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Another way to think of planar networks is by focusing on their faces and how to generate them. An example is given by tessellations of a plane that are divisions of the plane into polygons. There is a vast literature on tessellations (see [188] and references therein) and in this chapter, we will discuss selected examples only. Many tessellations are constructed from a random set of points and we will first focus in this chapter on the well-known Voronoi tessellation and its dual, the Delaunay graph. We then discuss briefly another class of tessellation obtained by growing lines from points (with the Gilbert model) or obtained by adding random lines (STIT models). Finally, we briefly discuss the case of planar fragmentation, and in the last section how we can use Delaunay graphs for constructing a null model of spatial multilayer networks.

Hard-decision decoders are considered for burst error correction for low-density parity-check codes. The decoder for block-permutation construction of low-density parity-check proposed. Experiments on complexity and error probability are conducted with burst lengths both within and beyond the burst error correction capability. Also simulation results for Gilbert model are presented.

We propose an iterated version of the Gilbert model, which results in a sequence of random mosaics of the plane. We prove that under appropriate scaling, this sequence of mosaics converges to that obtained by a classical Poisson line process with explicit cylindrical measure. Our model arises from considerations on tropical plane curves, which are zeros of random tropical polynomials in two variables. In particular, the iterated Gilbert model convergence allows one to derive a scaling limit for Poisson tropical plane curves. Our work raises a number of open questions at the intersection of stochastic and tropical geometry.

The last few years have witnessed an explosive growth in the research of information hiding in multimedia objects, but few studies have taken into account packet loss in multimedia networks. As one of the most popular real-time services in the Internet, Voice over Internet Protocol (VoIP) contributes to a large part of network traffic for its advantages of real time, high flow, and low cost. So packet loss is inevitable in multimedia networks and affects the performance of VoIP communications. In this study, a fractal-based VoIP steganographic approach was proposed to realize covert VoIP communications in the presence of packet loss. In the proposed scheme, secret data to be hidden were divided into blocks after being encrypted with the block cipher, and each block of the secret data was then embedded into VoIP streaming packets. The VoIP packets went through a packet-loss system based on Gilbert model which simulates a real network situation. And a prediction model based on fractal interpolation was built to decide whether a VoIP packet was suitable for data hiding. The experimental results indicated that the speech quality degradation increased with the escalating packet-loss level. The average variance of speech quality metrics (PESQ score) between the “no-embedding” speech samples and the “with-embedding” stego-speech samples was about 0.717, and the variances narrowed with the increasing packet-loss level. Both the average PESQ scores and the SNR values of stego-speech samples and the data-retrieving rates had almost the same varying trends when the packet-loss level increased, indicating that the success rate of the fractal prediction model played an important role in the performance of covert VoIP communications.

Most wireless networks incline to include FEC code (Forward error correction) to recover the corrupted packets without retransmission. The sequential packets transmitted over wireless channel are likely to be infected with various errors like noise or deep fading. In this paper, therefore, a frame-level FEC is added across packets at the application layer to define two analytical packet loss models. At the network layer level, Gilbert Elliot Model (GEM) and Extended Gilbert Model (EGM) are considered to characterize the MPEG-4 packets loss over the bursty error-prone wireless channels. The resultant video quality in terms of playable frame rate (PFR) is estimated at the client end when using the underlying TCP-Friendly protocol. Numerical results point out that the EGM-FEC model introduces a robust measure in estimating the perceived video quality in particular at higher packet loss rate and lower effect of packet correlation. Moreover, it is also found that the GEM-FEC model outperforms EGM-FEC but when ignoring the effect of packet correlation.

