Red
MAX
™
Base Station
user manual
Doc. #70-00058-01-01-DRAFT
Proprietary Redline Communications © 2006
November
29,
2006
Page 83 of 106
5. Receiver sensitivity is defined as the lowest RSSI value tested where samples for all
three packet sizes did not exceed the maximum number of lost packets. The 95%
confidence level indicates that if the test is repeated multiple times, you will obtain
passing results 95 times out of 100.
Refer to the following table for a summary of the test parameters.
Table 33
:
Op Notes: Receive Sensitivity Tests
Packet Payload
Size
Total Number of
Packets Sent
Max. Number of
Packets Lost
Equivalent BER
(95% Confidence)
288 50,000 97 1x10-6
300,000
100 1x10-9
864 20,000 118 1x10-6
100,000
55 1x10-9
1,488 10,000 100 1x10-6
60,000
57 1x10-9
6.2.3 General
Interference
Redline has introduced several techniques into its products to mitigate interference
issues:
1. OFDM: multiple carriers using both time and frequency diversity to provide high
tolerance to co-channel and adjacent channel interference, remove ISI due to
multipath and recover data from carriers falling in regions of deep channel fades.
2. Multiple channels (twenty-eight non-overlapping at 3.5 MHz) for diversity and
interference mitigation.
3. Adaptive modulation using six transmission rates to suit varying link conditions.
4. Adaptive encoding is heavily coded to substantially increase robustness. State of the
art FEC using Convolutional-coding gives the base station superior frequency
selective fading mitigation capability.
5. Narrow beam antennas with high side lobe and backlobe isolation and very low
VSWR.
6. Antenna cross-polarization enabling equipment co-location as well as effective
frequency planning.
7. Automatic repeat request (ARQ) function to address any instantaneous errors
detected on the RF interface (performed on a burst to burst basis). This avoids using
higher-level protocols (i.e., TCP) that introduce significant overhead and delay.
8. High receiver dynamic range to address dynamic interference.
9. State of the art filtering at the RF, IF and baseband levels to reduce interference.
10. Choice of non-adaptive modulation to provide stable burst rate during periods of
rapid interference variations on the link.
6.2.4 Time
Synchronization
When operating two or more collocated base stations (BSs), transmitter operations
MUST use synchronization to minimize inter-sector interference. Refer to the RedMAX
base station Installation Guidelines for complete details.