We analyze 20 large sets of actual variable-bit-rate (VBR) video data, generated by a variety of different codecs and representing a wide range of different scenes. Performing extensive statistical and graphical tests, our main conclusion is that long-range dependence is an inherent feature of VBR video traffic, i.e., a feature that is independent of scene (e.g., video phone, video conference, motion picture video) and codec. In particular, we show that the long-range dependence property allows us to clearly distinguish between our measured data and traffic generated by VBR source models currently used in the literature. These findings give rise to novel and challenging problems in traffic engineering for high-speed networks and open up new areas of research in queueing and performance analysis involving long-range dependent traffic models. A small number of analytic queueing results already exist, and we discuss their implications for network design and network control strategies in the presence of long-range dependent traffic. >

Long-range dependence in variable-bit-rate video traffic

One of the challenging research issues in building high-speed packet-switched networks is how to control the transmission rate of statistical data flows. This paper describes a new traffic control algorithm, VirtualClock, for high-speed network applications. VirtualClock monitors the average transmission rate of statistical data flows and provides every flow with guaranteed throughput and low queueing delay. It provides firewall protection among individual flows, as in a TDM system, while retaining the statistical multiplexing advantages of packet switching. Simulation results show that the VirtualClock algorithm meets all its design goals.

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VirtualClock: a new traffic control algorithm for packet-switched networks

A first course in stochastic processes

As new communications services evolve, professionals must create better models to predict system performance. The article provides an overview of computer simulation modelling for communication networks, as well as some important related modelling issues. It gives an overview of discrete event simulation and singles out two important modelling issues that are germane to extant and emerging networks: traffic modelling and rare event simulation. Monte Carlo computer simulation is used as a performance prediction tool and Markov models are considered. >

Traffic modeling for telecommunications networks

Current research on Internet of Things (IoT) security: A survey

The authors extend earlier work (ibid., vol.36, p.834-44, Jul. 1988) in modeling video sources using interframe coding schemes and in carrying out buffer queueing analysis for the multiplexing of several such sources. The previous models and analysis were suitable for relatively uniform activity scenes. Here, models are considered for scenes with multiple activity levels which lead to sudden changes in the coder output bit rates. Such models apply to talker-listener alternating scenes, as well as to situations where there is a mix of dissimilar services, e.g., television and videotelephony. Correlated Markov models for the corresponding sources are given. A flow-equivalent queueing analysis is used to obtain common buffer queue distributions and probabilities of packet loss. The results demonstrate the efficiency of packet video on a single link, due to the smoothing effect of multiplexing several variable-bit-rate video sources. >

Models for packet switching of variable-bit-rate video sources

A sparse wireless sensor network for forest fire detection is considered. It is assumed that two types of malicious nodes can exist in this network. The malicious behaviors are assumed to be concea...

https://journals.sagepub.com/doi/pdf/10.1177/1550147716657246

Lightweight trust model for the detection of concealed malicious nodes in sparse wireless ad hoc networks

IEEE 802.15.6 standard has emerged as the most suitable standard that fits the special requirements of WBANs. Although the published IEEE 802.15.6 standard draft provides flexibility to designers by recommending the use of several MAC layer techniques, it does not specify how to combine some or all of these recommended techniques to form the most efficient WBAN MAC for a specific scenario. Our main objective here is to combine various MAC techniques in an adaptive way that takes into consideration the types of sensors, their number, and their traffic and energy requirements. The performance of the proposed techniques will be evaluated using some of the standard performance measures such as throughput, delay and energy consumption.

Performance evaluation of IEEE 802.15.6 MAC in WBANs - A case study

In this paper, a network of smart meters that are part of the next generation electrical power system is considered, and are assumed to send their readings wirelessly. Cyber-attacks against such network will be addressed. An independent, distributed, and lightweight trust evaluation model is proposed and evaluated. The trust model is implemented at two levels: first at the smart meter level, where nodes collect information on its neighbor nodes and forward it to the collecting node; and second at the collecting node level, where malicious nodes are detected and isolated by requesting from the nodes to stop communicating with them. Simulation results present how fast the network use the collected data from the nodes to detect all malicious nodes.

Design of a trust security model for smart meters in an urban power grid network

In this paper, a VPN network simulation model will be built using the MPLS protocol and based on an existing network. Various queueing policies will be implemented to evaluate the provision of the end-to-end QoS requirements for various traffic types. Input traffic based on real data was used. After a thorough analysis of the policies, the merits and shortcomings of each policy are determined and recommendations are given along with future research directions.

Nasser-Eddine Rikli

Papers

Models for packet switching of variable-bit-rate video sources

Lightweight trust model for the detection of concealed malicious nodes in sparse wireless ad hoc networks

Performance evaluation of IEEE 802.15.6 MAC in WBANs - A case study

Design of a trust security model for smart meters in an urban power grid network

ORIGINAL ARTICLE: Efficient priority schemes for the provision of end-to-end quality of service for multimedia traffic over MPLS VPN networks