5 Frame structure

08.613GPPIn-band control of remote transcoders and rate adaptors for half rate traffic channelsTS

5.1 16 kbit/s submultiplexing

5.1.1 Frames for Speech Services

5.1.1.1 Frame for Half Rate speech

Bit number

Octet no.

1

2

3

4

5

6

7

8

1

0

0

0

0

0

0

0

0

2

0

0

0

0

0

0

0

0

3

1

C1

C2

C3

C4

C5

C6

C7

4

C8

C9

C10

C11

C12

C13

C14

C15

5

1

UFI

D1

D2

D3

D4

D5

D6

6

D7

D8

D9

D10

D11

D12

D13

D14

7

1

D15

D16

D17

D18

D19

D20

D21

8

D22

D23

D24

D25

D26

D27

D28

D29

9

1

D30

D31

D32

D33

D34

D35

D36

10

D37

D38

D39

D40

D41

D42

D43

D44

11

1

CRC2

CRC1

CRC0

D45

D46

D47

D48

12

D49

D50

D51

D52

D53

D54

D55

D56

13

1

D57

D58

D59

D60

D61

D62

D63

14

D64

D65

D66

D67

D68

D69

D70

D71

15

1

D72

D73

D74

D75

D76

D77

D78

16

D79

D80

D81

D82

D83

D84

D85

D86

17

1

D87

D88

D89

D90

D91

D92

D93

18

D94

D95

D96

D97

D98

D99

D100

D101

19

1

D102

D103

D104

D105

D106

D107

D108

20

D109

D110

D111

D112

1

1

1

1

21

1

1

1

1

1

1

1

1

22

1

1

1

1

1

1

1

1

23

1

1

1

1

1

1

1

1

24

1

1

1

1

1

1

1

1

25

1

1

1

1

1

1

1

1

26

1

1

1

1

1

1

1

1

27

1

1

1

1

1

1

1

1

28

1

1

1

1

1

1

1

1

29

1

1

1

1

1

1

1

1

30

1

1

1

1

1

1

1

1

31

1

1

1

1

1

1

1

1

32

1

1

1

1

1

1

1

1

33

1

1

1

1

1

1

1

1

34

1

1

1

1

1

1

1

1

35

1

1

1

1

1

1

1

1

36

1

1

1

1

1

1

1

1

37

1

1

1

1

1

1

1

1

38

1

1

1

1

1

1

1

1

39

1

1

1

1

1

1

C16

C17

40

C18

C19

C20

C21

T1

T2

T3

T4

5.1.1.2 Frames for Adaptive Multi-Rate Speech

See GSM 08.60 for16 kBit/s submultiplexing.

5.1.2 Data frame

Bit number

Octet no.

1

2

3

4

5

6

7

8

1

0

0

0

0

0

0

0

0

2

0

0

0

0

0

0

0

3

1

C1

C2

C3

C4

C5

C6

C7

4

C8

C9

C10

C11

C12

C13

C14

C15

5

1

D1

D2

D3

D4

D5

D6

D7

6

1

D8

D9

D10

D11

D12

D13

D14

7

1

D15

D16

D17

D18

D19

D20

D21

8

1

D22

D23

D24

D25

D26

D27

D28

Data frame

9

1

D29

D30

D31

D32

D33

D34

D35

position 1

10

1

D36

D37

D38

D39

D40

D41

D42

11

1

D43

D44

D45

D46

D47

D48

D49

12

1

D50

D51

D52

D53

D54

D55

D56

13

1

D57

D58

D59

D60

D61

D62

D63

14

1

1

1

1

1

1

1

1

15

1

1

1

1

1

1

1

1

16

1

1

1

1

1

1

1

1

17

1

1

1

1

1

1

1

1

18

1

1

1

1

1

1

1

1

19

1

1

1

1

1

1

1

1

20

1

1

1

1

1

1

1

1

21

1

1

1

1

1

1

1

1

22

1

1

1

1

1

1

1

1

23

1

D’1

D’2

D’3

D’4

D’5

D’6

D’7

24

1

D’8

D’9

D’10

D’11

D’12

D’13

D’14

25

1

D’15

D’16

D’17

D’18

D’19

D’20

D’21

26

1

D’22

D’23

D’24

D’25

D’26

D’27

D’28

Data frame

27

1

D’29

D’30

D’31

D’32

D’33

D’34

D’35

position 3

28

1

D’36

D’37

D’38

D’39

D’40

D’41

D’42

29

1

D’43

D’44

D’45

D’46

D’47

D’48

D’49

30

1

D’50

D’51

D’52

D’53

D’54

D’55

D’56

31

1

D’57

D’58

D’59

D’60

D’61

D’62

D’63

32

1

1

1

1

1

1

1

1

33

1

1

1

1

1

1

1

1

34

1

1

1

1

1

1

1

1

35

1

1

1

1

1

1

1

1

36

1

1

1

1

1

1

1

1

37

1

1

1

1

1

1

1

1

38

1

1

1

1

1

1

1

1

39

1

1

1

1

1

1

1

1

40

1

1

1

1

1

1

1

1

5.1.3 O&M frame

Bit number

Octet no.

