CEPT T R 24-03 E-1988 Radio Characteristics of Cordless Telephones《无绳电话无线电特征》.pdf

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1、CEPT T/R*24-03E m 23264/4 00067b0 9 24-03 Page E 1 Recommendation T/R 24-03 (Cannes 1983, revised in Copenhagen 1987) RADIO CHARACTERISTICS OF CORDLESS TELEPHONES Recommendation proposed by the “Radiocommunications” Working Group T/WG 3 (R) Text of the Recommendation adopted by the “Telecommunicatio

2、ns” Commission: “The European Conference of Postal and Telecommunications Administrations, considering (a) that there is an increasing interest by the public in using cordless telephones, (b) that the use of such equipment can cause problems for Administrations, (c) that harmonisation-on the broades

3、t possible basis-of the radiotechnical parameters for cordless telephones is highly desirable, (d) that it would be advantageous for the Administrations, the users and the manufacturers of cordless telephones to proceed to the exchange between Administrations of the reports on tests in accordance wi

4、th Recommendation (e) that the object aimed at should be the mutual recognition, by the member Administration of the CEPT, of such T/R 7 1-02, test reports, noting that Recommendation T/SF 30 deals with the requirements of the user and operational characteristics and Recom- mendation T/CS 34-18 deal

5、s with the switching and signalling requirements, recommends 1. that the cordless telephones operating in the paired bands 914-915 MHz and 959-960 MHz shall meet the radiotechnical specifications given in the Annex I of the present Recommendation, 2. that the methods of measurement, used to ascertai

6、n that the cordless telephones meet the requirements, shall be in conformity with those mentioned in the Annex I of the present Recommendation, 3. that, in drawing up the test reports, the Administration shall, as much as possible, follow the order of the tests and the numbering of the paragraphs us

7、ed in the Annex I to the present Recommendation.” Edition of September 15, 1988 CEPT T/R*24-03E 2326414 00067b1 O = i I. TIR 24-03 E Annex 1, Page 1 Annex I Technical characteristics, test conditions and methods of measurement for radio aspects of cordless telephones, operating in the paired bands 9

8、14-915 MHz and 959-960 MHz O Edition of September 15, 1988 CEPT T/R*24-03E 232bV14 0006762 2 W TIR 24-03 E Annex I, Page 2 Table of contents Pages 1. Definition, principles of operation and general requirements 3 1.1. Definition. 3 1.2. Procedure to set up the r.f.-connection between fixed and porta

9、ble part 3 1.3. Frequency aspects . 4 1.4. General requirements. . 4 2. Test conditions, power sources and ambient temperatures . 7 2.1. Normal and extreme test conditions . 7 2.2. Test power source . 7 2.3. Normal test conditions . 7 2.4. Extreme test conditions . 7 2.5. Procedure for tests at extr

10、eme temperatures 8 3. 3.1. 3.2. 3.3. 3.4. 3.5. 3.6. 3.7. 3.8. 4. 4.1. 4.2. 4.3. 4.4. 4.5. 4.6. 4.7. 5. 5.1. 5.2. 5.3. 5.4. 5.5. 5.6. 5.7. 6. 6.1. 6.2. 6.3. 7. 7.1. 7.2. General conditions . Arrangements for test signals applied to the receiver via a test fixture or a test antenna . Receiver circuitr

11、y . Receiver rated audio output . Normal test modulation. Encoder for receiver measurements Normal coded test signal Test fixture Test site and general arrangements for measurements involving the use of radiated fields 8 8 8 9 9 9 9 9 . . 10 Transmitter 12 Frequency error 12 Carrier power . 12 Adjac

12、ent channel power 13 Frequency deviation 16 Intermodulation attenuation 17 Residual modulation 18 Spurious emissions . 19 Receiver. . 19 Maximum usable sensitivity and secondary sensitivity expressed as fieldstrength 19 Message acceptance 20 Co-channel rejection 20 Adjacent channel selectivity . 20

13、Spurious response rejection . 22 Intermodulation rejection 23 Spurious radiations 23 Additional requirements . 24 Audio frequency response and harmonic distortion factor of the cordless telephone 24 Definitions 24 Method of measurement 24 Limits 24 Presentation of equipment for type approval 24 Choi

14、ce of model for type approval 24 Channel selection . 24 8. Accuracy of measurements 24 Appendix A. Guide on the use of radiation test sites 25 O Edition of September 15, 1988 CEPT T/R*24-03E 2326434 0006763 4 TIR 24-03 E Annex I, Page 3 1. DEFINITION, PRINCIPLES OF OPERATION AND GENERAL REQUIREMENTS

15、 1.1. Definition A cordless telephone is a telephone terminal connected to an exchange line or an extension line and is integrated with or accompanied by a normal telephone set. It consists of two parts which are connected by a radio link: - a fixed part - a portable part permitting the same basic f

