歡迎訪問中科光析科學(xué)技術(shù)研究所官網(wǎng)!
免費(fèi)咨詢熱線
400-635-0567
聲音廣播接收機(jī)設(shè)備檢測項(xiàng)目報價???解決方案???檢測周期???樣品要求? |
點(diǎn) 擊 解 答??![]() |
Countries around the world are in the process of migrating from analogue to digital broadcasting techniques for both television and radio. This Report looks at sound broadcasting in the bands below 30 MHz. It briefly examines the underlying reasons for the migration and looks at the technologies involved. Its focus is the DRM system as developed for use in the LF, MF and HF bands. The Report is intended to: 1) Explain why and how a broadcaster might go digital. 2) Be a reference technical document for DRM planning. 3) Provide new information based on the practical experience in DRM. 英:planning parameters;coverage;digital radio mondiale;broadcasting;frequency
This part of IEC 60728 lays down the measuring methods, performance requirements and datapublication requirements of optical equipment of cable networks for television signals, soundsignals and interactive services.This standard? applies to all optical transmitters, receivers, amplifiers, directional couplers, isolators,multiplexing devices, connectors and splices used in cable networks;? covers the frequency range 5 MHz to 3 000 MHz;NOTE The upper limit of 3 000 MHz is an example, but not a strict value.? identifies guaranteed performance requirements for certain parameters;? lays down data publication requirements with guaranteed performance;? describes methods of measurement for compliance testing.All requirements and published data relate to minimum performance levels within the specifiedfrequency range and in well-matched conditions as might be applicable to cable networks fortelevision signals, sound signals and interactive services.
This part of IEC 60728 is applicable to optical transmission system for broadcast signaltransmission that consists of a head-end equipment, optical transmission lines, in-housewirings and a system outlet. The system is primarily intended for television and sound signalsusing analogue and/or digital transmission technology. This standard specifies the basicsystem parameters and methods of measurement for optical distribution system having asystem outlet in order to assess the system performance and its performance limits.The purpose of this part of IEC 60728 is to describe the system specification of FTTH (fibre tothe home) network for broadcast signal transmission. This standard is also applicable to thebroadcast signal transmission using telecommunication network if it satisfies the opticalportion of this standard. This standard describes RF transmission for broadcast andnarrowcast (limited area distribution of broadcast) signals over FTTH, and introduces xPONsystem as a physical layer media. The detailed description of physical layer is out of thescope of this standard. The scope is limited to RF signal transmission over FTTH, thus, itdoes not include IP transport technologies, such as IP Multicast and associate protocols.Some interference descriptions between telecommunication system and broadcast systemaddressed in Clause 7 and Annex D should be referred to for detailed explanations. Annex Adescribes actual service systems with design consideration based on this standard. Annex Bgives an overview of the optical transmission systems applicable for broadcast signaltransmission.