1

2

3

4

5

6

7

8

1

0

0

0

0

0

0

0

0

2

0

0

0

0

0

0

0

0

3

1

C1

C2

C3

C4

C5

C6

C7

4

C8

C9

C10

C11

C12

C13

C14

C15

5

1

D1

D2

D3

D4

D5

D6

D7

6

D8

D9

D10

D11

D12

D13

D14

D15

7

1

D16

D17

D18

D19

D20

D21

D22

8

D23

D24

D25

D26

D27

D28

D29

D30

9

1

D31

D32

D33

D34

D35

D36

D37

10

D38

D39

D40

D41

D42

D43

D44

D45

11

1

D46

D47

D48

D49

D50

D51

D52

12

D53

D54

D55

D56

D57

D58

D59

D60

13

1

D61

D62

D63

D64

D65

D66

D67

14

D68

D69

D70

D71

D72

D73

D74

D75

15

1

D76

D77

D78

D79

D80

D81

D82

16

D83

D84

D85

D86

D87

D88

D89

D90

17

1

D91

D92

D93

D94

D95

D96

D97

18

D98

D99

D100

D101

D102

D103

D104

D105

19

1

D106

D107

D108

D109

D110

D111

D112

20

D113

D114

D115

D116

D117

D118

D119

D120

21

1

D121

D122

D123

D124

D125

D126

D127

22

D128

D129

D130

D131

D132

D133

D134

D135

23

1

D136

D137

D138

D139

D140

D141

D142

24

D143

D144

D145

D146

D147

D148

D149

D150

25

1

D151

D152

D153

D154

D155

D156

D157

26

D158

D159

D160

D161

D162

D163

D164

D165

27

1

D166

D167

D168

D169

D170

D171

D172

28

D173

D174

D175

D176

D177

D178

D179

D180

29

1

D181

D182

D183

D184

D185

D186

D187

30

D188

D189

D190

D191

D192

D193

D194

D195

31

1

D196

D197

D198

D199

D200

D201

D202

32

D203

D204

D205

D206

D207

D208

D209

D210

33

1

D211

D212

D213

D214

D215

D216

D217

34

D218

D219

D220

D221

D222

D223

D224

D225

35

1

D226

D227

D228

D229

D230

D231

D232

36

D233

D234

D235

D236

D237

D238

D239

D240

37

1

D241

D242

D243

D244

D245

D246

D247

38

D248

D249

D250

D251

D252

D253

D254

D255

39

1

D256

D257

D258

D259

D260

D261

D262

40

D263

D264

S1

S2

S3

S4

S5

S6

5.1.4 Coding

In the following clauses, the coding of the frames is described. Any spare or not used control bits should be coded binary "1".

5.1.4.1 Coding of frames for speech services

5.1.4.1.1 Coding of frames for Half Rate speech Control bits (C‑bits):

Description

Uplink

Downlink

Frame type

(Bits C1 ‑ C4)

C1 C2 C3 C4

0 0 0 1

C1 C2 C3 C4

1 1 1 0

Channel type

Bit C5

1: half rate

1: half rate

Time Alignment

(Bits C6 ‑ C11)

Binary number indicating the required timing adjustment to be in steps of 250/500 µs.

Binary number indicating the timing adjustment made.

The following values apply for the coding

C6C7 . . . C11

0 0 0 0 0 0 No change in frame timing

0 0 0 0 0 1 Delay frame 1 * 500 µs

0 0 0 0 1 0 Delay frame 2 * 500 µs

. . . ….

. . . ….

1 0 0 1 1 1 Delay frame 39 * 500 µs

1 0 1 0 0 0 Not used

. . . ….

1 1 1 1 0 1 Not used

1 1 1 1 1 0 Delay frame 1 * 250 µs

1 1 1 1 1 1 Advance frame 250 µs

Uplink

Bad Frame Indicator (BFI)

C12 (see GSM 06.41)

Downlink

Uplink Frame Error (UFE)

C12 (see clause 6.8.1.3)

0: BFI = 0

1: BFI = 1

0: UFE = 0: bad uplink framing

1: UFE = 1: good uplink

framing

Silence Descriptor (SID)

C13‑C14

(see GSM 06.41)

C13 C14: SID

SID1 SID0

0 0: SID = 0

0 1: SID = 1

1 0: SID = 2

Time Alignment Flag (TAF)

C15

(see GSM 06.41)

0: TAF = 0

1: TAF = 1

Spare

Speech indicator (SP)

C16

(see GSM 06.41)

Spare

0: SP = 0

1: SP = 1

DTX downlink indicator (DTXd)

C17

0: Downlink DTX shall not be applied

1: Downlink DTX shall be applied

Spare

Bits C18 ‑ C21

Spare

Spare

UFI bit: Unreliable Frame Indication (see GSM 06.41).

