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The 2018 Scott Helt Memorial Award was awarded to Seho Myung, Sung-Ik Park, Kyung-Joong Kim, Jae-Young Lee, Sunhyoung Kwon, Jeongchang Kim, for their paper, “Offset and Normalized Min-Sum Algorithms for ATSC 3.0 LDPC Decoder.” The papers appeared in the IEEE Transactions on Broadcasting, vol. 63, no. 4, pp. 734–739, Dec. 2017. The purpose of the IEEE Scott Helt Memorial Award is to recognize exceptional publications in the field and to stimulate interest in and encourage contributions to the fields of interest of the Society. [ABSTRACT FROM AUTHOR]

Reconfigurable intelligent surface (RIS), a recently introduced technology for future wireless communication systems, enhances the spectral and energy efficiency by intelligently adjusting the propagation conditions between base stations (BSs) and mobile equipments (MEs). An RIS consists of many low-cost passive reflecting elements that are optimized to improve the quality of the received signal. In this paper, we study the problem of power control at the BS and RIS optimization for application to physical-layer broadcasting. Our goal is to minimize the transmit power at the BS by jointly designing the transmit beamforming at the BS and the phase shifts of the passive elements at the RIS. Furthermore, to help validate the proposed optimization methods, we derive lower bounds to quantify the average transmit power at the BS as a function of the number of MEs, the number of RIS elements, and the number of antennas at the BS. The simulation results demonstrate that the average transmit power at the BS is close to the lower bound in an RIS-aided system, and is significantly lower than the average transmit power in conventional schemes without an RIS. [ABSTRACT FROM AUTHOR]

Mobile broadcasting services are considered effective methods for emergency alert delivery. Terrestrial digital multimedia broadcasting (T-DMB) offers an emergency alert service called automatic emergency alert service (AEAS). However, the conventional AEAS is inefficient in the aspects of alert service channel, disabled T-DMB receiver, and location-based service. Therefore, this paper proposes a novel signaling method in order to overcome the drawbacks of the AEAS. The presented alert system exploits an additional alert channel, which is multiplexed with the conventional T-DMB channel. This paper also addresses the multiplexing approach, which effectively eliminates the interference between the additional alert channel and the TDMB channel. The simulation results confirm that the proposed signaling method effectively offers the emergency alert services in T-DMB1. [ABSTRACT FROM AUTHOR]

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]

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]

Audience research is a vital part of TV and radio broadcasting, as well as of the more recent forms of media content delivery, such as the Internet, IPTV, mobile phones, Personal Video Recorders (PVRs) and portable media viewers. The uses of audience research range from self-promotion to refining service offerings and setting advertising rates. Without reliable audience data, many businesses will be reluctant to participate in the new platforms. This paper describes an end-to-end system for convergent audience measurement focused on IPTV but covering also terrestrial, cable, satellite and mobile broadcasting. We created the audience measurement system from the elaboration of a logical architectural model and a common data model which can be applied to any media scenario. We implemented this logical and data model in stationary and mobile media receivers (in the paper the particular case of IPTV is extensively explained). In addition user consumption is modeled and metrics are provided for user media consumption profiling and impact quantification in IPTV environments. [ABSTRACT FROM AUTHOR]

STiMi is a mobile multimedia broadcasting trade standard that was released by the Chinese State Administration of Radio Film and Television in 2006. This paper details the algorithm research and development work on the acquisition for STiMi. First, the STiMi physical layer is briefly reviewed. secondly, individual algorithms, including time slot detection, fractional frequency offset estimation, integer frequency offset estimation and fine timing synchronization are discussed with simulation results presented. An implemented STiMi receiver prototype is also introduced with a focus on the acquisition algorithms implementation. Finally, the whole acquisition procedure is summarized. Acquisition algorithms and structures presented in this paper are adopted for prototyping and perform well. [ABSTRACT FROM AUTHOR]

