Potential interference and rain attenuation at 21.4–22 GHz downlink broadcasting satellite signals

World Radio Conference WRC-1992 has allocated the frequency band 21.4–22.0?GHz to regions 1 and 3 to be utilised to carry direct broadcasting satellite (DBS) services. This high-frequency band is more susceptible to rain attenuation, leading to degradation of the signal quality. Moreover, this frequency band is assigned to two different services, i.e. satellite broadcasting and fixed mobile services at the same regions; hence, the impact of intersystem interference in a depredated signal is a critical issue in the DBS receiver. In this study, the effects of rain attenuation on the DBS downlink signals as well as the impact of the potential interference on the reception quality will be estimated. An interference scenario will be introduced to investigate the system performance in both propagation mechanisms of clear-sky and rain conditions.     

Efficient packet scheduling for heterogeneous multimedia provisioning over broadband satellite networks: An adaptive multidimensional QoS‐based design

With their inherent broadcast capabilities and reliable extensive geographical coverage, the broadband satellite networks are emerging as a promising approach for the delivery of multimedia services in 3G and beyond systems. Given the limited capacity of the satellite component, to meet the diverse quality of service (QoS) demands of multimedia applications, it is highly desired that the available resources can be adaptively utilized in an optimized way. In this paper, we draw our attention on the development and evaluation of an efficient packet scheduling scheme in a representative broadband satellite system, namely satellite digital multimedia broadcasting (SDMB), which is positioned as one of the most attractive solutions in the convergence of a closer integration with the terrestrial mobile networks for a cost‐effective delivery of point‐to‐multipoint services. By taking into account essential aspects of a successful QoS provisioning while preserving the system power/resource constraints, the proposed adaptive multidimensional QoS‐based (AMQ) packet scheduling scheme in this paper aims to effectively satisfy diverse QoS requirements and adaptively optimize the resource utilization for the satellite multimedia broadcasting. The proposed scheme is formulated via an adaptive service prioritization algorithm and an adaptive resource allocation algorithm. By taking into account essential performance criteria, the former is capable of prioritizing contending flows based on the QoS preferences and performance dynamics, while the latter allocates the resources, in an adaptive manner, according to the current QoS satisfaction degree of each session. Simulation results show that the AMQ scheme achieves significantly better performance than those of existing schemes on multiple performance metrics, e.g. delay, throughput, channel utilization and fairness. Copyright © 2008 John Wiley & Sons, Ltd.     

Dynamic resource allocation for DVB‐RCS networks

To provide high‐speed multimedia services using the digital video broadcasting‐return channel satellite (DVB‐RCS) standard, it is imperative to efficiently assign timeslots according to user demands and dynamically take into account the variations of the propagation conditions. In satellite networks operating above 10 GHz, rain fading constitutes the dominant factor deteriorating the quality of service. In this paper, a novel two‐phase resource allocation scheme for a DVB‐RCS compliant satellite network is proposed. The scheme operates in two phases, the resource calculation and the resource assignment. In the resource calculation phase, based on a dynamic channel model, an efficient algorithm is presented to determine the superframe design that maximizes system throughput. In the resource assignment phase, a novel Hybrid Bin‐packing algorithm is introduced maximizing the utilization of the multi‐frequency time division multiple access frame. The proposed algorithm has been compared with existing schemes exhibiting significantly better results with regard to overall system throughput. Copyright © 2008 John Wiley & Sons, Ltd.     

基于高频段卫星动态信道预约的自适应QoS切换算法

未来高频段卫星网络将为固定和移动用户提供多媒体通信业务,而为移动用户提供无线多媒体业务的一个最关键的问题是保证端到端连接的业务质量。该文提出了一种基于高频段卫星动态信道预约的自适应QoS切换算法,并与其它切换方式进行了性能比较。     

Code-division multiple access for provision of mobile multimediaservices with a geostationary regenerative payload

The design of a satellite mobile multimedia communication system operating at Ka band and using synchronous CDMA is presented. The air interface described in the paper was derived taking into account the requirements induced by the provision of multimedia services to compact portable and mobile terminals. In order to minimize the complexity of the satellite payload, the concept of partial frequency reuse is introduced. A novel algorithm based on evolutionary theory is derived in order to optimize the corresponding link dimensioning. The satellite payload is described, and techniques reducing the computational requirements are proposed. It is then shown that the on-board complexity associated with the given design is within acceptable technological limits     

Multimedia goes mobile in broadcast networks

In digital broadcasting systems, like Eureka 147 DAB, it is possible to separate the actual service from the transmission system. Such a separation enables the distribution of any type of digital data to stationary, portable, or mobile terminals. However, a radio channel for mobile reception has certain characteristics to which existing multimedia services must adapt. We present a multimedia system model for digital broadcasting. We also discuss implementing this model within the broadcasting framework     

