3 General approach

3GPP44.021Rate adaption on the Mobile Station - Base Station System (MS - BSS) interfaceTS

3GPP TS 43.010 defines the PLMN connection types necessary to support the GSM PLMN data and telematic services.

Within the MS there are several different data rate adaptation functions – and a Split/Combine-function in case of a multislot data configuration – which are combined as shown in 3GPP TS 43.010 as part of the connection type.

The rate adaptation functions are RA0, RA1′, RA1’/RA1", RA1’/RAA", RA1’/RAA’ and RA1/RA1′. The RA0 is similar to the RA0 function described in ITU-T recommendation V.110 [11] with the exception of the conversion of the rates 14.4 and 28,8 kbit/s.

The RA1′ function is similar to RA1 described in ITU-T recommendation V.110 [11] but has a reduced bit rate output compatible with the coding scheme proposed for data services on the radio interface.

The RA1/RA1′, RA1’/RA1", RA1’/RAA" and RA1’/RAA’ are relay functions, used as indicated in 3GPP TS 43.010.

In multislot data-configurations the overall data stream is split into parallel substreams between the Split/Combine-functions.

3.1 Overview of data rates and configurations

In Table 1, an overview of the supported transparent air-interface user rates is given. For each rate, also intermediate rates per channel between BTS and MSC, overall radio interface rates, and channel configurations are given. For single slot connections the intermediate rates are per channel carrying the overall data stream, whereas for multislot connections, the intermediate rates are per substream.

For single slot rates up to 4,8 kbit/s, the used intermediate rate is 8 kbit/s, and for the 9,6 kbit/s single slot rate 16 kbit/s.

For TCH/F9.6 and TCH/F4.8 channel codings, the multislot intermediate rates are 16 and 8 kbit/s per TCH/F, respectively.

For TCH/F14.4 channel coding, the multislot intermediate rate is 16 kbit/s per TCH/F.

Connections utilising TCH/F28.8 or TCH/F43.2 across the radio interface, use multislot combinations of TCH/F14.4 between BTS and MSC. Thus the corresponding multislot intermediate rate is 16 kbit/s.

No multislot intermediate rates are applicable to 56 and 64 kbit/s connections using TCH/F32.0 radio interface channels. The intermediate rate for the 32 kbit/s user rate using the TCH/F32.0 channel is 32 kbit/s.

Table 1: AIUR/Multislot intermediate rates

Air interface user rate

DTE/DCE statuses

RA0

RA1’/RA1

RA1’/RAA’

RA1’/RA1"

RA1’/RAA"

(Note 4)

RA1′

Multislot intermediate rate

Frame type

Radio interface rate

Padding

 600 bit/s

X

X

8 kbit/s

80 bit frames

3,6 kbit/s

1200 bit/s

X

X

8 kbit/s

80 bit frames

3,6 kbit/s

2,4 kbit/s

X

X

8 kbit/s

80 bit frames

3,6 kbit/s

4,8 kbit/s

X

X

8 kbit/s

80 bit frames

6 kbit/s

9,6 kbit/s

X

X

16 kbit/s or 28 kbit/s

80 bit frames

12 kbit/s or 26 kbit/s

14,4 kbit/s

X

X

216 kbit/s or 38 kbit/s

80 bit frames

212 kbit/s or 36 kbit/s

P

(note 1)

16 kbit/s

Note 5

14,5 kbit/s

19,2 kbit/s

X

X

216 kbit/s or 48 kbit/s

80 bit frames

212 kbit/s or 46 kbit/s

28,8 kbit/s

X

X

316 kbit/s

80 bit frames

312 kbit/s

2 x 16 kbit/s

Note 5

214,5 kbit/s

129 kbit/s

32 kbit/s

1 x 32 kbit/s

1 x 32 kbit/s

38,4 kbit/s

X

X

416 kbit/s

80 bit frames

412 kbit/s

3 x 16 kbit/s

Note 5

314,5 kbit/s

P

(note 1)

43.2 kbit/s

Note 6

X

3 x 16 kbit/s

Note 5

143.5 kbit/s

48 kbit/s

X

Note 2

Note 2

512 kbit/s

4 x 16 kbit/s

Note 5

414,5 kbit/s

P

(note 1)

56 kbit/s

Note 2

Note 2

512 kbit/s (note 3)

4×16 kbit/s

Note 5

414,5 kbit/s

P

(note 1)

Note 2

Note 2

232.0 kbit/s

64 kbit/s

Note 2

Note 2

612 kbit/s (note 3)

P

(note 1)

514,5 kbit/s

(note 1)

Note 2

Note 2

232.0 kbit/s

P=Padding used

NOTE 1: For information on the padding procedure, please refer to clause 11 of the present document.

NOTE 2: No multislot intermediate rate; substreams combined at the BSS with a resulting data rate of 64 kbit/s between BSS and MSC.

NOTE 3: AIUR 11,2 kbit/s per channel

NOTE 4: Different relay rate adaptation functions exist at the network side:
– RA1’/RA1 applies if the radio interface rate is n x 3,6, 6 or 12 kbit/s and the AIUR is less than 48 kbit/s,
– RA1’/RAA’ applies if the radio interface rate is n x 14,5, 29 or 43,2 kbit/s and the AIUR is less than 64 kbit/s,
– RA1’/RA1" applies if the radio interface rate is n x 12 kbit/s and the AIUR is equal to 48, 56 or 64 kbit/s,
– RA1’/RAA" applies if the radio interface rate is n x 14,5 kbit/s and the AIUR is equal to 64 kbit/s,
– a relay rate adaptation function does not apply if the radio interface rate is n x 32 kbit/s

NOTE 5: A 320-bit frame format described in 3GPP TS 48.060.

NOTE 6: Used only in non-transparent configurations.