User Manual

WIRELESS NETWORK DESIGN
Centralized (Star) Topology
2-4 P-Com AirPro Gold
2
Figure 2-3 Star Topology
A directional antenna can be used for the central site if all of the nodes
fall in the main lobe of the antenna pattern. Since the remote sites need
only communicate with the central site, directional, high gain antennas
can be used.
The range of a Star topology network can be increased if the remote
nodes are all located within a confined sector from the central site.
Communication between two remote sites must be relayed through the
central node.
Medium access contention on the Star Base is resolved by the specific
Star Base MAC protocol. Each Star Remote sends a data frame only
after it gets permission from the Star Base. Each frame transmitted by
Star Base contains a PID (polling ID) for the wireless cluster. If a polled
Star Remote has a frame to transmit, it explicitly sends the frame to the
Star Base. The Star Base relays this frame to itself or on to Star
Remotes indicated by the DID (destination ID) of the original frame. A
polled Star Remote does not reply to a PID if it has no frame to transmit.
APG1_001
BASE STATION
REMOTE STATIONS
Ethernet
Ethernet
Ethernet
Ethernet
Ethernet
RS232
RSQ/RSSI
Alarm
Link
Frame TX
Ethernet Link
Ethernet Activity
Power
Ethernet
RS232
RSQ/RSSI
Alarm
Link
Frame TX
Ethernet Link
Ethernet Activity
Power
Ethernet
RS232
RSQ/RSSI
Alarm
Link
Frame TX
Ethernet Link
Ethernet Activity
Power
Ethernet
RS232
RSQ/RSSI
Alarm
Link
Frame TX
Ethernet Link
Ethernet Activity
Power