Performance Evaluation of Public Key Based Authentication in Future Mobile Communication Systems

<p>While mobile hosts are evolving into full-IP enabled devices, there is a greater demand to provide a more flexible, reconfigurable, and scalable security mechanism in mobile communication systems beyond 3G (B3G). Work has already begun on such an &#147;all-IP&#148; end-to-end solution, commonly referred to as 4G systems. Fully fledged integration between heterogeneous networks, such as 2.5G, UMTS, WLAN, Bluetooth, and the Internet, demands fully compatible, time-tested, and reliable mechanisms to depend on. SSL protocol has proved its effectiveness in the wired Internet and it will probably be the most promising candidate for future wireless environments. In this paper, we discuss existing problems related to authentication and key agreement (AKA) procedures, such as compromised authentication vectors attacks, as they appear in current 2/2.5G/3G mobile communication systems, and propose how SSL, combined with public key infrastructure (PKI) elements, can be used to overcome these vulnerabilities. In this B3G environment, we perceive authentication as a service, which has to be performed at the higher protocol layers irrespective of the underlying network technology. Furthermore, we analyze the effectiveness of such a solution, based on measurements of a &#147;prototype&#148; implementation. Performance measurements indicate that SSL-based authentication can be possible in terms of service time in future wireless systems, while it can simultaneously provide both the necessary flexibility to network operators and a high level of confidence to end users.</p

A game theoretical formulation of integrated admission control and pricing in wireless networks

We consider a competitive environment with several wireless network providers offering high data rate services and assume that users activate ephemeral session subscriptions with these providers. In the cases of overcharging or substantial service degradation by the serving networks, the users have the possibility to withdraw their request or terminate earlier their session subscription, respectively. In this context, network providers should attempt to optimize a more general utility function that incorporates technical, as well as other subjective parameters like money revenue, reputation, and user satisfaction. Considering such parameters, we formulate the problem of session establishment as an extensive form game between the different parties involved namely the provider, its current users, and the potential customer. The solution of this game produces an integrated pricing and admission control policy that achieves the network provider's optimum utility, while ensuring the satisfaction of all sides. The main contribution of our study is an admission policy that can adapt to environmental variations by proper parameter tuning. We compare our session admission control scheme with a purely technical algorithm and prove that our admission policy reflects the current requirements of the environment, yielding higher utility values to the provider.

The Wisconsin Breast Cancer Problem: Diagnosis and DFS time prognosis using

probabilistic and generalised regression neural classifier

Reducing CQI Signalling Overhead in HSPA

The efficiency of adaptive modulation and coding (AMC) procedure in high speed Downlink packet access (HSDPA) depends on the frequency of the channel quality information (CQI) reports transmitted by the UE to Node B. The more frequent the reports are the more accurate the link adaptation procedure is. On the other hand, the frequent CQI reports increase uplink interference, reducing thus the signal reception quality at the uplink. In this study, we propose an improved CQI reporting scheme which aims to reduce the required CQI signaling by exploiting a CQI prediction method based on a finite-state Markov chain (FSMC) model of the wireless channel. The simulation results show that under a high downlink traffic load, the proposed scheme has a near-to-optimum performance while produces less interference compared to the respective periodic CQI scheme