In the original (1961) Gilbert model of random geometric graphs, nodes are placed according to a Poisson point process, and links formed between those within a fixed range. Motivated by wireless ad-hoc networks "soft" or "probabilistic" connection models have recently been introduced, involving a "connection function" H(r) that gives the probability that two nodes at distance r are linked (directly connect). In many applications (not only wireless networks), it is desirable that the graph is connected, that is every node is linked to every other node in a multihop fashion. Here, the connection probability of a dense network in a convex domain in two or three dimensions is expressed in terms of contributions from boundary components, for a very general class of connection functions. It turns out that only a few quantities such as moments of the connection function appear. Good agreement is found with special cases from previous studies and with numerical simulations., Comment: 16 pages; improved figures and minor edits

The article is dedicated to software implementation of the packet loss correction ARQ algorithm at application layer (AL-ARQ) for streaming in the wireless local area network. Functioning of the developed software verified experimentally using simulation of wireless transmission by the Gilbert model. Moreover, the algorithm was optimized for MPEG streaming by introducing the packets prioritization for retransmission taking into account time to deadline and frame type. It was experimentally obtained that the optimization had increased quality of service and quality of experience relatively to not optimized version of the algorithm.

This paper analytically evaluates the FEC(Forward Error Correction) symbol size`s effect on the performance and energy consumption of 802.11 protocol with the block FEC algorithm over WSN(Wireless Sensor Network). Since the basic recovery unit of block FEC algorithms is symbols not bits, the FEC symbol size affects the packet correction rate even with the same amount of FEC check bits over a given WSN channel. Precisely, when the same amount of FEC check bits are allocated, the small-size symbols are effective over channels with frequent short bursts of propagation errors while the large ones are good at remedying the long rare bursts. To estimate the effect of the FEC symbol site, the paper at first models the WSN channel with Gilbert model based on real packet traces collected over TIP50CM sensor nodes and measures the energy consumed for encoding and decoding the RS (Reed-Solomon) code with various symbol sizes. Based on the WSN channel model and each RS code`s energy expenditure, it analytically calculates the transmission efficiency and power consumption of 802.11 equipped with RS code. The computational analysis combined with real experimental data shows that the RS symbol size makes a difference of up to 4.2% in the transmission efficiency and 35% in energy consumption even with the same amount of FEC check bits.

Leaders such as Thomas Gilbert, Geary Rummier, and Edward Deming have argued that the greatest leverage for solving performance problems lies with solutions targeted at system or environmental factors (those under the control of management) versus individual performer factors. A 12-item research instrument titled Achieving Productive Performance (APP) was developed based on the six variables that make up Gilbert's human performance model. MBA candidates whoworkfull-time primarily in middle management positions were asked to make value judgments on strategies for producing productive performance (where value for the performance exceeds the costs), Results support the concept of leverage espoused by Gilbert, Rummier, and Deming. Implications for workplace learning and performance professionals are discussed.

Under the current Internet infrastructure, quality of service (QoS) in the delivery of continuous media (CM) is still relatively poor and inconsistent. In this paper we consider providing QoS through the exploitation of multiple paths existing in the network. Previous work has illustrated the advantages of this approach. Here we extend this work by considering a more expressive model for characterizing the network path losses. In particular, we propose a variation on the Gilbert model wherein the loss characteristics of a path depend on an application's transmission bandwidth. Using this model, we show the benefits of multi-path streaming over best single-path streaming, under optimal load distribution among the multiple paths. We use extensive simulation and measurements from a system prototype to quantify the performance benefits of our techniques.

Recently, it has a tendency to reduce an error correction and flow control in order to realize a high speed transmission in a burst transmission systems such as ATM network, IP (Internet Protocol) network, frame relay and so on. Therefore a degradation of network quality, an information loss caused by buffer overflow and decrease of average bit error rate, are occurred, especially for high speed information such as high definition television signals, it is necessary to improve these degradations.This paper proposes one of the typical reconstruction methods of lost information and an improvement of average bit error rate. In order to analyse the degradation phenomena, the Gilbert model is introduced for burst errors and the Fluid flow model for buffer overflow.This method is applied to ATM network which mainly transmit a video signals and it makes clear that proposed method is useful for high speed transmission.

