hash stringlengths 32 32 | doc_id stringlengths 5 12 | section stringlengths 5 1.47k | content stringlengths 0 6.67M |
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ad3845652ec99fdffd75badceec5143f | 06.32 | 3.3.2 Step‑up procedure to obtain the aav1[0..8] | Initialization of the step‑up recursion:
L_coef[0] = 16384 << 15;
L_coef[1] = vpar[1] << 14;
Loop on the LPC analysis order:
|= FOR m = 2 to 8:
|== FOR i = 1 to m‑1:
|== temp = L_coef[m‑i] >> 16; / takes the msb /
|== L_work[i] = L_add( L_coef[i], L_mult( vpar[m], temp ) );
|== NEXT i
|=
|== FOR i = 1 to m‑1:
|== L... |
ad3845652ec99fdffd75badceec5143f | 06.32 | 3.3.3 Computation of the rav1[0..8] | |= FOR i= 0 to 8:
|= L_work[i] = 0;
|== FOR k = 0 to 8‑i:
|== L_work[i] = L_add( L_work[i], L_mult( aav1[k], aav1[k+i] ) );
|== NEXT k:
|= NEXT i:
IF ( L_work[0] == 0 ) THEN normrav1 =0;
ELSE normrav1 = norm( L_work[0] );
|= FOR i= 0 to 8:
|= rav1[i] = ( L_work[i] << normrav1 ) >> 16;
|= NEXT i:
Keep the normrav1 for ... |
ad3845652ec99fdffd75badceec5143f | 06.32 | 3.4 Spectral comparison | This clause computes the variable stat needed for the threshold adaptation. It uses the array L_av0[0..8] computed in clause 3.2 and the array rav1[0..8] computed in clause 3.3.3.
Re‑normalize L_av0[0..8]:
IF ( L_av0[0] == 0 ) THEN
| FOR i = 0 to 8:
| sav0[i] = 4095;
| NEXT i:
ELSE
| shift = norm( L_av0[0] );
|= FOR i... |
ad3845652ec99fdffd75badceec5143f | 06.32 | 3.5 Periodicity detection | This clause just sets the ptch flag needed for the threshold adaptation.
temp = add( oldlagcount, veryoldlagcount );
IF ( temp >= 4 ) THEN ptch = 1;
ELSE ptch = 0; |
ad3845652ec99fdffd75badceec5143f | 06.32 | 3.6 Threshold adaptation | This clause uses the variables e_pvad, m_pvad, e_acf0 and m_acf0 computed in clause 3.1. It also uses the flags stat (see clause 3.4) and ptch (see clause 3.5). It follows the flowchart represented on figure 2.2.
Some constants, represented by a floating point format, are needed and a symbolic name (in capital letter) ... |
ad3845652ec99fdffd75badceec5143f | 06.32 | 3.7 VAD decision | This clause only outputs the result of the comparison between pvad and thvad using the pseudo‑floating point representation of thvad and pvad. The values e_pvad and m_pvad are computed in clause 3.1 and the values e_thvad and m_thvad are computed in clause 3.6.
vvad = 0;
IF (e_pvad > e_thvad) THEN vvad = 1;
IF (e_pvad... |
ad3845652ec99fdffd75badceec5143f | 06.32 | 3.8 VAD hangover addition | This clause finally sets the vad decision for the current frame to be processed.
IF ( vvad == 1 ) THEN burstcount = add( burstcount, 1 );
ELSE burstcount = 0;
IF ( burstcount >= 3 ) THEN
| hangcount = 5;
| burstcount = 3;
vad = vvad;
IF ( hangcount >= 0 ) THEN
| vad = 1;
| hangcount = sub( hangcount, 1 ); |
ad3845652ec99fdffd75badceec5143f | 06.32 | 3.9 Periodicity updating | This clause must be delayed until the LTP lags are computed by the RPE‑LTP algorithm. The LTP lags called Nc in the speech encoder are renamed lags[0..3] (index 0 for the first sub‑ segment of the frame, 1 for the second and so on).
