NetComm NP642 User Manual

Page 27

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NP642 IEEE 802.11g PCI Adapter


YML785 Rev1


Carrier Sense Multiple Access/Collision Detection, which is a

LAN access method used in Ethernet. When a device wants to

gain access to the network, it checks to see if the network is quiet

(senses the carrier). If it is not, it waits a random amount of time

before retrying. If the network is quiet and two devices access

the line at exactly the same time, their signals collide. When the

collision is detected, they both back off and wait a random amount

of time before retrying.


Dynamic Host Configuration Protocol, which is a protocol that lets

network administrators manage and allocate Internet Protocol

(IP) addresses in a network. Every computer has to have an IP

address in order to communicate with each other in a TCP/IP based

infrastructure network. Without DHCP, each computer must be

entered in manually the IP address. DHCP enables the network

administrators to assign the IP from a central location and each

computer receives an IP address upon plugged with the Ethernet

cable everywhere on the network.


Direct Sequence Spread Spectrum. DSSS generates a redundant

bit pattern for each bit to be transmitted. This bit pattern is called

a chip (or chipping code). The longer the chip, the greater the

probability that the original data can be recovered. Even if one or

more bits in the chip are damaged during transmission, statistical

techniques embedded in the radio can recover the original data

without the need for retransmission. To an unintended receiver,

DSSS appears as low power wideband noise and is rejected

(ignored) by most narrowband receivers.

Dynamic IP Address: An IP address that is assigned automatically to a client station in a

TCP/IP network by a DHCP server.