There are numerous research challenges that need to be addressed until a wide deployment of vehicular ad hoc networks (VANETs) becomes possible. One of the critical issues consists of the design of scalable routing algorithms that are robust to frequent path disruptions caused by vehicles' mobility. This paper argues the use of information on vehicles' movement information (e.g., position, direction, speed, and digital mapping of roads) to predict a possible link-breakage event prior to its occurrence. Vehicles are grouped according to their velocity vectors. This kind of grouping ensures that vehicles, belonging to the same group, are more likely to establish stable single and multihop paths as they are moving together. Setting up routes that involve only vehicles from the same group guarantees a high level of stable communication in VANETs. The scheme presented in this paper also reduces the overall traffic in highly mobile VANET networks. The frequency of flood requests is reduced by elongating the link duration of the selected paths. To prevent broadcast storms that may be intrigued during path discovery operation, another scheme is also introduced. The basic concept behind the proposed scheme is to broadcast only specific and well-defined packets, referred to as "best packets" in this paper. The performance of the scheme is evaluated through computer simulations. Simulation results indicate the benefits of the proposed routing strategy in terms of increasing link duration, reducing the number of link-breakage events and increasing the end-to-end throughput. [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]

Self-healing key distribution schemes allow group managers to broadcast session keys to large and dynamic groups of users over unreliable channels. Roughly speaking, even if during a certain session some broadcast messages are lost due to network faults, the self-healing property of the scheme enables each group member to recover the key from the broadcast messages he has received before and after that session. Such schemes are quite suitable in supporting secure communication in wireless networks and mobile wireless ad-hoc networks. Recent papers have focused on self-healing key distribution, and have provided definitions, stated in terms of the entropy function, and some constructions. The contribution of this paper is the following. • We analyze current definitions of self-healing key distribution and, for two of them, we show that no protocol can achieve the definition. • We show that a lower bound on the size of the broadcast message, previously derived, does not hold. • We propose a new definition of self-healing key distribution, and we show that it can be achieved by concrete schemes. • We give some lower bounds on the resources required for implementing such schemes, i.e., user memory storage and communication complexity. We prove that the bounds are tight. [ABSTRACT FROM AUTHOR]

Based on the cell broadcast service architecture, this paper proposes an efficient multicast mechanism for the universal mobile telecommunications system to support multimedia messaging service (MMS). We define a new interface between the serving GPRS support node and the cell broadcast center to track the current locations of the multicast members. Then we describe the location tracking procedures (including, attach, detach, and location update) of the multicast members and the multicast message delivery procedure. We use an analytic model to investigate the performance of our approach. This paper indicates that our MMS multicast mechanism outperforms the previous proposed approaches. [ABSTRACT FROM AUTHOR]

In this paper, we consider the issue of data broadcasting in mobile social networks (MSNets). The objective is to broadcast data from a superuser to other users in the network. There are two main challenges under this paradigm, namely 1) how to represent and characterize user mobility in realistic MSNets; 2) given the knowledge of regular users' movements, how to design an efficient superuser route to broadcast data actively. We first explore several realistic data sets to reveal both geographic and social regularities of human mobility, and further propose the concepts of geocommunity and geocentrality into MSNet analysis. Then, we employ a semi-Markov process to model user mobility based on the geocommunity structure of the network. Correspondingly, the geocentrality indicating the “dynamic user density” of each geocommunity can be derived from the semi-Markov model. Finally, considering the geocentrality information, we provide different route algorithms to cater to the superuser that wants to either minimize total duration or maximize dissemination ratio. To the best of our knowledge, this work is the first to study data broadcasting in a realistic MSNet setting. Extensive trace-driven simulations show that our approach consistently outperforms other existing superuser route design algorithms in terms of dissemination ratio and energy efficiency. [ABSTRACT FROM PUBLISHER]

Due to advances in techniques for digital ecosystems and cyber engineering, users can now submit queries to search for inclusive information from different Web objects using mobile handheld devices such as smartphones in many real-life situations. As these mobile devices are not necessarily connected to the Internet all the time, users usually want to be able to get information such as e-mail, news, weather, and Web feed as soon as their mobile devices are connected to the Internet. However, these mobile devices have relatively limited resources. In this paper, we focus on mobile web navigation. Specifically, we use rooted directed trees, which enable users to access valuable information from the highly ranked and relevant Web sites, for answering user-inclusive queries. [ABSTRACT FROM AUTHOR]