Loop on sub‑segments for the frame:
lagcount = 0;
|= FOR i = 0 to 3:
|= Search the max... |
ad3845652ec99fdffd75badceec5143f | 06.32 | 3.10 Tone detection | This clause computes the tone variable needed for the threshold adaptation. Tone is only calculated for the VAD in the downlink. In the uplink VAD tone=0.
To reduce delay, this clause should be calculated after the processing of the current speech encoder frame. |
ad3845652ec99fdffd75badceec5143f | 06.32 | 3.10.1 Windowing | This clause applies a Hanning window to the input frame sof[0..159] to form the output frame sofh[0..159]. The input frame is the current offset compensated signal frame calculated in the RPE‑LTP codec. The array of constants hann[i] is defined in table 3.2.
Multiply signal frame by Hanning window:
|== FOR i = 0 to 79:... |
ad3845652ec99fdffd75badceec5143f | 06.32 | 3.10.2 Auto‑correlation | This clause computes the auto‑correlation vector L_acfh[0..5] from the windowed input frame sofh[0..159]. The input frame must be scaled in order to avoid an overflow situation. This clause is identical to the one used in the RPE‑LTP algorithm, with the exception that only five auto‑correlation values are calculated.
D... |
ad3845652ec99fdffd75badceec5143f | 06.32 | 3.10.3 Computation of the reflection coefficients | This clause calculates the reflection coefficients rc[1..4] from the input array L_acfh[0..4]. This procedure is identical to the one in clause 3.3.1 and the RPE‑LTP codec, with the exception that only four reflection coefficients are calculated.
Schur recursion with 16 bits arithmetic:
IF( L_acfh[0] == 0 ) THEN
|== FO... |
ad3845652ec99fdffd75badceec5143f | 06.32 | 3.10.4 Filter coefficient calculation | This clause calculates the direct form filter coefficients a[1..2] from the reflection coefficients rc[1..4].
Step‑up procedure to obtain the a[1..2]:
temp = rc[1] >> 2;
a[1] = add( temp, mult_r( rc[2], temp ) );
a[2] = rc[2] >> 2; |
ad3845652ec99fdffd75badceec5143f | 06.32 | 3.10.5 Pole Frequency Test | This clause uses the direct form filter coefficients a[1..2] to determine the pole frequency of the second order LPC analysis. If the pole frequency is less than 385 Hz tone is set to 0 and clause 3 terminates.
L_den = L_mult ( a[1], a[1] );
L_temp = a[2] << 16;
L_num = L_sub ( L_temp, L_den );
If pole is not complex t... |
ad3845652ec99fdffd75badceec5143f | 06.32 | 3.10.6 Prediction gain test | This clause uses the reflection coefficients rc[1..4] to calculate the prediction gain. If the prediction gain is greater than 13,5 dB then tone is set to 1 otherwise tone is set to 0.
Calculate normalized prediction error:
prederr = 32767;
|== FOR i=1 to 4
| temp = mult ( rc[i], rc[i] );
| temp = sub ( 32767, te... |
ad3845652ec99fdffd75badceec5143f | 06.32 | 4 Digital test sequences | This clause provides information on the digital test sequences that have been designed to help the verification of implementations of the Voice Activity Detector. Copies of these sequences are available (see clause A.2). |
ad3845652ec99fdffd75badceec5143f | 06.32 | 4.1 Test configuration | The VAD must be tested in conjunction with the speech encoder defined in GSM 06.10. The test configuration is shown in figure 4.1. The input signal to the speech encoder is the sop[...] signal as defined in GSM 06.10 table 5.1. The relevant parameters produced by the speech encoder are input to the VAD algorithm to pro... |
ad3845652ec99fdffd75badceec5143f | 06.32 | 4.2 Test sequences | The test sequences are described in detail in clause A.2.
