1、Rec. ITU-R M.1033-1 3 RECOMMENDATION ITU-R M.1033-1 TECHNICAL AND OPERATIONAL CHARACTERISTICS OF CORDLESS TELEPHONES AND CORDLESS TELECOMMUNICATION SYSTEMS (Question ITU-R 114/8) (1994-1997) Summary This Recommendation provides the objectives and technical and operational characteristics for cordles
2、s telephones and cordless telecommunication systems. By summarizing and comparing the characteristics and providing associated references, the Recommendation provides guidance for administrations evaluating various cordless systems for their intended application. The ITU Radiocommunication Assembly,
3、 considering that new land mobile services, such as cordless telephones and cordless telecommunication systems providing a) communications in areas limited to a few hundred metres radius are becoming available to a large public; b) that in the longer term, Future Public Land Mobile Telecommunication
4、 Systems (FPLMTS) Recommendations will encompass future needs supported by digital cordless systems; however, in the interim, a Recommendation should include digital cordless systems; c) misused; d) access techniques conserves frequency spectrum; e) control of the radio path; 0 create operational pr
5、oblems; 8) between “cordless telephone” systems; h) for a Recommendation, that these services can use consumer-type devices which may create difficulties to administrations, and may be that the utilization of the radio spectrum should be as economical as possible and that the use of multi-channel th
6、at highly flexible and economical systems can be achieved without using a central controller for setting up that the widespread and increasing use of these equipments and the characteristics of their utilization may that certain administrations are encountering problems of mutual interference and in
7、advertent interaction that a number of systems have already been adopted by a wide range of administrations and can form the basis recommends that cordless telephones and cordless telecommunication systems (cordless systems) should conform to the following objectives and technical and operational ch
8、aracteristics: 1 General objectives Cordless systems should be designed with the following minimum basic objectives: - - - that the radio spectrum be used efficiently; that a system of high subscriber capacity be realized; that simple and miniature circuits be used to ensure that the weight and size
9、 of the equipment are comparable with ordinary telephones; that it can be provided economically and the cost of equipment can be reduced to be acceptable for a mass market; - 4 Rec. ITU-R M.1033-1 - that the system provide good quality for public communication and that a flexible system of operation
10、 can be provided that does not require complicated frequency management; that the system provide as far as possible normal telephone features; that the system provide security of call charges. - - 2 Operational and management objectives Cordless systems should allow operation and management procedur
11、es which ensure that: - in system operation, it is only necessary to manage the.number of cordless systems within the area determined by the distance at which interference occurs, while taking into account the subscriber capacity which is determined by the number of channels and the channel traffic:
12、 - flexible operation can be provided, so as to permit the use of a greater number of portable sets than the subscriber capacity per zone, if the number of cordless sets in use in the adjacent zone is small. 3 Access techniques Cordless systems should include the use of multi-channel techniques and
13、appropriate protocols which do not require the use of a centrai controller for the detection of idle channels. These techniques, also called self-trunking or dynamic channel selection, may employ FDMA-FDD, FDMA-TDD, as well as multi-carrier TDMA-TDD. Depending on the application the access technique
14、 should allow also in-call handover. 4 Since the start of cordless systems there has been an evolution in the areas of application which are covered. The services supported by cordless systems can therefore differ. Also, the service requirements can differ depending on the market segment to be serve
15、d, for example, public, residential, business, etc. Therefore the importance of the different features of a cordless system depends on its application. Features and areas of application To facilitate the characterization of different cordless systems, the following description of features and applic
16、ations should be used. 4.1 Cordless telephony (residential) Cordless telephony in its basic form is provided by a cordless telephone, which consists in its simplest version of two parts: - - a portable set. Each part uses multi-channel access techniques and can individually perform the following ope
17、rations: - search for idle channels; - - a fixed part which is connected to a subscriber line of the ordinary telephone network, and set up speech paths using the selected channel; check identification codes in the signals between the fixed part and the portable set in order to ensure that only asso
