Non-Cooperative Games for Service Differentiation in CDMA Systems

In this paper, we address the problem of user-class based service differentiation in CDMA networks. Users are categorized into three classes who get differentiated services based on their expected quality of service (QoS) from the service provider and the price they are willing to pay. We adopt a game theoretic approach for allocating resources through a two-step process. During a service admission, resource distribution is determined for each class. Then, the resource allocated to each class is distributed among the active users in that class. We devise a utility function for the providers which considers the expected revenue and the probability of users leaving their service provider if they are not satisfied with the service. Our model demonstrates how power can be controlled in a CDMA network to differentiate the service quality. Also, we show the impact of admitting high paying users on other users. Mainak Chatterjee received his Ph.D. from the department of Computer Science and Engineering at The University of Texas at Arlington in 2002. Prior to that, he completed his B.Sc. with Physics (Hons) from the University of Calcutta in 1994 and M.E. in Electrical Communication Engineering from the Indian Institute of Science, Bangalore, in 1998. He is currently an Assistant Professor in the department of Electrical and Computer Engineering at the University of Central Florida. His research interests include economic issues in wireless networks, applied game theory, resource management and quality-of-service provisioning, ad hoc and sensor networks, CDMA data networking, and link layer protocols. He serves on the executive and technical program committee of several international conferences. Haitao Lin received the BE degree in radio engineering from Southeast University, Nanjing, China, in 1996, the MS degree in computer applications from the Beijing University of Posts and Telecommunications, Beijing, China, in 2000, and Ph.D. in Computer Science and Engineering from The University of Texas at Arlington in 2004. He is currently with Converged Multimedia Services System Engineering at Nortel, Richardson, Texas. His research interests include wireless network performance evaluation and enhancement, wireless link adaptation, wireless network resource management, and applied game theory. Sajal K. Das received B.S. degree in 1983 from Calcutta University, M.S. degree in 1984 from Indian Institute of Science, Bangalore, and Ph.D. degree in 1988 from University of Central Florida, Orlando, all in Computer Science. He is currently a Professor of Computer Science and Engineering and also the Founding Director of the Center for Research in Wireless Mobility and Networking (CReWMaN) at the University of Texas at Arlington (UTA). Prior to 1999, he was a professor of Computer Science at the University of North Texas (UNT), Denton where he founded the Center for Research in Wireless Computing (CReW) in 1997, and also served as the Director of the Center for Research in Parallel and Distributed Computing (CRPDC) during 1995–97. Dr. Das is a recipient of the UNT Student Association's Honor Professor Award in 1991 and 1997 for best teaching and scholarly research; UNT's Developing Scholars Award in 1996 for outstanding research; UTA's Outstanding Faculty Research Award in Computer Science in 2001 and 2003; and the UTA College of Engineering Research Excellence Award in 2003. He is also frequently invited as a keynote speaker at international conferences and symposia. Dr. Das' current research interests include mobile wireless communications, resource and mobility management in wireless networks, mobile and pervasive computing, wireless multimedia, ad hoc and sensor networks, mobile internet architectures and protocols, distributed and grid computing, performance modeling and simulation. He has published over 350 research papers in these areas in international journals and conferences, directed numerous industry and government funded projects, and holds five US patents in wireless mobile networks. He received four Best Paper Awards in the ACM MobiCom'99, ICOIN'01, ACM MSWiM'00, and ACM/IEEE PADS'97. He as the Editor in Chief of the Pervasive and Mobile Computing (PMC) journal and also as an Associate Editor of IEEE Transactions on Mobile Computing, ACM/Kluwer Wireless Networks, Parallel Processing Letters, Journal of Parallel, Distributed and Emerging Systems. He served as General Chair of IEEE WoWMoM'05, PerCom'04, IWDC'04, MASCOTS'02, ACM WoWMoM'00-02; General Vice Chair of IEEE PerCom'03, ACM MobiCom'00 and IEEE HiPC'00-01; Program Chair of IWDC'02, WoWMoM'98-99; TPC Vice Chair of ICPADS'02; and as TPC member of numerous IEEE and ACM conferences. He is Vice Chair of the IEEE Computer Society's TCPP and TCCC Executive Committees.     

Secure Remote User Mutual Authentication Scheme with Key Agreement for Cloud Environment

Authentication schemes are widely used mechanisms to thwart unauthorized access of resources over insecure networks. Several smart card based password authentication schemes have been proposed in the literature. In this paper, we demonstrate the security limitations of a recently proposed password based authentication scheme, and show that their scheme is still vulnerable to forgery and offline password guessing attacks and it is also unable to provide user anonymity, forward secrecy and mutual authentication. With the intention of fixing the weaknesses of that scheme, we present a secure authentication scheme. We show that the proposed scheme is invulnerable to various attacks together with attacks observed in the analyzed scheme through both rigorous formal and informal security analysis. Furthermore, the security analysis using the widely-accepted Real-Or-Random (ROR) model ensures that the proposed scheme provides the session key (SK) security. Finally, we carry out the performance evaluation of the proposed scheme and other related schemes, and the result favors that the proposed scheme provides better trade-off among security and performance as compared to other existing related schemes.

