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    有效 ITU-R BT.1877-2019 Error-correction, data framing, modulation and emission methods and selection guidance for second generation digital terrestrial television broadcasting systems
    语言:英文
    适用范围:
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    有效 ITU-R BT.1877-2019 Error-Correction, Data Framing, Modulation And Emission Methods And Selection Guidance For Second Generation Digital Terrestrial Television Broadcasting Systems
    语言:英文
    适用范围:
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    有效 ITU-R F.387-2019 Radio-Frequency Channel Arrangements For Fixed Wireless Systems Operating In The 10.7-11.7 Ghz Band
    语言:英文
    适用范围:This Recommendation* provides radio-frequency channel arrangements for fixed wireless systems (FWSs) operating in the 11 GHz band (10.7-11.7 GHz), which may be used for high, medium and low capacity fixed service applications including mobile infrastructure. The channel spacing recommended in the main text is 40 MHz with 15 and 55 MHz guardbands as well as a second arrangement also using a channel spacing of 40 MHz but with a 35 MHz guardband. Arrangements with channel spacing other than 40 MHz and used in some countries are also provided in the recommends referring to several Annexes.
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    有效 ITU-R M.1808-2019 Technical And Operational Characteristics Of Conventional And Trunked Land Mobile Systems Operating In The Mobile Service Allocations Below 869 Mhz To Be Used In Sharing Studies In Bands Below 960 Mhz
    语言:英文
    适用范围:This Recommendation provides technical and operational characteristics of conventional and trunked land mobile systems to be used in sharing studies. Given the variety of those systems within the mobile service below 869 MHz, a range of parameters and typical values are provided for different analogue as well as digital systems. This Recommendation is not intended to deal with characteristics of digital cellular land mobile systems.
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    有效 ITU-R M.2084-2019 Radio Interface Standards Of Vehicle-Tovehicle And Vehicle-To-Infrastructure Twoway Communications For Intelligent Transport System Applications
    语言:英文
    适用范围:This Recommendation identifies specific radio interface standards of vehicle-to-vehicle and vehicle-to-infrastructure1 communications for Intelligent Transport System applications. The technical characteristics described in this Recommendation are based on current Intelligent Transport Systems (ITS) applications in the mobile service. 1 Vehicle-to-infrastructure communications includes two-way communications between vehicle and infrastructure.
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    有效 ITU-R M.2012-2019 Detailed Specifications Of The Terrestrial Radio Interfaces Of International Mobile Telecommunications-Advanced (Imt-Advanced)
    语言:英文
    适用范围:This Recommendation identifies the terrestrial radio interface technologies of International Mobile Telecommunications-Advanced (IMT-Advanced) and provides the detailed radio interface specifications. These radio interface specifications detail the features and parameters of IMT-Advanced. This Recommendation includes the capability to ensure worldwide compatibility, international roaming, and access to high-speed data services.
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    有效 ITU-R M.1826-2019 Harmonized Frequency Channel Plan For Broadband Public Protection And Disaster Relief Operations At 4 940-4 990 Mhz In Regions 2 And 3
    语言:英文
    适用范围:
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    有效 ITU-T K.20-2019 Resistibility Of Telecommunication Equipment Installed In A Telecommunication Centre To Overvoltages And Overcurrents
    语言:英文
    适用范围:This Recommendation specifies resistibility requirements and test procedures for equipment installed in a telecommunication centre where the earthing, bonding and cabling between equipment or racks are in accordance with [ITU-T K.27]. This Recommendation applies to both external and internal ports. [ITU-T K.44] is an integral part of this Recommendation and should be read in conjunction with [ITU-T K.11], [ITU-T K.39] and [ITU-T K.46]. This Recommendation applies to all telecommunication equipment, whether network operator or customer owned, including telephony, routers and modems. It does not apply to equipment such as personal computers or printers.
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    有效 ITU-R F.636-2019 Radio-Frequency Channel Arrangements For Fixed Wireless Systems Operating In The 14.4-15.35 Ghz Band
    语言:英文
    适用范围:This Recommendation provides radio frequency (RF) channel arrangements for fixed wireless systems operating in the 15 GHz (14.4-15.35 GHz) band. The main text of this Recommendation presents RF channel arrangements with separations of 3.5, 7, 14, 28, 56 and 112 MHz. Annexes 1 and 2 present arrangements with a separation of 2.5, 5, 10, 20, 30, 40 and 50 MHz based on a homogeneous 2.5 MHz pattern.
