6Harmonics GWS-3000, Руководство по эксплуатации

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Below is a description of how to perform power control manually using the GWS-
3000 user interface. 6Harmonics is currently developing a SON algorithm which will
perform power control at the network level. This algorithm is not yet released but
should become available sometime late in 2013 or early 2014.
8.1.1 Point to Point Link
For a point to point link, one BTS connected to a single CPE, we will adjust the
power of both the uplink and downlink to have an RSSI (Received Signal Strength)
of about -75 dBm at both nodes. To operate at our highest modulations, 64 QAM
5/6 encoding, we require a CINR of about 24 dB. For a 5 MHz modulation
bandwidth, kTBf = -107 dBm/5MHz. The noise figure of the radio is 5.0 dB and
hence the noise floor of the radio referred to the antenna port is -102 dBm/5MHz.
To maintain an SNR of 24 dB, the RSSI must be at -78 dBm/5 MHz carrier. An extra
3 dB is provided as margin and hence the recommended receive signal strangeth is
-75 dBm.
In certain deployments the noise floor of the channel may be higher than thermal
noise, due to interference power from nearby transmitters which are co-channel or
even adjacent or alternate channel to the link being configured. 6Harmonics has
surveyed the noise floor of UHF channels is several US and Canadian cities and
some channels are very clean with an integrated noise power near -102 dBm/5MHz
but many channels have an noise floor which is 3-6 dB above ktBf. If the RSSI is
at -75 dBm but the MCS is low, not consistently shown as MCS6 or 7, then the
power may need to be increased by a few dB until a satisfactory MCS is achieved.
8.1.1.1 Configure the link:
•
Telnet into the BTS and CPE.
•
From the telnet session type “monitor”
o
The monitor session will show you the RSSI as well as the MCS for
both the BTS and CPE.
•
Adjust the Uplink TX Power of the CPE.
o
Telnet to the CPE
o
If the RSSI at the BTS is below or above, – 75 dBm, increase or
decrease the CPE TX Power by using the following commands:
ƒ
U
Æ
Increases power by 0.5 dB (fine adjustment)
ƒ
C
Æ
Decreases TX power by 0.5 dB (fine adjustment)
ƒ
Cu
Æ
Increases power by 5 dB (course adjustment)
ƒ
Cd
Æ
Decreases TX power by 5 dB (course adjustment)
o
Between each adjustment observe the RSSI and MCS value at the
BTS RX until the desired value is achieved.
•
Adjust the Downlink TX Power of the BTS
o
Telnet to the BTS
o
If the RSSI at the BTS is below or above – 75 dBm, increase or
decrease the CPE TX Power by using the following commands: