Kalyan Basu

Intrusion detection in sensor networks: a non-cooperative game approach

Insufficiency of memory and battery power of sensors makes the security of sensor networks a hard task to do. This insufficiency also makes applying the existing methods of securing other type of networks on the sensor networks unsuitable. We propose a game theoretic framework for defensing nodes in a sensor network. We apply three different schemes for defense. Our main concern in all three schemes is finding the most vulnerable node in a sensor network and protecting it. In the first scheme we formulate attack-defense problem as a two-player, nonzero-sum, non-cooperative game between an attacker and a sensor network. We show that this game achieves Nash equilibrium and thus leading to a defense strategy for the network. In the second scheme we use Markov decision process to predict the most vulnerable sensor node. In the third scheme we use an intuitive metric (nodes traffic) and protect the node with the highest value of this metric. We evaluate the performance of each of these three schemes, and show that the proposed game framework significantly increases the chance of success in defense strategy for sensor network.

SIP-based vertical handoff between WWANs and WLANs

Future-generation wireless networks have been envisioned as the integration of various wireless access networks, including both wireless wide area networks and wireless local area networks. In such a heterogeneous network environment, seamless mobility support is the basis of providing uninterrupted wireless services to mobile users roaming between various wireless access networks. Because of transparency to lower-layer characteristics, ease of deployment, and greater scalability, the application-layer-based session initiation protocol has been considered the right candidate for handling mobility in heterogeneous wireless networks. However, SIP entails application-layer transport and processing of messages, which may introduce considerable delay. As a case study of the performance of mobility management protocols in the heterogeneous wireless networks, we analyze the delay associated with vertical handoff using SIP in the WLAN-UMTS internetwork. Analytical results show that WLAN-to-UMTS handoff incurs unacceptable delay for supporting real-time multimedia services, and is mainly due to transmission of SIP signaling messages over erroneous and bandwidth-limited wireless links. On the other hand, UMTS-to-WLAN handoff experiences much less delay, mainly contributed by the processing delay of signaling messages at the WLAN gateways and servers. While the former case requires the deployment of soft handoff techniques to reduce the delay, faster servers and more efficient host configuration mechanisms can do the job in the latter case.

Analysis of SIP-based mobility management in 4G wireless networks

Providing seamless mobility support is one of the most challenging problems towards the system integration of fourth generation (4G) wireless networks. Because of the transparency to the lower layer characteristics, application-layer mobility management protocol like the Session Initiation Protocol (SIP) has been considered as the right candidate for handling mobility in the heterogeneous 4G wireless networks. SIP is capable of providing support for not only terminal mobility but also for session mobility, personal mobility and service mobility. However, the performance of SIP, operating at the highest layer of the protocol stack, is only as good as the performance of the underlying transport layers in such a heterogeneous environment. In this paper we analyze the handoff performance of SIP in a IP-based 4G network with Universal Mobile Telecommunication System (UMTS) and Wireless LAN (WLAN) access networks. Analytical results show that the handoff to a UMTS access network introduces a minimum delay of 1.4048 s for 128kbps channel, while for handoff to a WLAN access network the minimum delay is 0.2 ms. In the former case the minimum delay is unacceptable for streaming multimedia traffic and requires the deployment of soft-handoff techniques in order to reduce the handoff delay to a desirable maximum limit of 100 ms.

ARC: an integrated admission and rate control framework for competitive wireless CDMA data networks using noncooperative games

The competition among wireless data service providers brings in an option for the unsatisfied customers to switch their providers, which is called churning. The implementation of Wireless Local Number Portability (WLNP) is expected to further increase the churn rate (the probability of users switching the provider). However, the existing resource management algorithms for wireless networks fail to fully capture the far-reaching impact of this unforeseen competitiveness. From this perspective, we first formulate noncooperative games between the service providers and the users. A users decision to leave or join a provider is based on a finite set of strategies. A service provider can also construct its game strategy set so as to maximize their utility (revenue) considering the churn rate. Based on the game theoretic framework, we propose an integrated admission and rate control (ARC) framework for CDMA-based wireless data networks. The admission control is at the session (macro) level while the rate control is at the link layer packet (micro) level. Two admission control modes are considered - one-by-one mode and batch processing mode, in which multiple users are admitted at a time. We show that: 1) for the one-by-one mode, the Nash equilibrium using pure strategy can be established for both under-loaded and fully-loaded systems and 2) for batch processing mode, there is either an equilibrium in pure strategy or a dominant strategy exists for the service provider. Therefore, the providers have clearly defined admission criteria as outcome of the game. Users are categorized into multiple classes and offered differentiated services based on the price they pay and the service degradation they can tolerate. We show that the proposed ARC framework significantly increases the providers revenue and also successfully offers differentiated QoS to the users.

