The test as called up in ETS 300 012 is more stringent that just an attenuation test but it is important to keep in mind that BABT is not expecting you to replicate the type test as defined in the standard. Our experience is that BABT will accept a simple attenuation test for the BRI receiver sensitivity, I would have to check what level of attenuation we have used in the past but something like 10dB sounds familiar.
You also do not, in our experience, need to use expensive test equipment. You can use a loopback to do the testing and measure BER if this feature is supported on your equipment or maybe choose a "gold" unit as the reference sender. The one thing we did come across in doing things this way is that the measurement has to be at layer 1 to avoid misleading results due to error correction at higher levels. I would concur with the statements about putting a proposal to BABT concerning end of line test equipment. Our experience is also that many companies expend a lot of money on expensive test equipment for end of line testing that is unneccessary. Not only is this equipment expensive but it also adds considerable cost to the entire production process due to the single item of complex "development" test equipment causing a bottle neck. Come up with a realistic EOL test proposal that fits into the production environment and BABT will consider it. You could save yourself a lot of up front money and considerable ongoing product cost. Hope this helps. Nick Genesys Worlwide Product Compliance and Localisation Services ---------- From: Dave Sanderson Sent: 21 August 1996 17:21 To: "'[email protected]'" Subject: BRI - rx sensitivity testing 2 Sender: [email protected] Received: from europe.std.com (europe.std.com [199.172.62.20]) by hil-img-1.compuserve.com (8.6.10/5.950515) id MAA04246; Wed, 21 Aug 1996 12:05:53 -0400 Received: by europe.std.com (8.7.5/BZS-8-1.0) id MAA12035; Wed, 21 Aug 1996 12:00:25 -0400 (EDT) X-Authentication-Warning: europe.std.com: daemon set sender to treg-approval using -f Received: from world.std.com by europe.std.com (8.7.5/BZS-8-1.0) id MAA12031; Wed, 21 Aug 1996 12:00:23 -0400 (EDT) Received: from nt-main.aculab.com (mailhost.aculab.com) by world.std.com (5.65c/Spike-2.0) id AA04238; Wed, 21 Aug 1996 11:57:17 -0400 Received: by nt-main.aculab.com with Microsoft Exchange (IMC 4.0.837.3) id <[email protected]>; Wed, 21 Aug 1996 16:50:12 -0000 Message-Id: <c=GB%a=_%p=Aculab%[email protected]> From: Dave Sanderson <[email protected]> To: "'[email protected]'" <[email protected]> Subject: BRI - rx sensitivity testing 2 List-Post: [email protected] Date: Wed, 21 Aug 1996 16:50:10 -0000 X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.837.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: [email protected] Precedence: bulk Reply-To: [email protected] Thanks for your response Pete. We also produce E1 cards and do a similar thing to yourselves. However, we additionally superimpose a noise signal onto the looped back signal. >From your reply, I can see that this is over the top! Still, too late, the test equipment is now designed and in place. The trouble with the basic rate rx sensitivity tests is that they are much more stringent than E1. The tests called up in ETS300 012 clause D.4.8.2 specify various levels of jitter, various bus configurations and various levels of superimposed noise. We already test to a cut down version of these tests (with BABTs approval) with the K1403 but we would like to eliminate the need for the K1403 altogether. It is difficult to know the minimum set-up that BABT will let us get get away with. I guess all we can do is put forward a proposal and hope that they go for it. >regards >David Sanderson >Aculab plc >[email protected] >---------- >From: Pete Van Raalte[SMTP:[email protected]] >Sent: 21 August 1996 15:31 >To: [email protected] >Subject: Re: BRI - rx sensitivity testing > >Dave, > >We have a similar problem on an E1 application (PRI physical layer). >BABT has permitted us to use the simple and inexpensive expedient of >looping XMT back to RCV through a 10 dB attenuator. If we get >error-free operation (no alarms), then we have proved receiver >sensitivity to BABT's satisfaction. I don't know if they would >accept this solution in a BRI application, but you might give them a >call to inquire. > >
