Hardware manual

Recommended test program 12
Nov 98
same time, there is a chance that unit B will never communicate with the Access Point. Robust radio protocols
ensure that all units can communicate regardless of the distance from the Access Point. In this example, both
unit A and unit B should be able to communicate at all times with the Access Point.
Hidden terminal
Another scenario you might encounter and should evaluate is the "hidden terminal" phenomenon. When
multiple radios establish communications, messages are sent and received by all units to ensure that only two
units communicate at any one time. However in some environments, not all of the radios will be in range to
receive these messages. For example, assume that three radio units are placed in a single row - unit A, unit B
and unit C. Both unit A and unit C are in range of unit B, however unit A and unit C are not in range. If both
unit A and unit C attempt to transmit to unit B at the same time, unit B will not be able to receive the
transmission. Good radio protocols consider the possibility of "hidden terminal" issues allow both unit A and
unit C to communicate with unit B even through unit A and unit C are not in range.