This paper analyzes the characteristics of packet losses in mobile computing environments based on the Gilbert model and then describes a mechanism that can recover the lost audio packets using redundant data. Using information periodically reported by a receiver, the sender dynamically adjusts the amount and offset values of redundant data with the constraint of minimizing the bandwidth consumption of wireless links. Since mobile computing environments can be often characterized by frequent and consecutive packet losses, loss recovery mechanisms need to deal efficiently with both random and consecutive packet losses. To achieve this, the suggested mechanism uses relatively large, discontinuous exponential offset values. That gives the same effect as using both the sequential and interleaving redundant information. To verify the effectiveness of the mechanism, we extended and implemented RTP/RTCP and applications. The experimental results show that our mechanism, with an exponential offset, achieves a remarkably low complete packet loss rate and adapts dynamically to the fluctuation of the packet loss pattern in mobile computing environments.

Dissipation properties of ferromagnetic thin films are traditionally characterized by phenomenological damping models related to ferromagnetic resonance (FMR) linewidths. They may also be analyzed in terms of thermal magnetization fluctuations, the connection being made through the fluctuation–dissipation theorem. This article describes how fluctuation–dissipation relations provide a means for discriminating between alternative phenomenological magnetic damping models in ways that are not obvious using traditional uniform-magnetization descriptions appropriate to FMR experiments. In particular, it is shown that recently proposed alternatives to the well-known Gilbert damping model lead to physically untenable predictions/contradictions when analyzed in this light, unlike the traditional Gilbert model itself.

Експериментально підтверджено відповідність каналів міської телефонної мережі (МТМ) моделі Гільберта з двома станами. Запропоновані нові методи передачі, що забезпечують необхідну якість передачі та передачу більшого обсягу інформації в заданому часовому проміжку. В роботі приведені результати статистичних вимірювань на вказаних каналах та розраховані ймовірнісні характеристики систем при використанні ТСК для передачі інформації по каналам МТМ., Экспериментально подтверждено соответствие каналов городской телефонной сети (ГТС) модели Гильберта с двумя состояниями. Предложены новые методы передачи, обеспечивающие необходимое качество передачи и передачу большего объема информации в заданном временном промежутке. В работе приведены результаты статистических измерений на указанных каналах и рассчитаны вероятностные характеристики систем при использовании ТСК для передачи информации по каналам ГТС., New, more efficient transmission methods, providing a necessary transmission quality and the transmission of more information in a given time interval are proposed. Use of time-coding in transmission systems reduces information delivery time by two times compared with BDC (bit-digital coding).It is experimentally shown that although power distance in timer signal constructions is defined by the area, much smaller relative to the bit-digital code, the probabilities of false acceptance of CW (code word) are not significantly different, and sometimes may be smaller than the bit-digital code.The results of statistical measurements on these channels are given, and probabilistic characteristics of systems when using timer signal constructions for the information transmission through the city telephone network channels are calculated in the paper.

In this contribution we propose an extension to the range-dependent modified Gilbert model introduced in [1]. With the proposed extension, the model can be used to generate realistic vehicle-to-infrastructure signal-to-noise ratio (SNR) traces along with the corresponding error patterns. We model the SNR as a combination of correlated large scale fading and small scale fading. The model parameters are derived from real-world measurements at 5.9 GHz. The accuracy of our simple and yet effective modeling approach is confirmed by comparing the model generated SNR traces to the measured performance.

This paper introduces extensions of a previously proposed range-dependent modified Gilbert model for generation of realistic error patterns. With the proposed extensions our model can be used to generate signal-to-noise ratio trends corresponding to the error patterns for infrastructure-to-vehicle communications. The model parameters are estimated based on realistic highway measurements using off-the-shelf IEEE 802.11p devices. Finally, a scalar quantization-based framework for reduction of the model complexity is introduced and evaluated.

For the multinode cooperation system, the Gilbert model behaves the DF protocol at relay nodes. At destination node, the expectation analysis of the total SNR is conducted, including exact result for MRC and proper upper bounds for EGC. Meanwhile, the diversity benefit is compared to the traditional MISO system.