Annex A (informative):
A.1 Simplified block filtering operation
Consider an 8th order transversal filter with filter coefficients a0..a8, through which a signal is being passed, the output of the filter being:
(1)
If we apply block filtering over 20 ms segments,... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 1 Scope | The present document specifies the digital test sequences for the GSM enhanced full rate speech codec. These sequences test for a bit exact implementation of the enhanced full rate speech transcoder (GSM 06.60 [2]), Voice Activity Detection (GSM 06.82 [6]), comfort noise (GSM 06.62 [4]) and the discontinuous transmissi... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 2 References | The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
• References are either specific (identified by date of publication, edition number, version number, etc.) or non‑specific.
• For a specific reference, subsequent revisions do not apply.
• Fo... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 3 Definitions and abbreviations | |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 3.1 Definitions | Definition of terms used in the present document can be found in GSM 06.60 [2], GSM 06.61 [3], GSM 06.62 [4], GSM 06.81 [5] and GSM 06.82 [6]. |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 3.2 Abbreviations | For the purposes of the present document, the following abbreviations apply:
ETS European Telecommunication Standard
GSM Global System for Mobile communications
For abbreviations not given in this subclause see GSM 01.04 [1]. |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 4 General | Digital test sequences are necessary to test for a bit exact implementation of the enhanced full rate speech transcoder (GSM 06.60 [2]), Digital test Voice Activity Detection (GSM 06.82 [6]), comfort noise (GSM 06.62 [4]) and the discontinuous transmission (GSM 06.81 [5]).
The test sequences may also be used to verify ... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 5 Test sequence format | This clause provides information on the format of the digital test sequences for the GSM enhanced full rate speech transcoder (GSM 06.60 [2]), Voice Activity Detection (GSM 06.82 [6]), comfort noise (GSM 06.62 [4]) and the discontinuous transmission (GSM 06.81 [5]). |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 5.1 File format | The test sequence files are provided in archive ts_100725v080100p0.zip which accompanies the present document.
Following decompression, four types of file are provided:
- Files for input to the GSM enhanced full rate speech encoder: *.INP
- Files for comparison with the encoder output: *.COD
- Files for input to t... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 5.2 Codec homing | Each *.INP file includes two homing frames at the start of the test sequence. The function of these frames is to reset the speech encoder state variables to their initial value. In the case of a correct installation of the ANSI-C simulation (GSM 06.53 [7]), all speech encoder output frames shall be identical to the cor... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 6 Speech codec test sequences | This clause describes the test sequences designed to exercise the GSM enhanced full rate speech transcoder (GSM 06.60 [2]). |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 6.1 Codec configuration | The speech encoder shall be configured to operate in the non-DTX mode. The VAD and SP flags shall be set to 1 at the speech encoder output. |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 6.2 Speech codec test sequences | Table 5 lists the location and size of the speech codec test sequences. |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 6.2.1 Speech encoder test sequences | Twenty-one encoder input sequences are provided. Note that for the input sequences TEST0.INP to TEST3.INP, the amplitude figures are given in 13-bit precision. The active speech levels are given in dBov.
- TEST0.INP - Synthetic harmonic signal. The pitch delay varies slowly from 18 to 143.5 samples. The minimum and max... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 6.2.2 Speech decoder test sequences | Twenty-one speech decoder input sequences TESTXX.DEC (XX = 0..20) are provided. These are derived from the corresponding TESTXX.INP sequences. In a correct implementation, the resulting speech decoder output shall be identical to the corresponding TESTXX.OUT sequences. |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 6.2.3 Codec homing sequence | In addition to the test sequences described above, two homing sequences are provided to assist in codec testing. TEST21.INP contains one encoder-homing-frame. TEST21.DEC contains one decoder-homing-frame. The use of these sequences is described in GSM 06.51 [8].