16、unctions as a normal telephone set within a limited area A cordless telephone may be either: (a) a fully functional cordless telephone, on which calls can be set up and answered by the portable part; (b) a limited cordless telephone where the portable part has no facility for initiating outgoing cal

17、ls. Facilities for answering calls without using a radio link shall be provided. Procedure to set up the r.f.-connection between fixed and portable part Occupancy of a radio frequency channel may be initiated by the fixed part, or the portable part, if suitably equipped, by following the same proced

18、ure. Both fixed and portable parts comprise a transmitter and a receiver which will perform full duplex operation. When the need for a radio frequency channel arises in any of the two parts of a cordless telephone set, this part will act in general as follows: (a) the initiating part searches for an

19、 idle duplex channel. A channel is considered to be idle if the initiating part of the cordless telephone senses that the radio frequency fieldstrength on that specific channel is below a specified limit; (b) on the ide1 (duplex) channel, found under (a), the initiating part starts transmitting sign

20、als to the other part of the same cordless telephone set. These signals contain an identification code which offers at least 999.999 different combinations; (c) the receiver of each part of a cordless telephone set is constantly scanning, searching for a signal which contains its matching identifica

21、tion code. Upon detection of this code, the receiver stops scanning and initiates its transmitter to occupy the corresponding return frequency of the duplex pair and to transmit its identification code to the initiating part; (d) as soon as the receiver of the initiating part detects its matching id

22、entification code on the return frequency of the selected duplex channel, the initiating transmitter stops transmitting identification signals; around the fixed part. or 1.2. (e) the duplex channel becomes available for the transmission of dialling tones and speech. Edition of September 15, 1988 CEP

23、T T/R*24-03E H 232b434 000bb4 b TIR 24-03 E Annex I. Page 4 1 .3, Operating frequencies Cordless telephones shall be constructed to use all of the following duplex frequencies. Transmitting frequencies Portable part 914.0125 MHz 914.0375 MHz 914.0625 MHz 914.0875 MHz 914.1125 MHz 914.1375 MHz 914.16

24、25 MHz 914.1875 MHz 914.2125 MHz 914.2375 MHz 914.2625 MHz 914.2875 MHz 914.3125 MHz 914.3375 MHz 914.3625 MHz 914.3875 MHz 914.4125 MHz 914.4375 MHz 914.4625 MHz 914.4875 MHz 914.5125 MHz 914.5375 MHz 914.5625 MHz 914.5875 MHz 914.6125 MHz 914.6375 MHz 914.6625 MHz 914.6875 MHz 914.7125 MHz 914.737

25、5 MHz 914.7625 MHz 914.7875 MHz 914.8125 MHz 914.8375 MHz 914.8625 MHz 914.8875 MHz 914.9125 MHz 914.9375 MHz 914.9625 MHz 914.9875 MHz Fixed part 959.0125 MHz 959.0375 MHz 959.0625 MHz 959.0875 MHz 959.1125 MHz 959.1375 MHz 959.1625 MHz 959.1875 MHz 959.2125 MHz 959.2375 MHz 959.2625 MHz 959.2875 M

26、Hz 959.3125 MHz 959.3375 MHz 959.3625 MHz 959.3875 MHz 959.4125 MHz 959.4375 MHz 959.4625 MHz 959.4875 MHz 959.5125 MHz 959.5375 MHz 959.5625 MHz 959.5875 MHz 959.6125 MHz 959.6375 MHz 959.6625 MHz 959.6875 MHz 959.7125 MHz 959.7375 MHz 959.7625 MHz 959.7875 MHz 959.8125 MHz 959.8375 MHz 959.8625 MH

27、z 959.8875 MHz 959.9125 MHz 959.9375 MHz 959.9625 MHz 959.9875 MHz Channel number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 The channel separation is 25 kHz. The duplex distance is 45 MHz. The frequency band 914-915 MHz shall be us

28、ed by the transmitter of the portable part. 1.4. General requirements The performance of a cordless telephone shall be such that its interaction with the public switched telephone network shall be as near as possible to that of a normal telephone. Only frequency or phase modulation (F3E or G3E) shal

29、l be used. 1.4.1. Modulation Edition of September 15, 1988 CEPT T/R*24-03E 2326434 0006765 8 1.4.2. 1.4.3. 1.4.4. 1.4.5. 1.4.6. 1.4.6.1. 1.4.6.2. 1.4.6.3. 1.4.6.4. TIR 24-03 E Annex I, Page 5 Antenna The equipment shall be constructed such as to function only by means of an integral antenna. The use

30、 of an external removable antenna shall be excluded in the design and construction of the equipment. In this specification, an integral antenna is defined as one which is designed to be connected permanently to the transmitter/receiver without the use of a connector and/or the use of a feeder. Only