Recent computer models of landform evolution have focused on surface processes of river networks and hillslopes (e.g., Ahnert, 1976; Kirkby, 1986; Willgoose et al., 1991a, b; Koltermann and Gorelick, 1992; Howard, 1994; Howard et al., 1994; Smith et al., 1997). Most of these models are based on complicated differential equations that are difficult to solve. Chase (1992) developed a cellular automata model (named Gilbert) that uses simple local rules of diffusion, erosion, and deposition to simulate the synoptic effects of fluvial processes. The Gilbert model applies simple rules iteratively to individual cells of a digital topographic grid after storm events (termed precipitons) randomly fall onto the grid. The rules are in a sense analogous to the natural processes. For example, precipitons move to lower elevations, simulating water running downhill; the amount of erosion is proportional to the local slope and to the erodibility of the rock, simulating speedier erosion of steeper slope and less erosion of hard rocks (Chase, 1992). The advantage of this approach is that it is simple and yet can still produce realistic first-order geomorphologic features and provide insights into landform evolution processes. The Gilbert model demonstrates that complex landscapes do not require complicated laws (Chase, 1992). Thus the cellular automata approach is ideal for simulating long-term landscape evolution that involves multiple interacting processes. This short note presents a model (LANDSAP) that extends the Gilbert model to combine both surface and subsurface processes. LANDSAP is designed to simulate the long-term landscape evolution from these processes and to test the effects of climatic changes. It is not designed to simulate every detail of the processes, but to help us understand the interactions among different processes and the overall effects of such interactions by comparing different simulation scenarios with field observations. A previous version of LANDSAP has been successfully used to model the groundwater sapping processes in Western Desert, Egypt and has provided insights into the paleoclimatic conditions of that area (Luo et al., 1997). The purposes of this Short Note are to describe the programming details in general terms and to make the updated program publicly available. LANDSAP could also be used as a teaching tool to demonstrate system interactions among surface, subsurface, and climatic processes.

The unidirectional transmission technology is designed to protect the confidentiality of data on the high assurance network. It allows data to transmit only in one direction and prevents the use of acknowledgements or other connection-oriented mechanisms. This makes packet loss become a key issue in unidirectional transmission because of its influence on reliability and performance. In this paper, we build test platform of unidirectional transmission to research on packet loss issues， measure the loss data in unidirectional transmission, and analyze the correlation of the loss rate and the transmission rate, the data packet load. We use these empirical measurements to derive a Gilbert model for the characterization of Packet loss process in unidirectional transmission. The research results can help in reducing packet loss, improving the performance, and designing a good error correction coding scheme for unidirectional transmission.

In this paper we present a novel error model for packet loss and subsequent error description. The proposed model simulates the error performance of wireless communication link. The model is designed as two independent Markov chains, where the first one is used for packet generation and the second one generates correctly and incorrectly transmitted bits for received packets from the first chain. The statistical analyses of real communication on the wireless link are used for determination of model-s parameters. Using the obtained parameters and the implementation of the generator, we collected generated traffic. The obtained results generated by proposed model are compared with the real data collection., {"references":["MadWifi project. Available: http://madwifi-project.org/.","Pavlovi─ì, J., Polec, J., Poctavek, J.and Kotuliakov├í, K., \"Markov Chain\nError Generator for Wireless Channel\". In: Proceedings of SPIE. Vol.\n8008: Photonics Applications in Astronomy, Communications, Industry,\nand High-Emergy Physics Experiments 2011, Wilga, Poland, 23-29 May\n2011. Belingham: SPIE - The International Society for Optical\nEngineering, 2011.","Polec, J. and Popovcov├í, K., \"An generalization of the Markov's model\nof errors appearance at data transfer\", in Proceedings of FEI'25\nConference on Electronic Computers and Informatics, Ko┼íice, sept.\n1994, pp. 98-102.","Mal├¢, O. and ┼áir├íň, J., \"Markov model for error occur-rence in discrete\ndata transmission channels\" (in Slovak), Informa─ìnésystémy, ─ì.5,\nBratislava, 1984, pp. 333-345.","Kanal, L. and Sastry, A.R.K., \"Models for Channels with Memory and\ntheir Applications to Error Control\", in IEEE Proceedings, Vol.66, No.8,\n1978, pp. 724-744.","Kotuliakov├í, K. \"Hybrid ARQ methods in wireless com-munication\nchannels\", PhD thessis, Dept. of Telecom-munications, Faculty of\nElectrical Engineering and In-formation Technology, Slovak University\nof Technology, Bratislava, 2006.","Aguiar, A. and Gross, J., \"Wireless channel models\", Technical Report,\nTU Berlin, Telecommunication Net-works Group, April 2003.","Lemmon, J.J., \"Wireless link statistical bit error model\",NTIA Report\n02-394, U.S. Departmentof Commerce, Boulder, June 2002.","Ebert, J.P.and Willig, A., \"A Gilbert-Elliot bit error model and the\nefficient use in packet level simulation\", TKN Technical Reports Series,\nTU Berlin, March 1999.\n[10] Sestrienka,M., Oravec,M. and Pavlovi─ìov├í,J., Simulation of Physical\nLayer and Medium Access Control Sublayer in IEEE 802.11x Networks,\nProc. ELMAR-2010, 52nd International Symposium ELMAR-2010, 15-\n17 September 2010, Zadar, Croatia, ISSN 1334-2630, ISBN 978-953-\n7044-11-4, pp. 261-264."]}