18、ciated units will lock to each other. More advanced installations allow the use of more portable sets. 4.2 Cordless PABX In addition to basic cordless telephony, single cell or multi-cell systems can serve the needs of small business or large business respectively for cordless extensions and on-prem
19、ises communications networks. STD*ITU-R RECMN M-LIl33-L-ENGL 1777 = 4855232 0527037 024 Rec. ITU-R M.1033-1 5 4.3 Seamless handover Seamless handover, which is an optional feature, allows systems to provide uninterrupted communications throughout the coverage area while the call is in progress. Hand
20、over may occur within a single cell or between adjacent cells. 4.4 Cordless local area networks (CLAN) Cordless LANs or more general non-voice services, including those available in the ISDN, can be offered by fully digital systems. They are the replacement of a drop-cable connection from teIminals
21、to an ISDN or LAN backbone in order to support the “wireless office” concept. 4.5 Telepoint In this application the system offers the portable set access to public base stations via a fully standardized air interface, including the necessary protocols for call Set-up and authentication which should
22、guarantee billing security. These systems may provide roaming, including international roaming. 4.6 Local loop replacement In this application the system provides a replacement of the local loop (extension of the PSTN, ISDN into the customers premises) by radio. Smooth billing should be guaranteed b
23、y secure authentication and the system should be capable of serving a large number of users. 4.7 Tandeming to cellular radio The flexibility and high quality of cordless communications offers a means of enhancing other mobile services by cordless extensions (e.g. telepoint in trains, handhelds conne
24、cted to a cellular mobile). 5 Existing systems Cordless systems employing dynamic multiple access techniques and supporting varying subsets of the possible features and areas of application have been developed in many countries. Annex 1 provides information about existing systems. ANNEX i Systems fe
25、atures and applications This Annex gives information about ten existing cordless systems. Table 1 shows the features and applications which can be supported by the different systems using the categories described in this Recommendation. The major specifications of these systems are summarized in Tab
26、les 2 and 3 for analogue and digital systems respectively. The main features of the ten systems and the references to the detailed specifications are described in Appendices 1 to 10. STD-ITU-R RECMN M=L033-L-ENGL 1997 = 98552LZ 0529040 89b = 6 RW. ITU-R M.1033-1 TABLE 1 Cordless telephony (residenti
27、al) Cordless PABX Features and applications X X X X X X X X X X X System No. il 213141516 Seamless handover Cordless local area network X X X X X X X Telepoint Local loop replacement X X X X X X X X Tandeming to cellular radio TABLE 2 System characteristics of analogue systems System i (1) Japan, 19
28、88 X X Class of emission Multiple access scheme Duplex type Transmit frequency band (MHz) - fixedpart - portableset Radio frequency channel spacing GHz) Number of speech channels Transmitted power, e.r.p. (mW) - fixedpart - portableset - indoor - outdoor Voice signals - type of modulation - processi
29、ng Typical service range (rn) Audio signal-to-noise ratio (a) Identification code FDD: frequency division duplex (I) System 1 is in use in Japan. FlD, F2 (A, B, C, D, N, X), F3E FDMA FDD 380.2-381.3 253.9-255.0 12.5 87 (adding two control channels) Maximum Maximum 50 100 Angular Minimum SINAD 20(4)
30、3 x lo7 combinations (*) (3) Antenna input power. System 2 is used by several European countries. 7 18 19 Il0 I I X X System 2) CEPT, 1987 F3E or G3E FDMA FDD 959-960 914-9 15 25 40 Maximum 10 Maximum 10 50 100 Angular syllabic compandor IT-T Rec. G. 162 (suggested) Minimum SINAD 20(5) 3 x lo4 combi
31、nations (4) 6) Suggested value using an IEC Publication 489-3 standard input signal level of 10 pV. Ratio measured through psophometric weighting network (according to iT-T Recommendation P.53 (same as 0.41) using an input signal field strength of 30 dBpV/m. z h m 08 mm 2 O 3 Ao 2 22 gg E 3 EE c1 ST
32、DOITU-R RECMN M*1033-1-ENGL 1777 = 4855232 052711i3 555 M Rec. ITU-R M.1033-1 APPENDIX 1 TO ANNEX 1 General description of System 1 (analogue) 1 System configuration RCR Standard, 19881 The basic configuration of a cordless telephone System 1 employing the analogue multi-channel access technique is
33、shown in Fig. 1. FIGURE 1 Basic block diagram of a cordless telephone system using multi-channel accessing techniques I I Fixed part A: subscriber line B: ordinary telephone C: hybrid D: signal controller E transmitter F: synthesizer G: receiver H: idle channel detector I: identification code ROM 1x
