User's Manual

Overview Hardware Installation Guide
1-6 Airspan Networks Inc. 02030311-07
1.3.3. Base Station Distribution Unit (BSDU)
The BSDU is an Ethernet switch implemented at Base Stations consisting of
multiple BSRs. The BSDU provides 100Base-T interface between the BSRs and the
provider's backbone. The BSDU is also responsible for providing BSRs with –48
VDC power supply and frequency hop synchronization between BSDUs, BSRs, and
Base Stations (when a GPS is implemented).
The BSDU is installed indoors in a standard 19-inch cabinet, and connects to the
BSRs by standard CAT-5 cables. Each BSDU can connect to a maximum of six
BSRs. In addition, up to four BSDUs can be daisy-chained to support a maximum of
24 BSRs. Therefore, a Base Station at maximum configuration can serve up to 3,024
subscribers.
Note: At a Base Station consisting of a single BSR, the BSR typicall
y
interfaces with the provider's backhaul through the SDA instead of the BSDU.
(See Section 1.4.1, "Outdoor Radio (SPR) with Indoor Switch/Hub").
1.3.4. SDA-1/48V
The SDA-1/48V is a compact indoor adapter, especially designed for use when
available power source is 48VDC (i.e. no AC power supply), and when no
synchronization is required (i.e. in licensed bands). The SDA-1/48V provides the
BSR with Ethernet connectivity to the backhaul.
1.3.5. Global Positioning System (GPS) - Optional
The GPS antenna is a rugged, self-contained GPS receiver and antenna that receives
a universal GPS satellite clock signal. The GPS is an optional unit that connects to
the BSDU. The GPS synchronizes frequency hopping of multiple Base Stations,
ensuring that the entire ASWipLL network operates with the same clock based on a
universal satellite clock signal, and, thereby, eliminating radio frequency ghosting
effects.