Multiple Description Coding (MDC) is one of the most efficient error resilient video coding methods especially when retransmissions are not acceptable. For applications in scalable, multicast and P2P environments, it is advantageous to use more than two descriptions. In this paper, we present two macroblock-level adaptive error concealment methods to improve the performance of MDC with four descriptions. A Gilbert model is used as the channel model to simulate burst packet loss. Experimental results demonstrate the efficacy of the two proposed methods.

This thesis combines the study of asymptotic properties of percolation processes with various dynamical concepts. First-passage percolation is a model for the spatial propagation of a fluid on a discrete structure; the Shape Theorem describes its almost sure convergence towards an asymptotic shape, when considered on the square (or cubic) lattice. Asking how percolation structures are affected by simple dynamics or small perturbations presents a dynamical aspect. Such questions were previously studied for discrete processes; here, sensitivity to noise is studied in continuum percolation. Paper I studies first-passage percolation on certain 1-dimensional graphs. It is found that when identifying a suitable renewal sequence, its asymptotic behaviour is much better understood compared to higher dimensional cases. Several analogues of classical 1-dimensional limit theorems are derived. Paper II is dedicated to the Shape Theorem itself. It is shown that the convergence, apart from holding almost surely and in L^1, also holds completely. In addition, inspired by dynamical percolation and dynamical versions of classical limit theorems, the almost sure convergence is proved to be dynamically stable. Finally, a third generalization of the Shape Theorem shows that the above conclusions also hold for first-passage percolation on certain cone-like subgraphs of the lattice. Paper III proves that percolation crossings in the Poisson Boolean model, also known as the Gilbert disc model, are noise sensitive. The approach taken generalizes a method introduced by Benjamini, Kalai and Schramm. A key ingredient in the argument is an extremal result on arbitrary hypergraphs, which is used to show that almost no information about the critical process is obtained when conditioning on a denser Poisson process.

In this work the problems of flexible access are considered. Two algorithms for construction of logical channels for secondary subscribers are described. Efficiency of algorithms is compared by final probability of slot inaccessibility in the logical channel.

We prove that, in the Gilbert model for a random geometric graph, almost every graph becomes Hamiltonian exactly when it first becomes 2-connected. This answers a question of Penrose. We also show that in the k-nearest neighbor model, there is a constant \kappa\ such that almost every \kappa-connected graph has a Hamilton cycle., Comment: Published in at http://dx.doi.org/10.1214/10-AAP718 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org)

One of the most difficult problems in video transmission is communication over error-prone channels, especially when retransmission is unacceptable. To address this problem, Multiple Description Coding (MDC) has been proposed as an effective solution due to its robust error resilience. Considering applications in scalable, multicast and P2P environments, it is advantageous to use more than two descriptions (which is designated multi-description MDC in this paper). In this paper, we present a new four-description MDC for high lossrate channel using a hybrid structure of temporal and spatial correlations. A Gilbert model is used as the channel model for burst packet loss simulation. Experimental results demonstrate the efficacy of the proposed method.

