User's Manual

FreeWave Technologies Spread Spectrum Transceiver User Manual

900 MHz and 2.4 GHz

V5.0S

Average noise levels will typically fall in the range of 15 to 30. Average noise

levels significantly higher than this are an indication of a high level of interference

that may degrade the performance of the link. High noise levels can often be

improved with bandpass filters, antenna placement or antenna polarization.

Please contact FreeWave Technologies for more information.

Average Signal Level

The average signal level indicates the level of received signal at this modem and

at each of the modems used as repeaters in the link. For each of these, the signal

source is the modem that transmits to it. The number is an average of the

received signal levels measured at each frequency in the modem's frequency hop

table. The individual measurement values at each frequency hop channel are

shown in the frequency table. The frequency table is accessed by pressing the

ENTER key on the computer when the radio statistics menu is displayed.

For a reliable link, the average signal level should be at least 15 higher than the

average noise level reading.

Low Average Signal Levels can often be corrected with higher gain antennas,

antenna placement, and use of repeaters or use of antenna amplifiers. Contact

FreeWave Technologies for more information.

Note, later revisions of the firmware show the signal level in RSSI units.

Overall Rcv Rate (%)

The Overall Rcv Rate measures the percentage of data packets that were

successfully transmitted from the master to the slave on the first attempt without

requiring retransmission. A number of 75 or higher indicates a robust link that will

provide very good performance even at high data transmission rates. A number of

25 or lower indicates a weak or marginal link that will provide lower data

throughput. An Overall Rcv Rate of 100% will provide approximately 100 Kbaud of

bandwidth with an RF data rate of 3 (Radio Transmission Parameters Menu) and

approximately 150 Kbaud of bandwidth with an RF Data Rate of 2. These

numbers are reduced approximately 50% if there are one or more repeaters in the

network.

Number of Disconnects

If, during the course of performing a link test, the link between the master and the

slave is broken, and the radios lose carrier detect, the occurrence is recorded in

the Number of Disconnects value. The value indicates the total number of

disconnects that have occurred from the time the link test started until the radio

was put into reset mode. Under normal operating conditions, the number of

disconnects should be 0. One or more disconnects may indicate a very weak link,

the presence of severe interference problems or loss of dc power to any of the

radios in the link.