Wireless Networking Flashcards
What is MIMO?
Multiple Input and Multiple Output transmission
Local Wireless Technology: RF
A generic term rather than a standard, used to apply to any number of proprietary radio frequency protocols.
Local Wireless Technology: RFID
Radio frequency identification is a technology which allows identification and communication between nodes using electromagnetic fields.
Local Wireless Technology: Bluetooth
Bluetooth operates in the same 2.4 GHz RF band used by Wi-Fi, and in fact, many Wi-Fi NICs include Bluetooth transceivers, but it’s a separate standard.
Local Wireless Technology: NFC
Near Field Communication is a set of standards based on RFID, and commonly found on mobile devices such as smartphones.
Local Wireless Technology: ANT+
A 2.4 GHz radio protocol similar to but separate from Bluetooth. It is a proprietary format owned by Garmin, but is available for other vendors by an open access agreement.
Local Wireless Technology: Z-WAVE
A proprietary wireless standard maintained by Silicon Labs. It uses the 800-900 MHz ISM band, with precise frequencies varying by country.
Local Wireless Technology: ZigBee
An open standard based on the IEEE 802.15.4 PAN standards, maintained by the ZigBee Alliance. It can use a variety of ISM bands, with 2.4 GHz and 915 MHz bands being the most common.
How could you tell if a wireless device used MIMO?
It might have multiple visible antennas.
What happens if two wireless networks use overlapping spread spectrum channels?
Since only some subchannels will experience interference at a given time, both networks will still work at a reduced data rate.
MIMO uses multiple antennas to simultaneously transmit and receive separate data streams on the same channel. True or False?
True
Radio frequency identification (RFID) is a technology which allows identification and communication between nodes using electromagnetic fields. True or False?
True
What wireless communication protocol is used primarily for home automation?
Z-Wave
Band and Speed: 802.11a
Supports speeds of up to 54Mbps on the 5 GHz band.
Band and Speed: 802.11b
Supports speeds of up to 11Mbps on the 2.4GHz band.
Band and Speed: 802.11g
Supports speeds up to 54MBps over the 2.4 GHz band.
Band and Speed: 802.11n
Supports speeds up to 600 Mbps over either the 2.4 GHz or 5 GHz band, if all 4 spatial streams are used.
Band and Speed: 802.11ac
Supports speeds of up to 6.93 Gbps in the 5GHz band using ODFM encoding, if all 8 spatial streams are used.
You’re setting up a Wi-Fi network for local sharing without internet access. Why would you still use a WAP rather than an ad-hoc network?
Infrastructure mode is generally more efficient and gives better performance.
Wi-Fi encryption standards: WEP
Wired Equivalent Privacy was part of the original Wi-Fi standard. It uses the RC4 encryption cipher, and it soon turned out to have some major problems.
Wi-Fi encryption standards: WPA
Wi-Fi Protected Access was included as part of the draft 802.11i standard, rushed a bit into service when WEP’s critical limitations became obvious.
Wi-Fi encryption standards: WPA2
WPA2 is the final version of WPA, based on the final 802.11i standard. It has a few changes, but the biggest one is mandatory support for 128-bit encryption using the strong and well-regarded Advanced Encryption Standard(AES) cipher.
WPA options: WPA-Personal
Also called pre-shared key (PSK). Uses a passphrase of between 8 and 63 ASCII characters, manually distributed to each authorized user.
WPA options: WPA-Enterprise
Also known as 802.1x mode. Connecting clients are only allowed to communicate to an external authentication server, usually RADIUS-based, with a username and password.
