There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

The Transmission Control Protocol.

/pdf/reversibility-and-stochastic-networks-17kl9p5ino.pdf

Reversibility and Stochastic Networks

We consider the application of compressed sensing (CS) to the estimation of doubly selective channels within pulse-shaping multicarrier systems (which include orthogonal frequency-division multiplexing (OFDM) systems as a special case). By exploiting sparsity in the delay-Doppler domain, CS-based channel estimation allows for an increase in spectral efficiency through a reduction of the number of pilot symbols. For combating leakage effects that limit the delay-Doppler sparsity, we propose a sparsity-enhancing basis expansion and a method for optimizing the basis with or without prior statistical information about the channel. We also present an alternative CS-based channel estimator for (potentially) strongly time-frequency dispersive channels, which is capable of estimating the ?off-diagonal? channel coefficients characterizing intersymbol and intercarrier interference (ISI/ICI). For this estimator, we propose a basis construction combining Fourier (exponential) and prolate spheroidal sequences. Simulation results assess the performance gains achieved by the proposed sparsity-enhancing processing techniques and by explicit estimation of ISI/ICI channel coefficients.

/pdf/compressive-estimation-of-doubly-selective-channels-in-30yljlclr1.pdf

Compressive Estimation of Doubly Selective Channels in Multicarrier Systems: Leakage Effects and Sparsity-Enhancing Processing

Artificial intelligence (AI) methods in optical networks: A comprehensive survey

This chapter contains sections titled: Introduction System Architecture Transmission Techniques in the LTE System Channels in the Radio Interface of the LTE System Radio Resource Management in LTE References

Long‐Term Evolution

Wireless Sensor Networks (WSNs) have been gaining growing interest in the past years, which has resulted in many proposals of their new applications. The main tasks of a sensor network include not only monitoring and measuring certain phenomena, but also delivering gathered data. Hence, every single node needs to be a wireless router aside from being only a simple sensing device. The idea and the attributes of a Wireless Sensor Network require designers to apply different techniques than those hitherto used in wired as well as in wireless networks. The dynamic progress in the field of WSNs entails the need of creating simulators that have more specific capabilities. Such simulation tools should allow researchers to verify new ideas and compare the proposed solutions in a virtual environment helping to avoid unnecessary, time-consuming or expensive hardware implementations. When beginning to work with Wireless Sensor Networks, it is important to choose a simulation environment that will be up to requirements and will allow the researcher to conduct experiments in a given area. Appropriately, the researcher faces a necessity of finding and getting oneself familiar with many simulators, often designed for radically different applications. This article presents a classification and a wide review the main features of various simulation platforms.

Surv ey of Simulators for Wireless Sensor Networks

Modeling and Dimensioning of Mobile Networks: Stasiak/Modeling and Dimensioning of Mobile Networks

Analytical Model of the Single Threshold Mechanism with Hysteresis for Multi-Service Networks

