802 Standards Flashcards
Frequency-Hopping Spread Spectrum (FHSS)
Is a physical layer technology for 802.11 at 1 Mbps and 2 Mbps data rates.
Direct-Sequence Spread-Spectrum (DSSS)
Utilized in the 2.4 GHz frequency, DSSS is a process where data is transmitted on as many frequencies as possible. And is a physical layer technology of 802.11
802.11 (PRIME) INFO
FREQ RANGE - 2.4 GHz
MODULATION - DSS, FHSS
SPEED - 2Mbps
802.11a INFO
FREQ RANGE - 5 GHz
MODULATION - OFDM
SPEED - 54Mbps
802.11b INFO
FREQ RANGE - 2.4 GHz
MODULATION - HR-DHSS
SPEED - 11Mbps
802.11g INFO
FREQ RANGE - 2.4 GHz
MODULATION - ERP-OFDM
SPEED - 54Mbps
802.11n INFO
FREQ RANGE - 2.4 GHz and 5Ghz
MODULATION - HT-OFDM
SPEED - up to 600Mbps
802.11ac INFO
FREQ RANGE - 2.4 GHz
MODULATION - DSS, FHSS
SPEED - up to 1.3Gbps
Higher Order of Modulation
Wireless information is converted to a digital format in the form of bits (0s & 1s). Bits are then sent over-the-air using electromagnetic waves (radio waves).
Orthogonal frequency-division multiplexing (OFDM)
- *In relation to OFDM - means signals are multiplexed in a way that the peak of one signal occurs at the null of the other neighbor signals.**
- *EX: Wi-Fi 802.11ac, 4G, 5G cellular technologies, WiMAX, satellite**
Channel Bonding
This is the process of combining one or more cellular modem connections into a single, faster virtual connection allowing the end user to utilize combined bandwidth.
WHAT ARE THE SIX TYPES OF STATIONS?
- MASTER
- MANAGED
- AD HOC
- MONITOR
- REPEATER
- MESH
What are the six types of Clients?
- ROOT MODE
- BRIDGE MODE
- WORKGROUP BRIDGE MODE
- REPEATER MODE
- MESH MODE
- SCANNER MODE
Bridge Mode (Clients)
Provides wireless connectivity between multiple wired networks.
Workgroup Bridge Mode (Clients)
Provides wireless connectivity between a group of wired network stations.
Wireless Distribution System (WDS)
Uses 802.11 connection to allow wireless access points. This allows a wireless network to expand using multiple access points without a traditional wired link between them
Three basic topologies for WLAN
- Independent Basic Service Set (IBSS)
- Basic Service Set (BSS)
- Extended Service Set (ESS)
IBSS
Also known as ad-hoc mode or peer-to-peer mode refers to an office network in which there is no single node required to functions as a server.
BSS
Contains at least one access point connected to a wired network infrastructure and a set of wireless end stations.
ESS
Has multiple overlapping BSSs (each BSS having at least one access point) connected by the means of a Distributed System. In 802.11 the client is in charge of determining which AP to connect to
