Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!richsun!lance@richp1.UUCP
From: lance@richp1.UUCP (Lance Hall)
Newsgroups: comp.dcom.modems
Subject: Comparison of V.32bis versus V.32
Keywords: V.32, V.32bis
Message-ID: <920@richsun.UUCP>
Date: 12 Jun 90 17:16:26 GMT
Sender: news@richsun.UUCP
Followup-To: comp.dcom.modems
Distribution: usa
Organization: Rich Inc., Oakbrook,IL
Lines: 38


A question to those folks who know ---

   The currently ratified standard for high speed modems is V.32 which
consists of the following:

	- 9600 bits per second
	- full duplex operation over voice grade 2-wire connections
	- fallback to V.22bis -> V.22/Bell212 -> V.21/Bell103
	- 600 baud with 16 point Trellis Coded Modulation
	      (or is 32 point TCM required/recommended/commonly used
		  for forward error correction?)
	- echo cancellation necessary
	- no inherent end-to-end reliability mode; i.e., V.42/Appendix
	      is required for such
	- no inherent end-to-end  compression mode; i.e., V.42bis is
	      required for such

I have seen reference to the V.32bis standard that is currently in
progress which consists of the following:

	- 14,400 bits per second
	      (why did this not double to 19,200 bps?)
	- full duplex operation over voice grade 2-wire connections
	- fallback mechanisms ???
	- modulation scheme ??? TCM ??? DAMQAM ??? Other ???
	- echo cancellation necessary
	- no inherent end-to-end reliability mode; i.e., V.42/Appendix
	      is required for such
	- no inherent end-to-end  compression mode; i.e., V.42bis is
	      required for such

I would appreciate some discussion to better understand what V.32bis is
now and what it may be when ratified as compared to V.32.
--
- - - - -
Lance N. Hall
lance@richp1.UUCP or lance@richsun.cpg.trs.reuter.com