Operations Manual

OPERATIONS 4-27
O&M of the MCC-545B PACKET DATA RADIO
12/2000
The Masters can communicate between themselves at any time since they are in complementary
roles; they can communicate with their Remotes when it is their time slot to transmit idle probes.
Example: ROLE, ACTIVE Set to active role. (Master with lowest ID)
ROLE, PASSIVE, N Set to passive role and wait N minutes for time probe from
ACTIVE Master before starting to transmit idle probes
(Master with highest ID)
4.8.1.2 Line of Sight Networks
An LOS network has all of its member units interconnected with RF links of a short enough
range where the meteor burst RF protocols are not necessary. The total width of the network
may exceed LOS range but the intermediate hops must be within LOS range. A slow rate idle
probe is used to let each Master identify itself and to establish connectivity, but a CSMA
protocol is used for link acquisition and communication. A special TDMA mode is used for
GPS location reporting. Units are assigned to be either Master Stations or Remotes. The Master
Stations provide a network backbone and the Remotes are the units connected to user equipment.
There are two modes of LOS network operation: multi-Master and Base/Repeater. The multi-
Master mode allows Master Stations to interconnect automatically and establish a network
backbone. The Base/Repeater mode is manually setup for Masters to act as either a Base Station
or a Repeater; Bases connect directly to a land line WAN and Repeaters connect via a Base.
Commands used are:
DEVICE, MASTER identify unit type
ID, MM, INIT define the ID (MM) of a Master
DEVICE, REMOTE identify unit type
ID, NNNN, MM, AUTO, INIT define the ID (NNNN) and Master-select mode
(MM,AUTO) of a Remote
ROLE, LOS setup the line-of-sight role and CSMA RF protocols.
LOSCHECKIN, P,R setup the CSMA period (P) and retry count (R).
4.8.1.2.1 Multi-Master Mode
With the BASE and REPEATER features disabled, a Master will connect to any other Master it
can hear well enough to get the required number of idle probe counts per minute. A Master will
connect to any Remote that acquires it, letting the Remote choose its best Master. Complete
Master-to-Master and Master-to-Remote connectivity tables are automatically exchanged
between Masters. Routing from any source unit to any destination unit is accomplished by the
Master Stations. Complete networks with no land line connections are supported in this manner.