User manual

DSSS: 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.

Encryption: A security method that uses a specific algorithm to alter the data

transmitted, thus prevent others from knowing the information transmitted.

ESS: ESS stands for “Extended Service Set”. More than one BSS is configured

to become Extended Service Set. LAN mobile users can roam between different

BSSs in an ESS.

ESSID: The unique identifier that identifies the ESS. In infrastructure association,

the stations use the same ESSID as AP’s to get connected.

Ethernet: A popular local area data communications network, originally

developed by Xerox Corp., that accepts transmission from computers and

terminals. Ethernet operates on a 10/100 Mbps base transmission rate, using

a shielded coaxial cable or over shielded twisted pair telephone wire.

Fragmentation: When transmitting a packet over a network medium,

sometimes the packet is broken into several segments, if the size of packet

exceeds that allowed by the network medium.

Fragmentation Threshold: The Fragmentation Threshold defines the number

of bytes used for the fragmentation boundary for directed messages. The

purpose of "Fragmentation Threshold" is to increase the transfer reliability thru

cutting a MAC Service Data Unit (MSDU) into several MAC Protocol Data Units

(MPDU) in smaller size. The RF transmission can not allow to transmit too big

frame size due to the heavy interference caused by the big size of transmission

frame. But if the frame size is too small, it will create the overhead during the

transmission.