Future Hybrid Technology for Pay TV Platform

International audience

The usage of live mobile TV and mobile video devices is increasing in Japan as well as in other countries. In the summer of 2007, in the Tokyo area, we conducted a user study by means of qualitative interviews with 11 participants in order to understand when, how, and why people use such devices. In contrast to previous work, our user study compared the usage of live mobile TV with that of mobile video. In this article, our findings reveal a sharp contrast in (1) the usage of live mobile TV and mobile video on commuter buses or trains, at home, and for sharing experiences; and (2) the interest that live mobile TV users have in mobile video, and vice versa. In this article we present (1) findings that reveal the different attitudes concerning usage of live mobile TV compared with that of mobile video; and (2) hypotheses on user motivations, intentions, and desires derived from the observed attitudes.

이 논문에서는 계층변조를 적용하는 AT-DMB (advanced terrestrial digital multimedia broadcasting) 시스템에 적용할 수 있는 블라인드등화 기법을 제시하고 그 성능을 살펴본다. AT-DMB 시스템은 기존 T-DMB의 DQPSK (differential quadrature phase-shift keying) 신호와 역방향 호환성을 보장하고 더 높은 데이터 전송률을 지원하기 위해 16-QAM (quadrature amplitude modulation) 계층변조 방식을 적용한다. 이 결과 SNR (signal to noise ratio)에 따라 기존 T-DMB 심볼과 추가된 심볼은 서로 다른 판정오율 (decision error rate)을 가진다. 따라서 판정한 신호로부터 채널을 추정할 때 판정오율이 낮은 선순위 심볼과 판정오율이 높은 후순위 심볼의 신뢰도에 따라 다른 가중치를 줌으로써 판정치의 전체적인 신뢰도를 향상시킬 수 있다. 이 논문에서는 계층변조에 따른 비트 오율(bit error rate) 성능의 악화정도를 분석하고, 모의실험을 통해 판정신호의 신뢰도에 따라 가중치를 주는 제안방식이 가중치를 주지 않은 경우에 비해 비트 오율 성능이 향상됨을 확인하였다. In this paper, we propose a blind equalization method for advanced terrestrial digital multimedia broadcasting (AT-DMB) systems which use hierarchical modulation. The AT-DMB system adopts hierarchical 16-ary quadrature amplitude modulation (16-QAM) to ensure backward-compatibly with the differential quadrature phase shift keying (DQPSK) signal of the legacy terrestrial digital multimedia broadcasting (T-DMB) systems and to support higher transmission rate. Due to the hierarchical modulation, the conventional T-DMB signal and the additional signal have different error rate at same signal to noise ratio (SNR). By weighting the decided symbols differently according to the reliability of the symbols, i.e., high priority symbol with low error rate and low priority symbol with high error rate, we can improve the channel estimation accuracy. In this paper, we analyze SNR loss by hierarchical modulation and confirm it through simulations. Moreover, through simulations, we verify that the proposed weighting method improve BER compared to the no-weighting method.

The usage of live mobile TV and mobile video devices is increasing in Japan as well as in other countries. We conducted a user study in the summer of 2007, in the Tokyo area of Japan, with 11 participants, in order to understand through qualitative interviews when, how, and why people were using such devices. In this chapter, we present several findings from this user study, which reveals the different attitudes concerning the usage of live mobile TV compared with that of mobile video. These findings consider the following points. (1) Usage on commuter buses or trains, (2) usage at home, (3) usage related to experience sharing, and (4) interest of live mobile TV users in mobile video, and interest of mobile video users in live mobile TV. This chapter also proposes some ideas to improve user experience with mobile TV and video, and compares the results of our user study with those conducted in Finland, Korea, the USA, and the UK.

ATSC 3.0 is a next-generation terrestrial broadcast standard that transmits UHD media content by DASH segment file, not media frame unit. The size of DASH segment files varies even though they have the same quality and playback time. In other words, the sizes of DASH segment files basically burst. Moreover, a DASH segment file size burst more due to the amount of UHD media, which is larger than HD media. However, the bandwidth of broadcast system is limited and transmits media as CBR. Therefore, there are problems of delays and resource efficiency when the segment files with large variability are transmitted through the terrestrial broadcasting. In order to reduce delays, this paper proposes Server DASH (S-DASH). S-DASH selects and transmits the proper quality of a DASH segment file among the various qualities of DASH dataset by a broadcast server. Simulation results show that S-DASH can reduce delays.

