User's Manual

170 Mercury Reference Manual 05-4446A01, Rev. C

from the number and order of bits in a data string. This value is com-

pared with a locally-generated value and a match indicates that the mes-

sage is unchanged, and therefore valid.

Data Circuit-terminating EquipmentSee DCE.

Data Communications EquipmentSee DCE.

DatagramA data string consisting of an IP header and the IP message

within.

Data Terminal EquipmentSee DTE.

dBdDecibels (dipole antenna).

dBiDecibels referenced to an ideal isotropic radiator in free space.

Frequently used to express antenna gain.

dBmDecibels referenced to one milliwatt. An absolute unit used to

measure signal power, as in transmitter power output, or received signal

strength.

DCEData Circuit-terminating Equipment (or Data Communications

Equipment). In data communications terminology, this is the modem

side of a computer-to-modem connection.

COM1 Port of the transceiver

is set as DCE.

Decibel (dB)A measure of the ratio between two signal levels. Fre-

quently used to express the gain (or loss) of a system.

DelimiterA flag that marks the beginning and end of a data packet.

Device ModeThe operating mode/role of a transceiver (Access Point

or Remote) in a wireless network.

DHCP (Dynamic Host Configuration Protocol)An Internet stan-

dard that allows a client (i.e. any computer or network device) to obtain

an IP address from a server on the network. This allows network admin-

istrators to avoid the tedious process of manually configuring and man-

aging IP addresses for a large number of users and devices. When a

network device powers on, if it is configured to use DHCP, it will con-

tact a DHCP server on the network and request an IP address.

The DHCP server will provide an address from a pool of addresses allo-

cated by the network administrator. The network device may use this

address on a time lease basis or indefinitely depending on the policy

set by the network administrator. The DHCP server can restrict alloca-

tion of IP addresses based on security policies. An Access Point may be

configured by the system administrator to act as a DHCP server if one

is not available on the wired network.