Digital ecosystems offer cost-effective digital services that attract and benefit the species within them (i.e., humans, organizations, and computers). As a cornerstone technology for digital information delivery, data broadcast provides a strong backbone for the digital ecosystem infrastructure. Its scalability feature is highly significant for various digital ecosystem applications, including mobile broadcast services. This paper proposes a novel structure and access for mobile data broadcast. The proposed scheme addresses the tradeoff for minimizing query-access and tuning times by specifying a new message structure. Correspondingly, a new access and processing mode for mobile clients is required. We study the effectiveness of the proposed approach in minimizing query-access time while maintaining low tuning time. The results of our experiments are used to make comparisons with existing approaches. The results affirm the effectiveness of our proposed scheme. [ABSTRACT FROM AUTHOR]

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]

The design of High Speed Railway Television (HSRT) system is presented in this paper. The system mainly includes two aspects, the coverage network and the modulation/demodulation technique. We suggest the deployment of HSRT single frequency network (SFN) taking GSM-R as reference and Advanced Digital Television Broadcasting--Terrestrial (ADTB-T) as demodulation technique (it is why HSRT is also called ADTB-R). Moreover, to ensure the reliable work of ADTB-T under the special environment of HSRT-SFN, directional coverage diversity receiving technique are proposed to simplify the equivalent channel model. The validity of this scheme is verified by theoretical analysis and also laboratory tests. The experimental network including the trial testing environment and equipment which constitute the network infrastructure of HSRT-SFN are described. The trial test results are presented to verify the validity of the network design which based on the directional coverage and diversity receiver. The test results accord with the theoretical analysis and prove that the HSRT-SFN is well suited for the special application of high speed railway television. [ABSTRACT FROM AUTHOR]

This paper describes the receiver design of active phased array antenna (APAA) for mobile broadcasting and communications service via satellite. This system was optimally designed with RX-channels on the consideration of minimum size and cost besides electric performances. A dual-band and dual-polarized microstrip 8 ..4 array antenna was designed as a radiator. This antenna had high directivity and wide impedance bandwidth with dual-feeding structures such as the microstrip direct feeding for Band1 and the aperture coupled strip-line feeding structure for Band2. For system minimization, active channel blocks (ACBs) playing the role for signal amplification and phase control were directly combined behind the radiators with band pass filters (BPF). A beam-forming module was designed by 10:4 channel combining structure. Thus, the satellite signal power received from 10 radiators was combined into 4 channels for satellite auto tracking and signal demodulation on vehicles. Finally, to confirm the normal operations of the system, the outdoor communications test in a satellite communication environment was accomplished by the main terminal that provided satellite Internet service. [ABSTRACT FROM AUTHOR]

Terrestrial or Handheld Digital Video Broadcasting (DVB-T/H) and Terrestrial Digital Multimedia Broadcasting (T-DMB) are two popular broadcasting standards that enable digital television transmissions to handheld receivers. This paper presents a comprehensive performance comparison between the physical layers of DVB-T/H and T-DMB when employed for mobile communications. By exploiting a recently proposed fast simulation model, we assess the BER of the two coded OFDM systems in several realistic scenarios, taking into account Rayleigh and Rice channels, different mobile speeds, inner and outer channel coding, channel estimation, and one or two receive an- tennas. Our comparison shows that the DVB-T/H physical layer performance highly depends on the delay spread of the channel, whereas T-DMB is less sensitive to the frequency selectivity of the channel. As a result, DVB-T/H yields better performance than T-DMB in typical Rayleigh channels with significant delay spread. On the contrary, at high SNR, T-DMB outperforms DVB-T/H in Rice channels with low delay spread. As a side result, we show the performance improvement of DVB-H produced by MPE-FEC at the data link layer. [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]

The problem of optimizing access and bandwidth sharing among Transmission Control Protocol (TCP) connections in the mobile digital video broadcasting return channel via satellite (DVB-RCS) is tackled in this paper. After sketching the general system architecture, we explicitly deal with the dynamic assignment of bandwidth to TCP connections on the return link, which is accomplished by a network control center (NCC) placed onboard the satellite. Mobile users access the satellite in multifrequency time-division multiple access (MF-TDMA), whereas they receive data from the NCC in time-division multiplexing (TDM). Two different techniques, based on deterministic and random access, are compared in terms of bandwidth usage and average completion time per connection, when the mobile user acts as both server and client. In the server case, to increase the TCP throughput, both packet-level forward error correction (FEC) on data sent by mobile users and a duplicated and delayed acknowledgment technique for TCP acknowledgment traffic from the NCC to the mobile users are applied. An analysis of the packet losses and a simulation campaign of file transfers by employing a realistic channel model has been carried out. The results of the analysis show the convenience of adopting a technique, in addition to the optimal data redundancy in different cases, such as the server or client role of users, their willingness to pay, the file size, and the environment type. [ABSTRACT FROM AUTHOR]

