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Future media transmission as a consistent target is pursued by both next mobile communication system (5G) and advanced digital terrestrial television system. High data rate and flexibility are major considerations for future media transmission. Broadcasting network facilitates high-efficiency transmission of popular or live video in large area, and while, cellular network tends to provide personalized and localized services with a unicast/multicast model. The broadcast-like scheme emerges in 5G to resolve the high demand for bandwidth. However, it requires high deployment cost and imposes much interference on unicast/multicast services. In this paper, a cooperative structure of cellular network and broadcasting network using cloud radio access network (C-RAN) is proposed. The expenses of constructing hybrid network can be significantly cut down by applying the centralization and virtualization of C-RAN. Besides, technical approaches for 3GPP and ATSC cooperation in physical layer is detailed. Dedicated return channel (DRC) of broadcasting network is proposed to enable seamless interaction between broadcasters and few users in a remote area with high expense of cellular tower deployment. To loosen the real-time physical layer pipes period restriction of DRC system, three alternative periods are investigated to provide more flexibility to broadcasters. [ABSTRACT FROM PUBLISHER]

This paper aims to improve the throughput of a broadcasting system that supports the transmission of multiple services with differentiated minimum signal-to-noise ratios (SNRs) required for successful receptions simultaneously. We propose a novel multiplexing method called bit division multiplexing (BDM), which outperforms the conventional time division multiplexing (TDM) counterpart by extending the multiplexing from symbol level to bit level. Benefiting from multiple error protection levels of bits within each high-order constellation symbol, BDM can provide so-called nonlinear allocation of the channel resources. Both average mutual information (AMI) analysis and simulation results demonstrate that, compared with TDM, BDM can significantly improve the overall transmission rate of multiple services subject to the differentiated minimum SNRs required for successful receptions, or decrease the minimum SNRs required for successful receptions subject to the transmission rate requirements of multiple services. [ABSTRACT FROM AUTHOR]

Long Term Evolution (LTE) standard enhances Multimedia Broadcast Multicast Services (MBMS) to provide highly efficient transmission of multicast/broadcast services. This paper aims at clarifying which is the best option for the Enhanced MBMS (E-MBMS) network configuration according to the operator needs. Besides, it describes the main technical features of the new E-MBMS LTE standard, for both streaming and file delivery, and derives optimum operation modes. Some relevant conclusions are drawn from a set of simulation results calibrated with International Telecommunication Union Radiocommunication (ITU-R) guidelines. Regarding streaming delivery, results show that increasing the MBMS over a Single Frequency Network (MBSFN) area size allows employing a higher modulation and coding scheme level, which entails more streaming channels per MBSFN area. Concerning file delivery, results show that the reduction in the mean throughput of unicast users matches exactly the percentage of stolen subframes. Besides, the hybrid approach suggested in this paper improves the file delivery efficiency while eliminating the dependency on a MBMS threshold. [ABSTRACT FROM PUBLISHER]

Helicopter-based digital electronic news gathering (H-DENG) systems play a crucial role for the live televised news broadcast, especially for disastrous or catastrophic events. In this paper, a special H-DENG system will be investigated thoroughly. Major aspects including resource allocation in spectrum, necessary services and mechanisms, wave propagation and channel modeling, as well as design rules have to be addressed for this system. Our studies are based on the actual prototype of the integrated H-DENG system. The evaluation and analysis of this system are also presented in this paper according to the measurement and simulation results from our test bed. [ABSTRACT FROM PUBLISHER]

Owning the merits of flexible networking, rapid deployment, strong line-of-sight communications and so on, Unmanned Aerial Vehicle (UAV) has been regarded as a promising technology for the Fifth-Generation (5G) wireless network to realise its ambition of ubiquitous connectivity to support the various applications, e.g., broadcasting/multicasting services. However, the unique features of the UAV systems, e.g., highly agile mobility in the three-dimensional space, and the significant size, weight and power constraints, pose new challenges for 5G broadcasting communications. In order to fully harvest the benefits of UAV-aided 5G communications for broadcasting services, a new position based lightweight beamforming technology is proposed in this paper to enhance the capability of signal reception in 5G UAV broadcasting communications. Instead of relying on the channel estimation to form beams, which would cause significant broadband consumption, the position and mobility information of UAV system is exploited to predict UAV movement and form narrow beams to track UAV for signal enhancement and interference cancellation. To flight against the inherent position error, a new position correction method is designed to jointly utilise the DoA information of 5G system and the position information of the UAV system. Comprehensive simulation experiments are conducted based on 3GPP 5G specifications and the results show that the proposed algorithm outperforms the benchmark Zero-Forcing (ZF) without position prediction and position-based beamforming without position correction. [ABSTRACT FROM AUTHOR]

The European Commission requires all European Union (EU) Member States to use telecommunications networks to alert the population of an ongoing crisis or an upcoming threat by June 2022. Public Warning System in Long Term Evolution (LTE) and 5G System currently supports a text-based warning using Cell Broadcast technology. Cell Broadcast does not support multimedia warning message delivery. This paper analyses requirements that need to be fulfilled to support multimedia warning message delivery in the 5G System and describes trials of a broadcast multimedia public warning alert system. The trials demonstrate delivery of multimedia public warning messages using Evolved Multimedia Broadcast Multicast Service (eMBMS), dynamic spectrum management and bonded connections. By using eMBMS the public warning messages can be sent with additional robustness and in multicast mode, resulting also in less congestion to the network as the messages do not need to be sent separately to each user. Dynamic spectrum management system allows to dynamically obtain spectrum resources for the public warning system messages and the bonded connections improves the throughput and reliability of the delivery by combining the capacity of several different networks. [ABSTRACT FROM AUTHOR]

