Performance and Analysis of Transfer Control Protocol Over Voice Over Wireless Local Area Network

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree Master of Science by Rajendra Patil in August of 2008

Voice over Internet Protocol over Wireless Local Area Network: A Review

The use of Voice over Wireless Local Area Network is seeing a meteoric rise in popularity as a result of its simplicity, non-intrusiveness, and cheap cost of implementation, as well as its low cost of maintenance, universal coverage, and fundamental roaming capabilities. Nevertheless, deploying Voice over Internet Protocol (VoIP) over Wireless Local Area Network (WLAN) is a challenging task for many network managers, architects, planners, designers, and engineers. Because of this, there is a need for a guideline to design, model, and simulate the network before it is deployed. In this work, a variety of models, including mathematical, theoretical, statistical, and graphical models, that are used to measure the quality and features of VoIP are discussed

Performance Evaluation of The Quality of VoIP Over WLAN Codecs

The adoption of Voice over Wireless Local Area Network is on tremendous increase due its ease, non-intrusive, inexpensive deployment, low maintenance cost, universal coverage and basic roaming capabilities. However, deploying Voice over Internet Protocol (VoIP) over Wireless Local Area Network (WLAN) is a challenging task for many network managers, architects, planners, designers and engineers. Voice codec is one of the most critical components of a VoIP system. This work evaluates the effects of various codecs such as G.711, G.723.1, G.729A, G.728, G.726, Adaptive MultiRate (AMR) and Global System for Mobile communication (GSM) codecs on a VoIP over WLAN. Result from simulated network shows that the GSM codec offers the best quality of service for VoIP over WLA

Modelling And Simulation of Voice Over Internet Protocol (Voip) Over Wireless Local Area Network (WLAN)

The adoption of Voice over Wireless Local Area Network is on tremendous increase due to its ease, non-intrusive and inexpensive deployment, low maintenance cost, universal coverage and basic roaming capabilities. However, deploying Voice over Internet Protocol (VoIP) over Wireless Local Area Network (WLAN) is a challenging task for many network managers, architects, planners, designers and engineers, hence the need for a guideline to design, model and simulate the network before deployment. This work analyzed parameters such as latency, jitter, packet loss, codec, bandwidth, throughput, voice data length and de-jitter buffer size, which quantify the quality of degradation over the network. The analytical mathematical E-model was used to predict the readiness of the existing network to support VoIP. The Transmission Rating Factor R was calculated as 85.08 indicating a high speech quality and excellent user satisfaction. Riverbed Modeller Academic Edition was used to model and simulate the network. Results from this project work show that VoIP can be successfully deployed on WLAN with perceived high speech quality, user’s satisfaction, low delay and high throughput

Modeling and Simulation of Quality of Service in VoIP Wireless LAN

This work presents computer modeling and simulation of the IEEE 802.11 standard to improve its QoS when different wireless stations are allowed for roaming. Request-to-Send and Clear-to-Send (RTS/CTS) frames are added as means to overcome the hidden node problem that could occur in wireless local area networks. The obtained results by simulation are presented and discussed including the ones for Quality of Services differentiation

Quality of Service in wireless local area networks

Kriittisen liikenteen määrä myös langattoman verkon yli on kasvamassa. Tässä työssä tutkittiin IEEE 802.11 -standardin mukaisia langattomia lähiverkkotekniikoita (WLAN, Wireless Local Area Network) sekä langattomien lähiverkkojen palvelunlaatua. Lisäksi perehdyttiin palvelunlaadun toteutumiseen keskeisesti liittyviin käsitteisiin palvelutasonhallinta (SLM, Service Level Management) sekä palvelutasosopimukset (SLA, Service Level Agreement). Langattomien lähiverkkojen palvelunlaatua tutkittiin keskittymällä erityisesti kriittisen liikenteen kuljetukseen. Kirjallisuustutkimusta ja sen tuloksia käytettiin hyödyksi asiakasprojektina toteutetuissa mittauksissa. Mittaukset toteutettiin Noval Networksin toimintatapaa ja mittausjärjestelmää apuna käyttäen Salon kaupungin verkkoon tehdyillä laatumittauksilla. Mittausten avulla selvitettiin pääterveyskeskuksen langattoman verkon laatua ja samalla todennettiin, miten kriittinen liikenne kulkee langattoman lähiverkon yli. Tulosten perusteella arvioitiin yleisellä tasolla vaatimuksia langattomalle lähiverkolle kriittisen liikenteen kuljetuksen osalta. Verkon viiveet sekä pakettihävikit osoittautuivat erittäin mataliksi ja langattoman verkon todettiin soveltuvan hyvin myös kriittiselle liikenteelle.The amount of critical traffic over wireless networks is growing rapidly. This thesis focuses on IEEE 802.11 standard and its Wireless Local Area Network (WLAN) technologies. Besides the technology, Quality of Service (QoS) and important factors behind that were examined. In addition Service Level Management (SLM) and Service Level Agreements (SLA), key concepts related to achieving QoS targets, were studied. This thesis examines the QoS in WLANs focusing especially in critical traffic. The results of literature study were used for measurement in a customer project. Practical measurements were conducted using Noval Networks' approach and measurement system. The measurements itself were carried out in the city of Salo, one of Noval Networks' customer. The target for the project was to find out the quality of Salo's health center's wireless network and also to find out if the critical traffic will transfer over WLANs without problems. The results were used to evaluate the needs for WLANs while using quality-critical traffic. The delays and packet losses of Salo's WLAN network seemed to be very low and network suits fine also for critical traffic