List of Figures. List of Tables. Preface. Part I Standards for Mobile Networks. 1 Global System for Mobile Communications. 1.1 Introduction. 1.2 System architecture. 1.3 Time structure of the GSM system. 1.4 Logical channels. 1.5 High Speed Circuit Switched Data (HSCSD). 1.6 GPRS packet transmission. 1.7 EDGE packet transmission. 1.8 Traffic management mechanisms in cellular networks. 2 Universal Mobile Telecommunications System. 2.1 Introduction. 2.2 Architecture of the system. 2.3 Wideband access with WCDMA coding and multiplexing - essentials. 2.4 Channels in the WCDMA radio interface. 2.5 Modulation. 2.6 Signal reception techniques. 2.7 Radio resource management in the UMTS system. 2.8 High-speed packet data transmission. 2.9 Services. 3 Long-Term Evolution. 3.1 Introduction. 3.2 System architecture. 3.3 Transmission techniques in the LTE system. 3.4 Channels in the radio interface of the LTE system. 3.5 Radio resource management in LTE. Part II Teletraffic Engineering for Mobile Networks. 4 Basic Definitions and Terminology. 4.1 Introduction. 4.2 Call stream. 4.3 Service stream. 4.4 Markov processes. 4.5 The concept of traffic. 4.6 Quality of service in telecommunication systems. 5 Basic Elements of Traffic Engineering used in Mobile Networks. 5.1 Introduction. 5.2 Erlang model. 5.3 Engset model. 5.4 Comments. 6 Modeling of Systems with Single-Rate Overflow Traffic. 6.1 Introduction. 6.2 Basic information on overflow systems. 6.3 Models of alternative groups. 6.4 Equivalent groups. 6.5 Modeling of overflow traffic in systems with finite number of traffic sources. 6.6 Comments. 7 Models of Links Carrying Multi-Service Traffic. 7.1 Introduction. 7.2 Multi-dimensional Erlang distribution. 7.3 Full-availability group with multi-rate traffic. 7.4 State-dependent systems. 7.5 Systems with finite and infinite number of traffic sources. 7.6 Limited-availability group. 7.7 Full-availability group with reservation. 7.8 Full-availability group with threshold mechanism. 7.9 Full-availability group with compression mechanism. 7.10 Full-availability group with priorities. 8 Modeling of Systems with Multi-Rate Overflow Traffic. 8.1 Introduction. 8.2 Single-service model of the group with overflow traffic. 8.3 Dimensioning of alternative groups with multi-rate traffic. 8.4 Multi-service model of the group with overflow traffic. 8.5 Comments. 9 Equivalent Bandwidth. 9.1 ON/OFF Source. 9.2 Markov Modulated Poisson Process. 9.3 Interrupted Bernoulli Process. 9.4 Comments. 9.5 Self-similar traffic. 9.6 Exemplary methods for determining equivalent bandwidth. 9.7 Bandwidth discretization. 10 Models of the Nodes in the Packet Network. 10.1 Introduction. 10.2 Little's law. 10.3 Model of the M/M/1 system. 10.4 Model of the M/M/1/N-1 system. 10.5 Model of the M/M/m system. 10.6 Model of the M/M/m/N system. 10.7 Model of the M/G/1 system. 10.8 M/D/1 system. 10.9 Queueing systems with one service station and non-preemptive priorities. 10.10 Model M/G/R PS. Part III Application of Analytical Models for Mobile Networks. 11 Modeling and Dimensioning of the Radio Interface. 11.1 Modeling of resource allocations in the radio interface of mobile cellular networks. 11.2 Cellular system with hard capacity carrying single-service traffic. 11.3 Cellular system with soft capacity carrying single-service traffic. 11.4 Cellular system with hard and soft capacity carrying a mixture of multiservice traffic streams. 11.5 HSPA traffic in the radio interface of the UMTS network. 11.6 Comments. 12 Modeling and Dimensioning of the Iub interface. 12.1 Introduction. 12.2 Exemplary architecture of the Iub interface. 12.3 Modeling of the Iub interface. 12.4 Comments. 13 Application of Multi-Rate Models for Modeling UMTS Networks. 13.1 Introduction. 13.2 Models of group of cells carrying multi-rate traffic. 13.3 Models of traffic overflow. 13.4 Handover mechanisms. 13.5 Comments. Conclusion. Appendix A. Index.

/pdf/modelling-and-dimensioning-of-mobile-networks-from-gsm-to-5c8plxp10r.pdf

Piotr Zwierzykowski

Papers

Long‐Term Evolution

Surv ey of Simulators for Wireless Sensor Networks

Modeling and Dimensioning of Mobile Networks: Stasiak/Modeling and Dimensioning of Mobile Networks

Analytical Model of the Single Threshold Mechanism with Hysteresis for Multi-Service Networks

Modelling and dimensioning of mobile networks : from GSM to LTE