Guided by Dr. K.R. Rao Irfan Kerawalla DVB-SH System for Broadcasting to Handheld Devices

Introduction Mobile TV is expected to become one of the largest markets for mass media. Growing number of mobile phone users around the globe has triggered excessive demand for multimedia content. People are constantly on the move and want all the latest updates ranging from news to social life on their fingertips. Users want high quality multimedia content delivered at fast speed.

What is DVB-SH? DVB-SH (Digital Video Broadcast - Satellite Services to Handheld Devices) is the name of a transmission system standard designed to deliver video, audio and data services to vehicles and handheld devices It is designed to use frequencies below 3GHz, typically around 2.2GHz. The system and waveform specifications have been published as ETSI standards. (TS , TS and EN ). [1]

Applications of DVB-SH Broadcasting of radio and TV content. Broadcasting of audio or video content customized for mobile TV (e.g. virtual TV channels, podcasts,). Data delivery (“push”), e.g. for ring tones, logos. Video-on-demand services. Informative services (e.g. news) including location-based services. Interactive services via an external communications channel e.g. Universal Mobile Telecommunications System(UMTS).

System Architecture of DVB-SH

Time Slicing The objective of time-slicing is to reduce the average power consumption of the terminal and enable smooth and seamless service handover. [8] Time-slicing enables a receiver to stay active only a fraction of the time, while receiving bursts of a requested service. Time-slicing also supports the possibility to use the receiver to monitor neighboring cells during the off-times. By accomplishing the switching of the reception from one transport stream to another during an off period it is possible to accomplish a handover decision.

Orthogonal frequency division multiplexing (OFDM) It is a frequency-division multiplexing (FDM) scheme used as a digital multi-carrier modulation method. OFDM (Orthogonal Frequency Division Multiplexing) [8] is the natural choice for terrestrial modulation and is the basis of both the DVB-H and DVB-T systems. DVB-SH introduces a second scheme, a time division multiplex (TDM), leading to two reference architectures termed SH-A and SH-B: [8] SH-A uses OFDM both on the satellite and the terrestrial link SH-B uses TDM on the satellite link and OFDM for the terrestrial link.

Compression in DVB-SH DVB-SH uses H.264/AVC compression standard.

Band used for DVB-SH transmission DVB-SH seeks to exploit the less congested, higher frequency, S-band where there are opportunities for mobile satellite services (MSS) systems, operating in conjunction with complementary ground components (CGC). Figure 4: S-Band used in DVB-SH transmission [7]

Block diagram of the DVB-SH system Figure 5. Conceptual description of a DVB-SH system [11]

Figure 6. Conceptual description of a DVB-SH receiver [11]

Basic parameters in DVB physical layer Table 1. Physical layer parameters and data rates of DVB-SH system [11]

Table 2. Time domain parameters for DVB-SH OFDM signal [11]

DVB-SH systems in the United States The telecom operator AT&T has agreed to buy spectrum in the lower 700 MHz frequency band licensed by Qualcomm. [12] Alcatel Lucent has hosted successful trials of DVB-SH systems across the United States. [12] ICO Global Communications has successfully launched a satellite named ICO G1 specifically for mobile television. [12]

References: [1] ETSI EN : Digital Video Broadcasting (DVB); DVB specification for data broadcasting (DVB-DATA). [2] ETSI TS : Digital Video Broadcasting (DVB); Specification for the use of video and audio coding in DVB services delivered directly over IP. [3] ETSI EN : Digital Video Broadcasting (DVB); Specification for Service Information (SI) in DVB systems (DVB-SI). References [1][2]and[3] can be accessed on [4] DVB BlueBook A079 Rev. 1: IP Datacast over DVB-H: PSI/SI. [5] DVB BlueBook A111: Framing structure, channel coding and modulation for Satellite Services to Handheld devices (SH) below 3GHz. dards/a111_DVB-SH_Specification.pdfhttp:// dards/a111_DVB-SH_Specification.pdf

[6] DVB-Scene edition No. 21: A New Star in the Sky, by Prof. Dr-Ing. Ulrich Reimers. [7] P. Kelley, C. Rigal, “DVB-SH in S-band” References [6] and [7] can be accessed from [8] DVB-SH fact sheet 0409, April [9] ETSI EN V ( ): Digital Video Broadcast [10]Block diagram for encoder and decoder of H [11] Faria et al. “DVB-H: Digital broadcast services to handheld devices”, Proceedings of the IEEE, vol. 94, no. 1, January 2006, pages 195 – 197. [12] DVB news updates

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