Configuration Manual

109
Dual-band 3x3 802.11 ac WiFi Access Point
Configuration Manual
5.8. WiFi Protect mechanism [Hidden node
problem]
In wireless networking, the hidden node problem or hidden terminal
problem occurs when a node is visible from a wireless access point (AP),
but not from other nodes communicating with that AP. This leads to
difficulties in media access control sublayer. IEEE 802.11 uses 802.11
RTS/CTS acknowledgment and handshake packets to partly overcome
the hidden node problem.
Figure 113 – Protection Mode Setting
1. 2.4G Interface: Go to Configuration > Wireless > Radio0 > Advanced
> Advanced Settings
5G Interface: Go to Configuration > Wireless > Radio1 > Advanced >
Advanced Settings
2. Select suitable mechanism on Protection Mode; options include:
None - no protect mechanism is used. It is the default setting.
CTS-only - also known as CTS-to-Self; AP issues a CTS frame to itself
before sending data. All clients will not transmit during the time.
RTS-CTS - AP sends a RTS frame, waits for the clients CTS frame and
then sends the data packet. It allow more robust operation, but at
the expense of additional overheads.
3. Specify frame size in byte between 0 and 2347 bytes on RTS/CTS
Threshold; 2346 is default setting.
If a frame is smaller than the RTS/CTS threshold, it will be sent by the
AP without modification. If a frame is larger than the RTS/CTS
threshold, then two frames will be sent by the AP. The first frame is an
RTS (request to send) frame. After the RTS frame is sent, the AP listens
for the corresponding CTS from the target client. Upon reception of
the CTS, the AP then sends the data frame. There are trade-offs
when considering what value you should set for the RTS/CTS
threshold. Smaller values will cause RTS to be sent more often,
increasing overheads. However, the more often RTS packets are
sent, the sooner the system can recover from collisions. It is
recommended to use the default value or only minor reductions of
the default setting.
4. Click Submit
5. Click Save & Apply from the top on the right.