Radio Advanced Properties

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Advanced Radio Properties

Field Description
Advanced Dialog - Base Settings
DTIM period Type the desired DTIM (Delivery Traffic Indication Message) period — the number of beacon intervals between two DTIM beacons. To ensure the best client power savings, use a large number. Use a small number to minimize broadcast and multicast delay. The default value is 5.
Beacon Period Defines the time, in milliseconds, between beacon transmissions. The default value is 100 milliseconds.
RTS/CTS Threshold Type the packet size threshold, in bytes, above which the packet is preceded by an RTS/CTS (Request to Send/Clear to Send) handshake. The default value is 2346, which means all packets are sent without RTS/CTS. Reduce this value only if necessary.
Frag. Threshold Type the fragment size threshold, in bytes, above which the packets are fragmented by the AP prior to transmission. The default value is 2346, which means all packets are sent unfragmented. Reduce this value only if necessary.
Maximum Distance Enter a value from 100 to 15,000 meters that identifies the maximum link distance between APs that participate in a WDS. This value ensures that the acknowledgement of communication between APs does not exceed the timeout value predefined by the 802.11 standard. The default value is 100 meters. If the link distance between APs is greater than 100 meters, configure the maximum distance up to 15,000 meters so that the software increases the timeout value proportionally with the distance between APs. For the AP38xx, this setting is only available on Radio 2. This setting is not applicable on either radio for the AP39xx.

Do not change the default setting for the radio that provides service to 802.11 clients only.

Advanced Dialog - Basic Radio Settings
Dynamic Channel Selection To enable Dynamic Channel Selection, click one of the following:
  • Monitor Mode — If enabled, a selection of DCS Interference Events appears in a separate dialog. If traffic or noise levels exceed the configured DCS thresholds, an alarm is triggered and an information log is generated.
  • Active Mode — If enabled, a selection of DCS Interference Events appears in a separate dialog. If traffic or noise levels exceed the configured DCS thresholds, an alarm is triggered and an information log is generated. In addition, the AP ceases operating on the current channel and ACS is employed to automatically select an alternate channel for the AP to operate on.
Probe Suppression Click to Enable Probe Suppression.
  • Forced Disassociate — Click to enable.
  • RSS Threshold — 90 (Range of -50 to -100).
Applies to AP37xx, AP38xx, and AP39xx series APs.
Min. Basic Rate Click the minimum data rate that must be supported by all stations in a BSS: 6, 12, or 24 Mbps and MCS0-MCS7 for n Radio (MCS0, 1 to MCS7,1 for a/n/c radio). If necessary, the Max Basic Rate choices adjust automatically to be higher or equal to the Min Basic Rate.
Advanced Dialog - Multicast Settings
Max % of non-unicast traffic per Beacon period Enter the maximum percentage of time that the AP transmits non-unicast packets (broadcast and multicast traffic) for each configured Beacon Period. For each non-unicast packet transmitted, the system calculates the airtime used by each packet and drops all packets that exceed the configured maximum percentage. By restricting non-unicast traffic, you limit the impact of broadcasts and multicasts on overall system performance.
Optimized for power save Click to optimize for power save.
Adaptable rate Click to enable adaptable rate capabilities.
Multicast to Unicast delivery Click to set the Multicast to Unicast delivery method from the drop-down list.
Advanced Dialog - 11n Settings
Guard Interval Intended to eliminate interference between symbols during transmission. It is the space between the symbols being transmitted. Valid values are Long or Short. Enabling Short Guard Interval increases throughput, but can increase interference. Enabling Long Guard Interval can increase overhead due to additional idle time.
Protection Mode Click a protection mode: None, Auto, or Always. The default and recommended setting is Auto. Click None if 11b APs and clients are not expected. Click Always if you expect many 11b-only clients.
Extension Channel Busy Threshold Click a protection type, CTS Only or RTS CTS, when a 40 MHz channel is used. This protects high throughput transmissions on extension channels from interference from non-11n APs and clients.
Aggregate MSDUs Click an aggregate MSDU mode: Enabled or Disabled. Aggregate MSDU increases the maximum frame transmission size.
Aggregate MPDUs Click an aggregate MPDU mode: Enabled or Disabled. Aggregate MPDU provides a significant improvement in throughput.
Aggregate MPDU Max Length Type the maximum length of the aggregate MPDU. The value range is 1024-65535 bytes. For the 802.11ac radio (Radio 1 of the AP38xx), the range is 1024-1048575.
Agg. MPDU Max # of Sub-frames Type the maximum number of sub-frames of the aggregate MPDU. The value range is 2-64.
ADDBA Support Click an ADDBA support mode: Enabled or Disabled. ADDBA, or block acknowledgement, provides acknowledgement of a group of frames instead of a single frame. ADDBA Support must be enabled if Aggregate APDU is enable.
LDPC Click an LDPC mode: Enabled or Disabled. LDPC increases the reliability of the transmission resulting in a 2dB increased performance compared to traditional 11n coding.
STBC Click an STBC mode: Enabled or Disabled. STBC is a simple open loop transmit diversity scheme. When enabled, STBC configuration is 2x1 (two spatial streams combine into one spatial stream). TXBF overrides STBC if both are enabled for single stream rates.
TXBF

Tx Beam Forming is a technique of re-aligning the transmitter multipath spatial streams phases in order to get better signal-to-noise ratio on the receiver side. Click a TXBF mode: For the AP37xx and AP38xx models, valid values are Enabled or Disabled. For the 39xx APs, this setting is only available on Radio1 and valid values are MU-MIMO and Disabled.

Advanced Dialog - 11b Settings
Preamble Click a preamble type for 11b-specific (CCK) rates: Short or Long. Click Short if you are sure that there is no pre-11b AP or a client in the vicinity of this wireless AP. Click Long if compatibility with pre-11b clients is required.
Advanced Dialog - 11g Settings
Protection Mode Click a protection mode: None, Auto, or Always. The default and recommended setting is Auto. Click None if 11b APs and clients are not expected. Click Always if you expect many 11b-only clients.
Protection Rate Click a protection rate: 1, 2, 5.5, or 11 Mbps. The default and recommended setting is 11. Only reduce the rate if there are many 11b clients in the environment or if the deployment has areas with poor coverage. For example, rates lower than 11 Mbps are required to ensure coverage.
Protection Type

Click a protection type: CTS Only or RTS CTS. The default and recommended setting is CTS Only.

Click RTS CTS only if an 11b AP that operates on the same channel is detected in the neighborhood, or if there are many 11b-only clients in the environment. The overall throughput is reduced when Protection Mode is enabled, due to the additional overhead caused by the RTS/CTS.

The overhead is minimized by setting Protection Type to CTS Only and Protection Rate to 11 Mbps. The overhead causes the overall throughput to be sometimes lower than if just 11b mode is used. If there are many 11b clients, it is recommended that you disable 11g support (11g clients are backward compatible with 11b APs).

An alternate approach, although potentially a more expensive method, is to dedicate all APs on a channel for 11b (for example, disable 11g on these APs) and disable 11b on all other APs. The difficulty with this method is that the number of APs must be increased to ensure coverage separately for 11b and 11g clients.