This paper presents Internet protocol (IP)-based convergence of broadcast and broadband networks using Advanced Television Systems Committee (ATSC) 3.0–the next generation terrestrial broadcasting standard. In the broadcast network, the combination of Layered Division Multiplexing (LDM) and Scalable High Efficiency Video Codec (SHVC) is used, enabling efficient use of spectrum when mobile and fixed services are intended in a single radio frequency (RF) channel. The proposed use case of IP-based convergence is that a service is largely consumed through the high power high tower (HPHT) based broadcast network, and then alternative streams are requested via unicast for areas where broadcast signals are not receivable. The implementation details of broadcast and broadband convergence include MPEG Media Transport (MMT)/Real-time Objective delivery over Unidirectional Transport (ROUTE) description for broadcast useand Dynamic Adaptive Streaming over HTTP (DASH) for broadband use. To achieve seamless convergence between broadcast and broadband, transmission and reception systems based on ATSC 3.0 are hardware-developed and their implementation details are described. The proposed IP-based convergence use case of ATSC 3.0 broadcast and broadband is verified in a real-field environment using a public cellular network. [ABSTRACT FROM AUTHOR]

This paper addresses the challenge of broadcast and unicast convergence by proposing a PHY/MAC (Physical Layer/Medium Access Control) architecture for 5G New Radio (NR). The solution is based on Power domain Non Orthogonal Multiple Access (P-NOMA). The main PHY/MAC configuration parameters have been analyzed theoretically and their impact on the service configurations is presented in this manuscript. The system concept has been translated into a prototype model and different evaluation tests are presented. First, simulations show that the PHY layer performs better than Time Division Multiplexing/Frequency Division Multiplexing (TDM/FDM) choices of current broadband access systems. Second, performance tests using a network simulation tool are described. The results for capacity, latency and reliability demonstrate that the proposed solution offers an excellent broadcast/unicast convergence choice with significant gain values with respect to legacy PHY/MAC alternatives. [ABSTRACT FROM AUTHOR]

Fifth-Generation (5G) mobile networks are expected to perform according to the stringent performance targets assigned by standardization committees. Therefore, significant changes are proposed to the network infrastructure to achieve the expected performance levels. Network Function Virtualization, cloud computing and Software Defined Networks are some of the main technologies being utilised to ensure network design, with optimum performance and efficient resource utilization. The aforementioned technologies are shifting the network architecture into service-based rather device-based architecture. In this regard, we introduce Media Casting as a service (MCaaS) and IoRL-Cache service (IoRL-C). The former is a service that proposed as an integration solution between the broadcasting industry and Mobile Network Operators, while the latter proposed as a solution for improving IoRL small-cells caching efficiency. IoRL is an emerging 5G small-cell for indoor environment, which utilises mmWave and Visible Light Communications (VLC) as access technologies, while exploiting Software Defined Networking (SDN) and Network Function Virtualisation (NFV) technologies to offer flexible and intelligent services to its clients. In this paper, we introduce MCaaS and IoRL-C services, we perform simulation work for testing IoRL-C as a proof of concept for both services. The network was simulated using OMNeT++ simulation tool, and we validated the services efficiency by comparing their performance with traditional deployments. We have also examined the cache service performance at different link lengths, and found out that IoRL-C is able to support IoRL small-cells with more than 50+Km separation distances. [ABSTRACT FROM AUTHOR]

This work presents eight demonstrators and one showcase developed within the 5G-Xcast project. They experimentally demonstrate and validate key technical enablers for the future of media delivery, associated with multicast and broadcast communication capabilities in 5th Generation (5G). In 5G-Xcast, three existing testbeds: IRT in Munich (Germany), 5GIC in Surrey (U.K.), and TUAS in Turku (Finland), have been developed into 5G broadcast and multicast testing networks, which enables us to demonstrate our vision of a converged 5G infrastructure with fixed and mobile accesses and terrestrial broadcast, delivering immersive audio-visual media content. Built upon the improved testing networks, the demonstrators and showcase developed in 5G-Xcast show the impact of the technology developed in the project. Our demonstrations predominantly cover use cases belonging to two verticals: Media & Entertainment and Public Warning, which are future 5G scenarios relevant to multicast and broadcast delivery. In this paper, we present the development of these demonstrators, the showcase, and the testbeds. We also provide key findings from the experiments and demonstrations, which not only validate the technical solutions developed in the project, but also illustrate the potential technical impact of these solutions for broadcasters, content providers, operators, and other industries interested in the future immersive media delivery. [ABSTRACT FROM AUTHOR]

In order to meet the tremendous requirements on the convergence between broadband and broadcast, this paper proposes to incorporate layered division multiplexing (LDM), an important variant of non-orthogonal multiple access (NOMA) technologies, into Millimeter wave (mmWave) multiple-input multiple-output (MIMO) system with device-to-device (D2D) communications to simultaneously provide broadcast and unicast services. The performance of the proposed full-duplex D2D-aided mmWave MIMO-NOMA with randomly deployed users is then analyzed under practical assumptions. Closed-form expressions of both the outage probability and the ergodic capacity are then derived by using the Laplace transform technique. Finally, detailed numerical results reveal the performance gains of the proposed scheme compared with the LDM without D2D communications and conventional time division multiplexing based scheme. The impacts of the antenna array gain and the transmission power of both the base station and the full-duplex link on system performance are also presented. Besides, we observe that it is vital to optimal the transmission power of the full-duplex link which ensures less self-interference to enhance the system capacity. [ABSTRACT FROM AUTHOR]

