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Private provision of public roads through build-operate-transfer (BOT) approaches is increasing around the world. By considering both social welfare gain and profitability, the BOT problem is to determine the optimal BOT contract which can be viewed as a combination of three primary variables of concession period, road capacity and toll charge. This paper models the BOT problem as the isoperimetric problem in calculus of variations to maximize the social welfare with a profit constraint. The model explicitly incorporates the effect of road deterioration and maintenance over the years, which is assumed to depend on the traffic loads, road capacity and road natural deterioration. We find that an optimal pricing policy requires toll increase over calendar time to reduce traffic load due to time-increasing and load-increasing maintenance cost. If, however, the marginal user damage on road is independent of time, then the optimal toll charge is free from the effect of road natural deterioration and thus time-invariant. We also discuss how to reach an optimal contract through government regulations and investigate the effects of economic growth on the solution properties of the problem.

According to PSM, each station must announce traffic before its transmis- sion. PSM requires for this purpose a rather large handshaking period to complete the required announcements. This functional behavior puts a heavy constraint on the size of the announcement period and consequently on throughput, delay and more importantly on power consumption. This paper proposes an optimization of some functional properties of PSM in order to improve its performances. Our proposed UTA-PSM (Unicast Topology Aware Power Saving Mechanism) aims to reduce the number of exchanged announcement frames in order to reduce the announcement period. Conducted simulations show that UTA-PSM outperforms superbly PSM and power saving mechanisms such as the DCS-ATIM that dynamically adjusts the handshaking period according to the traffic load. We show that UTA-PSM deliv- ers more throughput with a smaller average delay yet yielding a much better power saving and robustness.

This paper introduces a novel Management Traffic Clustering Algorithm (MTCA) based on a sliding window methodology for intrusion detection in 802.11 networks Active attacks and other network events such as scanning, joining and leaving in 802.11 WLANs can be observed by clustering the management frames in the MAC Layer. The new algorithm is based on a sliding window and measures the similarity of management frames within a certain period by calculating their variance. Through filtering out certain management frames, clusters are recognized from the discrete distribution of the variance of the management traffic load. Two parameters determine the accuracy and robustness of the algorithm: the Sample Interval and the Window Size of the sliding window. Extensive tests and comparisons between different sets of Sample Intervals and Window Sizes have been carried out. From analysis of the results, recommendations on what are the most appropriate values for these two parameters in various scenarios are presented.

Both real-time multimedia and mobile networks present challenges ripe for new analysis techniques. We examine the applicability of statistical design of experiments and inductive learning theory in the prediction of delay for real-time audio transmissions over mobile ad hoc networks. Utilizing analysis of variance methods and simple decision tree agents, we find both significant factor interaction between traffic load and node mobility as well as a dramatic reduction in error percentage in prediction of end-to-end delay.

The functional architecture and basic design principles for Multi-Granularity OXC (MG-OXC) networks have been introduced in Chapter 2. This chapter provides two dynamic algorithms for solving the problem of routing and wavelength assignment with tunnel allocation, namely Dynamic Tunnel Allocation and Capacity-Balanced Static Tunnel Allocation schemes. In addition to the routing algorithms, we will present their performance evaluation in two sample networks.

The maximum traffic load that can be supported by a wavelength division multiplexed (WDM) optical burst switched (OBS) network with dynamic wavelength allocation is studied. It is shown that it depends on the requirements of the class of service and on the efficiency of the dynamic routing and wavelength assignment (RWA) algorithm employed. Two methods to build the bursts are presented as well as their influence on the maximum traffic load that can be supported.

Simulation is used to investigate and compare the impact of two different traffic shaping policies on the quality of connectionless services in two ATM network topologies with various levels of traffic load. The first topology is asymmetric and bicentric, and is a possible candidate for an Italian ATM network. The second topology is symmetric and monocentric, and is a possible candidate for a Hungarian ATM network. The performance parameters collected during the execution of simulation runs comprise cell and message loss probabilities, cell and message delay jitter distributions, and the number of cells brought to destination that must be discarded because some other cells of the same message were lost.

In the paper, traffic adaptive Dynamic Channel Assignment (DCA) is investigated for a Manhattan microcellular system. As performance measure the assignment failure rate is used. This quantity is defined as the relative number of calls the DCA-algorithm fails to assign at some instant of time. For three different cell plans, we either derive the minimum assignment failure rate or a lower bound of this measure. The performance of a distributed call traffic adaptive DCA-algorithm is compared with the minimum assignment failure rate or the corresponding lower bound. This assignment scheme shows close to optimal results for all traffic loads. It is also shown, as in one-dimensional cellular systems, that traffic adaptive DCA-algorithms will only achieve a minor increase in the capacity compared to fixed channel assignment schemes.

In our daily business, we encounter situations where our demands are not immediately satisfied, for example at taxi stands, banks, and post offices. Some of these situations are tolerable; others are frustrating but beyond our control. The degree of importance of the service sought influences the choice between abandoning the service demand or increasing our threshold of tolerance and waiting until the demand is satisfied. In this chapter we describe the nature of one such service demand with respect to telecommunication networks and characterize this demand in mathematical terms. This chapter is an introduction to congestion theory with regard to new telecommunication environments and discusses how these problems influence the design of digital switching systems. No attempt is made to derive the theory of digital switching systems. No attempt is made to derive the theory or offer solutions for specific problems. The interested reader should consult the references for further study.