Detail of GB/Z 6113.404-2023

Introduction of GB/Z 6113.404-2023

GB/Z 6113.404-2023 Specification for radio disturbance and immunity measuring apparatus and methods - Part 4-4: Uncertainties, statistics and limit modelling - Statistics of complaints and a model for the calculation of limits for the protection of radio services 1 Scope This document contains a recommendation on how to deal with statistics of radio interference complaints. Furthermore it describes the calculation of limits for disturbance field strength and voltage for the measurement on a test site based on models for the distribution of disturbances by radiated and conducted coupling, respectively. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050-161 International Electrotechnical Vocabulary (IEV) – Part 161: Electromagnetic compatibility (available at http://www.electropedia.org) CISPR 11 Industrial, scientific and medical equipment - Radio-frequency disturbance characteristics - Limits and methods of measurement 3 Terms, definitions, symbols, and abbreviations 3.1 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60050-161 and the following apply. 3.1.1 complaint request for assistance made to the RFI investigation service by the user of a radio receiving equipment who complains that reception is degraded by radio frequency interference (RFI) 3.1.2 RFI investigation service institution having the task of investigating reported cases of radio frequency interference and which operates at the national basis Example: Radio service provider, CATV network provider, administration, regulatory authority. 3.1.3 source any type of electric or electronic equipment, system, or (part of) installation emanating disturbances in the radio frequency (RF) range which can cause radio frequency interference to a certain kind of radio receiving equipment 3.2 Symbols and abbreviated terms The following symbols and abbreviations apply to this document. Eir: permissible interference field strength at the point A in space where the antenna of the victim receiver is located – without consideration of probability factors. ELimit: permissible interference field strength at the point A in space where the antenna of the victim receiver is located – with consideration of probability factors RP: protection ratio CPV: coupling factor describing the proportionality of the field strength E with the square root of the power P injected as common mode into the radiating structure by the apparatus (GCPC) Group A defined PV generator group for single-family detached houses Group B defined PV generator group for multi-storey buildings with flat roof tops Group C defined PV generator group for sun tracking supports (“trees”) Group D defined PV generator group for large barns in the countryside 4 Statistics of complaints and sources of interference 4.1 Introduction and history The document contained, in its Clause 4, a complete reprint of CISPR Recommendation 2/3 on statistics of complaints and sources of interference. However, due to modern technological evolution in radio systems directed towards introduction of digital radio services, and due to increasing use of mobile and portable radio appliances by the public, the traditional CISPR statistics of complaints on radio frequency interference are experiencing a decreasing significance as an indicator of the quality of standardisation work for the protection of radio services and applications. That is why related information in this document is reduced to the necessary minimum allowing interested parties to continue their complaint-based collation of data on an annual basis. In order to accommodate the evolution in modern radio technology and mobile and portable use of radio receiving equipment, it may be necessary to replace or to gather the complaints-based CISPR statistics by other more modern statistics or means. These new statistics should be based on a systematic annual collation of data about degradation of quality of radio services and reception due to electromagnetic disturbances occurring in the environment. These data will have to be collected and processed, however, primarily by the radio service providers themselves. 4.2 Relationship between radio frequency interference and complaints Whatever the radio system involved, official complaints usually represent only a small subset of all occurring interference situations. Occasional interference generally does not lead to an official complaint if its duration is brief or if it happens only once in a while. It is only when the same interference situation occurs repetitively that an official complaint is reported. This situation also greatly depends on the conditions of use (fixed or mobile) of the victim radio system. 4.2.1 Radio frequency interference to a fixed radio receiver Before the wide development of portable radio devices, radio systems that suffered from interference were generally used in fixed locations. This is the case, for example for a TV set in a flat or home: if this TV set is regularly interfered with by radiation or conduction from other equipment located inside or just outside the house, then it is probable that a complaint will be issued. The same applies if a satellite antenna, a fixed radio link, or a cellular phone base station suffers from radio frequency interference. 4.2.2 Radio frequency interference to a mobile radio receiver The multiplication of portable radio systems such as cellular phones and short range radio systems has changed the conditions regarding interference situations and interference complaints. The ability for the user to move makes it easier to resolve a particular interference case, but makes it more difficult to recognise that an interference case has actually occurred. 4.2.3 Consequences of the move from analogue to digital radio systems In addition to the conditions of use of the victim radio system, technological evolution in radio services with successive phasing out of analogue and exponential growth of digital applications also has consequences on the number of reported interference cases. If a digital mobile phone or a wireless LAN receiver cannot receive the signal from the nearest base station or access point because of an unwanted emission from a nearby equipment, the user will never suspect this equipment and will not even consider the possibility of an Copyright International Electrotechnical Commission interference occurring. He will assume that the coverage of the network is poor and will move to another place to make his call or to get his connection. Furthermore, as these systems are generally frequency agile, if one channel is interfered with, the system will choose another channel, but if all other channels are occupied, then the phone will indicate that the network is busy, and once again, the user will think the network capacity is not large enough to accommodate his call, but he will never suspect an EMC problem. Generally for analogue systems, one can hear the interference. With digital and mobile systems, interference is much less noticeable (muting in audio reception, or frozen images on the TV set for DVB). In addition, modern digital modulations implement complex escape mechanisms (data error correction, frequency agile systems, etc.) so that the system can already be permanently affected from an EMC point of view before an interference case is actually detected. 4.3 Towards the loss of a precious indicator: interference complaints The evolutions detailed above - generalisation of mobile use of radio receivers and the move from analogue to digital radio services - will not reduce the number of interference situations, but continues to decrease the probability of getting significant numbers of interference complaints indicating an existing EMC problem. So, along with the growing development of portable digital radio devices, the usefulness of traditional interference complaints statistics to support the CISPR work will continue to diminish in importance.

Contents of GB/Z 6113.404-2023