The requirements for future DVB-TIH networks demand that broadcasters design and deploy networks that provide ubiquitous reception in challenging indoors and other obstructed situations. It is essential that such networks are designed cost-effectively and with minimized environmental impact. The EC funded project PLUTO has since its start in 2006 explored the use of diversity to improve coverage in these difficult situations. The purpose of this paper is to investigate the performance of Transmit Delay Diversity (DD) with two antennas to improve the reception of DVB-TIH systems operating in different realistic propagation conditions through a series of tests using a SPIRENT SR5500 dual channel emulator. The relationship between correlation coefficient between channels, receiver velocity and diversity gain is investigated. It is shown that transmit delay diversity significantly improves the quality of reception particularly in simulated fast fading mobile broadcasting applications. This paper documents research conducted by Brunel University and Broadreach Systems. [ABSTRACT FROM AUTHOR]

This paper presents a simple but effective IPTV channel control algorithm that keeps channel zapping time in the tolerable range with high network utilization. The proposed algorithm controls channel zapping time by adjusting the number of broadcasting channels that are located close to users over IP networks and the number of additional I-frames inserted into each channel, based on the user's channel preference information. Finally, experimental results are provided to show the performance of the proposed algorithm. [ABSTRACT FROM AUTHOR]

Low-density parity-check (LDPC) codes are playing more and more important role in digital broadcasting standards due to their excellent error correction performance. In this paper, we study the combination of LDPC codes over GF(q) with q-ary modulations for bandwidth efficient transmission over AWGN channel and consider the design of the codes. Specifically, we develop the concept of quasi-regular codes, and propose an improved Monte Carlo method to optimize the quasi-regular codes. To justify the performance of our proposed scheme, simulation results are presented and analysed. [ABSTRACT FROM AUTHOR]

Inter-destination media synchronization (IDMS) is a key requirement to enable successful networked shared media experiences between remote users. This paper presents an adaptive, accurate and standard-compliant IDMS solution for hybrid broadcast and broadband delivery. Apart from providing multi- and cross-technology support, the presented IDMS solution is able to accomplish synchronization when different formats/versions of the same, or even related, contents are being played out in a shared session. It is also able to independently manage the playout processes of different groups of users. The IDMS solution has been integrated within an end-to-end platform, which is compatible with the hybrid broadcast broadband TV standard. It has been applied to digital video broadcasting—terrestrial technology and tested for a Social TV scenario, by also including an ad-hoc chat tool as an interaction channel. The results of the conducted (objective and subjective) evaluations prove the statisfactory behavior and performance of the IDMS solution and platform as well as in terms of the perceived quality of experience. [ABSTRACT FROM AUTHOR]

A hybrid mobile communication network as considered in this paper consists of a point-to-point network (UMTS) and a point-to-multipoint network (DVB-H). The benefit of combining these two networks is an optimized transfer of data by collecting several user requests for a single response via the broadcast network. Thus, capacity can be saved, UMTS cells can be unloaded and the mean response time of the system can be reduced. Besides these advantages, hybrid networks can be applied to decrease electromagnetic exposure, especially at hot spot areas. In this paper, it is analysed how the hybrid network structure influences the electromagnetic exposure. Therefore, different scenarios have been developed consisting of different user behavior and different network structures. In order to evaluate the grade of exposure, criteria have been defined. These criteria have been used for comparing a hybrid network with a single UMTS network in terms of electromagnetic exposure. The results are shown for the different network structures and network configurations. [ABSTRACT FROM AUTHOR]

The objective of this work is to research and analyse the performance of Cyclic Delay Diversity (CDD) with two transmit antenna on DVB-H systems operating in spatially correlated channel. It is shown in this paper that CDD can achieve desirable transmit diversity gain over uncorrelated channel with or without receiver diversity. However, in reality, the respective signal paths between spatially separated antennas and the mobile receiver is likely to be correlated because of insufficient antenna separation at the transmitter and the lack of scattering effect of the channel. Under this spatially correlated channel, it is apparent that CDD cannot achieve the same diversity gain as obtained under the uncorrelated channel. In this paper, a new upper bound on the pairwise error probability (PEP) of the CDD with spatial correlation of two transmit antennas is derived. The upper bound is used to study the CDD theoretical error performance and diversity gain losses over a generalized spatially correlated Rayleigh channel. This theoretical analysis is validated by the simulation of DVB-H systems with two transmit antennas and the CDD scheme. Both the theoretical and simulated results give the valuable insight that the CDD ability to perform well with a certain amount of channel correlation. [ABSTRACT FROM AUTHOR]

This paper considers the potential for an HDTV delivery format with 1920 x 1080 pixels progressive scanning and 50 frames per second in broadcast applications. The paper discusses the difficulties in characterizing the display to be assumed for reception. It elaborates on the required bit rate of the 1080p/50 format when critical content is coded in MPEG-4 H.264 AVC Part 10 and subjectively viewed on a large, flat panel display with 1920 x 1080 pixel resolution. The paper describes the initial subjective quality evaluations that have been made in these conditions. The results of these initial tests suggest that the required bit-rate for a 1080p/50 HDTV signal in emission could be kept equal or lower than that of 2nd generation HDTV formats, to achieve equal or better image quality. [ABSTRACT FROM AUTHOR]

