1、DRAFT prETS 300 004 March 1990 UDC: Key words: Transmission characteristics at 2-wire analogue interface of a digital Private Automatic Branch Exchange (PABX) (TE 10-02) ETSI European Telecommunications Standards Institute ETSI Secretariat: B.P.152 F - 06561 Valbonne Cedex France TP. + 33 92 94 42 O
2、0 TF. + 33 93 65 47 16 Tx. 47 O0 40 F W 31.104583 0007273 I rd TE 10-02 TRANSMISSION CIiAACTEFUSTICS AT A %-WIRE ANALQGUE INTERFACE OF A DIGITAL PABX TABLE OF CONTENTS Eaiitioi;c;6inie.G, 6 4.1 . 6 4.2 Definition of Parameters, 6 4.2.1 Parame ters relevant for Echo and stabflity . 6 4.2.1.1 Terminai
3、 Balance Return Loss (TBRL) 7 4.2.1.2 StabilityLms . 8 4.2.2 n 8 %wire interface SDGC .cations . 9 5.1 Caracteristics h 9 5.1.1 acterlsticsofIeesK2andM2, . 9 5.1.1.1 PABXimpedance. 9 5.1.1.1.1 Nominalvalue . 9 5.1.1.1.2 RetumLoss . 9 5.1.1.2 Impedanceunbalanceaboutearth . 10 5.1.1.3 RelativeLevels .
4、 11 5.1.1.3.1 Nominallevels 11 5.1.1.3.1.1 InterfaceM21 . 11 5.1.1.3.1,2 InterfacesK2andM22 . 11 5.1.1.3.2 Tolerances of relative levels 12 5.1.2 Characte risticsofinterfaceL2 12 5.1.2.1 PABXimpedance 12 5.1.2.1.1 Nominalvalue 12 5.1.2.1.2 Returnloss . 12 5.1.2.2 Impedance unbalance about earth . 12
5、 5.1.2.3 Relativelevels . 13 5.1.2.3.1 Nominal levels . 13 5.1.2.3.2 Tolerances of relative levels 13 5.2 acteristics of half connect- . 14 Characteristics common to all 2-wirc a- Dterfaceg . 14 5.2.1.1 Transmissionloss . 14 5.2.1.1.1 Nominal value . ; 14 5.2.1.1.2 Tolerances of transmission loss .
6、14 5.2.1.1.3 Short-term variation of loss with time 14 5.2.1.1.4 Variation of gain with input level . 14 5.2.1.1.5 Loss distortion with frequency 15 5.2.1.2.1 Absolutegroupdelay . 18 5.2.1.2.2 Group delay distortion with frequency 18 I 6 5.2. l 5.2.1.2 Groupdelay . 18 ETS TE10-02 February7. 1990 Pag
7、e 1 9 311011583 00072711 3 W 5.2.1.3 Single frequency noise 19 5.2.1.4 Crosstaik 19 5.2.1.4.1 Inputcrosstalk 20 5.2.1.4.2 Outputcrosstalk . 21 5.2.1.5 Total distortion including quantizing distortion . 21 5.2.1.6 Discrimination against out-of-band signals appliedtotheinputintedace 22 5.2.1.6.1 Input
8、signalsabove4.6kHz. 22 . 5.2.1.6.2 signalsbe10w300Hz . 22 5.2.1.6.3 Overall requirement . 22 Spurious out-of-band signais received at the outputinterface 22 5.2.1.7.1 Level of individual components 22 5.2.1.7.2 Oviall requirement . 22 5.2.1.8 Echoandstabiity., . 23 5.2.1.8.1 TermlnalBalanceRetumLoss
9、UBlU) 23 5.2.1.8.2 Stabffltyloss . 23 5.2.2 CharacteristicsofintedacesK2andM2 24 5.2.2.1 Nominal value of transmission loss 24 5.2.2.2 Noise . 24 5.2.2.2.1 Weightednoise . 24 5.2.2.2.1.1 Outputconnection . 24 5.2.2.2.1.2 Input connection 25 5.2.2.2.2 Unweightednoise . 25 5.2.2.2.3 Impulsivenoise. .