A game theory based pricing strategy for job allocation in mobile grids

Summary form only given. This article realizes the vision of mobile grid computing by proposing a fair pricing strategy and an optimal, static job allocation scheme. Mobile devices has not yet been integrated into grid computing platforms mainly due to their inherent limitations in processing and storage capacity, power and bandwidth shortages. However, millions of laptops, PDAs and other mobile devices remain unused most of the time and this huge resource repository can be potentially utilized in the grid environment. Here, we propose a game theoretic pricing model, to address load balancing issues in mobile grids. In particular, by drawing upon the Nash bargaining solution (NBS), we show that we can obtain an unified framework for addressing such issues as network efficiency, fairness, utility maximization, and pricing. The advantage of this framework is that we have a precise mathematical characterization of the solutions and their properties. Our current endeavor characterizes a two-player alternating-offer bargaining game between the wireless access point (WAP) server and the mobile devices to determine the pricing strategy. This pricing strategy is then made use of to effectively distribute jobs to the mobile devices. Our job allocation scheme maximizes the revenue of the grid user, and yet is comparable to the overall system response time of other load balancing schemes.

A game theory based approach for security in wireless sensor networks

Based on cooperative game theory, we propose a new technique for handling security issues in mobile wireless sensor networks. We define a game between sensor nodes and concentrate on three fundamental factors: cooperation, reputation and quality of security. Stronger cooperation between two nodes implies more reliable data communication between them. And the more a node cooperates the better is its reputation, which decreases when misbehavior is detected. When security of the network is compromised, the percentage of exposed traffic measures the quality of security of sensor nodes. By incorporating these three factors, we cluster the sensor nodes such that within a cluster, the payoff function of all sensor nodes are close to each other, where payoff is the largest possible individual gain for each sensor according to a defined utility metric. We define one strategy set for each node, which guarantees reaching to an equilibrium point for payoff function.

An ubiquitous architectural framework and protocol for object tracking using RFID tags

A completely visible pervasive transaction environment where it is possible to link all related transactions of physical objects and trace their mobility through their entire life process, has been elusive. With the emergence of radio frequency identification (RFID) based tags, it is now practicable to automatically collect information pertaining to any objects place, time, transaction, etc. Based on the pervasive deployment of RFID tags, we propose A novel ubiquitous architecture followed by a protocol for tracking mobile objects in real-time. Our delay analysis and simulation results indicate that the delay incurred in the database update of current tag location is very low and is in the order of seconds, thus providing a very fine granularity in time for consistent location update requests.

A pricing strategy for job allocation in mobile grids using a non-cooperative bargaining theory framework

Due to their inherent limitations in computational and battery power, storage and available bandwidth, mobile devices have not yet been widely integrated into grid computing platforms. However, millions of laptops, PDAs and other portable devices remain unused most of the time, and this huge repository of resources can be potentially utilized, leading to what is called a mobile grid environment. In this paper, we propose a game theoretic pricing strategy for efficient job allocation in mobile grids. By drawing upon the Nash bargaining solution, we show how to derive a unified framework for addressing such issues as network efficiency, fairness, utility maximization, and pricing. In particular, we characterize a two-player, non-cooperative, alternating-offer bargaining game between the Wireless Access Point Server and the mobile devices to determine a fair pricing strategy which is then used to effectively allocate jobs to the mobile devices with a goal to maximize the revenue for the grid users. Simulation results show that the proposed job allocation strategy is comparable to other task allocation schemes in terms of the overall system response time.

A framework for bandwidth degradation and call admission control schemes for multiclass traffic in next-generation wireless networks

The next-generation wireless networks need to support a wide range of multimedia applications with limited radio resources like bandwidth. In this paper, we propose a novel integrated framework for bandwidth degradation and call admission control (CAC) for multiclass real-time multimedia traffic in such networks. To increase the total carried traffic in an overloaded (saturated) wireless system, some of the ongoing calls in our framework are allowed to operate under a degraded mode, thereby releasing wireless channels that can be used to accommodate new calls, however, at the cost of user satisfaction. Indeed, an increase in carried traffic (i.e., providers revenue generation) and users quality-of-service satisfaction are two conflicting goals in a bandwidth allocation scheme. The proposed framework adequately models this tradeoff by introducing the negative revenue (i.e., loss) from bandwidth degradation, and finding the optimal degradation and admission policies that maximize the net revenue. When there is a mixture of real-time and nonreal-time calls in the system, the former are given preemptive priority over the latter, which are buffered for future admission in case of preemption. A channel sharing scheme is proposed for nonreal-time traffic and analyzed using a Markov modulated Poisson process-based queueing model. Detailed simulation experiments are conducted to validate our proposed framework.

An architecture for next-generation radio access networks

With fourth-generation wireless technologies envisioned to provide high bandwidth for content-rich multimedia applications, next-generation mobile communication systems are well poised to lead the technology march. Incumbent with the new technology is the challenge of providing flexible, reconfigurable architectures capable of catering to the dynamics of the network, while providing cost-effective solutions for service providers. In this article we focus on IP-based radio access network architectures for next-generation mobile systems. We provide an insight into wireless mesh-based connectivity for the RAN network elements - using short high-bandwidth links to interconnect the network entities in a multihop mesh network for backhauling traffic to the core. A generic self-similar fractal topology, using optical wireless transmission technology, is described. We study the performance of the architecture and conclude that mesh-based architectures are well suited to provide highly scalable, dynamic radio access networks with carrier-class features at significantly low system costs.