Table 5: Location and size of speech codec test sequences... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 7 DTX test sequences | This subclause describes the test sequences designed to exercise the VAD algorithm (GSM 06.82 [6]), comfort noise (GSM 06.62 [4]) and discontinuous transmission (GSM 06.81 [5]). |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 7.1 Codec configuration | The VAD, comfort noise and discontinuous transmission shall be tested in conjunction with the speech encoder (GSM 06.60 [2]). The speech encoder shall be configured to operate in the DTX mode defined in GSM 06.62 [4]. |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 7.2 DTX test sequences | Each DTX test sequence consists of four files:
- Files for input to the GSM enhanced full rate speech encoder: *.INP
- Files for comparison with the encoder output: *.COD
- Files for input to the GSM enhanced full rate speech decoder: *.DEC
- Files for comparison with the decoder output: *.OUT
The *.DEC files... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 7.2.1 Predictor values computation | The computation of the predictor values described in GSM 06.82 [6] is not tested explicitly, since the results from the computation are tested many times via the spectral comparison and threshold adaptation tests. |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 7.2.2 Spectral comparison | The spectral comparison algorithm described in GSM 06.82 [6] is tested by the following test sequence:
- DTX01. * |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 7.2.3 Threshold adaptation | The threshold adaptation algorithm described in GSM 06.82 [6] is tested by the following test sequence:
- DTX02. * |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 7.2.4 Periodicity detection | The periodicity detection algorithm described in GSM 06.82 [6] is tested by the following test sequence:
- DTX03. * |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 7.2.5 Tone detection | The tone detection algorithm described in GSM 06.82 [6] is tested by the following test sequence:
- DTX04. * |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 7.2.6 Safety and initialisation | This sequence checks the safety paths used to prevent zero values being passed to the norm function. It checks the functions described in the adaptive filtering and energy computation, and the prediction values computation given in GSM 06.82 [6]. This sequence also checks the initialisation of thvad and the rvad array... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 7.2.7 Comfort noise test sequence | The test sequences described in sub-subclauses 7.2.2 to 7.2.6 are designed to exercise the VAD described in GSM 06.82 [6] and the discontinuous transmission described in GSM 06.81 [5]. The following test sequence is defined to exercise the comfort noise algorithm described in GSM 06.62 [4]:
- DTX06.* |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 7.2.8 Real speech and tones | The test sequences cannot be guaranteed to find every possible error. There is therefore a small possibility that an incorrect implementation produces the correct output for the test sequences, but fails with real signals. Consequently, an extra sequence is included, which consists of very clean speech, barely detecta... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 8 Sequences for finding the 20 ms framing of the GSM enhanced full rate speech encoder | When testing the decoder, alignment of the test sequences used to the decoder framing is achieved by the air interface (testing of MS) or can be reached easily on the Abis-interface (testing on network side).
When testing the encoder, usually there is no information available about where the encoder starts its 20 ms se... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 8.1 Bit synchronisation | The input to the speech encoder is a series of 13 bit long words (104 kbits/s, 13 bit linear PCM). When starting to test the speech encoder, no knowledge is available on bit synchronisation, i.e., where the encoder expects its least significant bits, and where it expects the most significant bits.
The encoder homing fr... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 8.2 Frame synchronisation | Once bit synchronisation is found, frame synchronisation can be found by inputting one special frame that delivers 160 different output frames, depending on the 160 different positions that this frame can possibly have with respect to the encoder framing.
This special synchronisation frame was found by taking one input... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 8.3 Formats and sizes of the synchronisation sequences | BIT SYNC.INP:
This sequence consists of 13 frame triplets. It has the format of the speech encoder input test sequences (13 bit left justified with the three least significant bits set to zero).
The size of it is therefore:
SIZE (BITSYNC.INP) = 13 * 3 * 160 * 2 bytes = 12480 bytes
SEQSYNC.INP:
This sequence consist of ... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 9 Trau Testing with 8 Bit A- and µ-law PCM Test Sequences | In the previous clauses, tests for the transcoder in the TRAU are described, using 13 bit linear test sequences. However, these 13 bit test sequences require a special interface in the TRAU and do not allow testing in the field. In most cases the TRAU has to be set in special mode before testing.