OFDM has been applied in a wide variety of wireless communications in recent years since it has the advantage over the conventional single-carrier modulation schemes when enduring the frequency-selective fading. However, intercarrier-interference (ICI) and interblock interference (IBI) due to the Doppler effect, carrier frequency drift of local oscillators and multipath fading limit the capability of OFDM systems. In this paper, a new generalized mathematical model for intercarrier and interblock interferences is derived for wireless mobile OFDM systems, in which Doppler frequency drift, local carrier frequency offset, multipath fading, and cyclic prefix coding are all present in reality. Such a new ICI/IBI model can be applied for OFDM performance evaluation in different environments. This new formulation of IBI and ICI provides a generalized framework which includes special ICI models appearing in the previous literature. Besides, the derived OFDM performance evaluation analysis in this paper can greatly benefit OFDM designers for wireless multimedia networks and digital video broadcasting technologies. [ABSTRACT FROM AUTHOR]

This paper investigates the possible system gain for a multiresolution broadcast system using multilayer transmission of multiresolution data by utilizing nonuniform layer transmission energies. It shows how to find the energy distribution that maximizes the system performance, measured in the form of a sum of a weighted layer values × population product (representing possible revenue for service providers). Through the introduction of the relative population coverage function P (ai) it is shown for a N layer system that in many cases when P(ai) is a concave function (equivalent to -P(ai) being convex) it is possible to reduce what seems to be an N-dimensional problem to N line searches. The paper also shows how the relative population coverage function can be constructed in two ways. The first uses analytic models for signal strength and population coverage (Uniform and Rayleigh). The second uses numerical signal strength and population estimates in grid format. The paper also includes examples to illustrate how the method works and the performance gain it provides. One of the examples uses actual grid estimates for an example transmitter located in Luleå, Sweden. [ABSTRACT FROM AUTHOR]

Broadcasting is a prospective approach to support near video-on-demand services with light communication overhead. By letting clients share channels, such approaches involve partitioning a video into segments and repeatedly broadcasting these segments in multiple channels. An early paper proposed a broadcasting scheme called RFS (recursive frequency splitting), which can significantly reduce clients' waiting time. While efficient, RFS suffers from a high computational complexity of O(n log n), where n is the number of segments of the video, which is typically very large. This paper proposes an efficient segmentation scheme, which can significantly reduce the computational overhead by slightly sacrificing the number of segments that can be arranged as compared to RFS. [ABSTRACT FROM AUTHOR]

The discussion around different network architectures, namely high power/high tower (HPHT) versus low power/low tower (LTLP) is currently a hot topic in different international fora. This paper presents the results of a study to compare coverage, number of sites, and network deployment/maintenance costs associated to three different network configurations (HPHT only, LTLP only, and mixed HPHT + LTLP) for rooftop, mobile, and portable indoor/outdoor digital terrestrial television service delivery. The analysis has been based on a practical network planning scenario. The results have been obtained with coverage simulations in the Basque Country, a region in northern Spain currently served with 64 transmitters of a traditional broadcast network. The results conclude that a LPLT network would require 3.3 more centers for providing the same coverage as the current HPHT network at a cost three times higher. Also, it has been observed that the current HPHT network fails to give portable and mobile coverage numbers close to real-service targets in urban areas. In those cases, the approach with lower number of sites and cost is a mixed HPHT + LTLP network, where a set of LPLT transmitters complement the coverage provided by the HPHT network. [ABSTRACT FROM AUTHOR]

The media landscape is undergoing unprecedented transformations. Content creators and service providers had been for decades in control of how technology tailored to media applications was deployed and adopted in networks and devices to serve audiences. Disruption started when the Internet and global technologies and networks enabled content delivery and consumption at anytime, anywhere, and by means of any device. This new paradigm, where the Internet is fully accessible to the media industry, creates opportunities for innovation across the entire value chain, involving new services, innovative products, and a direct relationship with users. [ABSTRACT FROM AUTHOR]

A broadcast encryption scheme enables a center to distribute keys and/or broadcast a message in a secure way over an insecure channel to an arbitrary subset of privileged recipients. In this paper, an ID-based broadcast encryption scheme is proposed, by which a center can distribute keys over a network, so that each member of a privileged subset of users can compute a specified key. Then a conventional private-key cryptosystem, such as DES, can be used to encrypt the subsequent broadcast with the distributed key. Because a key distribution can be done in an encrypted broadcast without any key pre-distribution, re-keying protocols for group membership operations can be simplified, a center can use the ID-based broadcast encryption scheme again to distribute a new and random session key. The ID-based broadcast encryption scheme from bilinear pairings is based on a variant of the Boneh-Franklin identity based encryption scheme. [ABSTRACT FROM AUTHOR]

