MDS 05-4846A01, Rev. F
SD Series Technical Manual
5
to use the RF channel before sending payload data, thus avoiding colli-
sions 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.
Data Validation
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 SD supports port-based VLAN at the Ethernet interface and over
the air, according to 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 (COM1/COM2) ports as IP packets, then transmitting it over the
air. At the receiving end, the data is decapsulated and delivered to the
appropriate COM port. See “Terminal Server COM1/2 Configuration”
on Page 58 for more information.
Store and Forward Capability
Store and forward (SAF) capability is available in Packet with MAC
mode. It allows a radio to store up incoming data, and retransmit it a
short time later to other stations. This can be used to link outlying
remote stations 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 so that only store and forward traffic is sent through the
SAF unit, conserving critical bandwidth in your network.
