Cerio PS-200N-AX User Manual page 89

Short Preamble : By default, it's "Enable". To Disable is to use Long 128-bit Preamble

Synchronization field.
The preamble is used to signal "here is a train of data coming" to the receiver. The short
preamble provides 72-bit Synchronization field to improve WLAN transmission efficiency
with less overhead.
IGMP Snooping : the process of listening to Internet Group Management Protocol (IGMP)

network traffic. The feature allows a network switch to listen in on the IGMP conversation
between hosts and routers. By listening to these conversations the switch maintains a
map of which links need which IP multicast streams. Multicasts may be filtered from the
links which do not need them and thus controls which ports receive specific multicast
traffic.
DFS : Is IEEE802.11H With DFS(Dynamic Frequency Selection) enabled, radio is

operating on one of the following channels, the wireless device uses DFS to monitor the
operating frequency and switch to another frequency or reduce power as necessary.
The maximum legal transmit power is greater for some 5 GHz channels than for others.
When the wireless device randomly selects a 5 GHz channel on which power is restricted,
the wireless device automatically reduces transmit power to comply with power limits for
that channel in that regulatory domain.
Greenfield : In wireless WLAN technology, greenfield mode is a feature of major

components of the 802.11n specification. The greenfield mode feature is designed to
improve efficiency by eliminating support for 802.11b/g devices in an all draft-n network.
In greenfield mode the network can be set to ignore all earlier standards.
Signal LED Thresholds : This function can setting RSSI number(1~99) to control signals

LED's, The PS-200N-AX system will calculate for RSSI number and total of three LED's
indicator, If LED's whole bright indicate signal is the strong.
The function only support Client Bridge + Repeater AP and WISP + Repeater AP
modes
 LED Indicator : Total of three LED's, the LED1 RSSI number is Minimum
CERIO software core : cen_v3.0