VIEWSONIC Wireless Media Gateway WMG80 - Manual (Page 90)

ViewSonic Wireless Media Gateway 84
CSMA/CA (Carrier Sense Multiple Access with Collision
Avoidance). The principle medium access method employed by
IEEE 802.11 WLANs. It is a "listen before talk": method of
minimizing (but not eliminating) collisions caused by simultaneous
transmission by multiple radios. IEEE 802.11 states collision
avoidance method rather than collision detection must be used,
because the standard employs half duplex radios—radios capable
of transmission or reception—but not both simultaneously. Unlike
conventional wired Ethernet nodes, a WLAN station cannot detect
a collision while transmitting. If a collision occurs, the transmitting
station will not receive an ACKnowledge packet from the intended
receive station. For this reason, ACK packets have a higher priority
than all other network traffic. After completion of a data
transmission, the receive station will begin transmission of the ACK
packet before any other node can begin transmitting a new data
packet. All other stations must wait a longer pseudo randomized
period of time before transmitting. If an ACK packet is not received,
the transmitting station will wait for a subsequent opportunity to
retry transmission.
CSMA/CD (Carrier Sense Multiple Access/Collision Detection). A
method of managing traffic and reducing noise on an Ethernet
network. A network device transmits data after detecting that a
channel is available. However, if two devices transmit data
simultaneously, the sending devices detect a collision and
retransmit after a random time delay.
DC power module. Modules that convert AC power to DC.
Depending on manufacturer and product, these modules can range