In a message dated 96-04-23, Chan Lee writes: > >I try to get some information of standards for G3 fax machine with >handset specially for UK. Is there anyone can tell me for the above subject >? >TBR21 or NTR2 ? > > Chan:
TBR 21 is a DRAFT pan-Europen standard that is not presently in force. Some countries, such as the UK and Sweden, have issued new national regulations that are based on (but not identical to) TBR 21. In the UK, the relevant specification is NTR 3. For your fax functions, NTR 3 is probably the way to go. You can still use the older UK specs (BS 6305), but NTR 3 is easier to meet. The presence of a handset on your fax machine introduces some possible problems for the telephone mode, since NTR 3 is restricted to non-voice equipment. One possible approach would be to comply with BS 6317 (Simple Extension Telephones) for this mode. When the predecessor to NTR 3 (BABT/SITS/94/54) came out last year, I published an article in the May/June issue of Compliance Engineering that described it. At that time, there was considerable debate among the "experts" as to whether equipment with handsets could be approved under BABT/SITS/94/54. I summarized the situation as best I could in the article. Briefly, the conservative view was that any equipment with a handset would be ineligible for BABT/SITS/94/54. This meant that BS6317 would have to be used until a (planned) NTR for voice terminals was issued. The liberal view was that the "handset telephony" restriction of BABT/SITS/94/54 was only meant to exclude "simple telephones". Products such as hands-free telephones, telephones connected behind a PBX, and telephones not powered by central office loop current would be approvable under BABT/SITS/94/54, with no tests whatsoever on speech quality. I notice that when BABT/SITS/94/54 finally became NTR 3, the title was changed. The BABT/SITS/94/54 title was "Attachment Requirements for the Connection of Terminal Equipment to the UK Public Switched Telephone Network (PSTN), Excluding Handset Telephony". The title of NTR 3 is "Attachment Requirements for the Connection of Non-Voice Terminal Equipment to the Analog Public Switched Telephone Network (PSTN)". Perhaps there is a clue here about how the debate was resolved. I have not revisited this issue during the last year. I suspect that by now, two things may have happened in the UK: 1) The applicability of NTR 3 to equipment with handsets has probably been clarified. 2) The planned NTR for voice telephony may have been issued or may be imminent. I hope that the above remarks get you pointed in the right direction. In the meantime, I would appreciate hearing from other members of treg who may have more up-to-date information on this subject. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 617-721-2848