Objective assessment of multimedia quality using machine learning (ML) has been gaining popularity especially in the context of both traditional (e.g., terrestrial and satellite broadcast) and advance (such as over-the-top media services, IPTV) broadcast services. Being data-driven, these methods obviously rely on training to find the optimal model parameters. Therefore, to statistically compare and validate such ML-based quality predictors, the current approach randomly splits the given data into training and test sets and obtains a performance measure (for instance mean squared error, correlation coefficient etc.). The process is repeated a large number of times and parametric tests (e.g., ${t}$ test) are then employed to statistically compare mean (or median) prediction accuracies. However, the current approach suffers from a few limitations (related to the qualitative aspects of training and testing data, the use of improper sample size for statistical testing, possibly dependent sample observations, and a lack of focus on quantifying the learning ability of the ML-based objective quality predictor) which have not been addressed in literature. Therefore, the main goal of this paper is to shed light on the said limitations both from practical and theoretical perspectives wherever applicable, and in the process propose an alternate approach to overcome some of them. As a major advantage, the proposed guidelines not only help in a theoretically more grounded statistical comparison but also provide useful insights into how well the ML-based objective quality predictors exploit data structure for learning. We demonstrate the added value of the proposed set of guidelines on standard datasets by comparing the performance of few existing ML-based quality estimators. A software implementation of the presented guidelines is also made publicly available to enable researchers and developers to test and compare different models in a repeatable manner. [ABSTRACT FROM AUTHOR]

The DVB standard does not mandate the use of authentication and integrity protection for transport streams. This allows malicious third parties to replace legitimate broadcasts by overpowering terrestrial transmissions. The rogue signal can then deliver a malicious broadcast stream to exploit security vulnerabilities on Smart TVs (STVs) in range. We implemented a proof-of-concept attack based on a malicious Hybrid Broadcast Broadband TV app, able to acquire permanent system-level access to an STV over the air, in less than 10 s. These attacks, however, are severely limited in range due to required co-channel protection ratios (CCPRs), which is in direct contradiction to previous publications. We present evidence for these limitations in form of laboratory experiments, extensive simulations, and field measurements. To this end, we developed an automated, low-cost method for CCPR determination, as well as a method for non-disruptive attack range measurements based on a gap filler and the resulting channel impulse response. [ABSTRACT FROM PUBLISHER]

In this paper, we derived the exact formula for the normalization factor of both B-mode and Q-mode hierarchically modulated symbols of the advanced terrestrial digital multimedia broadcasting (AT-DMB) system. This factor is required to scale the average energy of the transmit symbol to one. After investigating the average energy of hierarchically modulated symbols in AT-DMB, we formulate the normalization factor as a term of the constellation ratio. Based on this normalization factor, we have verified the effect after normalization on bit error rate (BER) performance. [ABSTRACT FROM PUBLISHER]

When adopting transmit diversity in the Chinese digital television terrestrial broadcasting (DTTB) system, there exists two kinds of interference: training sequences (TSs) from different transmit antennas are overlapped; and the TSs are interfered with OFDM data due to multipath fading. In order to distinguish different TSs, this paper proposes a method to design orthogonal TS set, which also have good correlation characteristic. Subsequently, an iterative algorithm to eliminate the interference between TSs and data is proposed and theoretically analyzed. Finally, simulations are performed and the results show that the system with the proposed scheme can achieve great diversity gain under acceptable computational complexity. [ABSTRACT FROM PUBLISHER]

The use of 3D models for progressive transmission and broadcasting applications is an interesting challenge due to the nature and complexity of such content. In this paper, a new image format for the representation of 3D progressive model is proposed. The powerful spectral analysis is combined with the state of art Geometry Image(GI) to encode static 3D models into spectral geometry images(SGI) for robust 3D shape representation. Based on the 3D model's surface characteristics, SGI separated the geometrical image into low and high frequency layers to achieve effective Level of Details(LOD) modeling. For SGI, the connectivity data of the model is implicitly encoded in the image, thus removing the need for additional channel bits allocated for its protection during transmission. We demonstrated that by coupling SGI together with an efficient channel allocation scheme, an image based method for 3D representation suitable for adoption in conventional broadcasting standard is proposed. The proposed framework is effective in ensuring the smooth degradation of progressive 3D models across varying channel bandwidths and packet loss conditions. [ABSTRACT FROM PUBLISHER]

The state-of-the-art time domain synchronous OFDM (TDS-OFDM) transmit diversity schemes are only suitable either for fast time-varying but weakly frequency-selective channels, or deeply frequency-selective but slowly time-varying channels. In this paper, a novel TDS-OFDM transmit diversity scheme based on the space-time shifted constant amplitude zero autocorrelation (CAZAC) sequence is proposed over doubly selective broadcasting channels. The space-shifted CAZAC sequence is used for the unbiased maximum likelihood (ML) channel estimation. The time-shifted sequence is utilized for the low-complexity cyclicity reconstruction of the received inverse discrete Fourier transform (IDFT) block. Compared with the existing solutions, the signal-to-noise ratio (SNR) gain of about 2.5 dB can be achieved by the proposed scheme at the uncoded bit error rate (BER) of 10^-2 over the deeply frequency-selective single frequency network (SFN) broadcasting channel when the receiver velocity is 140 km/h, at the cost of the spectral efficiency penalty of about 2.88%. [ABSTRACT FROM PUBLISHER]

By the end of 2009, the service for in-vehicle mobile digital TV has been successively carried out in many cities around the world. Viaducts over roads are common in urban areas. In this paper, a 3-dimension six-ray tracing model reveals the fading law of UHF wave for in-vehicle digital TV system under the impact from viaducts, subject to transmitting antenna being higher than viaduct deck. The model takes into account the six rays that undergo line-of-sight (or viaduct transmission) propagation, ground reflection, as well as edge diffraction. In order to obtain more accurate knowledge of path loss law in an actual moving TV system, the 90th percentile of path loss values within the space 10 m have been analyzed. It has been illustrated that factors that influence path loss law include wave polarization, height of two antennas and the horizontal distance between transmitting antenna and viaduct deck axis. The path loss law predicted by the six-ray model shows a reasonable match with measurement results which have a great disparity in those estimated by the popular used propagation models. [ABSTRACT FROM PUBLISHER]