In South Korea, Broadcast companies have begun a trial 3D broadcasting service by delivering dual streams, such as a left view sequence with MPEG-2 video and a right one with MPEG-4 AVC video, within the 19.4 Mbps terrestrial bandwidth. However, this limitation of transmission bandwidth in the terrestrial broadcasting system may cause quality degradation compared to the current 2D broadcasting service. Recently, the Advanced Television System Committee (ATSC) has released a new service model called non-real-time (NRT) technology, which provides file download functionality over a terrestrial broadcasting system. And electronic manufactures have developed smart TV which enables to receive RF channel and IP protocol. In order to operate a full quality 3D service, this paper proposes an NRT-based hybrid broadcasting system in which one of two view sequences is transmitted as a real-time broadcasting program, and the other is transmitted prior to a real-time broadcasting program and is stored as a file. This system uses a method of referential relation and synchronization between MPEG-2 transport stream (TS) and the file downloaded by ATSC NRT or IP. Therefore, the proposed hybrid broadcasting system can provide stable, high quality 3D content while maintaining a backward compatibility with the current 2D broadcasting system, despite the terrestrial bandwidth limitation.

With the increasing demand for efficient video delivery over terrestrial broadcasting systems, selecting the appropriate video compression standard is crucial for optimizing bandwidth usage and maintaining high-quality transmissions. This study presents a comparative analysis of MPEG-4 (H.264/AVC) and HEVC (H.265) video compression standards in the context of Digital Video Broadcasting - Second Generation Terrestrial (DVB-T2) transmission. MPEG-4 has been widely adopted in previous broadcasting systems, while HEVC offers improved compression efficiency, making it a promising alternative for modern broadcasting applications. The research evaluates both codecs based on key performance metrics including compression ratio, video quality (measured via PSNR and SSIM), bitrate efficiency, and computational complexity. Test scenarios are developed using standard-definition and high-definition video content, encoded under similar transmission parameters suitable for DVB-T2. The results demonstrate that HEVC achieves up to 50% bitrate savings compared to MPEG-4 for equivalent video quality, thereby allowing more channels or higher quality content within the same bandwidth. However, HEVC's increased encoding complexity and hardware requirements are noted as potential limitations for deployment in existing infrastructure. This analysis provides critical insights into the trade-offs between legacy and next-generation codecs for DVB-T2 broadcasting, supporting broadcasters and policymakers in making informed decisions regarding system upgrades and spectrum management.

A transmission system for digital terrestrial television broadcasting has been designed. This system is based on the European cable system but uses stronger error correction and better equalization. The stronger error correction is a concatenation of Reed Solomon coding RS [204,188,17] and convolutional coding with R/sub conv/=1/2, 2/3, 3/4, 5/6 and 7/8. The algorithm which is used for convolutional decoding is the Viterbi algorithm. To provide the Viterbi decoder with soft decision information, every symbol bit will be expanded with two soft decision (reliability) bits. The modulation scheme of the terrestrial transmission system is 64-QAM square root raised cosine filtered with a roll off factor /spl alpha/=0.15. The mapping of the symbols into the 64-QAM constellation is a Gray-mapping over the complete I,Q-plane. In this paper the performances of the terrestrial transmission system are simulated and analyzed.

The second generation digital video broadcasting system for terrestrial broadcasting (DVB-T2) was designed using a toolbox concept. Compared with its predecessor DVB-T, the new standard introduces many new algorithms and allows for a more flexible parameter configuration. The parameters can be perfectly optimized for each reception scenario, ranging from stationary reception with roof-top aerials, up to portable or mobile reception. However, all countries that have already introduced DVB-T2 mainly focus on stationary reception. In contrast, stationary reception is no relevant option for a potential introduction of DVB-T2 in Germany. Instead, a potential roll-out would focus on the benefits of terrestrial broadcasting compared to satellite and cable, i.e., mobility. Within an extensive field trial in northern Germany, the performance of the different parameter configurations and new algorithms offered by DVB-T2 were analyzed in detail, e.g., multiple physical layer pipes, rotated constellations, and multiple-input single-output. This paper presents the trial network and the obtained measurement results, which are based on thousands of individual measurements. Moreover, the document gives recommendations for an optimal parameter configuration.

