Appendix
FX-DS110-PCC 41
Roaming
This means the same as roaming of a mobile telephone or PHS.
The AP serves as the component commonly called as “antenna/base
station” in mobile telephone and PHS terminology; the
FX-DS110-PCC serves as the telephone itself.
IP tunneling
One of the features of the FX-DS110-APE. Using this feature enables
mail transmission and reception and database access without changing
the PC settings even at a roaming destination beyond the router.
Spectrum diffusion transmission
A method of transmission in which signals that are normally
transmitted over a given limited frequency band undergo narrow
band modulation (primary modulation), then again diffuse
modulation (secondary modulation) to intentionally diffuse the
signal over a broad frequency spectrum.
DS (Direct Sequence)
A type of spectrum diffusion signal using narrow band modulation
with phase modulation, in which the diffusion is by means of phase
modulation using a broad band diffusion signal (pseudo random
strings).
CSMA/CA (Carrier Sense Multiple Access with Collision
Avoidance)
CSMA is a method of avoiding collision by which wireless
terminals listen before transmitting and do not transmit if they can
year transmissions from other wireless terminals. CSMA/CA is
CSMA plus additional collision avoidance functions.
Hidden Terminal Problem
When wireless terminals are farther apart then their electric signals
can reach, or their signals are obstructed by objects, neither may be
able to receive the other's signals. Any two such wireless
terminals are said to be hidden from each other. In Ad Hoc mode,
because the carrier sense function is not effective between hidden
terminals there is a higher probability of collisions and throughput
(the volume of information sent in a given time interval) is reduced.