Digital satellite multimedia broadcasting services in Europe are specified in the Mobile Satellite Services (MSS) frequency band by two recently developed standards, namely the European Telecommunications Standards Institute (ETSI) Satellite Digital Radio (SDR) and the Digital Video Broadcasting—Satellite services to Handhelds (DVB-SH) standards. Commercial deployment of operational systems based on these standards is foreseen in the coming years targeting mainly six large European markets. For these standards, a state-of-the-art channel code is deployed based on the 3rd Generation Partnership Project 2 (3GPP2) specifications having a wide range of coding rates. The purpose of this paper is twofold: (i) It studies and compares, for the first time, the Bit Error Rate (BER) performance of the 3GPP2 turbo code used in the aforementioned systems, in order to serve as a benchmark for system design engineers; and (ii) It investigates novel alternative channel coding schemes, including other state-of-the-art turbo code configurations and also Low-Density Parity-Check (LDPC) codes with linear-time encoding, such as the Irregular Repeat-Accumulate (IRA) codes, in order to improve the performance and/or reduce the complexity in future mobile satellite broadcasting systems. Extensive performance evaluation results in the Additive White Gaussian Noise (AWGN) and uncorrelated Rayleigh/Rician fading channels have shown that the use of turbo codes with higher number of states improves performance against the 3GPP2 turbo codes of up to 0.25 dB but the decoding complexity is almost doubled. Furthermore, the use of duo-binary turbo codes reduces decoding latency and makes them more robust in puncturing with performance improvement against the 3GPP2 turbo codes of up to 0.3 dB but performance degrades at very low coding rates. On the other hand, the use of Rate Compatible (RC)-IRA codes results in smaller performance improvement against the 3GPP2 turbo codes, i.e. up to 0.1 dB, but rate compatibility is used to obtain different coding rates with simple puncturing/extending method. [ABSTRACT FROM PUBLISHER]

For broadcast networks, the Single-Frequency Network (SFN) mode is an alternative to the well-known Multi-Frequency Network (MFN) mode, where instead of transmitters operating at different frequencies, all base stations use the same frequency. Besides the optimal frequency reuse, it is usually expected that the more homogeneous distribution of received signal strength reception in an SFN will improve the quality of service. Nevertheless, it should be noted that not all the locations within the service area will benefit from the SFN configuration. Some areas will show a degraded quality caused by the SFN echoes. In this paper, the SFN gain is defined as a parameter describing potential gain or interference. An unambiguous methodology to obtain the actual SFN gain is presented and the variation of the gain is investigated for a DVB-H network as a function of the signal strength difference received from different transmitters. This SFN gain can be used for coverage planning of future broadcast networks. [ABSTRACT FROM AUTHOR]

Due to the recent popularization of digital broadcasting systems, selective contents, i.e., watching contents selected by users themselves, have attracted great attention. For example, in a news program, after a user selects an interesting content, he/she watches it. In selective contents broadcasting, since the server needs to deliver many contents, the necessary bandwidth for continuously playing the data increases. Conventional schemes reduce the necessary bandwidth by producing an effective broadcast schedule. However, they do not consider the upper limit in the bandwidth. When an upper limit exists in the bandwidth, users may wait to play the data. In this paper, we propose a broadcasting scheme that reduces waiting time by considering available bandwidth. In our proposed scheme, by acquiring the channel bandwidth that is the same as the data consumption rate, we effectively reduce the waiting time. [ABSTRACT FROM AUTHOR]

With the increasing popularity of wireless networks and mobile computing, data broadcasting has emerged as an efficient way of delivering data to mobile clients having a high degree of commonality in their demand patterns. This paper proposes an adaptive wireless push system that operates efficiently in environments characterized by high broadcasting speeds and a-priori unknown client demands for data items. The proposed system adapts to the demand pattern of the client population in order to reflect the overall popularity of each data item. We propose a method for feedback collection by the server so that the client population can enjoy a performance increase in proportion to the broadcasting speed used by the server. Simulation results are presented which reveal satisfactory performance in environments with a-priori unknown client demands and under various high broadcasting speeds. [ABSTRACT FROM AUTHOR]

The frequency assignment problem involves the assignment of discrete frequencies to the transmitters of a radio network, such as a radio broadcasting network. Frequency separation is necessary to avoid interference by other transmitters to the signal received from the wanted transmitter at the reception region. Here, it is of major importance to minimize the interference while at the same time using the spectrum efficiently. In this paper we present two original distributed algorithms implemented on clusters of PCs used to solve the frequency assignment problem in the field of radio broadcasting. The first one is based on the island distributed [1] implementation of our hybrid genetic algorithm [2]. The second one uses a distributed cooperative Tabu Search. Experimental results show that our algorithms, applied to several instances given by TDF-C2R, lead to important time performance improvements. [ABSTRACT FROM AUTHOR]