This bit is set to binary "1" in the downlink direction.

Data Bits (D‑bits)

Bits D1 .. D112: Speech block transferred in the same order as output from the transcoder (see GSM 06.20).

Cyclic Redundancy Check bits (CRC‑bits)

Bits CRC0 .. CRC2: CRC of the bits D1 to D44.

The bits are coded according to a cyclic code using the generator polynomial:

g(X) = X3+X+1

The encoding of the cyclic code is performed in a systematic form, which means that, in GF(2), the polynomial:

D1*X46 + D2*X45 + … + D44*X3 + CRC2*X2 + CRC1*X + CRC0.

where CRC0, CRC1, CRC2 are the parity bits, when divided by g(X) yields a remainder equal to:

1 + X + X2.

Time Alignment Bits

Bits T1 .. T4: Bits positioned at the end of the downlink and uplink TRAU speech frames.

Downlink:

If the timing of the frame is to be advanced 250 µs, these 4 bits are not transferred in order to reduce the frame length accordingly. When transferred, the bits are set to binary "1".

Uplink:

T1 and T2 are set to binary "1".

If the timing of the frame is to be advanced 125 µs, the bits T3 and T4 are not transferred in order to reduce the frame length accordingly. When transferred, the bits are set to binary "1" (see clause 6.6.1.1.2).

5.1.4.1.2 Coding of frames for Adaptive Multi-Rate speech

See GSM 08.60 for 16 kBit/s submultiplexing.

5.1.4.2 Coding of data frames

Any spare or not used control bits should be coded binary "1".

Control bits (C‑bits):

Description

Uplink

Downlink

Frame type

Bits C1‑C4

C1 C2 C3 C4

0 1 0 0: Data

C1 C2 C3 C4

1 0 1 1: Data

Channel type

Bit C5

1: half rate

1: half rate

Intermediate RA bit rate

Bit C6

0: 8 kbit/s

0: 8 kbit/s

Bits C7 ‑ C11

Spare

Spare

Bit C12

Uplink Frame Error (UFE)
C12 (see clause 6.8.1.3)

Spare

0: UFE = 0: bad uplink framing

1: UFE = 1: good uplink framing

Bits C13‑C15

Spare

Spare

Idle data frame

An idle data frame is a data frame with all data bit positions set to binary "1" (i.e. all bits of the modified V.110 frames are set to "1").

5.1.4.3 Coding of O&M frames

Control bits (C‑bits):

Description

Uplink

Downlink

Frame type

Bits C1‑C4

C1 C2 C3 C4

0 0 1 0: O&M

C1 C2 C3 C4

1 1 0 1: O&M

Channel type

Bit C5

1: half rate

1: half rate

Bits C6 ‑ C11

Spare

Spare

Bit C12

Uplink Frame Error (UFE)
C12 (see clause 6.8.1.3)

Spare

0: UFE = 0: bad uplink framing

1: UFE = 1: good uplink framing

Bits C13‑C15

Spare

Spare

Data Bits (D‑bits)

Bits D1 .. D264: Bits used for transfer of O&M information. The coding and use of these bits are left to the manufacturer of the BSC/TRAU.

Spare Bits (S‑bits)

Bits S1 .. S6: Spare.

5.1.5 Order of Bit Transmission

See GSM 08.60.

5.2 8 kbit/s submultiplexing

5.2.1 Frames for Speech Services

5.2.1.1 Frame for Half Rate Speech

Bit number

Octet no

1

2

3

4

5

6

7

8

1

0

0

0

0

0

0

0

0

2

1

C1

C2

C3

C4

C5

XC1

XC2

3

0

1

XC3

XC4

XC5

XC6

D1

D2

4

1

D3

D4

D5

D6

D7

D8

D9

5

1

D10

D11

D12

D13

D14

D15

D16

6

1

D17

D18

D19

D20

D21

D22

D23

7

1

D24

D25

D26

D27

D28

D29

D30

8

1

D31

D32

D33

D34

D35

D36

D37

9

1

D38

D39

D40

D41

D42

D43

D44

10

1

CRC2

CRC1

CRC0

D45

D46

D47

D48

11

1

D49

D50

D51

D52

D53

D54

D55

12

1

D56

D57

D58

D59

D60

D61

D62

13

1

D63

D64

D65

D66

D67

D68

D69

14

1

D70

D71

D72

D73

D74

D75

D76

15

1

D77

D78

D79

D80

D81

D82

D83

16

1

D84

D85

D86

D87

D88

D89

D90

17

1

D91

D92

D93

D94

D95

D96

D97

18

1

D98

D99

D100

D101

D102

D103

D104

19

1

D105

D106

D107

D108

D109

D110

D111

20

1

D112

C6

C7

C8

C9

T1

T2

5.2.1.2 Frames for Adaptive Multi-Rate Speech

5.2.1.2.1 Frame for Lower Codec Modes

This frame layout shall be used for No_Speech frames and speech frames for codec modes 4,75, 5,15 and 5,90 kBit/s.

