Konstantin E. Samouylov

Queuing Model for Loss-Based Overload Control in a SIP Server Using a Hysteretic Technique

In this paper, we develop a mathematical model of a load control mechanism for SIP server signaling networks based on a hysteretic technique developed for SS7 from ITU-T Recommendation Q.704. We investigate loss-based overload control, as proposed in recent IETF documents. The queuing model takes into account three types of system state – normal load, overload, and discard. The hysteretic control is made possible by introducing two thresholds in the buffer of total size B – the overload onset threshold H and the overload abatement threshold L. We denote the mathematical model using the modified Kendall notation as an \(M|G|1|\left\langle L,H\right\rangle |B\) queue with hysteretic load control. We also develop an analytical model for the case of an M|M|1 queue and a simulation model for an M|D|1 queue. We investigate the return time from an overload state as the target performance measure of overload control in a SIP server, and provide numerical examples in order to examine the difference between the M|M|1 and M|D|1 systems.

A new stage in mathematical teletraffic theory

History of the development of theory of queues and mathematical teletraffic theory achieved at the MSU and PFUR are outlined. Basic theorems and algorithms for calculation of probability measures for multiservice loss networks with unicast connections, multicast connections, as well as with both types of connections are presented. A Triple Play network analysis is determined to be the key task for the future.

Modelling and Analysing a Dynamic Resource Allocation Scheme for M2M Traffic in LTE Networks

One of the main problems in LTE networks is the distribution of a limited number of radio resources among Human-to-Human (H2H) users as well as the increasing number of machine-type-communication (MTC) devices in machine-to-machine (M2M) communications. Different traffic types from user’s equipment and MTC devices transmitted over the network suggests a dynamic resource allocation in order to provide a better quality of service (QoS). In this paper, we propose a dynamic resource allocation scheme for M2M traffic in LTE networks. The suggested method is based on fixed bandwidth intervals at which traffic from MTC devices is serviced according to the Processor Sharing (PS) discipline. By means of a Markov model, an estimation of the behaviour of LTE for H2H and M2M traffics characteristics is shown. We propose an analytical solution to calculate the model performance measures, such as blocking probabilities for H2H users.

Analyzing Impacts of Coexistence between M2M and H2H Communication on 3GPP LTE System

In this paper, we consider 3GPP LTE cellular system where machine-to-machine (M2M) devices and human-to-human (H2H) users transmit their data into the network. By contrast to previous studies which primarily focused on M2M overload protection and respective control mechanisms, this work concentrates on system operation when M2M and H2H data flows coexist in the network. In particular, we propose an integrated simulation-analytical framework to evaluate relevant performance characteristics (data transmission delays, blocking probabilities, etc.) with both Markov process based analysis and system-level simulations. Our results indicate that the proposed methodology demonstrates acceptable levels of convergence between analytical and simulations components, as well as becomes useful to characterize impacts of M2M/H2H coexistence on radio resource allocation in 3GPP LTE across a number of important M2M-centric scenarios.

Modeling of Hysteretic Signaling Load Control in Next Generation Networks

In this paper we investigate traffic load control mechanisms for controlling congestion in signaling networks based on three types of thresholds. The goal of the paper is to analyze congestion controlling mechanisms and develop corresponding queuing models of SIP servers. The study is based on hysteretic congestion control, which has been developed for Signaling System 7 (SS7). Models for describing the hysteretic control are developed. The current state and problems of basic overload control mechanism proposed by Internet Engineering Task Force (IETF) for SIP signaling networks are investigated. Approaches to building mathematical models of SIP servers in the form of a queuing system with hysteretic control are proposed.

Mathematical theory of teletraffic and its application to the analysis of multiservice communication of next generation networks

This paper presents a survey of the authors results to discuss the model of a multiservice network with “triple play” (unicast, multicast, and elastic) traffic. The main results are given for the model with multicast traffic. Two service disciplines for multicast traffic are considered in the form of systems with transparent requests. An algorithm for the calculation of the blocking probabilities for models involving both unicast and multicast traffic is proposed. In conclusion, the lines of further research are outlined: the analysis of models of the session initiation protocol (SIP), including design problems to control overloads in SIP server networks, the planning of cross-layer interfaces for orthogonal frequency division multiplexing in mobile networks long term evolution (LTE), and the design of methods for the analysis of the quality factors of the file exchange and streaming in peer-to-peer (P2P) networks.

Vehicle-Based Relay Assistance for Opportunistic Crowdsensing over Narrowband IoT (NB-IoT)

The Internet of Things (IoT) undergoes a fundamental transformation by augmenting its conventional sensor network deployments with more advanced and mobile devices, such as connected and self-driving cars. This fusion of embedded and automotive domains promises to deliver unprecedented mutual benefits, where vehicles will receive timely updates from their proximate sensors while assisting them in delivering their sensory data to the remote network infrastructure. In this paper, we put forward the vision of opportunistic crowdsensing applications, in which the ubiquitous deployments of low-cost and battery-constrained IoT sensors take advantage of more capable and energy-abundant vehicle-mounted mobile relays. In particular, we consider the use of the emerging narrowband IoT radio technology recently ratified by 3GPP and offering efficient means for underlying wireless connectivity. Our rigorous mathematical analysis supported with comprehensive system-level evaluations reveals the effects of vehicle-based relays on the important metrics of interest, such as connection reliability, transmission latency, and communication energy efficiency. These systematic findings advocate for an extensive utilization of vehicular relays as part of the next-generation IoT ecosystem.

Analysis of an M|G|1|R queue with batch arrivals and two hysteretic overload control policies

Abstract Hysteretic control of arrivals is one of the most easy-to-implement and effective solutions of overload problems occurring in SIP-servers. A mathematical model of an SIP server based on the queueing system M[X]|G|1(L,H)|(H,R) with batch arrivals and two hysteretic loops is being analyzed. This paper proposes two analytical methods for studying performance characteristics related to the number of customers in the system. Two control policies defined by instants when it is decided to change the system’s mode are considered. The expression for an important performance characteristic of each policy (the mean time between changes in the system mode) is presented. Numerical examples that allow comparison of the efficiency of both policies are given

Blocking probabilities in multiservice networks with unicast and multicast connections

This paper is concerned with blocking probabili- ties in loss networks where both multicast and unicast con- nections are present. Each connection specifies a route and a bandwidth requirement. Multicast connections are point-to- multipont and allow transmission from one source to several receivers, any of which can join the connection at any time. Users that subscribe to the same data stream share one mul- ticast connection so that no additional bandwidth is re- quired. We present a Markov process model of a single net- work link. We also develop a convolution algorithm that finds the blocking probabilities on a single link and a re- duced load approximation for estimating end-to-end block- ing probabilities in a network.

Modelling a Radio Admission Control Scheme for Video Telephony Service in Wireless Networks

Modern 4G wireless networks are multi-service networks, and an important issue is the development of an optimal radio admission control scheme (RAC) specific to various service types. The 3GPP recommendations for LTE and LTE-Advanced networks specify nine service classes that differ in terms of the priority level, bit-rate, and packet error loss. In this paper, we propose an RAC scheme for video telephony service that is provided in two modes: voice and video. Voice telephony users have a higher priority level than video telephony users; this is realised by the possibility of accepting voice calls owing to the degradation in video call quality. We analyse a model of a single cell with video telephony service, and we prove that the system state space is of an explicit form. This enables us to compute the performance measures, such as blocking probabilities, mean number of calls, and utilization factor.