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Chapter 8. Appendices
8.1. Appendix A: Glossary
Glossary
A
Absorption Antennas mounted too close to “soft” objects, such as trees, may
experience a reduction in signal strength due to absorption. Ab-
sorption is most often encountered in antennas installed during
fall or winter. The problem does not start until the spring, when
leaves appear.
Access Hub A group of APs, each serving a group of CPEs. Also called a cell
site.
Access Point The base station of the network. AP refers to the machinery –
ODU, and antenna – that comprises the link with the wired net-
work. Sometimes AP means the point where the wireless network
touches the wired network.
Agent An agent runs on each unit in a Simple Network Management
Protocol (SNMP) context. An agent accepts configuration com-
mands from the manager and collects network and terminal inform-
ation specified in the Management Information Base (MIB).
Antenna A device which takes electromagnetic energy from a circuit or
wire and radiates it.
Antenna Gain Gain of the antenna over a dipole antenna (dBd) or isotropic radi-
ator (dBi). Gain measures of the ability of an antenna to amplify
signals in its tuned band. Antenna gain comes from focusing the
signal. A higher-gain antenna has a more tightly directed signal.
ARP Address Resolution Protocol. This is low-level protocol that maps
IP addresses to Ethernet addresses. An ARP request goes out to
the network along with an IP address. The node with the address
responds to the request with a hardware address so the transmission
can take place.
ASCII American Standard Code for Information Interchange. A system
used by personal computers to convert letters, numbers and sym-
bols into binary notation.
Automatic Frequency Control A method by which the CPEs stayed tuned to the correct frequency
for communicating with the AP, despite frequency variations
caused by the hardware.
Attenuation Any loss in signal strength, due to resistance, absorption, capacit-
ance, or any characteristic of the medium or design of the system.
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