Bit number

Octet no

1

2

3

4

5

6

7

8

1

0

0

0

0

0

0

0

0

2

1

D1

D2

D3

D4

D5

D6

D7

3

1

C1

C2

C3

C4

C5

D8

D9

4

0

1

D10

D11

D12

D13

D14

D15

5

1

D16

D17

D18

D19

D20

D21

D22

6

1

D29

7

1

D36

8

1

D43

9

1

D50

10

1

D57

11

1

D64

12

1

D71

13

1

D78

14

1

D85

15

1

D92

16

1

D99

17

1

D106

18

1

D113

19

1

D120

20

1

D121

D122

D123

D124

D125

D126

T

5.2.1.2.2 Speech frame for Codec Mode 6,70 kBit/s

This frame layout shall be used for speech frames for codec mode 6,70 kBit/s. The synchronisation pattern is unique and identifies this codec mode.

Bit number

Octet no

1

2

3

4

5

6

7

8

1

0

0

0

0

0

0

0

0

2

1

D1

D2

D3

D4

D5

D5

D7

3

1

C1

C2

C3

D8

D9

D10

D11

4

1

D12

D13

D14

D15

D16

D17

D18

5

1

D19

D

D

D

D

D

D25

6

0

D26

D

D

D

D

D

D32

7

1

D33

D

D

D

D

D

D39

8

D40

D

D

D

D

D

D

D47

9

1

D48

D

D

D

D

D

D54

10

D55

D

D

D

D

D

D

D62

11

1

D63

D

D

D

D

D

D69

12

D70

D

D

D

D

D

D

D77

13

1

D78

D

D

D

D

D

D84

14

D85

D

D

D

D

D

D

D92

15

1

D93

D

D

D

D

D

D99

16

D100

D

D

D

D

D

D

D107

17

1

D108

D

D

D

D

D

D114

18

D115

D

D

D

D

D

D

D122

19

1

D

D

D

D

D

D

D129

20

D130

D

D

D

D

D

D

D137

5.2.1.2.3 Speech frame for Codec Mode 7,40 kBit/s

This frame layout shall be used for speech frames for codec mode 7,40 kBit/s. The synchronisation pattern is unique and identifies this codec mode.

Bit number

Octet no

1

2

3

4

5

6

7

8

1

0

0

1

D1

D2

D3

D4

D5

2

0

D6

D7

D8

D9

D10

D11

D12

3

1

C1

C2

C3

D13

D14

D15

D16

4

0

D17

D18

D19

D20

D21

D22

D23

5

D24

D

D

D

D

D

D

D31

6

D32

D

D

D

D

D

D

D39

7

D40

D

D

D

D

D

D

D47

8

D48

D

D

D

D

D

D

D55

9

D56

D

D

D

D

D

D

D63

10

D64

D

D

D

D

D

D

D71

11

D72

D

D

D

D

D

D

D79

12

D80

D

D

D

D

D

D

D87

13

D88

D

D

D

D

D

D

D95

14

D96

D

D

D

D

D

D

D103

15

D104

D

D

D

D

D

D

D111

16

D112

D

D

D

D

D

D

D119

17

D120

D

D

D

D

D

D

D127

18

D128

D

D

D

D

D

D

D135

19

D136

D

D

D

D

D

D

D143

20

D144

D145

D146

D147

D148

D149

D150

D151

5.2.1.2.4 Speech frame for Codec Mode 7,95 kBit/s

AMR Codec Mode 7,95 kBit/s is not supported in 8 kBit/s submultiplexing.

5.2.2 Data frame

Bit number

Octet no.

1

2

3

4

5

6

7

8

1

0

0

0

0

0

0

0

0

2

1

C1

C2

C3

C4

C5

D1

D2

3

0

1

D3

D4

D5

D6

D7

D8

4

1

D9

D10

D11

D12

D13

D14

D15

5

1

D16

D17

D18

D19

D20

D21

D22

Data frame

6

1

D23

D24

D25

D26

D27

D28

D29

position 1

7

1

D30

D31

D32

D33

D34

D35

D36

8

1

D37

D38

D39

D40

D41

D42

D43

9

1

D44

D45

D46

D47

D48

D49

D50

10

1

D51

D52

D53

D54

D55

D56

D57

11

1

D58

D59

D60

D61

D62

D63

D’1

12

1

D’2

D’3

D’4

D’5

D’6

D’7

D’8

13

1

D’9

D’10

D’11

D’12

D’13

D’14

D’15

14

1

D’16

D’17

D’18

D’19

D’20

D’21

D’22

15

1

D’23

D’24

D’25

D’26

D’27

D’28

D’29

Data frame

16

1

D’30

D’31

D’32

D’33

D’34

D’35

D’36

position 2

17

1

D’37

D’38

D’39

D’40

D’41

D’42

D’43

18

1

D’44

D’45

D’46

D’47

D’48

D’49

D’50

19

1

D’51

D’52

D’53

D’54

D’55

D’56

D’57

20

1

D’58

D’59

D’60

D’61

D’62

D’63

1

5.2.3 O&M frame

Bit number

Octet no.

1

2

3

4

5

6

7

8

1

0

0

0

0

0

0

0

0

2

1

C1

C2

C3

C4

C5

XC1

XC2

3

0

1

XC3

XC4

XC5

XC6

D1

D2

4

1

D3

D4

D5

D6

D7

D8

D9

5

1

D10

D11

D12

D13

D14

D15

D16

6

1

D17

D18

D19

D20

D21

D22

D23

7

1

D24

D25

D26

D27

D28

D29

D30

8

1

D31

D32

D33

D34

D35

D36

D37

9

1

D38

D39

D40

D41

D42

D43

D44

10

1

D45

D46

D47

D48

D49

D50

D51

11

1

D52

D53

D54

D55

D56

D57

D58

12

1

D59

D60

D61

D62

D63

D64

D65

13

1

D66

D67

D68

D69

D70

D71

D72

14

1

D73

D74

D75

D76

D77

D78

D79

15

1

D80

D81

D82

D83

D84

D85

D86

16

1

D87

D88

D89

D90

D91

D92

D93

17

1

D94

D95

D96

D97

D98

D99

D100

18

1

D101

D102

D103

D104

D105

D106

D107

19

1

D108

D109

D110

D111

D112

D113

D114

20

1

D115

D116

D117

D118

D119

D120

1

5.2.4 Coding

5.2.4.1 Coding for Half Rate Speech and Half Rate Data Services

In the following clauses, the coding of the frames is described for all services, except for Adaptive Multi-Rate Speech (AMR). Any spare or not used transmitted control bits should be coded binary "1".

5.2.4.1.1 Uplink coding

Control bits (C‑bits, for all frame types)

The control bits are coded according to the following table:

C1

C2

C3

C4

C5

Meaning

0

0

0

1

OP

Speech frame

0

0

1

1

OP

Data frame

0

1

0

1

OP

O&M frame

All other codings are reserved.

OP: odd parity of bits C1 to C4.

In the following, the term "frame type" refers to the control bits C1 to C3.

C6

C7

C8

C9

Meaning

TA2

TA1

TA0

DTXd

For speech frame only

DTXd: DTX downlink indicator.

0: Downlink DTX shall not be applied.

1: Downlink DTX shall be applied.

TA2‑TA0: Time Alignment Command, see clause 6.6.1.2.1.

Extended control bits

The extended control bits are coded according to the following table:

Frames for Half Rate Speech

XC1

XC2

XC3

XC4

XC5

XC6

Meaning

0

0

0

0

0

OP

Good speech frame with UFI = 0 (BFI=0, SID=0, TAF=1) (BFI=0, SID=0, TAF=0)

0

0

0

0

1

OP

Unreliable speech frame (if speech decoder is in speech decoding mode) or unusable frame (if speech decoder is in comfort noise insertion mode) with UFI = 1

(BFI=0, SID=0, TAF=1)

(BFI=0, SID=0, TAF=0)

0

0

0

1

0

OP

Valid SID frame with UFI = 0 (BFI=0, SID=2, TAF=1)

(BFI=0, SID=2, TAF=0)

0

0

0

1

1

OP

Invalid SID frame with UFI = 1 (BFI=0, SID=2, TAF=1)

(BFI=0, SID=2, TAF=0)

0

1

0

0

0

OP

Invalid SID frame at TAF=0 with UFI = 0

(BFI=0, SID=1, TAF=0)

(BFI=1, SID=1, TAF=0)

(BFI=1, SID=2, TAF=0)

0

1

0

0

1

OP

Invalid SID frame at TAF=0 with UFI = 1

(BFI=0, SID=1, TAF=0)

(BFI=1, SID=1, TAF=0)

(BFI=1, SID=2, TAF=0)

0

1

0

1

0

OP

Invalid SID frame at TAF=1 with UFI = 0

(BFI=0, SID=1, TAF=1)

(BFI=1, SID=1, TAF=1)

(BFI=1, SID=2, TAF=1)

0

1

0

1

1

OP

Invalid SID frame at TAF=1 with UFI = 1

(BFI=0, SID=1, TAF=1)

(BFI=1, SID=1, TAF=1)

(BFI=1, SID=2, TAF=1)

0

1

1

0

0

OP

Bad speech frame or unusable frame at TAF = 0 with UFI = 0

(BFI=1, SID=0, TAF=0)

0

1

1

0

1

OP

Bad speech frame or unusable frame at TAF = 0 with UFI = 1

(BFI=1, SID=0, TAF=0)

0

1

1

1

0

OP

Bad speech frame or unusable frame at TAF = 1 with UFI = 0

(BFI=1, SID=0, TAF=1)

0

1

1

1

1

OP

Bad speech frame or unusable frame at TAF = 1 with UFI = 1

(BFI=1, SID=0, TAF=1)

O&M frame

XC1

XC2

XC3

XC4

XC5

XC6

Meaning

1

1

1

1

1

OP

O&M frame

All other codings are reserved.

