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C. Glossary
Access Point — An internetworking device that seamlessly
connects wired and wireless networks together.
Bandwidth — The size (in Hertz) of the frequency range that a
signal transmission occupies. Typical narrow band signals oc-
cupy a 25 KHz bandwidth. The RangeLAN2 signal occupies a 1
MHz bandwidth.
Channel — In RangeLAN2 networks, the channel refers to the
frequency hopping sequence the card follows.
CSMA/CA — (Carrier Sense Multiple Access/Collision Avoid-
ance) — CSMA is a protocol in which each node senses whether
or not a channel is in use before attempting to transmit informa-
tion. CA is an optimization by which channel time is reserved to
avoid collisions.
Frequency Hopping — A spread spectrum technique by which
the band is divided into a number of channels and the transmis-
sions hop from channel to channel in a pre-specified sequence.
Interference — A situation that occurs when an unwanted RF
signal occupies the same frequency band as a desired signal.
Narrow Band — A channel of about 25 KHz bandwidth in the
RF spectrum. The FCC allocates Narrow Band channels and
issues a license to the user. Each user of a specific narrow band
frequency range must obtain a site license from the FCC.
Spread Spectrum — A radio data transmission modulation
technique by which the transmitted signal is spread over a band-
width wider than the information bandwidth. Spread Spectrum
bands are designated by the FCC and require no user license.
