Wireless engineer interview questions
A recruiter from Atlanta submitted this set of questions for interviewing at a wireless equipment company.
Describe your home WLAN setup.(Pay attention to candidate’s confidence. Plus if the candidate built it himself. Plus if the network is secured additionally, regardless of the protocols used. Plus if the candidate fought poor coverage.)
Ad-hoc vs. infrastructure topology. Advantages and disadvantages. Ad-hoc networks are easy to set up. By definition ad-hoc WLANs do not require access point, so they are cheaper. With infrastructured WLANs one can connect to wired LAN, enable wireless roaming for office workers, centralize WLAN management, boost the range.
Your preferred brand for wireless cards and access points. (An experienced candidate will be able to come up with strong argument to defend his preferences. He will point to the past projects as well.)
Range and throughput of 802.11a, 802.11b and 802.11g networks. The official spec for 802.11a is 54 Mbps and 25-75 feet indoors. The official spec for 802.11b is 11 Mbps and 100-150 feet indoors. The official spec for 802.11g is 54 Mbps and 100-150 feet indoors. An experienced candidate will provide his own observations.
How do you secure a wireless network? Forbid SSID broadcasting, enable MAC-level access where appropriate, enable WEP, enable 802.11i where available, enable firewalls, enable WPA.
What does Wi-Fi stand for? Wireless Fidelity.
What is 802.11i? It’s a new IEEE standard defining wireless network security.
What are the recommended channels if you’re setting up three WLANs and want minimum interference? 1, 6 and 11 for the US, 1, 7 and 13 for Europe and 1, 7 and 14 for Japan.
What are your preferred tools for wardriving? Somewhere the names Kismet, *stumbler or others should come up. Ask the candidate to describe his preferred configuration for wardriving.