OP: odd parity of bits XC1 to XC5.

BFI, SID, TAF: see description in clause 5.1.4.1.

UFI bit: Unreliable Frame Indication (see GSM 06.41).

Cyclic Redundancy Check bits (CRC‑bits)

Half Rate Speech frame: Bits CRC0 .. CRC2: CRC of the bits D1 to D44. Same coding as in clause 5.1.4.1.

Data bits (D‑bits)

Speech frame: Bits D1 .. D112:

For good speech frame: speech block transferred in the same order as output from the transcoder (see GSM 06.20).

For valid SID frame: SID data block transferred in the same order as output from the transcoder (see GSM 06.22).

Data frame: Bits D1 .. D63 for data frame position 1 and bits D’1 .. D’63 for data frame position 2 (see clause 6.7.1).

O&M frame: Bits D1 .. D120: Bits used for transfer of O&M information. The coding and use of these bits are left to the manufacturer of the BSC/TRAU.

Time Alignment bits (T‑bits)

Bits T1..T2: Bits positioned at the end of the uplink TRAU speech frame.

T1 is set to binary "1".

If the timing of the frame is to be advanced 125 µs , the bit T2 is not transferred in order to reduce the frame length accordingly. When transferred, the bit T2 is set to binary "1".

5.2.4.1.2 Downlink coding

Control bits

C1

C2

C3

C4

C5

Meaning

0

0

0

UFE

OP

Speech frame

0

0

1

UFE

OP

Data frame

0

1

0

UFE

OP

O&M frame

All other codings are reserved.

UFE: Uplink Frame Error.

UFE = 0: bad uplink framing.

UFE = 1: good uplink framing.

See clause 6.8.2.2.

OP: Odd parity of bits C1 to C4.

In the following, the term "frame type" refers to the control bits C1 to C3.

C6

C7

C8

C9

Meaning

1

1

1

1

Spare bits

Extended control bits

The extended control bits are coded according to the following table:

Frames for Half Rate speech

XC1

XC2

XC3

XC4

XC5

XC6

Meaning

0

0

0

0

0

OP

Good speech frame (SP = 1)

0

0

0

1

0

OP

Valid SID frame (SP = 0)

SP: Speech indicator (see GSM 06.41).

O&M frame

XC1

XC2

XC3

XC4

XC5

XC6

Meaning

1

1

1

1

1

OP

O&M

All other codings are reserved.

XC6: odd parity of bits XC1 to XC5.

Data bits (D‑bits)

Same as the uplink.

Time Alignment bits (T‑bits)

Bits T1..T2: Bits positioned at the end of the downlink TRAU speech frame.

If the timing of the frame is to be advanced 250 µs, the bits T1 and T2 are not transferred in order to reduce the frame length accordingly. When transferred, the bits are set to binary "1" (see clause 6.6.1.2.1).

Cyclic Redundancy Check bits (CRC‑bits):

Same as the uplink.

5.2.4.2 Coding for Adaptive Multi-Rate Speech

Coding in uplink and downlink direction is identical. The synchronisation patterns for the Adaptive Multi Rate speech differ from the ones used for the other services. An explicit Frame_Type is not defined for AMR, instead the synchronisation patterns itself identify the service (Frame_Type) and to some extent the Codec_Mode.

The CRC-bits inserted are calculated as described in clause 5.1.4.1. The control elements are as defined in GSM 08.60 (RIF, CMI, CMR, TAC, TAE, PAB, …). The coding is, however, sometimes different.

5.2.4.2.1 No_Speech Frame

The frame layout for lower modes shall be used.

Control Information (C-Bits):
C1 . C2. C3: set to “1.0.0”, if RIF equals "0" (frame with Codec_Mode Indication phase)

set to "1.0.1", if RIF equals "1" (frame with Codec_Mode Request phase)
C4 . C5: set to “0.0”, this is the Frame_Classification for No_Speech Frames.

Coding of D-Bits:

The D-Bits in No_Speech frames carry additional control information:

D1 .. D6: Time Alignment Field (as defined in GSM 08.60)
D7: In DL: Uplink Frame Error (UFE) , in UL: Downlink Frame Error (DFE)
D8 .. D10: No_Speech_Classification (as defined in GSM 08.60)
D11 .. D13: CMI_abs (as defined in GSM 08.60)
D14 .. D16: CMR_abs (as defined in GSM 08.60)

The Uplink Frame Error (UFE) is coded and defined as in GSM 08.60.
The Downlink Frame Error (DFE) is – different to 08.60 – defined in uplink direction to allow fast recovery from synchronisation loss in higher codec modes. The coding is like for UFE.
The procedure is described in clause 6.9.2.

The coding for D55…D59 is common to all three lower code modes. These bits are reserved for the Configuration Protocol (Config_Prot and Message_No) in case of Tandem Free Operation, see GSM 08.62. If the BTS does not support TFO or TFO is disabled, then these bits shall be set to "0.0.0.0.0".

