From GSM to LTE: An Introduction to Mobile Networks and Mobile Broadband

6.10 Questions

1. What are the differences between the ‘ad hoc’ and ‘BSS’ modes of a WLAN?

2. Which additional functionalities can often be found in WLAN access points?

3. What is an extended service set (ESS)?

4. What is an SSID and in which frames is it used?

5. What kinds of power-saving mechanisms exist in the WLAN standard?

6. Why are acknowledgment frames used in a WLAN?

7. Why do 802.11g networks use the RTS/CTS mechanism?

8. Why are three MAC addresses required in BSS frames?

9. How can a receiving device detect the speed at which the payload part of a frame was sent?

10. What is the maximum transfer rate that can be reached in a data transfer between two 802.11g devices in a BSS?

11. What disadvantages does the DCF method have for telephony and video streaming applications?

12. Which security holes exist in the wired equivalent privacy (WEP) procedures and how are they solved by WPA and WPA2 (802.1x)?

Answers to these questions can be found on the companion website for this book at http://www.wirelessmoves.com.

References

[1] IEEE, ‘Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications’, ANSI/IEEE Std 802.11, 1999 Edition (R2003).

[2] IEEE, ‘Part 3: Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications’, ANSI/IEEE Std 802.3, March 2002 Edition.

[3] IEEE, ‘Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications: High-Speed Physical Layer Extensions ...