     

联邦学习在移动通信网络智能化的应用

为解决移动通信网络智能化中因用户隐私保护、数据孤岛等因素导致数据无法集中训练等问题,网络可融入联邦学习技术,构建高效的分布式可信网络智能化架构。概述了联邦学习研究现状以及标准现状,介绍了基于联邦学习的网络智能化架构,并基于该架构验证了客户体验管理应用案例,为移动通信网络与联邦学习的融合提供了参考和借鉴,进一步推动了联邦学习技术在网络智能化的应用。     

Social‐based reputation‐aware data forwarding for improved multicast delivery in the presence of selfish nodes in DTNs

Delay/disruption tolerant networks (DTNs) are potentially applicable in the challenged scenarios like post‐disaster environments. In such networks, data forwarding generally relies on the mutual cooperation of the nodes. However, in reality, despite the availability of necessary resources for data forwarding, a node could misbehave by dropping messages received from other nodes with whom it has no strong social ties. Such a node is called a socially selfish node, which would cause a poor delivery ratio in the network. In this paper, we aim to address the problem of multicast data forwarding in the presence of such selfish nodes, by means of efficient relay selection in DTNs. First, we define a realistic reputation model, in contrast to existing models, to define the socially selfish/misbehaving nodes in the network. Further, a game‐theoretic analysis is carried out that implies data forwarding cost is also an influential parameter in handling selfishness/misbehavior. Subsequently, the problem is formulated as a constrained optimization problem, which is NP hard. Therefore, a heuristic is proposed by combining the reputation of a node and the cost of message forwarding to appropriately identify relay nodes, thus improve the performance of the multicast message delivery in the network. We utilize a social metric, centrality to minimize the message forwarding cost in terms of the number of relay nodes. Finally, the comparative performance evaluation in ONE simulator with practical scenarios shows the superiority of the proposed scheme over the other prominent schemes.     

An Integrated CAD Methodology for Evaluating MOSFET and Parasitic Extraction Models and Variability

An integrated computer-aided design (CAD) framework for evaluating MOSFET and layout parasitic extraction (LPE) models and circuit simulators used in the timing and power analysis of CMOS products is presented. This unified CAD methodology builds a step-wise understanding of the underlying parameter values in the models and their impact on circuit performance. A number of circuit experiments are included to extract the contributions of key MOSFET parameters and physical layout sensitive parasitic elements from circuit simulation results. This CAD setup thus allows easy and detailed comparison of different technologies, device models, and LPE tools to prevent possible bugs in the software as well as inaccuracies in device and parasitic models and timing tools. The software code to carry out the circuit simulations, analysis, and display of the results in an automated fashion has been specifically developed to support this framework. Some of the experiments designed for this work are also placed on the product chip for model-to-hardware correlation. The comparison of the hardware data to the model predictions points to the sources of any discrepancies and aids in tuning the product design to reflect changes in the technology as part of an overall design for manufacturing (DFM) platform     

Location Update versus Paging Trade-Off in Cellular Networks: An Approach Based on Vector Quantization

In this paper, we propose two information-theoretic techniques for efficiently trading off the location update and paging costs associated with mobility management in wireless cellular networks. Previous approaches always attempt to accurately convey a mobile's movement sequence and hence cannot reduce the signaling cost below the entropy bound. Our proposed techniques, however, exploit the rate distortion theory to arbitrarily reduce the update cost at the expense of an increase in the corresponding paging overhead. To this end, we describe two location tracking algorithms based on spatial quantization and temporal quantization, which first quantize the movement sequence into a smaller set of codewords and then report a compressed representation of the codeword sequence. Although the spatial quantization algorithm clusters individual cells into registration areas, the more powerful temporal quantization algorithm groups sets of consecutive movement patterns. The quantizers themselves are adaptive and periodically reconfigure to accommodate changes in the mobile's movement pattern. Simulation study with synthetic and real movement traces for both single-system and multisystem cellular networks demonstrate that the proposed algorithms can reduce the mobile's update frequency to 3-4 updates/day with reasonable paging cost, low computational complexity, storage overhead, and codebook updates.     

