Ilir Shinko

A Study on a Distributed Rerouting Scheme

This study is concerned with rerouting strategies in telecommunication networks. In particular, we discuss a rerouting strategy named ShRR (Shared Robust Rerouting), previously presented in [1] and propose a new variant, together with distributed versions of each of them. Numerical results are also provided to illustrate the cost-efficiency of the proposed rerouting strategies.

Elastic Routing: A Distributed Variant, Implementation Issues, and Numerical Results

This study is concerned with a specific rerouting strategy in telecommunication networks named Elastic Robust Rerouting (ERR), introduced first in [8]. We recall main points on this strategy, provide mathematical formulation and discuss in details a solution method. The second question studied in this paper is concerned with its distributed version and some related implementation issues. We report a numerical study on effectiveness of both versions in terms of dimensioning cost, restoration time and management effort.

Performance Analysis of WMNs by WMN-GA Simulation System for Exponential Distribution Considering EDCA and DCF

In this paper, we evaluate the performance of WMN using our WMN-GA simulation system considering throughput, delay, jitter and fairness index metrics. For simulations, we used ns-3 and Optimized Link State Routing (OLSR). We compare the performance of Distributed Coordination Function (DCF) and Enhanced Distributed Channel Access (EDCA) for exponential distribution of mesh clients by sending multiple Constant Bit Rate (CBR) flows in the network. The simulation results show that for Hybrid WMN, the throughput of both MAC protocols is higher than I/B WMN. The delay and jitter of Hybrid WMN are lower than I/B WMN. The fairness index of I/B WMN is a little bit higher than Hybrid WMN.

Performance Analysis of a Genetic Algorithm Based System for Wireless Mesh Networks Considering Weibull Distribution, DCF and EDCA

Wireless Mesh Networks (WMNs) are attracting a lot of attention from wireless network researchers. Node placement problems have been investigated for a long time in the optimization field due to numerous applications in location science. In this paper, we evaluate the performance of two WMN architectures considering throughput, delay, jitter and fairness index metrics. For simulations, we used ns-3 and Optimized Link State Routing (OLSR). We compare the performance of Distributed Coordination Function (DCF) and Enhanced Distributed Channel Access (EDCA) for Weibull distribution of mesh clients by sending multiple Constant Bit Rate (CBR) flows in the network. The simulation results show that for I/B WMN, the throughput of both MAC protocols is higher than Hybrid WMN. The delay and jitter of both architectures are almost the same. However, for 10 flows, the delay and jitter of I/B WMN is a lower compared with Hybrid WMN. The fairness index is a almost the same for both WMN architectures.

A Simulation System Based on ONE and SUMO Simulators: Performance Evaluation of First Contact, Prophet and Spray-and-Wait DTN Protocols

In this paper, we investigate the performance of First Contact, Prophet and Spray-and-Wait protocols in a Vehicular Delay Tolerant Network (VDTN) crossroad scenario. The mobility patterns of vehicles are generated by means of SUMO (Simulation of Urban MObility) and as communication protocol simulator is used ONE (Opportunistic Network Environment). For the simulations, we used IEEE 802.11p standard and TwoRayGround Propagation Loss Model. We use Packet Delivery Ratio (PDR), Relay Delivery Ratio (RDR), hop count and delay as evaluation metrics. We compared the performance of three protocols and the simulation results show that for PDR the Prophet protocol has better performance than other protocols. Considering RDR, the performance of First Contact and Spray-and-Wait protocols is better than Prophet protocol. For hop count, the performance of Spray-and-Wait protocol is better than other protocols. While for delay, the performance of Prophet protocol is better than other protocols.

A hybrid rerouting scheme

In this work we study a routing scheme combined with an end-to-end rerouting procedure. We focus in particular on a new rerouting strategy called Shared Robust Rerouting (ShRR). This strategy combines three other restoration techniques, namely path diversity, end-to-end rerouting with stub release and global rerouting, in order to achieve cost-effectiveness. Computational results on the bandwidth overhead required by the proposed scheme are provided, as well as a comparison with some conventional restoration schemes.