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    有效 ITU-R M.1826-2019 Harmonized frequency channel plan for broadband public protection and disaster relief operations at 4 940-4 990 MHz in Regions 2 and 3
    语言:英文
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    有效 ITU-R F.758-2019 System Parameters And Considerations In The Development Of Criteria For Sharing Or Compatibility Between Digital Fixed Wireless Systems In The Fixed Service And Systems In Other Services And Other Sources Of Interference
    语言:英文
    适用范围:This Recommendation contains principles for the development of sharing criteria of digital systems in the fixed service. Considerations are mainly given on how to properly design performance and availability degradations due to interference within the allowable objectives, as specified in Recommendation ITU-R F.1094, under the various interference environments. It also contains information on representative technical characteristics and typical system sharing parameters of digital fixed wireless systems in the fixed service for use in sharing studies above about 30 MHz. In cases where analyses indicate sharing issues, additional information on specific fixed systems deployed by administrations can be found in Report ITU-R F.2108.
    电子版¥195.00
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  • 有效 ITU-T K.66-2019Protection Of Customer Premises From Overvoltages
    发布日期:
    2019-11
    语言:
    英文
    来源:
    新信标准
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    有效 ITU-T K.66-2019 Protection Of Customer Premises From Overvoltages
    语言:英文
    适用范围:This Recommendation: – provides practices for installing protection at residential and commercial customers' premises; – is intended to comply with [IEC 60364-5-54] or national standardizing bodies on a.c. power installations; – is intended for use with new installations as well as for expansion and upgrading of existing installations; – is intended to encourage planning for electromagnetic compatibility and safety, which should include bonding and earthing arrangements that accommodate installation tests and diagnostics; – is not intended to replace national regulations on bonding configurations and earthing. For telecommunication equipment resistibility requirements, see [ITU-T K.21]. Permissible levels of electromagnetic emissions are covered by [CISPR 22], or by national regulations. Concerning the need for overvoltage protectors, see [ITU-T K.11], [ITU-T K.39], [ITU-T K.46], [ITU-T K.47] and [IEC 62305-2]. Concerning the need for a lightning protection system (LPS), see [IEC 62305-2] and national regulations. This Recommendation is intended for customers' buildings, including residential and commercial installations. This Recommendation is not mandatory but intends to promote 'best practice' protection methods by operators and regulators. Areas subject to a.c. earth potential rise (EPR), e.g., substations, may require additional protection measures. See "Directives concerning the protection of telecommunication lines against harmful effects from electric power and electrified railway lines", Volumes VII and VIII (ITU handbook).
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    有效 ITU-T K.40-2019 Protection Against Lightning Electromagnetic Pulses In Telecommunication Centres
    语言:英文
    适用范围:This Recommendation addresses new and existing structures, such as telecommunication centres, large installations at a subscriber's premises and remote sites, and gives advice on the design and installation of protective measures against lightning electromagnetic pulses (LEMPs), in order to reduce damages to the equipment and cabling inside these structures.
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    有效 ITU-T K.144-2019 Surge Protective Component Application Guide – Self-Restoring Thermally Activated Overcurrent Protectors
    语言:英文
    适用范围:This Recommendation in the surge protective component application guide series covers self-restoring thermally activated overcurrent protectors (OCPs). These OCPs are operated by self-heating and are automatically reset after the end of the overcurrent condition without the need for manual intervention. This Recommendation covers the two types of body material; polymer and ceramic. These components are referred to as follows: a) polymer positive temperature coefficient (PPTC) thermistors; b) ceramic positive temperature coefficient (CPTC) thermistors; Guide topics include: – Construction – Operation – Production – Ratings – Characteristics – Application examples
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    有效 ITU-R M.1746-2019 Harmonized Frequency Channel Plans For The Protection Of Property Using Data Communication
    语言:英文
    适用范围:This Recommendation addresses system interoperability and harmonized frequency channel plans for the protection of property using data communication.
