The user equipment reference configurations described in this clause are defined as per
TS 27.001.
The teleservice definitions in
TS 22.003 regard the facsimile group 3 terminal as a 2-wire analogue terminated equipment. In order to connect this to the MT a separate
"FA" device is necessary. This configuration, shown in
Figure 2 (a), shall be considered as the standard configuration, so that all the existing facsimile group 3 terminals may be connected to the PLMN.
An alternative realization would be to combine a facsimile group 3 terminal and the FA into a special
"UMTS facsimile machine", directly providing a digital output. Although such a terminal shall appear to the MT as identical as the FA (i.e. with an identical interface and protocol), it would allow for a significantly smaller and simpler facsimile machine. This configuration is shown in
Figure 2 (b).
In addition of course, it is always possible to realize a single device, as per
Figure 2 (c), where both the facsimile and mobile termination functions are considered to be part of one integrated unit.
The particular terminal adaptation functions used are those detailed in
TS 27.002 for non-transparent bearer capability. The interface to the MT used is according to ITU-T Recommendation V.24 with an option for support of
TS 27.007 procedures for auto calling and auto answering.
The FA block,
Figure 3, is intended to specifically complement the facsimile group 3 terminal in order to be able to communicate over a UMTS PLMN.
Whether it has to be a function internal to the UMTS PLMN, or an external accessory associated with the facsimile group 3 terminal, is beyond the scope of the present document, and in any case, does not affect the working of the procedure as described here.
It may be functionally partitioned in two sections:
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an analogue section, dealing with:
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the modulation and demodulation processes according to ITU-T Recommendation V.21, V.27ter, V.29 and V.17 as explained in ITU-T Recommendation T.4 and T.30;
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handling of the signalling on a 2-wire path to the associated facsimile terminal, including auto calling and auto answering functions where necessary (see clause 7).
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a digital section, dealing with:
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overall control of the FA;
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where necessary, manipulating the ITU-T Recommendation T.30 protocol as detailed in the present document;
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connection to the TAF using the interface according to ITU-T Recommendation V.24 as described in TS 27.002;
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where necessary, auto calling and auto answering functions according to TS 27.007.
The special UMTS facsimile machine shown in the UE configuration of
Figure 2 (b) is similar to the digital part of the FA, but without any of the analogue portions.
It appears at the ITU-T Recommendation V.24 interface as identical as the FA, i.e. the MT needs to have no knowledge of the particular configuration used.