D55 .. D57: Config_Prot
D58 . D59: Message_No

Time Alignment Extension and Phase Alignment:
D60: Phase Alignment Bit (PAB) (as defined in GSM 08.60)
D61 . D62: Time Alignment Extension (TAE) (as defined in GSM 08.60)

DTX and TFO control:

D63: DTX in downlink requested (DTXd) (as defined in GSM 08.60)
D64: TFO Enabled (TFOE) (as defined in GSM 08.60)

The bits D65…D125 (61 bits) are reserved for Tandem Free Operation (see GSM 08.62). If the BTS does not support TFO or TFO is disabled, then these bits shall be set to all "1".

The bits D17…D54 (38 bits) are also reserved for Tandem Free Operation (see GSM 08.62), if not needed otherwise, i.e. in all No_Speech frames classified neither as SID_Update nor as SID_Bad. If the BTS does not support TFO or TFO is disabled, then these bits shall be set to all "1" in these cases.

In case the frames are classified as SID_Update or SID_Bad the bits D17…D54 code the

Silence Description parameters (as defined in GSM 06.90):

Silence Description parameters (as defined in GSM 06.90):
D17 .. D19: Moving average predictor, initial values (s1…s3)
D20 .. D45: Indexes of LSF submatrices (s4…s29)
D46 .. D51: Logarithmic frame energy (s30…s35)
D52 .. D54: CRC1 over bits C1…C5, D1…D51.

Time Alignment Bits:
D126 .. T: Coding as defined for Half Rate speech (T1 .. T2).

5.2.4.2.2 Speech Frames for 4,75, 5,15 and 5,90 kBit/s

The frame layout for lower modes shall be used. Speech Frames for 4,75, 5,15 and 5,90 kBit/s are defined, if Frame Classification is not set to “0.0” , otherwise the frame is a No_Speech Frame (see above).

Coding of Control Information (C-Bits):
The coding for C1 to C5 is common in all three Codec_Modes. Codec Mode Indication (CMI) plus Codec Mode Request (CMR) plus Request or Indication Flag (RIF) are coded with one 3-bit field. These three control elements are as defined in GSM 08.60. The coding is somewhat different:
C1.C2.C3:
0 . 0 . 0: CMI = 4,75; CMR = ?; RIF = 0.
0 . 0 . 1: CMI = 5,15; CMR = ?; RIF = 0.
0 . 1 . 0: CMI = 5,90; CMR = ?; RIF = 0.
0 . 1 . 1: CMI = ?; CMR = 4,75; RIF = 1.
1 . 0 . 0: CMI = ?; CMR = 5,15; RIF = 1.
1 . 0 . 1: CMI = ?; CMR = 5,90; RIF = 1.
1 . 1 . 0: CMI = ?; CMR = 6,70; RIF = 1.
1 . 1 . 1: CMI = ?; CMR = 7,40; RIF = 1.

Frame_Classification (C4…C5) is defined and coded as in GSM 08.60.

Coding of D-Bits:

The coding for D55…D59 is common to all three lower code modes. These bits are reserved for the Configuration Protocol (Config_Prot and Message_No) in case of Tandem Free Operation, see GSM 08.62. If the BTS does not support TFO or TFO is disabled, then these bits shall be set to "0.0.0.0.0".

AMR_Mode 4,75 kBit/s, see GSM 06.90:
D1 .. D3: spare (3 bits), set to “1”
D4 .. D26: Indexes of the LSF submatrices (s1…s23)
D27 .. D51: Indexes of the parameters of first sub-frame (s24…s48)
D52 .. D54: CRC1 over bits C1…C5, s1…s16, s18, s19, s21…s29, s45…s48.
D55 .. D59: reserved for TFO
D60 .. D72: Indexes of the parameters of second sub-frame (s49…s61)
D73 .. D75: CRC2 over bits D55…D59, s49, s50.
D76 .. D96: Indexes of the parameters of third sub-frame (s62…s82)
D97 .. D99: CRC3 over bits s62, s63, s79…s82.
D100 .. D112: Indexes of the parameters of fourth sub-frame (s83…s95)
D113 .. D115: CRC4 over bits s83, s84.
D116 .. D126: spare (11 bits); set to "1".

AMR_Mode 5,15 kBit/s, see GSM 06.90:
D1 .. D5: spare (5 bits); set to "1"
D6…D28: Indexes of the LSF submatrices (s1…s23)
D29…D51: Indexes of the parameters of first sub-frame (s24…s46)
D52 .. D54: CRC1 over bits C1…C5, s1…s16, s19…s29, s42…s46.
D55 .. D59: reserved for TFO
D60 .. D78: Indexes of the parameters of second sub-frame (s47…s65)
D79 .. D81: CRC2 over bits D55…D59, s47, s48, s61…s65.
D82 .. D100: Indexes of the parameters of third sub-frame (s66…s84)
D101 .. D103: CRC3 over bits s66, s67, s80…s84.
D104 .. D122: Indexes of the parameters of fourth sub-frame (s85…s103)
D123 .. D125: CRC4 over bits s85, s86, s99…s103.
D126: spare (1 bits); set to "1".

