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I just can't get my head around this. Considering a system using stop-and-wait ARQ, does the PER include the packets that has to be resent? I mean, isn't the PER value the probability of a packet containing an error? If so, every time a packet is received, there's a PER chance it's erroneous. If the packet is indeed erroneous a second time, it has to be resent, and that resent packet also has a probability of PER that it arrives with an error, and if that one also contains an error, it has o be resent, and so on... This would imply that there's a difference of a total PER and the PER given by the BER value. Or isn't the PER value really the probability of one packet containing a bit error, but rather the total ratio between correct and incorrect packets received over time including the packets that were resent?

I would really appreciate it if somebody would try to explain so i'd understand.

Hi, I was wondering if there is any data on different "typical" bit-error rates for different broadband technologies (esp. adsl, adsl2+, vdsl2, caple tv (docsis 3.0) and 3g (cdma2000)). I've been searching the internet for quite some time now without any luck. If anybody could help me out here it would be very appreciated!

Well, thanks a lot for the help, still. But the thing is, my teacher told us that, if we were good at finding information on the internet, the assignment could take only like 20 minutes to finish.

http://en.wikipedia.org/wiki/Modem

http://en.wikipedia....ata_compression

http://en.wikipedia.org/wiki/Data_rate

http://en.wikipedia..../Bit_error_rate

Yes, those articles were of course among the first ones I looked up. I still can't apply that information to this assignment, that is, i can't find which techniques of molulation, compression are used in what broadband technologies, or what specific BER that technology has. Could you help me out, please?

I've got an assignment on my data communications course, and I really can't figure out what my lecturer means. The exact text he wrote as the assignment is as follows:

"Using our course documentation, and available information on the

Internet, answer the following questions:

During the past few years, broadband Internet access to private homes

has been offered using several different broadband technologies, such

as cable TV, ISDN, ADSL, VDSL, Wireless Broadband, Satellite links, 3G

and 4G networks, etc.

Using the textbook and the Internet, research and compare the

following technical parameters for five (5), or more, broadband

Internet access technologies:

- modulation

- compression

- datarate

- reliability (bit errors - BER)

I suggest you document this in table format, such as in MS Excel.

Tip: Find out which companies manufacture modem chips for the

different technologies, and download their technical specifications.

More information can be obtained from the International

Standardization documents, as well as from scientific articles. You

can even search Wikipedia for ADSL, etc"

With only a first look at it, it seemed to be a rather easy task, but I've been searching the web for like two days without any luck, and the assignment is due tomorrow. The bit rates are obviously not the tricky part. We haven't started reading about any modulation techiques yet, nor any compression techniques, so I don't even know if the answer he wants should be displayed as a value in some unit or if the answer is some name for a standard or protocol. And despite his "tip", i can't seem to find anything relevant.

Please help me out here!