Fachbereich Physik and Forschungszentrum OPTIMAS,Technische Universita¨t Kaiserslautern, 67663 Kaiserslautern, Germany(Dated: July 13, 2010)We report on the fast relaxation behavior of a high-density magnon gas, created by a parametric amplificationprocess. The magnon gas is probed using the technique of spin-wave packet recovery by parallel parametricpumping. Experimental results show a damping behavior deviating both from the classical Gilbert model andobservations of non-linear damping described so far. In particular, the inherent magnon damping is found todepend upon the presence of the parametric pumping field. The data is supported by a phenomenological model,taking into account the influence of the parametric pumping o n non-linear damping, as well as the dephasing ofthe previously injected magnons.

The bit error and packet loss in unreliable channels such as Internet and wireless networks lead the quality of video data unacceptable, which force us to take the network adaptive transmission into account. In this paper, we firstly propose a novel Greedy Spread (GS) ROI extraction method to extract ROI effectively, and then the network state changing is quickly perceived without occupying additional network overhead. According to the feedback about current network state from the receiver, Gilbert model is used to predict network packet loss, which enables the source encoder to dynamically adjust the ROI protecting schemes. Experimental results shows that the GS method extracts the ROI at high accuracy, also the adaptive method is of low computational complexity and high protection capability, suitable for real-time applications, so make a notable improvement in visual quality.

This work describes a cognitively realistic approach to social simulation. It begins with a model created by Gilbert [4] for capturing the growth of academic science. Gilbert's model, which was equation-based, is replaced here by an agent-based (neural network) model, with the (neural network based) cognitive architecture CLARION providing greater cognitive realism. Using this agent model, results comparable to previous simulations and to human data are obtained. It is found that while different cognitive settings may affect the aggregate number of scientific articles produced by the model, they do not generally lead to different distributions of number of articles per author. It is argued that using more cognitively realistic models in simulations may lead to novel insights.

In distributed speech recognition, speech features are transmitted inside packets from a channel to speech recognition server. Some problems such as channel noise, packet loss and delay decrease distributed speech recognition rate. Several methods including packet-loss recovery approaches have been proposed to overcome to this decrease in recognition rate. Most of packet-loss recovery methods, don't notice to type of information existing in packets. In this paper, we propose two methods for packet-loss recovery based on type of existed information (speech features) in packets. In addition, we combine these two methods with conventional packet-loss recovery methods such as repetition, interleave and interpolation. We evaluate the combinational methods in two cases: random packet loss and packet loss based on Gilbert model. Recognition results on isolated words of TIDIGITS show that proposed combinational methods outperform the conventional methods.

The emergence of fourth generation wireless networks poses great challenges in video transport. Two of these prominent challenges are: a) providing and maintaining visually acceptable video quality given variations in channel conditions and b) the accurate measurement of this quality in network simulators using standard verbose trace flies. To address these challenges, in this paper, we propose and analyze an end-to-end (E2E) model for mean packet loss probability of H.264/AVC-based data partitioning (DP) substreams. The model we're presenting is based on the extended Gilbert model. We then incorporate the parametric formulation in our proposed base layer trace format that records E2E distortion coefficients for DP streams on a per slice level.

WSNs (Wireless Sensor Network) can employ a burst technique known as 802.11e TXOP (Transmission Opportunity) operation to send sensor data backlogged during the sleep period [1] and FEC (Forward Error Correction) techniques to resist against their high BER (Bit Error Rate) [2]. This paper extends the 802.11e evaluation model [3], [4] to accurately calculate the performance of two TXOP schemes such as BI (Basic Immediate ACK) and BB (Basic Block ACK) with FEC codes. The generalized model accounts for the effect of propagation errors negligible in wireless LANs, the impact of HOB (Head-Of-Block) collision, and the effect of adopting FEC codes. This paper evaluates this extended model over real WSN channels abstracted by Gilbert model. The numerical calculations over real WSN traces confirm that the inclusion of HOB collisions causes the throughput difference of BB by up-to 194% comparing to [3]. They also predicts a trade-off between the performance improvement and the overhead of FEC codes over WSN channels.