As an alternative, th... |
2d561ed8a3b06dda8ca0195c2d72b489 | 06.54 | 10 Alternative Enhanced Full Rate implementation using the Adaptive Multi Rate 12.2 kbit/s mode | The 12.2 kbit/s mode of the Adaptive Multi Rate speech coder described in TS 26.071 is functionally equivalent to the GSM Enhanced Full Rate speech coder. An alternative implementation of the Enhanced Full Rate speech service based on the 12.2 kbit/s mode of the Adaptive Multi Rate coder is allowed. Alternative impleme... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 1 Scope | The present document defines rate adaptation functions to be used in GSM PLMN Base Station Systems (BSS) transcoders and IWF for adapting radio interface data rates to the 64 kbit/s used at the A-interface in accordance with 3GPP TS 03.10.
The number of Base Station System - Mobile-services Switching Centre (BSS - MSC)... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 2 References, abbreviations and definitions | |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 2.1 References | The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
• References are either specific (identified by date of publication, edition number, version number, etc.) or non‑specific.
• For a specific reference, subsequent revisions do not apply.
• Fo... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 2.2 Abbreviations | For the purposes of the present document, the following abbreviations apply:
FPS Frame Pattern Substitution
FSI Frame Start Identifier
ZSP Zero Sequence Position |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 2.3 Definitions | For the purposes of the present document, the following terms and definitions apply.
Substream: Stream of data with explicit or implicit numbering between splitter and combine functions.
Channel: A physical full rate channel on the radio interface (TCH/F) independent of the contents.
A interface circuit: The 8 bits tha... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 3 General approach | 3GPP TS 03.10 (clause 6) defines the PLMN connection types necessary to support the GSM PLMN data and telematic services.
Within the BSS , transcoder and IWF, there are several data rate adaptation functions which are combined as shown in 3GPP TS 03.10 as part of a connection type.
These functions are RA0, RA1, RA1/RA1... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 4 The RA0 Function | The RA0 function is specified in 3GPP TS 04.21 |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 5 The RA1 Function | For connections where only one channel is allowed used on the radio interface, the specification in 3GPP TS 04.21 for adaptation of synchronous data rates up to and including 9,6 kbit/s to intermediate rates 8 or 16 kbit/s shall apply.
For connection where more than one channel are used on the radio interface, rate ada... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 6 The RA1’’ Function | The RA1’’ function is specified in 3GPP TS 04.21. The RA1’’ function is only applicable in BSS for AIUR higher than 38,4 kbit/s. |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 7 Split/Combine and Padding Functions | The Split/Combine-function in the IWF shall be used in cases when up to and including 4substreams are used.
The Split/Combine-function in the BSS shall be used only when more than four substreams are used. |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 7.1 Data Frame distribution into the channels by the Split/Combine function | Described in 3GPP TS 04.21 |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 7.2 Substream numbering | Described in 3GPP TS 04.21 |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 7.3 Initial Substream Synchronisation for Transparent Services | Described in 3GPP TS 04.21 |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 7.4 Frame Synchronisation and Action on loss of Synchronisation | When in the IWF, the Split/Combine function is responsible for controlling the initial frame synchronisation procedure and re-synchronisation procedure as described in 3GPP TS 29.007. |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 7.5 Network Independent Clocking | NIC is specified in 3GPP TS 04.21 |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 7.6 Padding | Padding is specified in 3GPP TS 04.21 |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 8 The EDGE Multiplexing Function | In EDGE configurations where the number of radio interface channels and number of channels or substreams used between BTS and MSC do not match, a multiplexing function described below shall be used at BTS to perform data multiplexing/demultiplexing between the radio interface and network channel configurations. A simil... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 9 The RA1/RA1' Function | For AIURs less than or equal to 38,4 kbit/s, the RA1/RA1’ function in the BSS shall be applied on each of the n substreams and there are no significant differences between the single slot case and the multislot case. For AIURs less than or equal to 38,4 kbit/s RA1/RA1’ is as specified in 3GPP TS 04.21 for the single sl... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 9.1 Radio Interface rate of 12 kbit/s | Described in 3GPP TS 04.21. |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 9.2 Radio Interface rate of 6 kbit/s | Described in 3GPP TS 04.21. |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 9.3 Radio Interface rate of 3.6 kbit/s | Described in 3GPP TS 04.21. |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 9.4 Synchronisation | Refer to 3GPP TS 04.21. |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 9.5 Idle frames | Refer to 3GPP TS 04.21 |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 10 THE RA1'/RAA' FUNCTION | The RA1'/RAA' shall be applied only when TCH/F14.4, TCH/F28.8, or TCH/F43.2 channel coding is used. The RA1/RAA' converts 290-bit blocks from the channel coder or EDGE multiplexing function into E-TRAU frames and vice versa. The format of E-TRAU frame is specified in 3GPP TS 08.60.
