DVB-H Networks Research Articles

A novel idea on supporting mobile IPTV services over mixed DVB-H and 3G networks

Mobile IPTV is one of the IPTV branches applied to small and handheld devices such as mobile phones, where users can access shared videos on IPTV servers by their mobile devices everywhere. Because of the availability of small-size mobile phones, mobile IPTV is going to be turned into a main part of hobbies and information gathering. This paper presents a novel concept for mixing 3G and DVB-H network to develop mobile IPTV. In this paper, we propose a framework to combine DVB-H and 3G cells in order to extend coverage area of mobile IPTV and increase penetration of mobile IPTV. By combining these two technologies, users leaving a 3G area and entering a DVB-H area (or vice versa) can continue watching their videos by vertical handover between 3G and DVB-H networks. Switching a video stream between DVB-H and 3G networks to reduce the usage fee and extend the coverage area is the main idea of this paper. In fact, this paper introduces a cheap and suitable solution for extending Mobile IPTV with available facilities in underdeveloped countries. Our performance evaluation shows the effectiveness of the proposed combination on improving the quality of service for mobile IPTV users.

Extensive Penetration Loss Measurements and Models for Different Building Types for DVB-H in the UHF Band

DVB-H networks allow high data rate broadcast access for hand-held terminals. Building penetration loss measurements of a DVB-H signal at 602 MHz are performed in 100 buildings in Belgium. Buildings are categorized in different types (office buildings, apartments, villas, mansions, row houses, stations) and the rooms are classified according to the number of outside radiated walls. The cumulative distribution function of the penetration loss is determined and lognormality is investigated. Models are developed to calculate the penetration loss as a function of the number of radiated walls. Also models for apartments as a function of the floor level are developed. This research enables the calculation of indoor coverage probability for wireless networks.

New Method to Determine the Range of DVB-H Networks and the Influence of MPE-FEC Rate and Modulation Scheme

DVB-H networks allow high data rate broadcast access for hand-held terminals. A new method to determine the range of good reception quality of such a DVB-H network will be investigated in this paper. To this end, a new subjective criterion is proposed, based on the viewing experience of the users. This criterion is related to the percentage of valid reception. A comparison with existing criteria, based on measured signal strengths, is also made. The ranges are determined for mobile reception inside a car. The influence of the MPE-FEC rate and the modulation scheme on the range is also investigated, enabling wireless telecom operators to select optimal settings for future networks.

DVB-H Systems: Quality-Based Active Handoff Assisted by UMTS Return Channels

Digital Video Broadcasting for Handheld terminals (DVB-H) is a new standard developed by DVB Project consortium to enable the delivery of broadcast transmissions to mobile terminals (such as, cellular telephone, PDA, pocket PC, etc.). Being the DVB-H network characterized by a cellular structure, a key issue to avoid the service interruption in these systems is the design of effective handoff procedures. This paper introduces a novel seamless handoff approach for DVB-H networks, which is designed to reduce the user terminal power consumption and to make the handoff algorithm be driven by the quality of the user received signal. This implies the adoption of a method based on the constant monitoring of the Modulation Error Rate (MER), instead of standard RSSI-based procedures. Additional advantages in terms of power saving derive from the use of an Active Handoff procedure that exploits the UMTS return channel as an interaction channel. The proposed scheme has been successfully tested and obtained results make us confident that this can be an interesting research direction to investigate in the view of effective DVB-H handoff protocol design.

Analysis of DVB-H Network Coverage With the Application of Transmit Diversity

This paper investigates the effects of the cyclic delay diversity (CDD) transmit diversity scheme on DVB-H networks. Transmit diversity improves reception and quality of service (QoS) in areas of poor coverage such as sparsely populated or obscured locations. The technique not only provides robust reception in mobile environments thus improving QoS, but it also reduces network costs in terms of the transmit power, number of infrastructure elements, antenna height and the frequency reuse factor over indoor and outdoor environments. In this paper, the benefit and effectiveness of CDD transmit diversity is tackled through simulation results for comparison in several scenarios of coverage in DVB-H networks. The channel model used in the simulations is based on COST207 and a basic radio planning technique is used to illustrate the main principles developed in this paper. The work reported in this paper was supported by the European Commission IST project - PLUTO (physical layer DVB transmission optimization).

Influence of Reception Condition, MPE-FEC Rate and Modulation Scheme on Performance of DVB-H

DVB-H networks allow high data rate broadcast access for hand-held terminals. A method to analyze the performance is developed. The influence of different MPE-FEC rates and modulation schemes on the performance of a DVB-H network is analyzed in this paper for 9 different reception conditions. Portable (indoor and outdoor) and mobile reception (car, train, tram, bus) are investigated. This analysis enables better estimations of the performance of DVB-H systems and an optimized DVB-H performance model. The percentage of valid reception, MPE-FEC gains, carrier to interference-plus-noise ratios, and minimal signal strengths for the different reception conditions and modulation schemes are presented.

‘Podracing’: experimenting with mobile TV content consumption and delivery methods

Recently, mobile TV has been launched in several countries. While mobile TV integrates television contents into mobile phones, the most personal of communication devices, it becomes interesting to know how this feature will be used throughout the day and in varying contexts of everyday life. This paper presents empirical results on the use of mobile TV with different delivery mechanisms and both quantitative and qualitative results on how end-users prefer to use mobile TV contents in different situations. The data is based on ongoing empirical research in Finland in 2006 and 2007. The mobile TV services under study included both news and entertainment contents, and were tested in 3G, DVB-H and Wi-Fi networks using different delivery paradigms: broadcast, on-demand and download. To explore the use of different delivery methods and content consumption, we have developed a mobile TV service protoype, called Podracing. The analysis shows that users appreciated up-to-date information and information-rich media forms and contents especially for mobile news delivery. There was high demand for only the latest news on mobiles. The real-time property was considered important. Most of the users looked at the headlines or followed the news several times a day --- much more often than the traditional TV and news prime times would allow.