Digital video broadcasting for handhelds (DVB-H) is the standard for broadcasting Internet Protocol (IP) data services to mobile portable devices. To provide interactive services for DVB-H, the Universal Mobile Telecommunications System (UMTS) can be used as a terrestrial interaction channel for the unidirectional DVB-H network. The converged DVB-H and UMTS network can be used to address the congestion problems due to the limited multimedia channel accesses of the UMTS network. In the converged network, intersystem soft handover between DVB-H and UMTS is needed for an optimum radio resource allocation, which reduces network operation cost while providing the required quality of service. This paper deals with the intersystem soft handover between DVB-H and UMTS in such a converged network. The converged network structure is presented. A novel soft handover scheme is proposed and evaluated. After considering the network operation cost, the performance tradeoff between the network quality of service and the network operation cost for the intersystem soft handover in the converged network is modeled using a stochastic tree and analyzed using a numerical simulation. The results show that the proposed algorithm is feasible and has the potential to be used for implementation in the real environment. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a new communications paradigm, namely, reliable neighborcast, and present a reliable neighborcast protocol (RNP) that operates as an overlay on the existing reliable broadcast protocols. The protocol is intended for vehicle-to-vehicle communications networks that communicate the speed, position, and state of nearby vehicles to coordinate or control their operation. The implementation of RNP that we describe operates on top of overlapping groups that use the mobile reliable broadcast protocol and provides the guarantees and characteristics of that protocol to each neighborhood. The efficiency of the overlays—defined as the fraction of the received messages that apply to a neighborhood—widely varies. We present an efficient overlay for 1-D networks, which is implemented in many highway applications. The characteristics of mobility are considered, and techniques are presented to eliminate delays as vehicles change neighborhoods and to move the underlying broadcast groups with the general flow of traffic. [ABSTRACT FROM AUTHOR]

Data broadcasting is an efficient way of delivering data to mobile clients having a high degree of commonality in their demand patterns. This paper proposes the use of multiple directional antennas to increase the performance of an adaptive wireless push system in environments that are characterized by the locality of client demands. Simulation results reveal that using up to three antennas suffices for a significant performance increase over the single-antenna adaptive wireless push system. [ABSTRACT FROM AUTHOR]

Flexible multimedia broadcast/multicast services such as mobile auction and advertisements are vital services for future mobile ad hoc networks. A great number of applications rely on a reliable and efficient medium access control (MAC) layer broadcast. The current IEEE 802.11 broadcast protocol based on carrier sense multiple access with collision avoidance does not offer any MAC layer recovery on broadcast frames. Consequently, unexpected lost frames may deteriorate the quality of broadcast/multicast services. Previous protocols extended request-to-send, clear-to-send, and acknowledgement to enhance the broadcast reliability. However, they still suffered from the hid- den terminal problem and the excessive retransmission problem at the same time. In this paper, we first formulate the excessive retransmission problem as an optimization problem and show that it is NP-hard even if the upper layer service is periodical beacon exchange. An approximation algorithm with a guaranteed approximation ratio is also suggested. Then, a reliable and efficient MAC layer broadcast protocol, which is named broadcast protocol with busy tone (BPBT), is proposed. BPBT applies a busy tone to solve the hidden terminal problem and applies the proposed approximation algorithm to solve the excessive retransmission problem. Finally, BPBT is compared with previous protocols for performance evaluation by simulation. [ABSTRACT FROM AUTHOR]

