Hello Bob:

Some significant differences in requirements exist in two areas:

Safety:  The two current US safety standards are UL 1459, and UL 1950.  UL 1459 
will soon be obsolete, and designing to this standard will leave you 
non-compliant in the European market.  UL 1459, for example, has much less 
stringent isolation requirements between TNV and SELV.  Designing to UL 1950 
will bring one much closer to the European requirements outlined in EN 60950 
and EN 41003, however, there are differences here to.  For example, some 
European countries have more stringent isolation requirements between ground 
and the network than the US UL 1950 standard outlines.  Conversely, if you 
design for European concerns only, you may have troubles in the US passing the 
power cross requirements outlined in the domestic standards.  These are only a 
few examples of things to be aware of, I am sure.

Telecom Requirements:  For example, a Modem designed for the US, FCC part 68 
has no Return Loss requirement.  For Europe, every country has differing Return 
Loss requirements.  These are outlined in a document titles ETS 300 001 or NET 
4.  There is another harmonized standard emerging, it is now titled TBR21.  For 
the UK, the national standard is NTR3, which is aligned closely with TBR21.  
Many (I believe) European countries have now subscribed to this (TBR21) 
standard.  Other differences between the requirements of these countries and 
the US will be impedance unbalance about earth, billing tones, maximum 
transmission levels, etc., etc., etc.

In short, there are many differences.  If you are designing for the UK and US 
alone, you may have good shot.  However, if it is your companies first time 
designing for all of Europe, I would advise your company to hire an outside 
consultant to help you through the maze of requirements each country has.  I 
believe most everyone on TREG would agree.

Hope this helps, feel free to call me for more information.  I am by no means 
an expert (yet) on the topic, but could possibly fill you in on a few details...

Mel Pedersen                              Midcom, Inc.
Homologations Engineer             Phone:  (605) 882-8535
[email protected]  Fax:  (605) 886-6752

----------
From:   Bob Sykes[SMTP:[email protected]]
Sent:   Thursday, November 13, 1997 10:59 PM
To:     [email protected]
Subject:        US vs. UK modems

Treggers,

I have what is probably an elementary question.

Will a 14.4 modem designed for US use work OK in the UK?
I understand that the UK jack is a little smaller than a
RJ11, but adapters are available.  I think there might be
some other subtle differences, but don't know the parameters
of concern.

Thanks in advance,

Bob Sykes
EMC Engineer, Telcom dummy



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