User's Manual Part 1

BreezeCOMPACT System Manual
Chapter 1 - System DescriptionThe BreezeCOMPACT Solution
Chapter 1 - System Description The BreezeCOMPACT Solution
12
1.2.4 Antennas
In the 4Motion architecture, the antenna is approached as an independent element. This provides the
operator with the flexibility to select the antennas source according to its supplier policy. To ensure the
availability of antennas that complement the 4Motion solution, Alvarion works closely with several
antenna suppliers to ensure availability of antennas that comply with its requirements.
In cases where the operator prefers other antenna vendors, Alvarion can provide a recommended
antenna specification based on the required antennas types.
Antennas may support mechanical down-tilt (MDT) using a suitable mounting kit, or electrical down-tilt
(EDT) that may be either fixed or adjustable using a special adjustment screw.
In addition to a range of standard commercial antennas, Alvarion offers also a special attached antenna
design for convenient installation on top of the BreezeCOMPACT unit.
For details on antennas offered by Alvarion refer to “Antennas” on page 18.
1.2.5 GPS
GPS is used to synchronize the air link frames of Intra-site and Inter-site located Base Transceiver Stations
to ensure that in all Base Stations the air frame will start at the same time, and that all Base Stations will
switch from transmit (downlink) to receive (uplink) at the same time. This synchronization is necessary to
prevent Intra-site and Inter-site interference and Base Stations saturation (assuming that all Base Stations
are operating with the same frame size and with the same DL/UL ratio).
The all-outdoor GPS Receiver is a pole mountable GPS receiver and antenna in a single environmentally
protected enclosure that is powered from the unit. GPS signals chaining (not supported in current
release) enables using a single GPS receiver for several collocated units.
Figure 1-7: Two Sectors, Two Carriers (One Carrier per Sector)