10、25 5.2.2.3 Values of total distortion . 26 5.2.3 j 28 5.2.3.1 Nominal value of transmission loss 28 5.2.3.2 Noise . 28 5.2.3.2.1 Wefghtednoise . 223 5.2.3.2.1.1 Output connection . 29 5.2.3.2.1.2 Input connection 30 5.2.3.2.3 Impulsive noise 31 5.2.3.3 Valuesoftotaldistortion 31 Test networks for PA
11、J3X input imwdances at interfaces K2 and M2 33 Relative levels for K2 and M22 interfaces in dRr 34 Test Networks for PABX input imp- . 35 5.2.1.7 Annex A nostandard TE 10-02) Annex B (To Standard TE 10-02) Annex c (to standard TE 10-02) Annex D (FStandard TE 10-02) Relative levels at interface L2 an
12、d M21 in dBr, . 36 Test networks for TBlU in diEe rent EuInDean Administrations . 37 C0rnDe-n of Losses on Loner - or Short 2 Wm . 1.39 ImDedance unbalance about eart h in dinerent Eurouean Administrations 40 Annex E (To Standard TE 10-02) rdTE 1o-ou AnnexGI to Standard TE 10-021 W for sinusoidal si
13、gnals at all frequencies between 200 Hz and 3600 Hz. This frequency band is determined by the fiiters used in the interface designs. Note L : Certain implementations of the I2 interface, designed for use together with a minimum line length, will achieve a half connection stability loss of 6dB if thi
14、s half connection stability bss is detexmined with the “worst case“ temation which includes this minimum extension line. pote 2 : Some Administrations may find that open- and short-circuit terminations are sufffciently representative of worst case conditions. Note 3 : in some PABXS the 4-wire call p
15、ath is left open during the dialling or before the terminating equipment has answered the call. thus preventing the effects due to short-circuit and open-circuit termination conditions. m TE10-02 February 7, 1990 Page 23 - 3404583 0007276 2 5.2.2 5.2.2.1 Note 4: Where the digital PABX is connected t
16、o the public digital exchange using a 4-wire line, the half connection of the digital PABX may provide the total stability loss of the entire path across the public network. The value of stabiiity loss (SL) that is required for a 2-wire interface is a matter of national control provided that the req
17、uirements of CClT Recommendation G. 122 are met. A SL value of 6 dB at ail frequencies between 200 Hz and 3600 Hz will ensure that the CCITT G. 122 requirements are met. However, SL values of between 6 dB and O dB wiu. formaily comply with the present requirements of G. 122 (Red Book 1984) but furth
18、er study is required to provide guidance in this area. Note 5 : in the case that the input impedance is not equal to the balance impedance, the Austrian FTT accept a, 2 4 dB under open- or short-circuit terminating conditions. Nominal value of transmission loss. Note : According to the relave levels
19、 defined in paragraph 5.1.1.3, the nominal transmission losses of input or output connection half connection with K2 and M2 interfaces can be calculated according to and - 75.0 dBmp for equipment with signaliing on separate wires. Note 1: For calculation of these values, two components of noise must
20、 be considered. One of these arises at the quiet decoder output. the other from dogue sources, such as signang equipment. The first component is Wted by CCl“ Recommendation G.714 8 10 as receiving equipment noise to -75 dBmp: the other component is limited to -70 dF3mOp for K2 interface and M22 inte
21、rface without feeding bridge and to -67 dBmp for M2 1 interface and M22 interface with feeding bridge. pote 2 : The Ilmit for interfaces with feeding bridge (ali M21 interfaces and some M22 interfaces) depends on the output relative levels and can be calculated by the same formula reported in Q 5.2.
22、3.2.1.1 for interface L2, considering the same range of output relative levels for M21 interface and a wider range for M22 interface (see Annex B TE 10-02). m TE10-02 February 7, 1990 Page 24 - I 3404583 0007277 4 52.2.2.1.2 Input connection. The maximum value for the overall weighted noise measured
23、 at the testpoint To in the talking state at the K2 and M2 interface shaii be :- - 64.5 dBmOp for equipment with signalling on the speech wires and without feeding bridge (ali K2 interfaces and some M22 interfaces): - 66.0 di3mOp for equipment with signalling on separate wires. Note 1 : For calculat
24、ion of these values two components of noise must be considered. One of these arises from the encoding proCess, the other from analogue sources, such as signalling equipment. The first component is limited by CClT Recommendation G.714 9 as idle channel noise to -66 dBmOp: the other component is limit
25、ed to - 70 dBmp for f B u3 O Em TE10-02 I I/ I/ 1 February7, 1990 Page 27 W 390LI5B3 0007300 O W 5.2.3 Characteristics of interface L2 5.2.3.1 Nominal value of transmission loss : According to the relative levels defined in 5.1.1.3, the nominal transmission losses of input or output connections conn
26、ection with L2 interfaces can be computed according to Standard “E 10- 01.8 4.3.1 and NL, of a half 5.2.3.2 Noise 5.2.3.2.1 Weighted noise. : For the calculation of noise, worst case conditions at the L2 interface are assumed. The band limiting effect of the encoder on the noise has not been taken i
27、nto account. m TE10-02 February 7, 1990 Page 28 5.2.3.2. I. 1 Output connection. pote 1 : fio components of noise must be considered. One of these, (noise arising from the decoding process) is dependent upon the output relative level. The other (power supply noise from the feeding bridge) is indepen
28、dent of the output relative level. The first component is iimited by CCl“ Recommendation G.7 14, !j 10 as receiving equipment noise to -75 the other component is assumed by CC“ Recommendation C. 103, to be 200 pWp (-67 dBmp). Thls can be caused by the main DC power supply and auxiliary DC-DC convert
29、ers. Note 2 : Inormation about the subject of noise on the DC power supply is given in Supplement No. 13 to the G-Series Recommendations (Orange Book, Volume III-3). The total psophometric power allowed at a L2 interface with a relative output level of PAN: weighted noise power caused by analogue fu
30、nctions according to CCiTT Recommendation G. 103; LIN: receiving equipment noise (weighted) for PCM translating equipment according to CCflT Recommendation G.7 14, Q 10, Le. - 75 dBmOp; bo: total weighted noise level for the output connection of the digital PAB2C. The resulting psophometrfc powers and the total noise levels for the output connection shall be: Io = -5.0 -6.0 -7.0 dBr PTN =210 208 206 pWp ho =46.8 46.8 46.9 dBmp m TE10-02 February 7, 1990 Page 29