An aeronautical multimedia service demonstration at highfrequencies

An aeronautical measurement campaign for the satellite channel at the K band and an aeronautical multimedia service demonstration campaign for high data rate satellite services at the K/Ka band aim to provide high data rate services for all kinds of mobile terminals     

Summary of conclusions of the 1992 World Administrative RadioConference

The major decisions made at the conference are briefly described. Additional frequency bands for shortwave (HF) radio broadcasting were agreed upon. Frequency allocations were made to support a number of US proposals, to provide advanced mobile radio services using low Earth orbit satellites. Allocations for land based mobile services adopted at WARC '92, in the range 1700 to 2600 MHz, are meant to foster improved mobile services that can be used worldwide. An allocation was also made to support commercial telephone service between passengers flying on aircraft and individuals on the ground. Allocations were made for sound broadcasting from satellites, as well as for providing a means to accommodate a complementary terrestrial-based digital audio broadcasting service. New frequency allocations to support space activities were agreed upon, and an allocation was made to the fixed satellite service in the band 13.75 to 14.0 GHz     

A Cross-Layer Packet Scheduling Scheme for Multimedia Broadcasting via Satellite Digital Multimedia Broadcasting System [Advances in Mobile Multimedia]

In recent years, multimedia content broadcasting via satellite has attracted increased attention. The satellite digital multimedia broadcasting (S-DMB) system has emerged as one of the most promising alternatives for the efficient delivery of multimedia broadcast multicast service (MBMS). The design of an efficient radio resource management (RRM) strategy, especially the packet scheduling scheme, becomes a key technique for provisioning multimedia services at required quality of service (QoS) in S-DMB. In this article, we propose a novel cross-layer packet scheduling scheme that consists of a combined delay and rate differentiation (CDRD) service prioritization algorithm and a dynamic rate matching (DRM)-based resource allocation algorithm. The proposed scheme considers multiple key factors that span from the application layer to the physical layer, aiming at simultaneously guaranteeing diverse QoS while utilizing radio resources efficiently under the system power and resource constraints. Simulation results demonstrate that the proposed cross-layer scheme achieves significantly better performance than existing schemes in queuing delay, jitter, and channel utilization.     

Channel Capacity Statistics of an Interfered Broadband Satellite Link

Satellite communication networks play an important role in the “digital divide” problem, by offering broadband services everywhere in the world. The ever increasing demand for multimedia services has led to the use of Ku, Ka and V band in modern satellite communication networks. In these frequency bands, rain attenuation is the most dominant propagation fading mechanism. Moreover, interference due to propagation phenomena deteriorates the performance of the satellite links and should be taken into account for the reliable design of satellite communication networks. In this paper, an analytical physical mathematical propagation model is presented for the prediction of channel capacity statistics of a dual-polarized interfered broadband satellite link. Rain attenuation spatial inhomogeneity is incorporated in the analysis with the employment of correlated slant paths. The obtained numerical results show the significance of these effects to channel capacity estimation. Finally, the proposed model may be used towards the optimum utilization of the satellite channel capacity by means of adaptive fade mitigation schemes.     

快速发展的蜂窝网通信和卫星通信

主要说明无线通信将应用于移动通信、个人通信和全球通信。数字蜂窝网将增设微蜂窝区 ,频率从 90 0MHz升至 1 .8～ 2GHz ,向宽带和多媒体方向发展 ,数据速率从 1 44kb /s升至 2Mb /s。手机将是TDMA /CDMA双模。蜂窝网不仅用于移动通信 ,而且用于固定用户的市内接入网。卫星通信将加快发展低轨道 /中轨道卫星通信网 ,而同步卫星仍需利用。移动卫星网可通电话 ,可进行多媒体通信 ,速率为 2Mb /s,并通过地面信关站 ,与陆地固定通信网结合一起 ,实现全球个人通信。     

Multimedia services in the HDTV MUSE system

Experimental equipment to investigate multimedia service functions for application to MUSE (multiple sub-Nyquist sampling encoding) HDTV broadcasting has been developed. This system is called the multimedia MUSE system. Programs have also been produced to evaluate service functions of the system taking into account the capacity of the transmission path. This paper describes the configuration of the multimedia MUSE System, service examples, and evaluation of transmission capacity making use of test programs. Our studies reveal that multimedia broadcasting services can be provided when storage memory is installed for achieving interactive viewing and multimedia programs are appropriately configured. In addition, the services described here will provide the basic concept for multimedia broadcasting in future digital broadcasts     

