6.4 Flashcards
Improving upon earlier technology called – – – – the new – – – – – support more efficient multi user functionality for 802.1 1AX devices in essence allows the 802.11 a X axis point to subdivide each shadow into smaller frequency allocations for each client such as a 2 MHz or 4 MHz of each 20 MHz channel. The a peek and then transmit multiple small frames to multiple clients at one time using parts of the channel
OFDMA orthogonal frequency division multiple access
Beginning with 802.1 1N networks can use one or two techniques for combining multiple data frames into one larger frame this is known as
Frame aggregation
Wireless devices are not designed to transmit and receive simultaneously and so cannot prevent collisions instead 802.11 standards specify the use of – – – – – – – – procedures to access a shared medium compared with – – – – – – this version minimizes the potential for Collisions but cannot detect the occurrence of a collision and so cannot take steps to recover from the collision that your car
CSMA/CA carrier sensor multiple access with collision avoidance
CSMA/CD carrier sense multiple access with collision detection
One way to ensure the packets are not inhibited by other transmissions it is to reserve the medium for one nose use. In 802.11 accomplished through the optional – – –/ – – – protocol
RTS – CTS request to send/clear to send
This seemingly simple process known as – – – – involves the number of packet exchanges between the cafés access point and your computer
Association
While wireless devices on and it’s wireless protocols running It periodically service at surroundings for evidence of an access point Itaska known as – – –
Scanning
A small number of nose position transmit directly to each other without Intervening connectivity device
I’ll be SS independent basic service set using an ad hoc topology
A group of notes share an access point as shown. The access point excepts wireless signal from multiple nose and retransmit them. Usually on a wire connection to the rest of the networks. To cover its intended range and access point must have sufficient power and must be strategically placed so that all connect to nodes can’t communicate with it.
Basic service set or BSS
Using a messed apology several access points work as pure devices on the same Netwerk where the AP devices cooperate to provide more fault tolerant net work access to clients across larger geographical range
Ess Extended service sets
Involved in association and we association examples of this type of frame include probe and big and frames. This is known as
Management frames
Related to medium access and did a delivery examples of this type of frame include ACK & RTS/CTS frames
Control frames
Responsible for carrying data between nodes
Data frames
The ———— includes from left to right frame control End duration at two bites each, address 1 2 and three at six by each. This is followed by sequence control read to bites, address for at six bytes. This is followed by data 0 to 2312 bites and frame check sequence at six bytes
802.11 data frame
The Mac header of the 802.1 data frame is made up of the first seven boxes out of nine from
The date of frame
———includes preamble at eight bites destination address at six bites source address at six bites type At two bites data at 46 to 1500 bites and last but not least FCS at four bytes
802.3 ethernet to frame