31、the use of an omnidirectional antenna shall be allowed. Compending To improve the signal to noise ratio and the subjective quality it is suggested that syllabic compression and expanding of the audio signal in accordance with CCITT Recommendation G. 162 be incorporated or that a speech controlled am

32、plifier at the audio input of the base stations be used. In the latter case the time constant should be less than 10 milliseconds for amplification reduction and between 100 milliseconds and 1 second for regaining full amplification. Threshold level for R.F.-sensing and minimum observation time To d

33、etermine the availibility of a channel during the scanning procedure both parts of a cordless telephone set shall be equipped with an R.F.-level detector which provides a R.F.-sensing facility. A channel shall be considered as “not in use” if the median level of the fieldstrength is lower than 20 dB

34、 relative to 1 microvolt per metre. The minimum observation time before a channel is considered to be available shall be 100 milliseconds. The maximum observation time of occupied channels not loaded by a datasignal shall not exceed 30 milliseconds per channel. Scanning time In case of an incoming r

35、inging voltage from the telephone line, the scanning procedure shall start within one second after detection of the ringing signal. When a call is initiated from the portable part, the scanning procedure shall start immediately. When a channel is available, the time between initiating a connection a

36、nd seizure of the channel shall be no more than 5 seconds. When a free channel is located the initiating part shall transmit identification signals for no longer than 3 seconds. If the opposite part has not responded after 3 seconds, the initiating part recommences searching for another free channel

37、. In the case of an incoming call this procedure continues as long as there is a ringing tone. In the case of an outgoing call from the portable part and when no channel is seized within 5 seconds a local busy tone shall appear for at least 3 seconds. Use of the identiJ5cation code General In the pr

38、ocedure to set up the RF connection between the fixed part and the portable part, the initiating part shall transmit a unique identification code until an answer from the opposite part containing the same unique identification code is received (see Clauses 1.2. and 1.4.5.). The exchange of identific

39、ation codes shall ensure that only associated parts will lock to each other. The exchange of the code The identification code shall also be transmitted with every signalling information transmitted over the radio channel from the portable part, which is intended for the telephone line. Signalling in

40、formation shall only be forwarded to the telephone line if the identification code, which was received, matches to the identification code of the fixed part. As an alternative to the above, the identification code shall be used to ensure that only the associated fixed and portable parts will lock to

41、 each other. To ensure continued locking during a call this identification procedure shall be exchanged between the fixed and the portable part and be repeated at intervals no longer than 45 seconds. This may be achieved by audible signalling during the conversation or preferably by inaudible out-of

42、-band signalling. The number of codes and their protection The number of code combinations shall be at least 999.999. Protection against unauthorised changes of the code shall be incorporated. Administrations may coordinate the assignment of codes. Wrong identification codes If wrong identification

43、codes are received twice, the RF-connection shall be terminated (see Clause 1.4.8.). Edition of September 15, 1988 CEPT T/R*Z4-03E 232b4L4 000b7bb T = TIR 24-03 E Annex 1, Page 6 r 1.4.7. 1.4.8. 1.4.8.1. 1.4.8.2. 1.4.8.3. 1.4.9. 1.4.9.1. 1.4.9.2. 1.4.9.3. 1.4.9.4. Answering incoming culls When an in

44、coming call is answered by means of the portable part, it shall transmit a coded answer signal, including the identification code. On receipt of this signal the fixed part shall create the appropriate line condition. Termination of the R.F.-connection and line connection After termination of the R.F

45、.-connection in accordance with points 1.4.8.1. to 1.4.8.3. the telephone line loop connection should be immediately released, unless the conversation has been taken over by the fixed part. Termination of the R.F.-connection When the R.F.-connection is to be terminated, the part of the cordless tele

46、phone set which initiates the termination shall transmit 4 times a coded termination message, including the identification code which would be used for initiating a R.F.-connection. The R.F. circuit shall then be disconnected and the cordless telephone set shall return to the idle condition. Time li

47、mitation on channel occupancy To prevent unintended occupation of a radio channel the equipment shall automatically terminate a connection after 10 to 15 minutes by cutting the radio link. Termination shall be preceded by a warning signal. A facility for the subscriber to cancel this termination may

48、 be provided. Interruption of a connection due to low fieldstrength The portable part of the cordless telephone is considered to be “out of range” if the median level of the fieldstrength at the receiving part is less than 30 dB relative to one microvolt per metre, in which case the portable part sh

49、all produce a warning signal after 0.5 f 0.1 second. The line connection and R.F. circuit in use by the cordless telephone set shall be terminated automatically if the portable part of the cordless telephone has remained “out of range” for more than 10f 1 sec. Co-operation with the normal telephone set Incoming calls Incoming calls shall initially activate the normal telephone set and the fixed part of the cordless telephone. If this incoming call is answered by the normal telephone set any action by the cordless telephone shall cease. When the call is answered by the portable part, an indi