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2005-01-13 22:57:00 ET Just trying to get my head around different concepts. I now realize that my lack of math knowledge is a hinderance to the further advancement of my knowledge (it sounds like I'm wiritng a suicide note for some reason) and so I shall begin to learn math in the morning. Fuck, I've got so many things to do that I've been putting off. Anyways, I'm currently reading about the PSTN which stands for Public Switched Telephone Network. (Interrupted for link: http://www.cdg.org/technology/applications/operator_services.asp and http://www.cdg.org/index.asp plus http://www.cdg.org/worldwide/index.asp ) How your average phone line aka suscriber loop aka local loop is called a DS0 circuit and is a 64kilobit/s channel that is multiplexed inside junction boxes and connected to the exchange/CO (not interchangeable terms. A CO usually services more than one exchange but I don't think that one exchange could be served by more than 1 CO) through what's known as the "access network". Exchanges are connected together through the "Inter-Exchange Network". I hope that that is the official term. I hate when there's 60 different names for the exact same thing. Anyway, you can have 24 DS0 circuits in one circuit called a DS1 circuit which we all probably know by it's other name: A T-1 line. The T-1 line, called an E-1 line in Europe (which is composed of 32 DS0 circuits instead of the American 24. Same bandwidth though.) Now a BRI (Basic Rate Interface) connection is an ISDN connection made out of 2 "B" channels (64kbit/s each), which can be used for voice or for data, and 1 "D" channel (16 kilobits/s) which is used for call information. What the hell does the "D" and "B" stand for? Crap. I forgot. Oh, okay. The "B" in B-channel stands for "Bearer". The "D" in D-channel stands for "Delta". The D channel carries control and switching information. A PRI line (if "line" is the right word. or connection. or whatever. Oh, okay, it is called a "line". I just checked.) is composed of 24 b-channels (64kilobit/sec, plus 32 b-channels in Europe) and 1 d-channel (also 64kilobit/sec.) BRI is also known as ISDN. PRI is a T-1. There must be a difference between the terms DS1 and PRI. Or at least I hope so. That's all for know. More links: http://www.ericsson.com/cdmasystems/press/IEEE_DV.pdf http://www.telular.com/products/brSX5P_CDMA.pdf http://www.cdmatech.com/solutions/pdf/msm6100_chipset.pdf IS2000 Standard?!!! http://eesof.tm.agilent.com/docs/adsdoc2003C/pdf/cdma2k-doc.pdf |
