QoS-guaranteed Mobile IPTV service in heterogeneous access networks

Abstract

Internet Protocol Television is defined as a multimedia service delivered over IP-based networks supporting quality of service (QoS), quality of experience (QoE), security, interactivity, and reliability. This service is rapidly expanding to both wireless and mobile networks through mobile devices. This trend demands a seamless IPTV service architecture for those mobile devices in heterogeneous access networks. This is because the convergence of the heterogeneous access networks can resolve their own service-coverage limitations, eliminating dead spots. We first briefly research on the background and trend for the seamless IPTV service for heterogeneous networks. Next we propose a new system architecture taking the relevant technical issues into account. This architecture is mainly composed of three parts, (i) information of network conditions on client, (ii) signaling for communicating between client and server with information of network conditions, and (iii) adaptive streaming based on information of network conditions. The proposed architecture can be deployed on any Internet protocol layers such as application layer, transport layer and network layer. In this paper, we evaluate two cases such as (i) RTSP in application layer and (ii) SCTP in transport layer and compare them through the performance evaluation. The results in the evaluation show that the proposed architecture meets well the requirements of the minimum IPTV service performance recommended by ITU-T international standard for the QoE over heterogeneous access networks.

Introduction

Internet Protocol Television (IPTV) service has rapidly been expanded to wireless mobile areas. In other words, users are able to use IPTV services everywhere and even in motion. The traditional IPTV service targets for the quality-of-service (QoS) and the quality-of-experience (QoE) guaranteed wired networks which should provide at least 10 Mbps according to the ITU-T specification. Therefore, seamless IPTV service in wireless mobile environments (a.k.a. Mobile IPTV) [1] must overcome several technical obstacles for the commercial service. Mobile IPTV implies at least one wireless network between the source and the destination. Therefore, most of the technical challenges are related to the lack of bandwidth and the mobility of mobile devices in the wireless networks.

In particular, mobile devices equipped with multiple access technologies including wired and wireless network interfaces are becoming common. Consequently, more frequent handovers between different access technologies become required. These mobile devices (e.g., mobile phones, smartphones or even laptops) may be reachable through multiple interfaces even simultaneously. The possibility of using a single or multiple interfaces at a time for sending and receiving IP packets depends on the mobile device capabilities. In both cases, handover between heterogeneous networks (a.k.a. vertical handovers) can occur. A significant change in the access network as a result of a handover may also affect End-to-End (E2E) path properties such as bandwidth, latency, data throughput, bit-error rate, and so on. Eventually, this situation makes IPTV systems have more challenges to provide seamless IPTV services with IPTV mobile devices equipped with multiple network interfaces.

The rest of this paper is organized as follows. Section 2 shows the background and motivation of Mobile IPTV in brief. Section 3 describes related work and Section 4 describes our Mobile IPTV system architecture, service modeling, and vertical handover decision algorithm. Section 5 describes evaluation criteria based on the ITU-T requirements. Based on the system architecture and evaluation criteria, we describe two approaches such as RTSP-based approach in Section 6 and SCTP-based approach in Section 7, respectively. Finally, Section 8 concludes this paper along with future work.