D

B1 :16 bits B2 :16 bits D : 4 bits overhead : 12 bits (not shown)

BR1 = 4000 frames/sec = 4000 * 48 bits/frame = 192 kbps

B1 :16 bits B2 :16 bits D : 4 bits overhead : 12 bits (not shown)

BR1 = 4000 frames/sec = 4000 * 48 bits/frame = 192 kbps

Fig. 12.4. BRI frame format.

Each B channel is sampled two times during each frame (8 bits per sample). D channel is sampled four times during each frame (one bit per sample). The overhead are not shown. The reason for interleaved sampling is to create long frame. This is useful in many cases, for example the size of the BRI frame matches for a data portion of an ATM cell.

BRI functionality is attainable without any modification to the existing telephony infrastructure. Telephone companies must change the signalling on the local loop to support ISDN, but no physical modifications are required.

Was this article helpful?

0 0
DIY Battery Repair

DIY Battery Repair

You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.

Get My Free Ebook


Post a comment