Computer Networks (CITS3230) - Tutorial 1
(for the week commencing 17 March 2008)
- The federal Ministers for Education,
and Innovation, Industry, Science & Research
call a joint press conference one afternoon
and espouse the belief that Higher Education and Information Technology
are worthy societal resources.
How would you (quickly) spend any increased funding to equip
a university campus and its undergraduate computing laboratories
to connect heterogeneous computer hardware running different operating systems?
- Make three clear predictions for network technologies in the future.
Base your predictions on specific examples or current trends in networking.
What advantages are offered,
and what threats posed,
by each of these new technologies?
- Order the bandwidths of the following "communication technologies",
and the times taken to perform each transfer:
- Australia Post delivering a movie on DVD overnight,
- transferring a large file over the UWA campus network
(try ftp://ftp.uwa.edu.au/mirrors/linux/kernel/v2.6/linux-2.6.24.3.tar.bz2),
- copying the same large file from a hard disk drive to the same disk,
- copying the same large file to a USB drive,
- copying one 1Mb array to another in a high-level programming language,
- refreshing the screen of an ASCII terminal using a 56Kbps modem,
- transmitting an A4 sized FAX in 30 seconds,
- transmitting data across an IEEE 802.11b network, and
- transmitting data across a Bluetooth network.
In each case state your assumptions about the amount of data transfered.
- What is the Hamming distance of the following code?
000000 111111 001101 110100 101010
What type of errors can be detected and what type corrected with this code?
- Much harder: Hamming's method of error correction,
described in Week 1,
can only detect and correct single bit errors.
However, we know that errors occur in bursts, typically 100 bits long.
How can Hamming's method be adapted to correct burst errors,
without introducing an enormous overhead in additional check bits?
Chris McDonald
March 2008.
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