Due to its large coverage area, low cost of deployment and high speed data rates, WiMAX is a promising technology for providing wireless last-mile connectivity. Physical and MAC layer of this technology refer to the IEEE 802.16e standard, which defines 5 different data delivery service classes that can be used in order to satisfy Quality of Service (QoS) requirements of different applications, such as VoIP, videoconference, FTP, Web, etc. The main aim of the paper is to examine a case of QoS deployment over a cellular WiMAX network. In particular, the paper compares the performance obtained using two different QoS configurations differing from the delivery service class used to transport VoIP traffic, i.e. UGS or ertPS. Results indicate that for delay-sensitive traffic that fluctuates beyond its nominal rate, having the possibility to give back some of its reserved bandwidth, ertPS has the advantage to permit the transmission of BE traffic.
Performance Analysis of VoIP Traffic in WiMAX using various Service Classes
全球微波接入互操作性（Worldwide Interoperability for Microwave Access，WiMAX）是目前无线领域最热门的技术之一，它是基于IEEE 802.16无线技术的标准，能够提供长距离的高吞吐量宽带连接，支持点到多点（Point to MultiPoint，PMP）宽带无线接入。与此同时，基于互联网协议的语音是一种很有前途的新技术，它提供了基于互联网协议的网络上的语音通信的访问，它成为一个替代公共交换电话网，由于其传输语音的能力，作为分组在IP网络。因此，VoIP在很大程度上不能容忍延迟，因此它需要高优先级传输。在本文中，我们研究了最常见的VoIP编解码器，这是G711，G7231和G729在WiMAX网络使用各种服务类和NOAH作为传输协议的性能。为了分析QoS参数，使用流行的网络模拟器ns2。分析了决定实际应用场景和业务流的QoS的各种参数。我们的目标是比较不同类型的服务类的QoS参数，如吞吐量，平均抖动和平均延迟。
This work presents an analysis of the effect of the access router buffer size on packet loss rate and how it can affect the QoS of multimedia services when bursty traffic is present. VoIP traffic, real traces of viedoconferencing and videosurvellance are used in two different scenarios with medium link utilization. The study shows that the bursty nature of some applications may impair the MOS of voice calls especially when a certain number of bursts overlap. When link utilization is above 70% good values of VoIP QoS cannot be obtained.
VoIP transfer voice over networks such as LAN. This technology is growing rapidly due to support of existing network infrastructure at low cost. Various simulations have been done and it is observed that by increasing the VoIP client, packet length and traffic arrival rate the performance of step network affected. In the current work packet dropped, packet received, voice traffic sent and end-to-end delay is estimated for various queuing disciplines like PQ, FIFO and WFQ. It is depicted that queuing disciplines effects the applications performance and utilization of resources.
Mobile telecommunications are converging towards all-IP solutions. This is the case of the Long Term Evolution (LTE) technology that, having no circuit-switched bearer to support voice traffic, needs a dedicated VoIP infrastructure, which often relies on the IP Multimedia Subsystem architecture. Most telecom operators implement LTE-A, an advanced version of LTE often marketed as 4G+, which achieves data rate peaks of 300 Mbps. Yet, although such novel technology boosts the access to advanced multimedia contents and services, telco operators continue to consider the VoIP market as the major rev…
For seamless QoS, it is important that all the stakeholders, such as the hosts, applications, access networks, routers, and other middleboxes, follow a single protocol and they trust each other. In this article, we investigate the participation of these entities in providing QoS over wireless networks in light of DiffServ QoS architecture. We initiate the study by investigating WiFi and Cellular network traces, which further motivates us a thorough investigation of these stakeholders with empirical measurements. Our findings are the followings. (i) Modern mobile VoIP applications request QoS t…
