GE MDS ORBIT ECR, Техническое руководство

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96 MDS Orbit MCR/ECR Technical Manual MDS 05-6632A01, Rev. F
For the advanced user, the module supports configuring more items including:

Data Retries - Number of times to retry unicast data before declaring NACK.

Fragment Threshold - Fragmentation threshold

Lna State - Controls the low noise amplifier

Mcast Repeat - Number of times to repeat downstream broadcast and multicast data.

Propagation Delay - Correction for the propagation delay of the RF signal.

Stale Packet Timeout - If the MAC is unable to transmit a packet in this time, it will drop the packet.
In general, it is recommended that users start with the simplest configuration and then make parameter
changes as necessary to meet specific needs.
NOTE
Frequency blocking to meet country specific regulatory requirements may be configured for by
the factory to disallow operation. These settings can NOT be changed or modified by the user.
See the table below:
Table 3-12. Country Limitations Example
Country Limitation
Brazil Operate only in the band 902-907 and 915-928 MHz
Australia/Chile Operate only in the band 915-928 MHz
New Zealand Operate only in the band 921-928 MHz
Table 3-13. NxRadio Interface LED Descriptions
LED - NIC2 State Description
NxRadio Interface Off Interface disabled
Access Point Mode Blink Red
Solid Red
Solid Green
NIC Initialization
No Remotes connected
Linked with at least 1 Remote
Remote Mode Blink Red
Solid Green
NIC Initialization / Not linked to an Access Point
Linked with Access Point
Important Notes and Information Regarding LQI
LQI is dependent on the modulation format and should be used as a relative measurement of the link
quality. A low LQI value indicates a better link quality than a high value. Algorithmically, using GFSK
modulation, the transceiver calculates the value by measuring the frequency of each "bit" and compares it
with the expected frequency based on the channel frequency and the deviation and the measured
frequency offset.
- LQI is a metric of the quality of the received signal. It is a dynamic value that is computed only
when data is received on the RF interface, and should be refreshed accordingly.
- Unlike RSSI which simply measures signal strength, LQI is only a measurement of the
"correctness" of this signal. (This means how easily the received signal can be correctly
demodulated.)
- In general the lower the LQI the better the quality.
- LQI should be used as a "relative" measurement. Precision is fairly loose and subject to
variation from radio to radio and modulation format.