In the best-effort IP network, packet delay/loss will inevitably degrade the perceptual quality of real-time multimedia service, such as Voice-over-IP (VoIP), Video-on- Demand (VoD), etc. Modeling, prototyping, and analysis of traffic traces have always been very important and challenging topics in the area of multimedia communication. In general, packet loss/delay exhibits temporal dependence. Different prototyping tools, such as Bernoulli model, Gilbert model, Extended Gilbert model, Markov model, etc, have been proposed to model network trace. In this research, one VoD server and three clients have been setup to simulate a real VoD system. Different models have been applied to analyze and model the video transmission network traces obtained under RTP/UDP/IP protocol stack. Compared to the other tools, Markov model offers the best prototyping precision, in the sense of loss-run distribution and Forward Error Correction (FEC) performance prediction. As a powerful fast prototyping tool, Markov model will be very useful to model and analyze network traces and further improve the QoS in multimedia-over-IP.

Network impairments such as delay and packet losses have severe impact on the presentation quality of many predictive video sources. Interleaved Source Coding (ISC) [5][6][7] is one of the error resilient coding methods for predictive video coded frames transmitted over a single erasure channel. ISC has shown to significantly improve the overall quality of predictive coded video stream over a lossy channel [5][6][7]. In this paper, ISC is evaluated over channels with memory. In particular, we analyze the impact of packet correlation [11][13] of the popular Gilbert model on ISC-based packet video over a wide range of packet loss probabilities. Simulations have shown that ISC advances the traditional method as either the loss rate increases or the packet correlation decreases.

Consider two situations where events occur randomly in a system with a common average rate, but with different distributions for the size of bursts of events. Assume that the performance measure of interest is the probability that less than h events occur in a given time period. Is it possible to decide which of the two situations is the best? It turns out that when the average rate varies whereas the burst distributions are fixed, the winning situation may change: there is a tradeoff between burstiness and frequency. The purpose of this paper is to investigate this tradeoff. We use two simple models for this: the discrete-time two-state Markov chain (known as the Gilbert model) and a compound Poisson process, viewed as an approximation of the Gilbert model. For each of them, we show that indeed there exists a threshold value for the event rate at which the best configuration changes. We analytically derive the asymptotic value of this threshold when the number h grows. We apply this analysis to the performance evaluation of Forward Error Correction applied to flow of packets in networks with different Queue Management schemes, namely: RED and Drop Tail. The measure of interest is the probability of losing less than h packets in a certain block. Through simulation measurements, we exhibit the same tradeoff phenomenon, and we collect statistics showing that the Gilbert model is partly adequate to represent the situation.

In this paper the analysis of packet loss for Gilbert-model with loss rate feedback is performed. Based on the historical loss rate feedbacks, an iterative algorithm can be derived to compute the conditional version of P(m, n), and which is the probability of m lost packets within a block of n packets. Experimental simulations validate the analytical results, and they are helpful for any joint source-channel coding system for which FEC protection with loss rate feedback is suitable.

The features of operative estimation of discrete channel parameters are considered in this paper, on the basis of the known data sequence transmitted. The channel is supposed to be described by the Gilbert model. The influence of inaccuracy of primary channel parameters on the inaccuracy of secondary channel parameters is examined. The estimations of training time of adaptative system are presented.

The technique of calculation of the modified parameters of discrete channel received by application of frequency hopping operation for two discrete channels, described by Gilbert model is offered. Results of this work are the expressions, allowing to calculate the modified parameters of the discrete channel received by using of frequency hopping of two discrete channels, described by Gilbert model with various parameters.

This appendix discusses channel error/packet loss model. Digital channels and packet networks can be modelled as a discrete two-state Elliot Gilbert model.

The Gilbert channel is a model for representing a multipath fading channel for multicarrier transmission using various parameters, such as the steady state probabilities, power ratio between each state and so on. However, a method to set parameters has not been studied. The validity of this channel model has also not been confirmed. Moreover, this channel modeling considering the effect of the non-linear amplifier has not been investigated. In this paper, we propose a more detailed Gilbert channel, including the effect of the non-linear amplifier, and a method to set parameters of the Gilbert channel. We also compare the error performance between the Gilbert channel and multipath fading channel on a convolutional coded multicarrier modulation (MCM) system. Numerical results show that our proposed channel model can approximately express the multipath fading channel.