AMR_Mode 5,90 kBit/s, see GSM 06.90:
D1 .. D26: Indexes of the LSF submatrices (s1…s26)
D27 .. D51: Indexes of the parameters of first sub-frame (s27…s51)
D52 .. D54: CRC1 over bits C1…C5, s1…s17, s27…s34, s48…s51.
D55 .. D59: reserved for TFO
D60 .. D80: Indexes of the parameters of second sub-frame (s52…s72)
D81 .. D105: Indexes of the parameters of third sub-frame (s73…s97)
D106 .. D126: Indexes of the parameters of fourth sub-frame (s98…s118).

Time Alignment Bit:
T: Set to “1”. May be omitted, then the next frame is advanced by 125 µs.

5.2.4.2.3 Speech Frame for 6,70 kBit/s

The frame layout for codec mode 6,70 shall be used. By this the Codec Mode Indication is defined to be 6,70 kBit/s, regardless of the phase of the RIF bit.

Coding of Control Information (C-Bits):
Codec Mode Request (CMR) plus Request or Indication Flag (RIF) plus Frame Classification (FC) are coded with one 3-bit field. These three control elements, are as defined in GSM 08.60. The coding is somewhat different:
C1.C2.C3:
0 . 0 . 0: CMR = ?; RIF = 0; FC = "Speech_Bad".
0 . 0 . 1: CMR = ?; RIF = 0; FC = "Speech_Good".
0 . 1 . 0: CMR = (D1…D3); RIF = 1 FC = "Speech_Bad".
0 . 1 . 1: CMR = 4,75; RIF = 1; FC = "Speech_Good".
1 . 0 . 0: CMR = 5,15; RIF = 1; FC = "Speech_Good".
1 . 0 . 1: CMR = 5,90; RIF = 1; FC = "Speech_Good".
1 . 1 . 0: CMR = 6,70; RIF = 1; FC = "Speech_Good".
1 . 1 . 1: CMR = 7,40; RIF = 1; FC = "Speech_Good".

"CMR = (D1…D3)" indicates that the CMR is defined in this specific case of "Speech_Bad" within the D-Bits, which would be otherwise undefined. The coding of CMR in this case is:

D1.D2.D3:
0 . 0 . 0: undefined, reserved
0 . 0 . 1: undefined, reserved
0 . 1 . 0: undefined, reserved
0 . 1 . 1: CMR = 4,75.
1 . 0 . 0: CMR = 5,15.
1 . 0 . 1: CMR = 5,90.
1 . 1 . 0: CMR = 6,70.
1 . 1 . 1: CMR = 7,40.

Coding of D-Bits, see GSM 06.90:
D1 .. D26: Indexes of the LSF submatrices (s1…s26)
D27 .. D55: Indexes of the parameters of first sub-frame (s27…s55)
D56 .. D58: CRC1 over bits C1…C3, D1…D3, s4…s17, s20, s24, s27…s34, s49…s53.
D59 .. D83: Indexes of the parameters of second sub-frame (s56…s80)
D84 .. D112: Indexes of the parameters of third sub-frame (s81…s109)
D113 .. D137: Indexes of the parameters of fourth sub-frame (s110…s134).

5.2.4.2.4 Speech Frame for 7,40 kBit/s

The frame layout for codec mode 7,40 shall be used. By this the Codec Mode Indication is defined to be 7,40 kBit/s, regardless of the phase of the RIF bit.

Coding of Control Information (C-Bits):
Codec Mode Request (CMR) plus Request or Indication Flag (RIF) plus Frame Classification (FC) are coded with one 3-bit field. These three control elements are as defined in GSM 08.60.

The coding is exactly as described for codec mode 6,70, except that the CMR in case of "Speech_Bad" is defined in bits D6…D8 (instead of D1…D3) and thus at exactly the same position within the frame.

Coding of D-Bits, see GSM 06.90:
D1 .. D26: Indexes of the LSF submatrices (s1…s26)
D27 .. D58: Indexes of the parameters of first sub-frame (s27… s58)
D59 .. D61: CRC1 over bits C1 to C3, D1… D20, s22…s24, s27…s32, s52, s53, s55…s57.
D62 .. D90: Indexes of the parameters of second sub-frame (s59…s87)
D91 .. D122: Indexes of the parameters of third sub-frame (s88…s119)
D123 .. D151: Indexes of the parameters of fourth sub-frame (s120…s148).

5.2.4.2.5 Speech Frame for 7,95 kBit/s

Codec mode 7,95 kBit/s is not supported in 8 kBit/s submultiplexing.

5.2.5 Order of Bit Transmission

The order of bit transmission is:

Bit m of octet n shall be transmitted as bit ((n‑1)*8+m) with m=(1..8) and n=(1..20).