180 likes | 408 Views
DVB-SH System for Broadcasting to Handheld Devices. Guided by Dr. K.R. Rao Irfan Kerawalla irfan.kerawalla@mavs.uta.edu. Introduction. Mobile TV is expected to become one of the largest markets for mass media.
E N D
DVB-SH System for Broadcasting to Handheld Devices Guided by Dr. K.R. Rao Irfan Kerawalla irfan.kerawalla@mavs.uta.edu
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 102 584, TS 102 585 and EN 302 583). [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).
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 Figure 4: S-Band used in DVB-SH transmission [7] 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).
Block diagram of the DVB-SH system Figure 5. Conceptual description of a DVB-SH system [11]
Basic parameters in DVB physical layer Table 1. Physical layer parameters and data rates of DVB-SHsystem [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 301192: Digital Video Broadcasting (DVB); DVB specification for data broadcasting (DVB-DATA). [2] ETSI TS 102005: Digital Video Broadcasting (DVB); Specification for the use of video and audio coding in DVB services delivered directly over IP. [3] ETSI EN 300468: Digital Video Broadcasting (DVB); Specification for Service Information (SI) in DVB systems (DVB-SI). References [1][2]and[3] can be accessed on http://www.dvb-h.org [4] DVB BlueBook A079 Rev. 1: IP Datacast over DVB-H: PSI/SI. http://broadcasting.ru/pdf-standard-specifications/internet%20protocol/a079.pdf [5] DVB BlueBook A111: Framing structure, channel coding and modulation for Satellite Services to Handheld devices (SH) below 3GHz. http://www.dvb.org/(RoxenUserID=9b5031601a81d830f6f38d9ed110cb03)/technology/standards/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 http://www.ebu.ch/fr/technical/trev/trev_311-dvb_sh.pdf [8] DVB-SH fact sheet 0409, April 2009 http://www.dvb-h.org/PDF/dvb-sh-fact-sheet.0409.pdf [9] ETSI EN 302304 V1.1.1. (2004-11): Digital Video Broadcast www.dvb-h.org [10]Block diagram for encoder and decoder of H.264 http://nuntius.com/technology3.html [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 http://www.dvb.org/about_dvb/dvb_worldwide/usa/