Wireless crash course? Interview in two days

popquizkid95

So I have an interview for a Wireless Engineer job coming up Thursday. I am a CCNA: R&S and have a pretty good background supporting wireless networks. However, I'm sure I need to brush up on any technical questions that will likely be asked in the interview. Any suggestions for a crash course, any resources for good interview questions that will likely be asked?

I hope I asked this in the right forum.. Thanks in advance!

Burns82

good luck mate, to determine if some one has a good understanding of wireless regards less of vendor I usually question.
what is RF?
what is ## dBm to mW?
what are the 802.11phy and their characteristics?
how do you fault find a client that is having connectivity issue?
describe CCI, ACI and was to reduce its impact on a wireless network
they are just some question ,depending on the CV of the person

popquizkid95

Thanks! So if you were interviewing me and asking those questions, here would be my responses: [inlineblock]what is RF? RF stands for Radio Frequency which is used for wireless communication. The most common frequency ranges are in the 2.4GHz and 5GHz bands.[/inlineblock] [inlineblock]what is ## dBm to mW? If I understand correctly, you are wanting to convert dBm to MW? dBm is the most common method of measuring wireless signal strength although it can also be measured in mW. mW is actually more accurate, but you end up with a bunch of decimal places. Example -40 dBm is 0.0001 mW. Typically if I need to make a conversion, there are calculators online that do it for me. [/inlineblock] [inlineblock]what are the 802.11phy and their characteristics? 802.11 consists of a set of wireless networking standards. Typical standards used are 802.11b and 802.11g (which are now legacy.) They use the 2.4GHz band. 802.11a uses 5GHz exclusively. 802.11n can use both 5GHz and 2.4GHz. 802.11ac is exclusively 5GHz but has a wider channel range among other improvements.[/inlineblock] [inlineblock]how do you fault find a client that is having connectivity issue? Typically I will retrieve the mac address of the client and perform client level debugging on the wireless controller.[/inlineblock] [inlineblock]describe CCI, ACI and was to reduce its impact on a wireless network - CCI (co-channel interference) is when two or more APs are transmitting on the same channel. ACI (adjacent channel interference) are when two or more APs are transmitting on adjacent or partially overlapping channels. In a CAPWAP environment, interference problems are addressed by the use of DCA (dynamic channel assignment.) In a non CAPWAP environment, interference can be resolved by proper channel planning by the use of software, handheld wifi analyzers, to discover the APs causing CCI or ACI.[/inlineblock] Please let me know if these are good answers, or they need some work. Thanks again!

popquizkid95

@Burns82 - What do you think of my answers? The interview is this afternoon. Thanks again!

soccarplayer29

https://www.cwnp.com/wireless-knowledge-quiz

There are some interesting looking whitepapers and other resources on this sight that might be worth looking over also. Best of luck!

Edit:

802.11i details: https://nvlpubs.nist.gov/nistpubs/legacy/sp/nistspecialpublication800-97.pdf
Securing WANs: https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-153.pdf

popquizkid95

soccarplayer29 wrote: »

https://www.cwnp.com/wireless-knowledge-quiz There are some interesting looking whitepapers and other resources on this sight that might be worth looking over also. Best of luck! Edit: 802.11i details: https://nvlpubs.nist.gov/nistpubs/legacy/sp/nistspecialpublication800-97.pdf Securing WANs: https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-153.pdf

Good site, thanks! I took the little quiz and the results came back that "I know my wireless." So I suppose I did pretty well.

Cat5

So how did you do in your interview? I'm studying for my CCNA-Wireless, but I have zero wireless experience and no LWAPP GUI to practice with. Gonna make it challenging to get a job requiring wireless.

popquizkid95

Cat5 wrote: »

So how did you do in your interview? I'm studying for my CCNA-Wireless, but I have zero wireless experience and no LWAPP GUI to practice with. Gonna make it challenging to get a job requiring wireless.

Thanks for asking, I got the job. It was actually very brief and very few wireless questions were asked. So I actually way over-prepared for it.. lol. I think my Cisco experience and background supporting an enterprise wireless network is what landed me the job.

soccarplayer29

Congrats!

popquizkid95

soccarplayer29 wrote: »

Congrats!

Thanks a lot!

Mooseboost

Congrats on the new job! It is always better to be overprepared than under!

popquizkid95

Mooseboost wrote: »

Congrats on the new job! It is always better to be overprepared than under!

Thanks! I agree 100% to over-prepare. Same goes for cert exams.

Burns82

Congrats mate.