The RA1'/RAA' function in the BSS sha... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 10.1 Radio Interface rate of 14,5 kbit/s | See 3GPP TS 08.60. |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 10.2 Synchronisation | See 3GPP TS 08.60. |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 10.3 Idle frames | See 3GPP TS 08.60. |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 11 THE RAA' FUNCTION | The RAA' function shall be applied only when TCH/F14.4, TCH/F28.8, or TCH/F43.2 channels are used.
The RAA' converts E-TRAU frame into A-TRAU frame and vice versa.
The format of the E-TRAU frame is specified in 3GPP TS 08.60. |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 11.1 Coding of A-TRAU frame | The format of the A-TRAU frame is given in Figure 5.
An A-TRAU frame carries eight 36 bit-data frames.
C Bits
Table 3
C1
C2
C3
C4
Date Rate
0
1
1
1
14,4 kbit/s
0
1
1
0
14.4 kbit/s idle (IWF to BSS only)
Table 4
C5
BSS to IWF
Frame Type
note 1
IWF to BSS
UFE (Uplink Frame Error)
1
idle
framing error
0
data
no framing er... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 11.2 Framing Pattern Substitution in A-TRAU frame | The Framing Pattern Substitution is used in each of the eight 36 bit data fields of the A-TRAU frame (see Figure 5) to avoid transmitting a sequence of eight zeroes (called Z sequence in the following).
The purposes of FPS is to avoid erroneous synchronisation to the A-TRAU due to sixteen zeroes occurring accidentally ... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 11.2.1 FPS encoding | A Zero Sequence Position (ZSP) field is used to account for the occurrence of eight zeroes in the 36 bit data field.
NOTE: A sequence of eight zeroes is considered as a block (e.g. a stream of eleven consecutive zeroes produces only one ZSP and not four ZSPs).
The ZSP field is defined as follows:
Table 5
1
2
3
4
5
6
7
... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 11.3 A-TRAU Synchronisation Pattern | The frame synchronisation is obtained by means of the first two octets in each frame, with all bits coded binary "0" and the first bit in octet no 2 coded binary "1". The following 17 bit alignment pattern is used to achieve frame synchronisation :
00000000 00000000 1XXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 12 THE RAA'' FUNCTION | On the IWF side of the A interface, the RAA" function shall convert between the A-TRAU format and a synchronous stream. FPS shall be performed by this function as well, see subclause 11.2. In transparent operation, the RAA" function shall handle the M1 and M2 bits as specified for the RA1' function in 3GPP TS 04.21.
In... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 13 The RA2 Function | Described in 3GPP TS 04.21. The RA2 function shall be applied only for single slot operations. |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 14 The A-interface Multiplexing Function | The multiplexing function shall be applied only for AIUR up to and including 57.6 kbit/s for multislot operations.
The multiplexing function is based on the ITU-T I.460. The multiplexing function is used to combine n (n=2 to 4) substreams of multislot intermediate rate of 8 kbit/s or n substreams of multislot intermedi... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 15 Support of non-transparent bearer services | |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 15.1 TCH/F9.6 and TCH/F4.8 kbit/s channel codings | In the case of non-transparent services the RA1/RA1' function shall perform the same mapping as that described for transparent services, using 12 and 6 kbit/s radio interface data rates, with the following modification.
The E2 and E3 bits in the modified ITU-T V.110 80 bit frames shown in Figure 3 (derived from the sta... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 15.1.1 Alignment | An alignment window spanning four modified ITU-T V.110 80 bit frames shall be used to search for the pattern of 8 bits described above in order to identify alignment with an RLP frame.
