7 Synchronization
The Flexi Zone Pico Indoor BTS supports the following synchronisation mechanisms:
•
Integrated GPS/GLONASS receiver
•
Synchronous Ethernet (ITU-T G.8261)
•
Timing over Packet according to IEEE 1588v2
7.1 GPS / GLONASS
Instead of using the transport network for carrying the Primary Reference Clock (PRC)
traceable synchronization reference, it is possible to use a distributed PRC architecture.
In this case, every site in the network has a GPS-based or other synchronization source
which provides a PRC traceable synchronization reference signal for RAN NEs. It is also
possible to use a combination of distributed and hierarchical master-slave architecture.
In some cases, other Network Elements (for example transmission nodes) at the same
site provide the synchronization reference for RAN Network Elements through external
synchronization interfaces.
7.1.1 Overall GPS / GLONASS Antenna RF Requirements
Antenna Requirements
The Nokia recommended GPS / GLONASS antennas meet all quality and field
performance requirements along with criteria outlined in the table below and have proven
quality with good field performance. While it is possible to use other antennas,
considerable care must be exercised when selecting alternatives to ensure full BTS
compatibility for all conditions.
Table 9
Recommended GPS / GLONASS Antenna Specifications
Requirement / Recommendations
Gain
+25 dB (recommended)
Noise Figure
<2.5 dB (recommended)
Operating Frequency
GPS: 1575.42 MHz with less than 3 dB attenuation at a +1.2 MHz offset from
center (Required)
GLONASS: 1602 MHz with less than 3 dB attenuation at a +8 MHz offset from
center (Required)
Filtering
>40 dB attenuation at +50 MHz offset from L1 center (Recommended) )
LNA Supply Voltage
Operation with a supply voltage of +4.6 VDC +/- 0.25 V (Required)
LNA Supply Current
<30 mA (Required)
Azimuth Coverage
360° (Required)
Elevation Coverage
10° to 90° (Required)
Flexi Zone Indoor Pico BTS Product Description
Synchronization
Issue: 01
DN09210454
21