Performance analysis of a genetic algorithm based system for wireless mesh networks considering exponential and weibull distributions, DCF and EDCA, and different number of flows

In this paper, we evaluate the performance of two WMN architectures (infrastructure/backbone WMNs (I/B WMNs) and Hybrid WMN architectures) considering throughput, delay, jitter and fairness index metrics. For simulations, we used ns-3 and optimized link state routing. We compare the performance of distributed coordination function and enhanced distributed channel access (EDCA) for exponential and Weibull distributions of mesh clients by sending multiple constant bit rate flows in the network. The simulation results show that for exponential distribution, in case of Hybrid WMN, the throughput of both MAC protocols is higher than I/B WMN. For 30 flows, the throughput of EDCA in case of hybrid WMN is about 1.4 times higher than I/B WMN. For Weibull distribution, in case of I/B WMN, the throughput of both MAC protocols is higher than Hybrid WMN. For 30 flows, the throughput of EDCA in case of I/B WMN is about 2.6 times higher than Hybrid WMN. For exponential distribution, the delay and jitter of Hybrid WMN are lower than I/B WMN. For 20 flows, the delay of EDCA in case of hybrid WMN is about 10 times lower than I/B WMN. For Weibull distribution, the delay and jitter of both architectures are almost the same. However, for 10 flows, the delay of I/B WMN is lower compared with hybrid WMN. For exponential distribution, the fairness index of I/B WMN is a little bit higher than hybrid WMN. For Weibull distribution, the fairness index is almost the same for both WMN architectures.

Data Interpretation Using Mobile Uncalibrated Sensor for Urban Environmental Monitoring

Intelligent Transportations Systems (ITS) are complex information and communication technologies platforms aimed for a better and cost effectiveness public transport organization. Our aim is to extend the basic of ITS platform for real time environmental data monitoring and processing. Mobile environmental sensing is becoming one of the best options to monitor our environment due to its high flexibility. In this context, the proposed system utilizes public transportation vehicle intelligence and sensing to monitor a set of environmental parameters over a large area by “filling in the gaps” where people go but environmental monitoring sensor infrastructure has not yet been installed. In this article, we show as well how to extract useful data from low cost and uncalibrated environmental sensor nodes. The presented architecture is focused on low cost and highly scalable architecture in term of type and number of sensors that can be installed and processed. This work presents some data from a testing deployed infrastructure in Albania and the measured data indicate the usefulness of the proposed architecture.

Performance analysis of different architectures and TCP congestion-avoidance algorithms using WMN-GA simulation system

In this paper, we evaluate the performance of two Wireless Mesh Networks (WMNs) architectures considering throughput, delay, jitter and fairness index metrics. For simulations, we used ns-3, Distributed Coordination Function (DCF) and Optimized Link State Routing (OLSR). We compare the performance of WMN for different Transmission Control Protocol (TCP): Tahoe, Reno and NewReno considering normal and uniform distributions of mesh clients by sending multiple Constant Bit Rate (CBR) flows in the network. The simulation results show that for normal and uniform distributions and both WMN architectures, the PDR values are almost the same. For Hybrid WMN, the throughput of TCP NewReno is good, but for I/B WMN, the throughput of TCP Tahoe is higher than other algorithms. For normal distribution, the delay and jitter of I/B WMN are lower compared with Hybrid WMN, while for uniform distribution, the delay and jitter of TCP NewReno are a little bit lower compared with other algorithms. The fairness index of normal distribution is higher than uniform distribution.

Performance Analysis of WMNs by WMN-GA Simulation System for Different WMN Architectures and TCP Congestion-Avoidance Algorithms Considering Uniform Distribution

In this paper, we evaluate the performance of two Wireless Mesh Networks (WMNs) architectures considering throughput, delay, jitter and fairness index metrics. For simulations, we used ns-3, Distributed Coordination Function (DCF) and Optimized Link State Routing (OLSR). We compare the performance for Transmission Control Protocol (TCP) Tahoe, Reno and NewReno for uniform distribution of mesh clients by sending multiple Constant Bit Rate (CBR) flows in the network. The simulation results show that for both WMN architectures, the PDR values of TCP congestion-avoidance algorithms are almost the same. For Hybrid WMN architecture, the throughput of TCP Reno is better than other algorithms. However, for I/B WMN, the throughput of TCP Tahoe is higher than other algorithms. The delay and jitter of TCP NewReno are a little bit lower compared with other algorithms. The I/B WMN architecture, the fairness index of TCP congestion-avoidance algorithms is almost the same.