User's Manual

TS4000 Radio Modem User’s Manual Radio Setup 23
Clear Channel
Scan
Activates Clear Channel Scan Operation (see below).
The bottom box is the scan list which indicates the channels
that will be scanned. The scan list can be changed with
the channel box, add button and delete button.
Channel List The bottom box is the scan list which indicates the channels
that will be scanned.
Channel Box,
Add Button,
Delete Button
These controls are used to change the channel numbers in
the channel list.
CCS Remote
Operation
When this is checked the TS4000 will transmit on the same
channel that it last received a packet from another TS4000.
This function is useful for systems where a unit (the CCS
Remote) needs to respond back to another TS4000 that is at
an advantaged site (a site that has wide radio coverage and
therefore can hear interference that the CCS Remote does
not hear). By transmitting back on the same channel as the
advantaged unit, the CCS Remote unit minimizes the
likelihood that it chooses a channel with interference.
When Clear Channel Scan operation is enabled, the TS4000 will automatically
and dynamically select the least congested channel from the clear channel scan
list. This operation is completely transparent to the host equipment and does not
require any operator intervention.
When clear channel scan is enabled, all of the TS4000s (both transmitters and
receivers) constantly scan the channels of the scan list looking for valid TS4000
transmissions and also looking for interference (noise or transmissions from
other sources). The TS4000s keeps track of the amount of interference on each
channel. Before transmitting, a TS4000 will select the best channel and switch to
the channel with the least amount of interference. The receiving TS4000s will
then see this valid TS4000 transmission during their scans and receive the
packet.
To insure that receiving TS4000s have time to detect and lock up to the
transmissions, the transmit preamble time is increased based on the number of
channels on the scan list. Note that the transmit attack time can be read out of
the modem with the Retrieve Radio Hardware command.
For systems that require very high reliability at some or all sites, Teledesign has
a Redundancy Switch that provides hot standby redundancy for the TS4000.
The Redundancy Switch requires two TS4000s and can be used with one or two
power supplies and one or two external amplifiers.
When using the TS4000s with the Redundancy Switch, the TS4000s can be
configured with any of the options. However, it is essential that the two
redundant modems are configured identically except of the Enable
Redundancy settings.
Clear Channel Scan
Redundancy