LDPC codes are state-of-art error correcting codes, included in several standards for broadcast transmissions. Iterative soft-decision decoding algorithms for LDPC codes reach excellent error correction capability; their performance, however, is strongly affected by finite-precision issues in the representation of inner variables. Great attention has been paid, in recent literature, to the topic of quantization for LDPC decoders, but mostly focusing on binary modulations and analysing finite precision effects in a disaggregrated manner, i.e., considering separately each block of the receiver. Modern telecommunication standards, instead, often adopt high order modulation schemes, e.g. M-QAM, with the aim to achieve large spectral efficiency. This puts additional quantization problems, that have been poorly debated in previous literature. This paper discusses the choice of suitable quantization characteristics for both the decoder messages and the received samples in LDPC-coded systems using M-QAM schemes. The analysis involves also the demapper block, that provides initial likelihood values for the decoder, by relating its quantization strategy with that of the decoder. A new demapper version, based on approximate expressions, is also presented, that introduces a slight deviation from the ideal case but yields a low complexity hardware implementation. [ABSTRACT FROM AUTHOR]

This paper presents the development of Neural Network models to predict the likelihood of interference experienced by Broadcast users in the HF spectrum (3-30 MHz). The models are based upon several years of measurements recorded at Linköping (Sweden) across the HF band, covering a substantial part of a sunspot cycle. The dataset used for the model development is a result of a long-term project being undertaken jointly by the University of Manchester and by the Swedish Defence Research Establishment, to measure systematically and to analyze the occupancy of the entire HF spectrum. The measure of occupancy used is congestion, which is defined as the fraction of channels within a certain frequency allocation with signals exceeding a given threshold. The procedures for measuring and modeling congestion as a function of solar activity, time of day, day of year and incident field strength threshold are briefly presented. The accuracy of the predictions produced by the developed models demonstrate their ability to successfully capture the 24-hour, seasonal and long-term trend in the variability of congestion. These models can be used to advise operators on typical interference occupancy levels and assist the HF broadcast service in the planning of frequency usage and management by assessing the interference effect to short-wave, broadcasting in an effort to alleviate spectral congestion in the HF broadcast bands. [ABSTRACT FROM AUTHOR]

In this paper we analyze the performance of a low complexity superimposed channel estimation technique for orthogonal frequency division multiplexing (OFDM). In particular, an analytical model of interference due to channel estimation errors and imperfect superimposed sequence cancellation at receiver is proposed, whose effectiveness is validated by simulations. Indeed, the significative length of OFDM symbols used in new wide area broadcasting applications makes the superimposed technique a viable alternative to the classical pilot aided technique. For the same computational complexity, the comparison between the two techniques is based on the achievable system throughput both for the current terrestrial digital video broadcasting (DVB-T) standard and for the proposed next generation DVB-T (DVB-T2). Our results show that superimposed technique provides higher bit-rates than the pilot aided technique, with a gain in the range of 4% to 10%. [ABSTRACT FROM AUTHOR]

The MobileTV, IPTV, and DVB standards (DVB-HIT) have been defined to offer mobile users interactive multimedia services with quality of service (Q0S) consistency analogous to TV services. However, the market has yet to provide effective and economical solutions for the real-time delivery of such services to the corresponding transmitters over multi-domain IP networks. The monitoring system proposed in this paper enables the Q0S in the IP networks involved in the delivery of real-time multimedia content to the transmitters to be ascertained. The system utilizes the Q0S parameters defined in MPEG-2 Transport Streams to detect problems occurring in the heterogeneous multi-domain IP networks. The ability to detect problems having an adverse effect on Q0S allows appropriate control actions to be determined to recover the QoS across the composite IP network. The design and implementation of the proposed QoS-Monitoring system (QoS-MS) is presented, followed by analysis of experimental results that demonstrate the feasibility of the system. [ABSTRACT FROM AUTHOR]

Commercial terrestrial digital multimedia broadcasting (T-DMB) service was launched in the Republic of Korea. Reflecting recent demands of high quality video, Advanced T-DMB(AT-DMB) adopting a hierarchical modulation is being developed as the way to increase the payload data. Based on the AT-DMB system, this paper proposes a method to provide increased video quality with high spatial resolution. By using the emerging H.264/MPEG-4 AVC amendment 3 scalable extension (SVC), the proposed method is able to support high spatial resolution as well as the currently serviced spatial resolution while retaining the backward compatibility to T-DMB. In the experimental results, the benefits in terms of coding efficiency and spatial scalability are proven in comparison with the conventional T-DMB and alternative methods to provide a high spatial resolution video. [ABSTRACT FROM AUTHOR]

In this paper, we consider a peer-to-peer (P2P) network, where multimedia streams are broadcast by matched peers based on their resource reciprocation profiles. We propose a new framework where each peer creates a coalition of matched peers with which it can exchange resources in order to improve its utility. The utility is determined based on explicit consideration of the peer's multimedia attributes and the quality derived by the peers' reciprocation behavior. We adopt the proportional bargaining solution to negotiate the upload bandwidth among the matched peers. Proportional bargaining allows to determine each peer's optimal (in a Pareto optimal sense) upload rates in a coalition in terms of its utility impact. The impact of an incoming peer on the coalition value, which represents the collective utility achieved by the peers in a coalition, is assessed by explicitly investigating the coalition value improvement. Finally, our results show that the proposed coalition-based resource reciprocation can improve the resource allocation/scheduling algorithms deployed in existing P2P systems such as BitTorrent and CoolStreaming. We also discuss how the proposed resource reciprocation approach can be implemented in other multimedia broadcasting applications. [ABSTRACT FROM AUTHOR]

