User's Manual
TS4000 Radio Modem User’s Manual AirNet Packet Protocol 22
logistically difficult and may not completely solve all propagation problems. The
AirNet protocol provides an option where nodes can be set up as store and
forward relays. The relay nodes store packets that they receive and repeat
(forward) the packets when the channel is idle. The relay nodes can be set to
relay all packets or only packets with certain source or destination addresses.
Complete Packet Capability
Nodes automatically re-send packets which are not received correctly.
Robust 32 bit CRC ensures that packets are received correctly.
Adjustable maximum number of retries.
Adjustable maximum packet size - Large packets can be automatically
broken up into smaller packets for reliable transmission.
Easy to Use Host Control and Status
The host (user equipment) controls operation of the packet protocol with
simple ASCII command strings.
No special formatting of user data is required.
Status strings can be enabled to provide information on the success or failure
of packet transmissions.
Addressing
Individual addresses from 1 to 999.
Group addresses from 1 to 60.
Various transfer types
Individual (point to point with acknowledge) - The acknowledgment
provides for guaranteed delivery of the data packets.
Individual without acknowledgment.
Group broadcast - Unacknowledged transfer to all members of a group.
Network broadcast - Unacknowledged transfer to all modems.
Multicast receptions - Allows a modem to receive group broadcasts to groups
other than its own. This can be used to create sub-groups or super-groups of
modems.
Channel Access
CSMA/CA - Carrier Sense Multiple Access with Collision Avoidance.
Adjustable Transmission Index (transmit probability) - Allows a network to be
optimized for maximum efficiency.
Adjustable Slot Time - Allows the modem to be optimized for different radios
and repeater systems.
Store and Forward Data Repeater
Any unit can be configured as a relay node. Allows for easy expansion of the
network.
Relay filter allows for relaying of only packets to or from select nodes. This
minimizes the amount of relay traffic created.
These configuration options are set using the Packet General tab of the Modem
Configuration.
Features
Configuration
Options
Packet General