Orthogonal frequency division multiplex-single frequency network (OFDM-SFN) has been widely used in the digital audio broadcasting system (DAB) and the terrestrial digital video broadcasting system (DVB-T) as a scheme of downlink broadcasting service. A novel system structure of single frequency cellular network (SFCN) is proposed by applying OFDM-SFN to conventional cellular systems. Transmitter macrodiversity and receiver selective diversity are adopted in the downlink and the uplink respectively. Theoretical analysis and numerical simulation in comparison with conventional cellular systems demonstrate the performance improvement of the proposed system.

Digital television based on ISO MPEG-2 is now widely deployed. The Digital Video Broadcast (DVB) standards that are used for this service in Europe, and many parts of the world, also allow the same system to transmit Internet Protocol (IP) data. Satellites, terrestrial broadcast, and cable systems are well suited to the delivery of high bandwidth data to the end user. DVB/MPEG-2 transmission offers a good solution to this last mile delivery problem. In addition the low transport overhead and ready availability of MPEG-2 make it very appealing as an Internet-work IP bearer. This paper therefore compares existing and recently proposed methods for transmission of IP data over digital television networks, to examine their behaviour and overall efficiency. (7 pages)

In order to improve current transmission capacity of the ancillary data in terrestrial digital multimedia broadcasting (T-DMB) system, the hierarchical modulation is adopted. The hierarchical modulation consists of Higher-priority (HP) data, which is the same as in the legacy T-DMB, and Low-priority (LP) data, which carriers the additional data for the upgrade system, while the backward compatibility is guaranteed. Both QPSK modulation and 4ASK modulation are good candidates for LP data modulation. So in this paper we adopt coherent detection with comb-type pilot arrangement, the Least Squares (LS) estimate of pilot signals and the piecewise-linear interpolation channel estimation. Simulation results show that LP-QPSK provides a better choice than LP-4ASK for achieving a higher data rate in the Advance T-DMB (AT-DMB).KeywordsAT-DMBLP-4ASKLP-QPSKHierarchical modulation

With the development of wireless network technologies, the number of mobile devices (MDs), such as smartphones and wearable devices, is growing at an unprecedented rate. In the 5G networks, mobile devices obtain wireless network services from the Internet Service Providers (ISPs) by signing contracts. Generally speaking, there are usually more than one ISP in the network service market. Therefore, mobile users (MUs) face the difficulty of selecting network services from these ISPs. In this paper, we consider a network service market with MUs selecting network services from one ISP who prices are set differently for different MUs. We model the interaction between the ISP and MUs as a Stackelberg game, under which the prices of the network service of the ISP are firstly determined, and the MUs make decisions based on the network service prices. We applied the backward induction way to prove the unique existence of the equilibrium. Simulation results are provided to show the analysis results.

In this paper, we study the performance of a synchronization scheme in VSB modulation systems for terrestrial 3-D HDTV broadcasting. The synchronization scheme consisted of the symbol timing recovery, the frame controlling and the carrier recovery. The proposed scheme shows a bit error rate (BER) performance that is almost the same as the ideal synchronization in VSB modulation systems.

In this paper, we propose a modulation scheme, which can improve the performance of a variety of wired and wireless communication systems. We call this scheme "Single Carrier Multi-Tone" (SCMT) because it is a name well describes the physical principles on which it is made. This scheme was developed based on a study known SC-FDMA, OFDM and SC-FDE technologies. The aim of this research was to improve the performance of existing communication systems for terrestrial television broadcasting. The proposed modulation scheme combines the advantages of known technologies and devoid of their shortcomings. The several key characteristics of the SCMT are illustrated by the results of MATLAB simulation.