Progettazione e realizzazione di una rete wireless per telefonia VoWLAN: Site Survey

Nelle recenti reti di telecomunicazioni, la rete wireless è stata molto importante nello sviluppo della telefonia IP detta Voice over IP o Voice over Wireless LAN. L'obiettivo principale dello stage di una durata di 3 mesi svolto presso la RETECO, leader nel Triveneto delle soluzioni di videosorveglianza urbana, è stato di progettare e realizzare una rete wireless per la telefonia IP dell'Ospedale Civile Maggiore (Verona). La soluzione trovata è stata la Cisco Unified Wireless Solution, idonea per un traffico voce attraverso la rete senza fili e interoperabile con i dispositivi WI-FI odierni. Per la realizzazione fisica della rete abbiamo fatto un Site Survey « studio del luogo » per trovare il posizionamento migliore dei punti di accesso (AP, Access Point) di modo ad avere una copertura totale del sito e un livello di segnale idoneo alla comunicazione voc

AN ANALYSIS OF THE MOBILE WIRELESS SERVICES INDUSTRY IN CANADA

This essay examines the mobile wireless services industry Canada. The industry is on the precipice of what could be a major change in the dynamics of competition. Industry Canada recently facilitated the market entry of new service providers in order to increase competition for the benefit of consumers. This has the potential to affect the success and future growth prospects of the industry?s leading three companies Rogers Communications Inc., Bell Canada Enterprises and Telus Corporation. The paper provides an overview of the industry?s structure, sources of growth, and key challenges. Performance of the leading companies is compared over the past five years. Conclusions are drawn about which company may be best positioned to gain increased market penetration and higher average revenues per user. The paper also highlights sources of advantage that incumbent firms can leverage to maintain their market share in the face of increasing competition and technological change

Modelling the IEEE 802.11 wireless MAC layer under heterogeneous VoIP traffic to evaluate and dimension QoE

PhDAs computers become more popular in the home and workplace, sharing resources and Internet access locally is a necessity. The simplest method of choice is by deploying a Wireless Local Area Network; they are inexpensive, easy to configure and require minimal infrastructure. The wireless local area network of choice is the IEEE 802.11 standard; IEEE 802.11, however, is now being implemented on larger scales outside of the original scope of usage. The realistic usage spans from small scale home solutions to commercial ‘hot spots,’ providing access within medium size areas such as cafés, and more recently blanket coverage in metropolitan. Due to increasing Internet availability and faster network access, in both wireless and wired, the concept of using such networks for real-time services such as internet telephony is also becoming popular. IEEE 802.11 wireless access is shared with many clients on a single channel and there are three non-overlapping channels available. As more stations communicate on a single channel there is increased contention resulting in longer delays due to the backoff overhead of the IEEE 802.11 protocol and hence loss and delay variation; not desirable for time critical traffic. Simulation of such networks demands super-computing resource, particularly where there are over a dozen clients on a given. Fortunately, the author has access to the UK’s super computers and therefore a clear motivation to develop a state of the art analytical model with the required resources to validate. The goal was to develop an analytical model to deal with realistic IEEE 802.11 deployments and derive results without the need for super computers. A network analytical model is derived to model the characteristics of the IEEE 802.11 protocol from a given scenario, including the number of clients and the traffic load of each. The model is augmented from an existing published saturated case, where each client is assumed to always have traffic to transmit. The nature of the analytical model is to allow stations to have a variable load, which is achieved by modifying the existing models and then to allow stations to operate with different traffic profiles. The different traffic profiles, for each station, is achieved by using the augmented model state machine per station and distributing the probabilities to each station’s state machine accordingly. To address the gap between the analytical models medium access delay and standard network metrics which include the effects of buffering traffic, a queueing model is identified and augmented which transforms the medium access delay into standard network metrics; delay, loss and jitter. A Quality of Experience framework, for both computational and analytical results, is investigated to allow the results to be represented as user perception scores and the acceptable voice call carrying capacity found. To find the acceptable call carrying capacity, the ITU-T G.107 E-Model is employed which can be used to give each client a perception rating in terms of user satisfaction. PAGE 4 OF 162 QUEEN MARY, UNIVERSITY OF LONDON OLIVER SHEPHERD With the use of a novel framework, benchmarking results show that there is potential to maximise the number of calls carried by the network with an acceptable user perception rating. Dimensioning of the network is undertaken, again compared with simulation from the super computers, to highlight the usefulness of the analytical model and framework and provides recommendations for network configurations, particularly for the latest Wireless Multimedia extensions available in IEEE 802.11. Dimensioning shows an overall increase of acceptable capacity of 43%; from 7 to 10 bidirectional calls per Access Point by using a tuned transmission opportunity to allow each station to send 4 packets per transmission. It is found that, although the accuracy of the results from the analytical model is not precise, the model achieves a 1 in 13,000 speed up compared to simulation. Results show that the point of maximum calls comes close to simulation with the analytical model and framework and can be used as a guide to configure the network. Alternatively, for specific capacity figures, the model can be used to home-in on the optimal region for further experiments and therefore achievable with standard computational resource, i.e. desktop machines