24.65～25.25 GHz频段IMT-2020（5G）系统对卫星广播系统干扰分析

基于WRC-19 1.13议题研究框架和国内6 GHz以上IMT-2020（5G）候选频段的兼容性分析要求,针对24.65～25.25 GHz频段IMT-2020（5G）系统对卫星广播系统的干扰进行研究。采用蒙特卡洛的仿真方法,比较了静止轨道卫星经度分别在东经59°、85°、113°时,IMT-2020（5G）系统基站对卫星广播系统上行馈线链路的集总干扰情况。通过仿真分析,评估了5G系统对不同轨位卫星两类载波的集总干扰水平。研究结果表明,在该频段,IMT-2020（5G）系统不会对卫星广播系统产生有害干扰,相关研究结果可为未来毫米波频段IMT-2020（5G）系统频率规划以及保护卫星广播系统提供技术依据。     

DAB信道编码算法研究与实现

数字音频广播（DAB）具有节约频率资源、提供优质多媒体广播服务和能够移动接收的突出优点。由于DAB系统设计复杂，使得目前DAB接收机开发迟缓．为进一步改善DAB信号在无线信道传输中的衰落和干扰性能，研究了DAB信道编码算法，用软件实ETI数据流的实时信道编码，并得到了验证。     

An HDTV Broadcasting System Utilizing a Bandwidth Compression Technique?MUSE

An HDTV broadcasting service on one satellite broadcast channel became available after the development of a transmission system called MUSE involving bandwidth compression. Using MUSE, a satellite channel of width 27 or 24 MHz in the 12 GHz band can carry an HDTV picture, digitally-coded four-channel sound and independent digital signal at about 100 Kb/s.     

卫星移动数字多媒体广播技术

介绍了卫星移动数字多媒体广播系统结构，阐述了其信道传输、调制方式、填空发射机补盲及无线信号移动接收等关键技术，并对数字多媒体广播的应用前景进行了简要分析。     

Terrestrial Broadcasting Changes at the 1979 World Administrative Radio Conference

Because all of the countries attending the 1979 World Administrative Radio Conference (WARC-79) are substantially involved in broadcasting, the discussion of broadcasting and related subjects at WARC-79 developed top level interest. The changes in the terrestrial broadcasting bands as the result of the WARC-79 negotiations were for the most part positive. Objectionable interference was removed from the LF band; the MF band in Region 2 was expanded by 110 kHz; the FM Aural broadcasting band in Region 1 was expanded by 8 MHz; some of the less usable frequencies in the Low VHF TV band were eliminated, but TV broadcasting frequency allocations were added to the High VHF band to compensate. In the use of the UHF TV band, the United States proposal to share the band on a primary basis with fixed and mobile services created substantial controversy, which lead to a reservation on the part of the United States Government. In addition to the expansion of the MF band by 110 kHz in Region 2, a proposal was made to the Region 2 MF Regional Administrative Radio Conference to adopt a 9-kHz channel spacing so the channel spacing in all three Regions would be identical. It was the proposal of the USA to use the additional channels generated by 9-kHz spacing for minority ownership, educational ownership, and to provide full-time schedules for daytime-only stations. The controversy over this change is far from being resolved, and it can be expected to be an important topic of the second meeting of the Region 2 MF Administrative Radio Conference. Plans for a High Definition broadcasting system at 12.0 GHz are also discussed.     

基于地面广播的手机电视

手机电视业务可以利用蜂窝移动网络和地面/卫星数字广播来实现,其相关技术有4种:基于移动网实现技术、基于地面数字广播网实现技术、基于卫星实现技术和基于应用层实现技术。DVB-H和T-DMB是2种典型的地面数字广播电视标准,前者是DVB组织为通过地面数字广播网络向手持终端提供多媒体业务所制订的传输标准,后者是韩国推出的基于欧洲厂商开发的尤里卡147数字音频广播(Eureka-147DAB)的地面数字多媒体广播标准。目前开展手机电视业务面临着标准、频率资源、管制和终端等方面的问题,其运营模式存在移动运营商单独运营、广电单独运营和两者合作运营模式3种。手机电视是广电和通信产业融合的重要尝试,主管部门的协调和技术标准的制订将直接影响未来三网融合的进程。     

A Novel Mobile Antenna for Ku‐Band Satellite Communications

A mobile antenna for multimedia communications with Ku‐band geostationary satellite KOREASAT‐3 and JSAT‐2A is presented. The forward link of the satellite communication is 11.7 to 12.75 GHz, and the return link is 14.0 to 14.5 GHz. The mobile antenna is designed to be a stair structure using 24 active phased array elements in order to provide a low profile, and to be at a non‐periodic array distance using the genetic algorithm. Also, the designed antenna uses the double beam forming method for stable satellite tracking. The fabricated mobile antenna is examined using various experiments to confirm its capability for practical application. From the measured results, the fabricated mobile antenna system is confirmed to have a good performance.