Glossary - 5

Encryption. Encryption is the scrambling and coding of data, typically using mathematical formulas called
algorithms, before information is transmitted over any communications link or network. A key is the specific
code used by the algorithm to encrypt or decrypt the data. Also see, Decryption and Key.
ENQ (RS-232). ENQ software handshaking is also supported for the data sent to the host.
ESD. Electro-Static Discharge
ESN. Electronic Serial Number. The unique hardware number associated with a cellular device, which is
transmitted to the system when the device communicates with the cellular system.
ESS_ID. Extended Service Set Identifier, defines the coverage area. Prior to the release of the 802.11
specification the ESS_ID was called the Net_ID or Network Identifier. For mobile computers using
Spectrum24 radios with the 802.11 protocol, an ESS_ID allows facilities to limit which Access Points a
mobile computer can communicate with. It is set on the Network tab of the Control Panel. The mobile
computer can only communicate with Spectrum24 Access Points that have matching ESS_IDs.
Ethernet. Ethernet communication port. Allows a wired interface to a radio network.
F
File Transfer Protocol (FTP). A TCP/IP application protocol governing file transfer via network or telephone
lines. See TCP/IP.
Flash Disk. An additional megabyte of non-volatile memory for storing application and configuration files.
Flash Memory. Flash memory is responsible for storing the system firmware and is non-volatile. If the system
power is interrupted the data is not be lost.
Frequency Hopping. The use of a random sequence of frequency channels to achieve spread spectrum
compliance. Stations that use frequency hopping change their communications frequency at regular
intervals. A hopping sequence determines the pattern at which frequencies are changed. Messages take
place within a hop. See Hopping Sequence and Spread Spectrum.
FTP. See File Transfer Protocol.
G
Gateway Address. An IP address for a network gateway or router. A mobile computer may be part of a subnet
as specified by its IP address and Netmask. It can send packets directly to any node on the same subnet.
If the destination node is on a different subnet, then the mobile computer sends the packet to the gateway
first. The gateway determines how to route the packet to the destination subnet. This field is an option used
by networks that require gateways.