The document contains 8 questions for an assignment on wireless application protocol. The questions cover topics such as comparing circuit-switched and packet-switched networks, frequency division multiplexing of voice channels, spread spectrum techniques, calculating bandwidth requirements for frequency division multiplexing with guard bands, advantages and disadvantages of bursty versus continuous data transmission in wireless systems, and disadvantages of wireless LANs compared to wired LANs. The last question discusses applications where the disadvantages of wireless LANs may be outweighed or override the advantages of wireless mobility.

1. Sir Syed University of Engineering & Technology, Karachi
Department of Computer Science
Wireless Application Protocol
Assignment#1
Last Date: 15 /03/12
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Q#1 Compare and contrast a circuit-switched network and a packet-switched network.
Q#2 Assume that a voice channel occupies a bandwidth of 4 kHz. We need to combine three voice
channels into a link with a bandwidth of 12 kHz, from 20 to 32 kHz. Show the configuration,
using the frequency domain. Assume there are no guard bands.
Q#3 Five channels, each with a l00-kHz bandwidth, are to be multiplexed together. What is the minimum
bandwidth of the link if there is a need for a guard band of 10kHz between the channels to prevent
interference?
Q#4 Discuss following four types of wireless networks, with examples.
PAN, LAN, MAN, and WAN
Q#5 Define spread spectrum and its goal. Explain two spread spectrum techniques
Q#6 Assume that a voice channel occupies a bandwidth of 4 kHz. We need to multiplex 10 voice
channels with guard bands of 500 Hz using FDM. Calculate the required bandwidth.
Q#7 Describe two technical advantages and disadvantages of wireless systems that use bursty data
transmission rather than continuous data transmission.
Q#8 Describe three disadvantages of using a wireless LAN instead of a wired LAN. For what applications
willthese disadvantages be outweighed by the benefits of wireless mobility. For what applications
will the disadvantages override the advantages.