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.
WPA options: WPS
Wi-Fi Protected Setup was designed to make it easy for non-technical users of home networks to easily control network access. It’s an addition to PSK mode, but also allows the key to be shared with a new device by other methods like a PIN, a push-button pairing mechanism, or NFC pairing.
CCMP
Counter Mode Cipher Block Chaining Message Authentication Code Protocol
AES
Advanced Encryption Standard
Why is it easier to compromise and harder to maintain WPA-Personal vs WPA-Enterprise, even when they use the same key length?
WPA-Personal uses the same shared key for everyone on the network. That makes it easier for unauthorized people to learn it and join unnoticed, and harder for administrators to change the password without affecting everyone.
Which Wi-Fi standard can operate in either the 2.4 GHz or 5 GHz band?
802.11n
Which Wi-Fi standard operates at 2.4 GHz frequency and provides data transmission of up to 54 Mbps?
802.11g
802.11ac supports the speed up to 10 Gbps in the 2.4GHz band using OFDM encoding, if all 8 spatial streams are used. True or False?
False
What technology supports throughput up to 40 kbps over distances of 10-100 m?
Z-Wave
What technology uses a variety of ISM bands, with 2.4 GHz and 915 MHz bands being the most common?
ZigBee
What wireless technology allows identification and communication between nodes using electromagnetic fields?
Radio frequency identification
What Wi-Fi standard supports speeds up to 54 Mbps over the 2.4 GHz band?
802.11g
Which WPA option is also called pre-shared key (PSK)?
WPA-Personal
Which WPA option is also known as 802.1x mode?
WPA-Enterprise
Which Wi-Fi encryption standard encrypts traffic using Temporal Key Integrity Protocol (TKIP)?
WPA
