ch could compensate for the delay in delivery mail or local area networks to request interoperation. This is usually and the subsequent confirmation report necessary. achieved by fitting a gateway on the computer network to convert the information to the T.4 and T.30 facsimile format for onward 60.6.2 Facsimile switches transmission. The problem is for incoming documents in the facsimile domain. The requirements of some major users include facsimile traffic These are virtually impossible to convert to the text environment control and costing, archival recording of all transferred facsimile and require onward transmission in a graphics mode with the high G4/G3 Fax Distributed G4/G3 Fax for input/output G3 Fax Storing /distribution Storing /distribution G3 Fax Communication record Traffic record Network access Operating state to other units Operator console Facsimile message switch Graphics printer Figure 60.8 G3 fax switch block diagram Facsimile futures 60/15 bandwidth and large storage capacity associated with raw image Facsimile futures data. These facsimile documents are most conveniently printed out on a local facsimile unit and kept separate from the data system. The PSTN remains the major communication network for the fore- seeable future with increasing opportunities on the ISDN. Facsimile 60.6.4 PC fax cards terminals G3, G3-64kbit/s and G4 will continue to operate on these networks. The widespread availability of G3 machines and the expansion card Facsimile transmission is particularly appropriate for the future provision in desktop personal computers, has encouraged the devel- because of the large compatible equipment base and because of the opment of specialised fax cards. With the addition of a dedicated vast and continuing information base on paper and film. PSTN interface card and support software, it is possible to make Documents are required on paper for convenience, for availability facsimile transmissions directly from PC memory without the (even in power failure) and for use when out of communi