One way to broadcast a popular video is to partition the video into segments, which are transmitted on several channels currently and periodically. The approach lets multiple users share channels, and thus obtains high bandwidth utilization. Many previous studies such as the recursive frequency-splitting (RFS) and harmonic broadcasting schemes focus on decreasing clients' waiting time. Another issue on reduction of clients' buffer demands is also important, especially for the goal to provide video services using limited-capability client devices such as PDAs and set-top boxes (STBs). Related work includes the skyscraper broadcasting (SkB), client-centric approach (CCA), greedy disk-conserving broadcasting (GDB), and reverse fast broadcasting (RFB) schemes. By combining RFS and RFB, this paper designs a hybrid broadcasting scheme (HyB), which exhibits a good tradeoff between client buffering spaces and waiting time. In comparison with SkB, CCA, GDB, RFB, and RFS, HyB requires smallest buffers, only 25% of video size. For waiting time, the scheme also outperforms all the schemes, except RFS. [ABSTRACT FROM AUTHOR]

After coarse synchronization in orthogonal frequency division multiplexing (OFDM) systems, there might still be a residual frequency offset (RFO) and a sampling clock frequency offset (SFO), which seriously degrade the performance of the systems. This paper suggests a simple way of estimating the SFO in OFDM-based digital radio mondiale (DRM) system. To demonstrate the efficiency of the proposed SFO estimator, comparisons are made with other existing estimators in terms of mean square error (MSE) performance, estimation range, and complexity. [ABSTRACT FROM AUTHOR]

The threat of interference to licensed DTV by clusters of unlicensed and uncontrolled broadband devices (BDs) transmitting simultaneously on unoccupied DTV channels remains. DTV channels in major U.S. cities could be victimized by interference from unlicensed or uncontrollable clusters. This paper shows how and why interference by clusters of broadband devices would be significantly higher than interference by individual broadband devices or by interference from clusters of single-tone devices. This paper also provides a real-world assessment of the maximum interference that consumer-grade receivers can accept from clusters of broadband devices operating on unoccupied DTV channels. To prevent interference to DTV and to maximize spectral efficiency individual base stations would have to be licensed as part of a network, and portable unlicensed devices would have to be equipped with dual DTV tuners with GPS chips. [ABSTRACT FROM AUTHOR]

In this paper we present a Base-matrix based decoder architecture for multi-rate QC-LDPC codes proposed in broadband broadcasting system. We use the Modified Min-Sum Algorithm (MMSA) as the decoding algorithm in this architecture, which lowers the complexity of the LDPC decoder while keeping almost the same performance or even better. Based on this algorithm, we designed a novel check node processing unit to reduce the complexity of the decoder and facilitate the multiplex of the processing units. The decoder designed with hardware constraints is not only scalable in throughput, but also easily configurable to support different QC-LDPC codes flexible in code rate and code length. [ABSTRACT FROM AUTHOR]

Video-on-demand (VoD) is an essential technology for many multimedia applications. However, it remains challenging to efficiently deliver on-demand streams to a large number of receivers in a heterogeneous network environment. Although a number of VoD broadcasting protocols have been proposed for heterogeneous receivers, these protocols considers only single-bit-rate VoD services, which cannot satisfy the diverse quality-of-service requirements of heterogeneous receivers. In this paper, we propose a unified approach to heterogeneous VoD broadcasting, called unified heterogeneous broadcasting (UHB). As a unified approach, UHB is design to integrate different VoD broadcasting protocols and different scalable video coding schemes. The main merits of UHB are threefold. First, unlike conventional VoD broadcasting protocols, UHB supports multiple-bit-rate VoD services. Second, UHB is capable of adapting to network bandwidth fluctuations. Third, UHB enables each heterogeneous receiver to obtain the best visual quality by selecting the optimum system joining time. Our performance evaluation results indicate that UHB is superior to conventional heterogeneous VoD broadcasting protocols under various network conditions. [ABSTRACT FROM AUTHOR]

This paper introduces a layered structure of the Korean terrestrial digital multimedia broadcasting (T-DMB) ensemble based on Eureka-147 and suggests a new transmission architecture for flexible T-DMB service. In the suggested transmission architecture, MPEG-2 transport stream (TS) for T-DMB multimedia service is inserted into the ensemble distributed via the ensemble transport interface (ETI). Thus, we propose a novel algorithm remultiplexing the ETI with MPEG-2 TS. The architecture of ETI remultiplexing algorithm is described as a four-step process, and implemented as real-time embedded software in an ETI remultiplexing system. The design and implementation of the interoperable ETI remultiplexing system available for a small-scale transmission system for T-DMB service is described in detail. [ABSTRACT FROM AUTHOR]

Due to the recent popularization of mobile multi- media broadcasting, broadcasting continuous media data such as audio and video has attracted great deal of attention. In general continuous media data broadcasting, since clients have to wait to receive data before playing it, various schemes to reduce waiting time have been studied. Some reduce the waiting time by dividing the data into several segments and broadcasting preceding segments frequently with a single channel. However, by dividing the data into numerous segments and producing an effective broadcast schedule, the waiting time can be further reduced. In this paper, we propose a scheduling protocol to reduce waiting time with large-scale data segmentation. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a new scheme to improve the performance of the terrestrial - digital multimedia broadcasting (T-DMB) system, which exploits the burst error characteristics at the output of the convolutional decoder and the properties of the Reed-Solomon (RS) decoder to correct more errors by predicting erasures in each RS packet in advance as many as possible before decoding in the RS decoder. Simulation results show that the proposed scheme yields performance gain of around 1 dB at BER of 10-8 which can result in the extended coverage area of the T-DMB system. [ABSTRACT FROM AUTHOR]