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    有效 ITU-T K.145-2019 Assessment And Management Of Compliance With Radio Frequency Electromagnetic Field Exposure Limits For Workers At Radiocommunication Sites And Facilities
    语言:英文
    适用范围:This Recommendation identifies three groups of workers: radiofrequency (RF) workers (for whom RF-EMF exposure is intrinsic to the nature of their work); informed workers (who have been provided with information on RF-EMF safe working practices for a site) and all other workers who are regarded as members of the public for the purposes on RF-EMF exposure limits. It provides guidance on the management of situations where RF workers and informed workers can be exposed under controlled/occupational exposure conditions at levels higher than general population/uncontrolled exposure limits. Reference is made to the difference between general public and occupational limit levels. Good practices are described for workers and employers, including workers, such as pregnant women, and workers with implanted or external medical devices, that can be active or non-active (passive), for whom other limits may apply.
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    有效 ITU-R F.1565-2019 Performance Degradation Due To Interference From Other Services Sharing The Same Frequency Bands On A Co-Primary Basis, Or From Other Sources Of Interference, With Real Digital Fixed Wireless Systems Used In The International And National Portions Of A 27 500 Km Hypothetical Reference Path At Or Above The Primary Rate
    语言:英文
    适用范围:This Recommendation* specifies performance degradation due to interference from other services sharing the same frequency bands on a co-primary basis, or from all other sources of interference, with real digital fixed wireless systems used in the international and national portions of a 27 500 km hypothetical reference path at or above the primary rate. These performance degradations are defined, for each direction of real fixed wireless links, for synchronous digital hierarchy (SDH) systems designed according to Recommendation ITU-T G.828, or for other systems designed according to Recommendation ITU-T G.826. * The structure and format of this Recommendation may need to be revised in the future to include the detailed technical information from the recommends part to a separate Annex.
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    有效 ITU-T K.39-2019 Risk Assessment Of Damages To Telecommunication Sites Due To Lightning Discharges
    语言:英文
    适用范围:This Recommendation comprises a method for the risk assessment of damages to equipment at telecommunication sites and personnel safety due to overvoltages and overcurrents caused by lightning discharges.
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    有效 ITU-T X.520-2019 Information Technology – Open Systems Interconnection – The Directory: Selected Attribute Types
    语言:英文
    适用范围:This Recommendation | International Standard defines a number of attribute types and matching rules which may be found useful across a range of applications of the Directory. Attribute types and matching rules fall into three categories, as described below. Some attribute types and matching rules are used by a wide variety of applications or are understood and/or used by the Directory itself. NOTE 1 – It is recommended that an attribute type or matching rule defined in this Recommendation | International Standard be used, in preference to the generation of a new one, whenever it is appropriate for the application. NOTE 2 – The attribute and context types definitions by this Recommendation | International Standard have some associated semantics. Such specifications should not be used in situations where these semantics do not apply. Some attribute types and matching rules are internationally standardized, but are application-specific. These are defined in the standards associated with the application concerned. Any administrative authority can define its own attribute types and matching rules for any purpose. These are not internationally standardized, and are available to others beyond the administrative authority which created them only through bilateral agreement.
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    有效 ITU-T X.500-2019 Information Technology – Open Systems Interconnection – The Directory: Overview Of Concepts, Models And Services
    语言:英文
    适用范围:The Directory provides the directory capabilities required by many application layer standards and telecommunication services. Among the capabilities which it provides are those of "user-friendly naming", whereby objects can be referred to by names which are suitable for citing by human users (though not all objects need have user-friendly names); and "name-to-address mapping" which allows the binding between objects and their locations to be dynamic. The latter capability allows networks, for example, to be "self-configuring" in the sense that addition, removal and the changes of object location do not affect network operation. The Directory is not intended to be a general-purpose database system, although it may be built on such systems. It is assumed, for instance, that, as is typical with communication directories, there is a considerably higher frequency of "queries" than of updates. The rate of updates is expected to be governed by the dynamics of people and organizations, rather than, for example, the dynamics of networks. There is also no need for instantaneous global commitment of updates; transient conditions, where both old and new versions of the same information are available, are quite acceptable. It is a characteristic of the Directory that, except as a consequence of differing access rights or un-propagated updates, the results of directory queries will not be dependent on the identity or location of the inquirer. This characteristic renders the Directory unsuitable for some telecommunication applications, for example some types of routing. For cases where the results are dependent on the identity of the inquirer, access to directory information and updates of the Directory may be denied.
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