A dynamic quarantine scheme for controlling unresponsive TCP sessions

In addition to unresponsive UDP traffic, aggressive TCP flows pose a serious challenge to congestion control and stability of the future Internet. This paper considers the problem of dealing with such unresponsive TCP sessions that can be considered to collectively constitute a Denial-of-Service (DoS) attack on conforming TCP sessions. The proposed policing scheme, called HaDQ (HaTCh-based Dynamic Quarantine), is based on a recently proposed HaTCh mechanism, which accurately estimates the number of active flows without maintenance of per-flow states in a router. We augment HaTCh with a small Content Addressable Memory (CAM), called quarantine memory, to dynamically quarantine and penalize the unresponsive TCP flows. We exploit the advantage of the smaller, first-level cache of HaTCh for isolating and detecting the aggressive flows. The aggressive flows from the smaller cache are then moved to the quarantine memory and are precisely monitored for taking appropriate punitive action. While the proposed HaDQ technique is quite generic in that it can work with or without any AQM scheme, in this paper we have integrated HaDQ and an AQM scheme to compare it against some of the existing techniques. For this, we extend the HaTCh scheme to develop a complete AQM mechanism, called HRED. Simulation-based performance analysis indicates that by using a proper configuration of the monitoring period and the detection threshold, the proposed HaDQ scheme can achieve a low false drop rate (false positives) of less than 0.1%. Comparison with two AQM schemes (CHOKe and FRED), which were proposed for handling unresponsive UDP flows, shows that HaDQ is more effective in penalizing the bandwidth attackers and enforcing fairness between conforming and aggressive TCP flows.     

Media-independent pre-authentication supporting secure interdomain handover optimization [architectures and protocols for mobility management in all-IP mobile networks]

Handovers may cause delays and packet losses that affect real-time communication performance. Mobility protocols at several layers are designed to support handover, but they need to be optimized to ensure high-quality application performance. Existing optimization techniques are not sufficient to take care of interdomain and intertechnology handovers involving different access technologies, such as Wi-Fi, GSM, CDMA, and WiMAX. We categorize several types of handover, describe handover delay components, and propose a handover optimization framework called media independent pre-authentication that can provide optimizations for interdomain and intertechnology handover in a manner that is transparent to mobility management protocols. In addition, we also present experimental results demonstrating that this framework can achieve a significant reduction in handover delays for both network-layer and application-layer mobility management protocols.     

A time optimal wavelength rerouting algorithm for dynamic trafficin WDM networks

In this paper, we consider wavelength rerouting in wavelength routed wavelength division multiplexed (WDM) networks with circuit switching, wherein lightpaths between source-destination pairs are dynamically established and released in response to a random pattern of arriving connection requests and connection holding times. The wavelength continuity constraint imposed by WDM networks leads to poor blocking performance. Wavelength rerouting is a viable and cost effective mechanism that ran improve the blocking performance by rearranging certain existing lightpaths to accommodate a new request. Recently, a rerouting scheme called “parallel move-to-vacant wavelength retuning (MTV-WR)” with many attractive features such as shorter disruption period and simple switching control, and a polynomial time rerouting algorithm, for this scheme, to minimize the weighted number of rerouted lightpaths have been proposed. This paper presents a time optimal rerouting algorithm for wavelength-routed WDM networks with parallel MTV-WR rerouting scheme. The algorithm requires only O(N²W) time units to minimize the weighted number of existing lightpaths to be rerouted, where N is the number of nodes in the network and W is the number of wavelength channels available on a fiber link. Our algorithm is an improvement over the earlier algorithm proposed in that it requires O(N³W+N²W²) time units, which is not time optimal. The simulation results show that our algorithm improves the blocking performance considerably and only very few lightpaths are required to be rerouted per rerouting. It is also established through simulation that our algorithm is faster than the earlier rerouting algorithm by measuring the time required for processing connection requests for different networks     

Minimized SER and QOS Based Power Allocation Strategies for Multi HDAF Relay Cooperative Network

In this paper, a multi hybrid decode-amplify-forward relay cooperative network with perfect CSI in flat Rayleigh fading channel is considered. Using moment generating function based approach, the closed form of symbol error rate (SER) with asymptotic approximation is derived. Based on the lower bound of SER (Olfat and Olfat in IET Commun 5(4):2018–2027, 2011), Lagrange multiplier method and differential evolution (DE) algorithm based power allocation schemes are proposed. With fixed source power, the relay powers are optimized with the proposed schemes by the power allocation factor. Further the SER performance of proposed power allocation schemes is investigated by varying the location of the relays. The performance gain of proposed power allocation schemes depends on the channel quality of source to relay and relay to destination links. It is observed that the proposed power allocation schemes outperform the equal power allocation scheme and DE based power allocation provides SER response close to power allocation with Lagrange multiplier method. In order to achieve the target SER (quality of service) minimum power allocation is introduced as minimum relay power allocation and minimum source and relay power allocation.