User Manual

CDMA PicoBTSTM Hardware Description Page 13
2.2.5 PMU heat management system (HMS)
The HMS maintains the internal temperature of the PMU
in the range +5°Cto+70°C when the external ambient
temperature is in the range of –40°Cto+52°C. The HMS has
heating, cooling, and heat transfer components that raise or
lower the internal temperature to meet these requirements.
The HMS reports alarms and other performance data to the
PMCC.
2.2.6 PMU power supply assembly (PSA)
The PSA converts commercial AC power to +48Vdc and +5Vdc
for PMU operation and distributes this power to PicoBTS
components (PMCC, PCCs, TRIC, TFC and PRU).
2.3 PMU communication with the network
From the PicoBTS
TM
base station standpoint, the network
consists of the T1 network and the BSC rack. A BSC rack
controls as many as 48 PicoBTS
TM
base stations. The T1s
terminate at a local communication interconnection network
(LCIN). The unchannelized T1 link from a PicoBTS
TM
base
stationishardwiredtoaportintheLCIN.
2.4 PRU
The PRU performs signal conversion between the CDMA
interface and the transmission band RF interface. The PRU
provides a radio transceiver and RF front-end to establish the
interface to mobile subscribers.
For the transmitted signal, the PRU modulates the PCS band
carrier frequency with the I and Q signals from the CDMA
interface. In addition, the PRU amplifies the PCS-band RF
signal to the RF transmission power level with a maximum of 5
W at the antenna port.