In traditional mobile streaming networks such as 3G cellular networks, all users pull streams from a server. Such pull model leads to high streaming cost and problem in system scalability. In this paper, we propose and investigate a fully distributed, scalable, and cost-effective protocol to distribute multimedia content to mobiles in a peer-to-peer manner. Our protocol, termed Collaborative Streaming among Mobiles (COSMOS), makes use of broadcasting and data sharing to achieve high performance (in terms of delay, cost fairness, stream continuity, etc.). In COSMOS, only a few peers pull video descriptions from base stations. Using a free broadcast channel (such as Wi-Fi and Bluetooth), they share the streams to nearby neighbors. As a result, COSMOS greatly reduces the streaming cost and cellular bandwidth requirement. Furthermore, as video streams are supplied by multiple peers, COSMOS is robust to peer failure. Since broadcasting is used to distribute video data, COSMOS is highly scalable to large number of users. In COSMOS, peers autonomously determine whether to broadcast packets or not in order to efficiently use of the channel bandwidth. By taking turns to pull descriptions, peers can effectively share, and hence substantially reduce, streaming cost. As broadcast scope is small and peers can often obtain a number of streams from its neighbors, COSMOS achieves low delay and excellent stream continuity. [ABSTRACT FROM AUTHOR]

There are many asynchronous communication situations for which the prevalent continuous connectivity paradigm is not needed. Communication with a fair delay tolerance may instead be provided by intermittent store-and-forwarding between nodes. This paper proposes a design for an open, receiver-driven broadcasting system that relies on delay-tolerant forwarding of data chunks through mobility of wireless nodes. The system provides public broadcast channels, which may be openly used for both transmission and reception. We show by analysis and simulation under benchmark mobility models that a delay-tolerant broadcast channel has both a sufficiently high throughput and reach to be interesting as a competitive alternative to the regulated wireless broadcast channel. The analysis is based on a queuing model to study the interactions among the mobile nodes in a street. The simulations complement this analysis for mobile nodes moving on a square according to benchmark mobility models. Finally, we present the design of, and experiences with, a proof-of-concept prototype. [ABSTRACT FROM AUTHOR]

Multimedia Broadcast/Multicast Service (MBMS) supports downlink streaming and download-and-play type services to large groups of users. From the radio perspective, MBMS includes point-to-point (PtP) and point-to-multipoint (PtM) modes. This paper investigates and presents different multi-resolution broadcast systems for Wideband Code Division Multiple Access (WCDMA) cellular mobile networks, namely, multi-code, hierarchical QAM constellations and multi-antenna (MIMO) systems. Each one present performance gains over conventional single-resolution broadcast systems. A comparison is made between the three proposed multi-resolution systems. The use of High Speed Downlink Packet Access (HSDPA) to multicast video streaming as a multi-resolution system, associated or not to MIMO, can be employed by the MBMS PtP mode, but dependently on the deployment scenarios it can yield substantial reduction in resource demand and optimization of the allocated radio resources. [ABSTRACT FROM AUTHOR]

TV is regarded as a key service for mobile devices. In the past, Mobile TV was often associated with broadcast transmission. However, unicast technology is sufficient in many cases, especially since mobile users prefer to access content on-demand, rather than following a fixed schedule. In this paper we will focus on 3G mobile networks, which have been primarily optimized for unicast services. Based on a traffic model we will discuss the capacity limits of 3G networks for unicast distribution of Mobile TV. From the results it can be concluded that the capacity is sufficient for many scenarios. In order to address scenarios in which broadcast is a more appropriate technology, 3GPP has defined a broadcast extension, called Multimedia Broadcast Multicast Service (MBMS). MBMS introduces shared radio broadcast bearers and has thus the capabilities of a real broadcasting technology. We will give a short overview about MBMS including a discussion on MBMS capacity. Since MBMS is primarily a new transport technology, additional application and service layer technologies are required, like electronic service guide and service protection. These mechanisms are standardized by the Open Mobile Alliance (OMA) and are favorably combined with MBMS or 3G unicast distribution in order to create complete end-to-end solutions. In order to optimize a system for delivery of broadcast services over 3G networks, the advantages of broadcast and unicast should be combined. We argue that hybrid unicast-broadcast delivery offers the best system resource usage and also the best user experience, and is thus favorable not only for broadcast delivery in 3G net- works, but actually also for non-cellular broadcast systems like DVB-H or DMB. [ABSTRACT FROM AUTHOR]

DVB-H is a new broadcasting standard, which offers reliable high data rate reception of IP packets for mobile handheld battery-powered devices. A link layer with multiprotocol encapsulation (MPE), including Reed-Solomon forward error correction (FEC) combined with a cyclic redundancy check (CRC), is defined in the standard to work on top of the DVB-T physical layer. For error correction in the receiver the DVB-H standard suggests to use erasure decoding based on the CRC information. Yet, the decoding method is not strictly determined in the standard. This paper investigates the performance of five different Reed-Solomon decoding schemes for the DVB-H link layer forward error correction called MPE-FEC. They differ on utilization strategy of existing erasure information. The performance of different decoding methods are evaluated analytically in an binary symmetric channel (BSC) and with simulations in the additive white Gaussian noise (AWGN) and a mobile fading channel. For the simulations in the fading channel a packet channel model based on actual measurements is designed. It is shown that more sophisticated decoding methods than the one suggested in the standard are required for efficient retrieval of IP packets. [ABSTRACT FROM AUTHOR]

In cellular environments, video broadcasting is a challenging problem in which the number of users receiving the service and the average successfully decoded video data-rate have to be intelligently optimized. When video is broadcasted using the 3G packet data standard, 1xEV-DO, the code space may be divided among the multiple layers if scalable video coding is employed. In this paper, we propose a novel, multi-objective optimized video broadcasting scheme for 1xEV-DO and investigate the feasibility of using multiple layers for transmission. The multi-objective optimization aims to find the best compromise between maximizing the average decodable video data-rate and minimizing the basic quality video outage probability. Simulations conducted for the ITU Pedestrian A and Vehicular B channels show that high data-rates with low outages are possible when 1xEV-DO is used for video broadcasting, however, it may not be desirable to use scalable video coding for this purpose. [ABSTRACT FROM AUTHOR]

A new mobile multimedia broadcasting service using a geostationary satellite was launched on May 2005 in Korea. The Satellite Digital Multimedia Broadcasting (S-DMB) system provides high quality audio, video and data broadcasting services to handheld and mobile receivers. S-DMB is a personal digital media which can provide bidirectional and interactive services via the convergent platform of broadcasting and communication. At present, TU Media, the only S-DMB service provider in Korea, provides 15 TV channels, 19 audio channels, and 3 data channels. The number of subscribers is about 890,000 by Nov. 2006. Thousands of low power gap fillers (repeaters) have been installed in the shadowed or blocked reception areas in the metropolitan Seoul. This paper presents the system requirements, standards and specifications, architecture, and service status of S-DMB in Korea. Comparisons with other satellite broadcasting systems and the services are also presented. Link budget analysis on the direct path down-link (satellite to receivers) and relay path feeder link (gap fillers to receivers) are carried out in order to ensure the satisfactory QoS. [ABSTRACT FROM AUTHOR]

Broadcasting in wireless mobile computing environments is an effective technique to disseminate information to a massive number of clients equipped with powerful, battery operated devices. To conserve the usage of energy, which is a scarce resource, the information to be broadcast must be organized so that the client can selectively tune in at the desired portion of the broadcast. In this paper, the efficient, energy conserving transaction processing in mobile broadcast environments is examined with widely accepted approaches to indexed data organizations suited for a single item retrieval. The basic idea is to share the index information on multiple data items based on the predeclaration technique. The analytical and simulation studies have been performed to evaluate the effectiveness of our methodology, showing that predeclaration-based transaction processing with selective tuning ability can provide a significant performance improvement of battery life, while retaining a low access time. Tolerance to access failures during transaction processing is also described. [ABSTRACT FROM AUTHOR]

Digital multimedia broadcasting service has been at the center of developing issues in mobile environment. in contrast to traditional multimedia broadcasting systems, mobile devices have limit of information handling capacity. In order to solve the problem, this paper presents a personalized channel recommendation system at client side in mobile environment. The system includes four modules: client manager agent, monitoring agent, data preparation agent and recommendation agent. Within the recommendation agent, we develop a recommendation algorithm using users' preference transitions for the channels. Also, we design and implement the prototype system on the Wireless Internet Platform for Interoperability. In the experiment, we compare the proposed algorithm with a conventional method. The experimental results show that the proposed recommendation system can provide better performance than the conventional method. [ABSTRACT FROM AUTHOR]