In the event of failure to detect the 8 bit pattern, the alignment window is shifted one complete modified V.110 80 bit frame, discardi... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 15.1.2 Support of Discontinuous Transmission (DTX) | The E1 bit in the modified ITU-T V.110 80 bit frame shown in Figure 3 shall be used in the direction MSC-BSS to indicate that DTX may be invoked (see 3GPP TS 24.022). The E1 bit in all of the four consecutive frames relating to the RLP frame to which DTX may be applied shall be set to 1. If DTX is not to be applied, th... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 15.1.3 Order of Transmission | The first bit of each quarter of an RLP frame to be transmitted shall correspond to bit D1 of a modified V.110 frame (figures 3 and 4). The remaining 59 bits of each quarter of an RLP frame shall correspond to the D and D' bits , D2 - D'12, in order left to right and top to bottom as shown in figures 3 and 4.
The first... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 15.2 TCH/F14.4, TCH/F28.8, and TCH/F43.2 channel codings | In case of non-transparent service, a 576 bit RLP frame shall be mapped over two consecutive A-TRAU frames.
Because of that mapping, it is required, following a transmission break and at start up, to determine which A-TRAU frame of the stream is the first for a particular RLP frame. This is needed so that correct align... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 15.2.1 Alignment | An alignment window spanning two 290 bit blocks in case of TCH/F14.4 channel shall be used to search for the pattern of 2 bits '01' described in subclause 15.2, in order to identify alignment with an RLP frame.
In the event of failure to detect the 2 bits pattern the alignment window is shifted one 290 bit block, disca... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 15.2.2 Support of Discontinuous Transmission (DTX) | The M2 bit in the A-TRAU frame shown in Figure 5 shall be used in the direction MSC to BSS to indicate that DTX may be invoked (see 3GPP TS 24.022). The M2 bit in all of the two consecutive A-TRAU frames relating to the RLP frame to which DTX may be applied shall be set to 1. If DTX is not to be applied, the M2 bit sha... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 16 Support of transparent bearer services | |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 16.1 TCH/F9.6 and TCH/F4.8 channel codings | |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 16.1.1 User rate adaptation on the A interface, AIUR less than or equal to 38,4 kbit/s | The ITU-T V.110 80 bit frame shall be used for transparent data on the A interface. These frames are transmitted on up to four substreams multiplexed into one stream sent over the A interface. The split/combine function is applied on the substreams as specified in clause 5 of this GSM TS. The relation between the AIUR ... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 16.1.2 User rate Adaptation on the A-interface, AIUR greater than 38,4 kbit/s | For AIUR of 48 kbit/s, 56 kbit/s and 64 kbit/s one stream consisting of ITU-T V.110 32 bit frames or 64 bit frames, as specified in 3GPP TS 04.21 shall be transmitted over the A-interface. Splitting/Combining which occurs in the BSS, is as specified in 3GPP TS 04.21.
Table 11 gives the relation between the User Rate, S... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 16.1.3 Relation between AIUR and the number of channels | Table11: Relationship between the AIUR, substream rate, channel coding, intermediate rate and number of channels
AIUR
Number of channels x Substream Rate
Channel Coding
(Multislot) intermediate Rate (Note1)
2,4 kbit/s
2-8 times duplication of each bit to reach 4,8 kbit/s
TCH/F4.8
8 kbit/s
4,8 kbit/s
4,8 kbit/s
TCH/F4.... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 16.1.4 Handling of status bits X, SA, SB | In the single slot case, status bit SA shall be coded repeatedly as S1, S3, S6, S8, and SB is coded repeatedly as S4 and S9 in Figure 2. In the multislot case, status bit SA is coded repeatedly as S6, S8 and SB is coded as S9 in figures 2, 5 and 6.
The handling of the status bits shall comply with the synchronisation p... |
d584819bc08aaf1044fa432bfa99ac6d | 08.20 | 16.1.5 Handling of bits E1 to E7 | Bits E1 to E3 shall be used according to 04.21.
Bits E4 to E7 may be used for network independent clocking as indicated in 3GPP TS 04.21. |
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