Vlan Capability; Terminal Server Capability; Store And Forward Capability - GE MDS SD Series Technical Manual

Data Validation
MDS 05-4846A01, Rev. H
and other units are designated as Remotes. The AP serves as the con-
troller of the RF network. Remotes request permission from the AP to
use the RF channel before sending payload data, thus avoiding collisions
of data, and creating a highly reliable wireless network. The MAC is
responsible for allocating which unit gets access to the broadcast
medium (the RF channel), when, and for how long.
Additionally, the MAC validates all messages and purges corrupted data
from the system. Successful delivery of data is ensured through the use
of retries and acknowledgements. Minimal overhead is used to accom-
plish these tasks, which translates to increased bandwidth efficiency of
the radio channel with minimal latency, ensuring that messages are
delivered in a timely manner.

VLAN Capability

A Virtual Local Area Network (VLAN) is essentially a limited broad-
cast domain, meaning that all members of a VLAN receive broadcast
frames sent by members of the same network, but not frames sent by
members of a different network.
The radio supports port-based VLAN at the Ethernet interface and over
the air, in accordance with the IEEE 802.1Q standard. When VLAN
Mode is enabled, the wireless ports of both AP and Remote radios act as
a "trunk port" to carry data.

Terminal Server Capability

The unit's Terminal Server option allows serial port data to be sent over
the air in the form of IP packets. It works by encapsulating data from the
serial ( / ) ports as IP packets, then transmitting it over the air.
COM1 COM2
At the receiving end, the data is decapsulated and delivered to the appro-
priate COM port. The Terminal Server option provides a front-end RTU
conversion for TCP MODBUS Data. See "Terminal Server COM1/2
Configuration" on Page 61 for more information.

Store and Forward Capability

Store and Forward (SAF) capability is only available in Packet w/MAC
mode. It allows a radio to store incoming data and retransmit it a short
time later to other stations. This can be used to link outlying Remote sta-
tions to the AP when direct communication is not possible due to terrain,
distance, or other obstructions.
Communication routes are automatically discovered and traffic is intel-
ligently filtered such that only store and forward traffic is sent through
the SAF unit, conserving critical bandwidth in the network.
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