Broadcasting has been widely used in mobile Ad hoc networks as a communication means to disseminate information to all reachable nodes. Because radio signals are likely to overlap with others in a geographical area, straightforward broadcasting by flooding becomes very costly and results in serious redundancy, contention and collision, to which we refer as the broadcast storm problem. In this paper we propose the Relative Degree Adaptive flooding Broadcast (RDAB) algorithm for Ad hoc networks to efficiently reduce the broadcast overhead in the network. Based on the current situation of the network and the degree of the nodes, RDAB calculates the relative degree of the nodes, decides which nodes need to re-transmit and which nodes only need to receive. The higher the neighbor node's relative degree, the more uncovered nodes it can cover, hence these nodes can be selected to re-transmit broadcasting packets in the networks. We analyze the reliability and the validity of the RDAB algorithm to prove that the RDAB algorithm is a valid flooding broadcast algorithm. Simulation results show that the RDAB strategy outperforms the Ordinary Flooding Broadcast Method (OBM) and the Multipoint Relaying (MPR) protocol for Ad hoc networks. [ABSTRACT FROM AUTHOR]

The growing interest in the relation between electromagnetic fields and human health forces the assumption of national and international regulations on emission levels. In order to reduce the risks, restricted access around transmitting antennas have to be defined according with those regulations. This paper offers a guideline to determine the boundary of the potentially risky volumes around radio broadcasting antennas for AM-MF and FMSVHF services. With the proposed method, a complete reference volume is defined by just five parameters. [ABSTRACT FROM AUTHOR]

Due to their low computational requirements, two-dimensional semiempirical wave propagation algorithms are still indispensable tools for terrestrial mobile communications and radio broadcasting coverage predictions in the very high and ultrahigh frequency bands. In this paper, we discuss various improvements of an algorithm based on digital terrain data. The algorithm combines the basic empirical propagation curves of Okumura et al. [1] with terrain adaptive propagation curves derived from Freshet zone clearance analyses of several terrain subsections. Also, a multiple knife-edge diffraction algorithm with approximate evaluation of the Kirchhoff diffraction integrals is applied when the line of sight is obstructed. Prediction quality is further improved by a robust algorithm for determination of effective transmitter antenna heights, and land usage along the terrain profile different from "open terrain" is considered by a multilevel Fresnel zone blockage evaluation. Prediction errors with standard deviations of about 6 to 7 dB were found for a great variety of measurements th ilar and moderately undulating terrain. Transmitter stations with very high antennas (more than 200 m) caused larger standard deviations of the prediction errors. However, improvements of the predictions could be achieved in these cases by evaluating street orientations with respect to the direct path. [ABSTRACT FROM AUTHOR]

In this paper, we propose an advanced method for improving the performance of the H.264/AVC deblocking filter, which efficiently removes blocking artifacts and reduces computational complexity for stereoscopic video coding in mobile broadcasting. Right image filtering is performed rapidly based on the human visual system (HVS) and the variable block sizes of the left images. The proposed method could achieve about 40% increase in the speed of right image filtering, which could save more than 20% of the entire filtering time without a loss of visual quality. [ABSTRACT FROM AUTHOR]

The availability of infotainment contents to be accessed while driving constitutes an added value to both drivers and passengers, improving their travel experience. These contents can be already on-board, diffused through broadcast networks (e.g., FM radio) or delivered on demand by servers as data streams. Vehicular ad-hoc networks (VANET) allow envisaging a new way to access contents based on epidemic data dissemination, tearing down the costs for both the user and the content publisher, and increasing system scalability. In this paper, we present the design and the evaluation of a collaborative system for content diffusion and retrieval among traveling vehicles. This system relies on multicast epidemic dissemination of messages and exploits vehicles mobility and their local storage capabilities. In order to assess its performance, several simulations have been carried out, using real-world maps and realistic mobility models, and varying intrinsic system parameters. Experimental results suggest that the system is feasible, produces reliable results, almost independent of the mobility scenario, and can be used as a peer-to-peer download accelerator for improving client-server access. [ABSTRACT FROM PUBLISHER]