

		     Firmware 6.12 release note	     04-26-1994
		   ------------------------------

New Feature:

Modem

1. ZyCellular mode added

ZyXEL U-1496 Series modems are equipped	with a special cellular	communication 
mode which enables the modem to	provide	reliable high speed data transmissions 
over cellular phone links
	  
In addition to normal modem, fax and voice operation modes, the	following
cellular modes are offered in ZyXEL's U-1496 series modems:
	  
Mode	     Speed
	  
Multi-Auto:  ZyX modes V.32bis/V.32/V.22bis/G3 FAX/Cellular Modes
CELL 14400:  14400/12000/9600/7200/4800	(AT&N42)
CELL 12000:  12000/9600/7200/4800 (AT&N43)
CELL 9600:   9600/7200/4800 AT&N44)
CELL 7200:   7200/4800 (AT&N45)
CELL 4800:   4800 (AT&N46)
	  
CELL 14400 will	connect	with another modem using cellular mode at a speed
of up to 14400bps.  It will also connect with another V.32bis/V.32 modem.
The actual speed depends on the	line condition.	The modem will automatically
fall-back or fall-forward within its speed range. CELL 12000, CELL 9600,
CELL 7200 and CELL 4800	limit the maximum speed	to 12000bps, 9600bps, 7200bps
and 4800bps, respectively.
	  
In Multi-Auto mode a ZyXEL modem will automatically and	dynamically select
the best speed and mode	in which to operate. Selecting one of the above
cellular modes manually	will limit the maximum speed at	which the modem	will
operate.

The ZyCellular mode is recommended when	using cellular links for modem
connection. It can also	be used	on other poor line conditions such as a
line with frequent large impulse noises.  ZyCellular mode is more noise
resistant, impairment resistant, and error resistant.
	  
It is simple to	use the	ZyCellular modems. Everything is determined
automatically by the modem.  The user needs only to set	S-register S49
bit 7 to leave the modem on cellular mode. S49 bit 7 tells the modem
where it is installed.	If S49.7=0, the	modem is installed in an office
connected to a normal telephone	line.  If S49.7=1, it means the	modem is
a mobile unit connected	to a cellular phone.  When a ZyCellular	modem
calls or answers another modem,	it will	indicate its cellular capability
and whether it is using	a cellular phone.  If both sides have the ZyCellular
capability and at least	one side is using a cellular phone, the	connection
will automatically be a	cellular mode connection.  If one side is a
non-cellular modem the connection will automatically be	a standard mode.
	  
If manual transmit power setting is desired, set S43.2=1 to disable auto
transmit power adjustment and use S49 bit 0-3 to set transmit power at -9
to -24 dBm.
	  
If cellular mode connection is never desired, set S43.3=1 to disable the
cellular mode connection.  The default is enabled (S43.3=0).
	  
You are	also able to send and receive faxes on cellular	links by just
setting	S49.7=1	on the ZyCellular modem	that is	installed on the cellular
site.  Now your	modem can send and receive faxes from fax machines and other
fax modems.

2. Support 100 dial digits on one dial string.

3. Bit s48.3 is	used to	reverse	V.23 channel speed.

	     Originate speed (send/receive)  Answer speed (send/receive)
   s48.3=0		      75/1200			   1200/75
   s48.3=1		      1200/75			   75/1200

4. Add ATO1 command, this command can force modem to request a retrain.

5. Set s48.4=1 and &D1,	DTR ON will make the modem dial	the default number
   and DTR OFF will make the modem hangup and reset profile 0. When the	modem
   is idle -wait for command- it will not dial a number	when the DTR signal
   changes from	ON to OFF.

6. In EG+ model, no more blacklist but the modem delays	30 seconds between
   every call. Press D/V button	on EG+ or "MENU" key on	SG+ will skip the delay
   and dial immediately.

7. Set s25 to define DTR delay timing. s25 specifies the minimum time that
   DTR signal must be off to be	recognized. Each units represents 10 ms.
   At least 4 ms for s25=0.


FAX

1. Class 2.0 Fax command is available on this version.

2. Add new command for class 2 .
    2.1:+FMINSP= Minimum phase C speed parameter (0 to 5).
	0:2400bps	1:4800bps	2:7200bps
	3:9600bps	4:12000bps	5:14400bps
    2.2:+FCQ= Copy quality check capability parameter (0 to 2).
	0:No copy quality check	capability.
	1:Only check 1D	phase C	data.
	2:Check	both 1D	& 2D phase C data.
    2.3:+FK  orderly fax abort command.

3. Report Detailed HangUp code information for both Class 2 and	Class 2.0.

4. Support T.4 1D/2D decompression, error line report and correction.
   Correction method for 1D: if	the number of consecutive error	lines are
   less	than 4 lines the error line is substituted by the previous good	line,
   otherwise the bad line is deleted. For 2D the error line is simply deleted.


VOICE

1. AT+VDD, This	command	sets the duration of DTMF tone detection. The unit is
   5 msec, default value is 6 (30msec).	The modem reports DTMF event when it
   detects a continuous	tone for this period.

2. AT+VDH, This	command	sets the threshold of the DTMF tone detection. The
   default value is 16.	Decreasing the value makes the modem more sensitive.
   The range of	VDH is 0-31.

3. The 2 and 3-bit ADPCM format	is changed. It is necessary to add the leakage
   coefficient for every sample. Please	refer to the C code program VCNVT.C
   and 610TO612.C for detail information. It is	recommended to re-record your
   greeting message because the	new leakage will give better voice quality.

4. AT+VGT, This	command	sets the playing volume	of voice. The default value
   is 192, a higher value makes	the voice louder. The range of VGT is 0-255.



Improvement:

Modem

1. Endless retrain on S48.1=1 (data mode only) is fixed.

2. Performance on V.26bis dial-up line half-duplex mode	is improved.

3. In security call back mode, the DSR and DCD will turn on only after call
   back	has established.

4. In ATI2 response, ">100M" error message fixed.

5. Set s43.7=1 to fix DCE connection speed. Modem will disconnect if the line
   condition does not permit the highest speed set by AT&N command.

6. In EG+ model, Flash "!" function is modified	to be the same as in E+.

Voice

1. "AT+VLS=16" command used to get response of "OK", it	is corrected to	"VCON".

2. Sending the "ATH" command in	voice mode and off hook	state used to hang
   the modem, bug fixed.

3. Sending "AT&F" following the	command	"AT+FCLASS=8" used to gets "NO CARRIER"
   , it	is corrected to	"OK".
