INTERNATIONAL  TELECOMMUNICATION  UNION

		     ITU-T RECOMMENDATION SUMMARY

Rec. No. : V.17

Title :	A 2-wire modem for facsimile applications with rates up to 
	14 400 bit/s

Study Group : XVII - Data Transmission over the Telephone Network

Version : New

Date of adoption : 1991

Notes :	


Recommendation V.17 defines the modulation methods and operating 
sequences for a modem intended only for use in high speed facsimile 
applications.

Appropriate T-Series Recommendations should be consulted regarding 
operating procedures and other features employed in facsimile 
transmission applications, as these differ from those recommended for 
high speed modems for general applications.

The modem has the following principal characteristics:

	a) Provision for half duplex operation at data signalling 
	   rates of:

	-   14 400 bit/s synchronous,

	-   12 000 bit/s synchronous,

	-   9600 bit/s synchronous,

	-   7200 bit/s synchronous;

	b) Quadrature amplitude modulation with synchronous line 
	   transmission at 2400 symbols per second.

	c) Inclusion of data scramblers, adaptive equalizers and 
	   eight-state trellis coding.

	d) Two sequences for training and synchronization: long train 
	   and resync.



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