6.4.1 Limited set of PLMN connection types (for TCH/F4.8 and TCH/F9.6 channel codings)

3GPP43.010GSM Public Land Mobile Network (PLMN) connection typesRelease 16TS

From the two connection elements defined in subclause 6.2, the list of attributes and their possible values given in subclause 6.3, and from the service requirements defined in 3GPP TS 22.002 and 22.003, a limited set of PLMN connection types have been identified (see also table 5 and table 6 for the relationship between connection elements and telecommunication services).

Figure 6 gives the information transfer protocol models for the identified set of PLMN connection types. The S bits correspond to status bits and the D bits to data bits (3GPP TS 44.021); S* indicates that S bits are used only when 3.1 kHz audio ex PLMN. D’ bits corresponds to user bits passed in the place of status bits in the non transparent case Moreover, it should be noted that the RLP rate of 6 and 12 kbit/s correspond to the 8 and 16 kbit/s intermediate rate in the transparent case.

Protocol Models 1 b and e are the models for asynchronous data transmission in the transparent mode.

Protocol Models 2 b and e are the models for synchronous data transmission in the transparent mode.

Protocol Models 3 b and e are the models for character "asynchronous" mode data transmission in the non-transparent mode. In this case, L2RCOP represents the protocol used between the Layer 2 Relay functions (L2R) to convey characters between the MS and the IWF (see 3GPP TS 27.002). The data compression function is located in the L2R COP function.

In all of the above models, the b variants are for singleslot, the e variants are for multislot data configurations.

Protocol Model 5a is the model for the transparent support of group 3 facsimile transmission. Model 5b is for transparent support of group 3 facsimile transmission in multislot data configurations.

Protocol Model 6 is the model for speech transmission.

In the multislot-data models the data is split into parallel substreams between the Split/Combine-functions (S/C). These substreams are transmitted through parallel TCH/Fs which are treated as independent channels. Between the S/C-functions parallel RA- and FEC-functions are used.

For all the models, only the minimum functionality of the IWF is shown. Additional functions will be required for various interworking situations. These additional functions are described in specification 3GPP TS 29.007.

It should be noted that, in Figure 6, the representation of the transcoding and rate adaptation from the intermediate rate on the radio interface to the 64 kbit/s rate required by the MSC is not intended to indicate a particular implementation. The annex B to 3GPP TS 43.010 identifies alternative arrangements.

Figure 6: Information transfer protocol models for PLMN connections

Figure 6 (continued): Information transfer protocol models for PLMN connections

Figure 6 (continued): Information transfer protocol models for PLMN connections

Figure 6 (concluded): Information transfer protocol models for PLMN connections

Legend

to Figure 6:

FA

= Fax Adaptor

GSC

= GSM Speech Codec

FEC

= Forward Error Correction

MPX

= Multiplex/Demultiplex

MUX

= Multiplex/Demultiplex

S/C

= Split/ Combine