code For Embedded Computing Platforms, Tao Ma, Pradhumna Shrestha, Michael Hempel, Dongming Peng, Hamid Sharif Jan 2011

Low-Complexity Image Coder/Decoder With An Approaching-Entropy Quad-Tree Search Code For Embedded Computing Platforms, Tao Ma, Pradhumna Shrestha, Michael Hempel, Dongming Peng, Hamid Sharif

Faculty Publications in Computer & Electronics Engineering (to 2015)

In this paper, we propose a fast, simple and efficient image codec applicable for embedded processing systems. Among the existing image coding methods, wavelet quad-tree is a foundation leading to an efficient structure to encode images. By searching significant coefficients along quad-trees, an embedded efficient code can be obtained. In this work, we exploit hierarchical relations of the quad-tree structure in terms of searching entropy and present a quad-tree searching model that is very close to the searching entropy. By applying this model, our codec surpasses SPIHT [1] by 0.2-0.4 db over wide code rates, and its performance ...


Impact Of Interference On Secrecy Capacity In A Cognitive Radio Network, Zhihui Shu, Yaoqing Lamar Yang, Yi Qian, Rose Qingyang Hu Jan 2011

Impact Of Interference On Secrecy Capacity In A Cognitive Radio Network, Zhihui Shu, Yaoqing Lamar Yang, Yi Qian, Rose Qingyang Hu

Faculty Publications in Computer & Electronics Engineering (to 2015)

In this paper, we investigate secrecy capacity of a cognitive radio network based on stochastic geometry distributions. We consider the Poisson process of both the secondary users and the eavesdroppers, and analyze how the stochastic interference from the secondary users can influence the secrecy capacity of the primary users. First, we describe a network model with primary users, secondary users and eavesdroppers in a cognitive radio communication network environment, and derive the expression of secrecy capacity in an additive white Gaussian noise channel. Then, we study the outage probability of secrecy capacity of a primary node from a secure communication ...


Battery Capacity Footprinting And Optimization Analysis For Wireless Multimedia Communication, Jianxin Sun, Dalei Wu, Song Ci Jan 2011

Battery Capacity Footprinting And Optimization Analysis For Wireless Multimedia Communication, Jianxin Sun, Dalei Wu, Song Ci

Faculty Publications in Computer & Electronics Engineering (to 2015)

Micro-electronic industry has been boosting the capability of wireless mobile devices on full-scale. However, battery, as the only power source of most mobile devices, is experiencing a relatively slow development. Therefore, how to optimally utilize the limited battery energy on mobile devices under a predefined performance requirement becomes a critical issue. On the other hand, it is still unclear that how the battery capacity consumption is allocated on different working pattern of a specific video codec under various tempo-spatial scales and parameters, which has posed a design challenge on power management on multimedia communication system. Furthermore, an optimization method is ...


Video Surveillance Over Wireless Sensor And Actuator Networks Using Active Cameras, Dalei Wu, Song Ci, Haiyan Luo, Yun Ye, Haohong Wang Jan 2011

Video Surveillance Over Wireless Sensor And Actuator Networks Using Active Cameras, Dalei Wu, Song Ci, Haiyan Luo, Yun Ye, Haohong Wang

Faculty Publications in Computer & Electronics Engineering (to 2015)

Although there has been much work focused on the camera control issue on keeping tracking a target of interest, few has been done on jointly considering the video coding, video transmission, and camera control for effective and efficient video surveillance over wireless sensor and actuator networks (WSAN). In this work, we propose a framework for real-time video surveillance with pan-tilt cameras where the video coding and transmission as well as the automated camera control are jointly optimized by taking into account the surveillance video quality requirement and the resource constraint of WSANs. The main contributions of this work are: i ...


A Novel Adaptive Distributed Cooperative Relaying Mac Protocol For Vehicular Networks, Ting Zhou, Hamid Sharif, Michael Hempel, Puttipong Mahasukhon, Wei Wang, Tao Ma Jan 2011

A Novel Adaptive Distributed Cooperative Relaying Mac Protocol For Vehicular Networks, Ting Zhou, Hamid Sharif, Michael Hempel, Puttipong Mahasukhon, Wei Wang, Tao Ma

Faculty Publications in Computer & Electronics Engineering (to 2015)

Explosive growth in Information Technology has enabled many innovative application areas such as large-scale outdoor vehicular networks for vehicle-to-vehicle communications. By providing time-sensitive and location-aware information, vehicular networks can contribute to a safer and more efficient driving experience. However, the performance of vehicular networks requires robust and real-time data communications and is impacted by high mobility, intermittent connectivity, and unreliability of the wireless channel. In this paper, a novel adaptive distributed cooperative medium access control (ADCMAC) protocol is proposed in order to address the inherent problems in the IEEE 802.11 standard when employed in vehicular networks. ADC-MAC exploits spatial ...


A Cross-Layer Parallel Handover Optimization Scheme For Wimax Networks, Ting Zhou, Hamid Sharif, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Pradhumna Shrestha Jan 2011

A Cross-Layer Parallel Handover Optimization Scheme For Wimax Networks, Ting Zhou, Hamid Sharif, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Pradhumna Shrestha

Faculty Publications in Computer & Electronics Engineering (to 2015)

The handover performance plays a crucial role in guaranteeing the quality of real-time applications in WiMAX networks. In general, a handover process can be divided into four stages: i) cell reselection, ii) handover preparation, iii) link layer handover, and iv) IP layer handover. A cross-layer parallel handover optimization (CPHO) scheme is proposed in this paper to reduce the handover signaling overhead and latency in each stage. The key idea of our proposed scheme is that uses the knowledge achieved from the backhaul inter-BS communications to reduce the HO control message load in wireless links and overlaps the executions of the ...