34、 K: control channels L: speech channels M: receiver N: synthesizer O: transmitter P: signal controller Q: idle channel detector R: handset S: identification code ROM 9 Portable set This system does not use a central controller. In the system, two dedicated control channels are assigned. Each cordles
35、s telephone itself performs the functions of searching for idle channels and setting up a speech path over the selected channel. 10 Rec. ITU-R M.1033-1 Figure 2 shows the configurations of a multi-function cordless telephone. FIGURE 2 Configuration of multi-function cordless telephone a Portable set
36、 Portable set a) Block diagram of a multi-terminai cordless telephone I I I I I I ine m Portable set v Fixed part b) Block diagram of a cordless key telephone a Portable set I * “ / Fixed part 1 . - - - - - - - Portable set Portable set m Portable set 4 / Fixed part m c) Block diagram of a multi-zon
37、e cordless telephone A: subscriber line B: signal controller C: transceiver L: line controller Rec. ITU-R M.1033-1 The following types are typical examples: - multi-terminal cordless telephone, - cordless key telephone, - multi-zone cordless telephone. 11 2 Operational characteristics 2.1 Identifica
38、tion code 2.1.1 Only when its own identification code coincides between the fixed part and the portable set in the control channel, the fixed part and portable set shall switch to a speech channel. The length of the identification code shall be 25 bits. 2.1.2 Subcarrier MSK (fast FSK): 1 200,2400 bi
39、ds Direct modulation: 600,1200,2 400,4 800 bit/s Modulation methods and bit rates for an identification code are as follows: 2.2 Idle channel decision Carrier sense shall be performed immediately before transmission and if more than 2 pV is sensed, a radio signal shall not be emitted. 2.3 Occupied t
40、ime of control channels Considering the common use of dedicated control channels and easy introduction of sleep mode in portable sets, for originating calls from portable sets the occupied time shall be 1.3 s or less. For originating calls from fixed parts the occupied time shall be 4 s or less. 2.4
41、 Transmitter power-off on disconnection When disconnection is initiated, or when a radio signal is not received on any speech channel, the transmitter shall be turned off automatically. 2.5 Transmitter power-off in case of failure When a failure in the radio equipment causing continuous transmitter
42、power in the control channel is found, the transmitter shall be automatically turned off within 60 s. REFERENCES RCR Standard December, 19881 250 MHd380 MHz Band Radio Equipment for Cordless Telephone. STD-13. Research and Development Centre for Radio Systems, Japan. 12 Rec. ITU-R M.1033-1 APPENDIX
43、2 TO ANNEX 1 General description of System 2 (analogue) 1 System configuration The configuration of an analogue cordless telephone of System 2 employing the multiple channel access technique is shown in Fig. 3. FIGURE 3 System configuration 7- I I l l l I I I C t l I l I I 1 I J I I I l l I I I I Ra
44、dio paths I I I l I I I y; I- 40 paired channels I ma I L I Fixed set Portable set A: B: C: D: E: F: G: H I: subscriber line line interface signal controller and CPU identification code PROM frequency synthesizer transmitter receiver duplexer associated telephone J: duplexer K receiver L synthesizer
45、 M: transmitter N: signal controller and CPU O: identification code PROM P: handset The system configuration that has been adopted does not use a control channel to set up the RF connection between the fixed part and portable sets. Occupancy of an RF channel may be initiated by the fixed part or the
46、 portable set by following the same procedure. 2 Call setting-up procedures The procedures for setting up a call are given in Fig. 4. STD-ITU-R RECMN M-1033-3-ENGL 1777 4855232 05270Li7 LTO Rec. ITU-R M.1033-1 13 FIGURE 4a Cordless originated call Telephone line Fixed set Portable set : II Scanning
47、Line connection test I- I monitor I I Scanning Scanning I f by identification I Il I Dialling monitor - On-hook Scanning u STD-ITU-R RECMN M*L033-L-ENGL 1797 4855232 0527048 037 M 14 Rec. ITU-R M.1033-1 FIGURE 4b Cordless terminating call Telephone line Ring detection search for free channel - Tx on
48、 I Fixed set Portable set . I. I. i j I I I I Radio link test I Call message with ID I-. Reply message with ID 4 - Incoming cd? - I I I I I I I II Disconnection of line relay Scanning I . I I Off hook signal I iI I. I I I I I I I Calldetected I Handshaking by identification code (ID) exchange I i Ri
49、nging 0 - Off-hook I-, Channel U monitor r Call clearing signal sequence I- On-hook TY nff Tx off Ir Rec. ITU-R M.1033-1 15 2.1 Waiting mode In this mode, the receiver of each part of the cordless telephone set is constantly scanning the available FW channels, searching for a signal which contains its matching identification code. 2.2 Call originating mode When the need for a radio-frequency channel arises in either of the two parts of a cordless telephone set, that part searches for an idle duplex channel by sensing the field strength on
