Radio

Radio 1 (5G) — Support 5G Radio with a 4x4 MIMO mode.

Radio 2 (2.4 G) — Support 2.4G Radio with a 3x3 MIMO mode.

Radio — Check Enable to enable the radio interface.

Wireless Network Mode — The IEEE 802.11 standard and frequency the radio uses. The default value of Mode is 802.11b/g/n for Radio 2 and 802.11a/n/ac for Radio 1. For each radio, select one of the available modes.

Radio 2(2.4G) supports the following radio modes:

• 802.11b/g — 802.11b and 802.11g clients can connect to the WAP device.

• 802.11b/g/n (default) — 802.11b, 802.11g, and 802.11n clients operating in the 2.4-GHz frequency can connect to the WAP device.

• 2.4 GHz 802.11n — 802.11n clients operating in the 2.4-GHz frequency can connect to the WAP device.

Radio 1(5G) supports the following radio modes:

• 802.11a — 802.11a clients can connect to the WAP device.

• 802.11a/n/ac — 802.11a clients, 802.11n, and 802.11ac clients operating in the 5-GHz frequency can connect to the WAP device.

• 802.11n/ac — 802.11n clients and 802.11ac clients operating in the 5-GHz frequency can connect to the WAP device

Wireless Band Selection (802.11n and 802.11ac modes only) — The 802.11n specification allows a coexisting 20/40 MHz band in addition to the legacy 20 MHz band available with other modes. The 20/40 MHz band enables higher data rates but leaves fewer bands available for use by other 2.4 GHz and 5 GHz devices.

The 802.11ac specification allows an 80 MHz-wide band in addition to the 20 MHz and 40 MHz band.

Set the field to 20 MHz to restrict the use of the wireless band selection to a 20 MHz band. For the 802.11ac mode, set the field to 40 MHz to prevent the radio from using the 80 MHz wireless band selection.

Primary Channel (802.11n modes with 20/40 MHz bandwidth only) — A 40 MHz channel can be considered to consist of two 20-MHz channels that are contiguous in the frequency domain. These two 20-MHz channels are often referred to as the primary and secondary channels. The primary channel is used for 802.11n clients that support only a 20-MHz channel bandwidth and for legacy clients.

Choose one of these options:

• Upper — Sets the primary channel as the upper 20-MHz channel in the 40-MHz band.

• Lower — Sets the primary channel as the lower 20-MHz channel in the 40-MHz band. Lower is the default selection.

Channel — The portion of the radio spectrum that the radio uses for transmitting and receiving.

The range of available channels is determined by the mode of the radio interface and the country code setting. If you select Auto for the channel setting, the WAP device scans available channels and selects a channel where the least amount of traffic is detected.

Each mode offers a number of channels, depending on how the spectrum is licensed by national and transnational authorities such as the Federal Communications Commission (FCC) or the International Telecommunication Union (ITU-R).

Scheduler — For the radio interface, select the profile from the list.

DFS Support—This field is available only if the selected radio mode operates in the 5GHz frequency.

For radios in the 5 GHz band, when DFS support is on and the regulatory domain requires radar detection on the channel, the Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC) features of 802.11h are activated.

DFS is a mechanism that requires wireless devices to share spectrum and avoid co-channel operation with radar systems in the 5 GHz band. DFS requirements vary based on the regulatory domain, which is determined by the country code setting of the AP.

When using the 802.11h Wireless Mode, there are a number of key points about the IEEE 802.11h standard:

• 802.11h only works for the 5 GHz band. It is not required for the 2.4 GHz band.

• If you are operating in an 802.11h enabled domain, the AP attempts to use the channel you assign. If the channel has been blocked by a previous radar detection, or if the AP detects a radar on the channel, then the AP automatically selects a different channel.

• When 802.11h is enabled, the AP will not be operational in the 5 GHz band for at least 60 seconds due to radar scanning.

• Setting up WDS links may be difficult when 802.11h is operational. This is because the operating channels of the two APs on the WDS link may keep changing depending on channel usage and radar interference. WDS will only work if both the APs operate on the same channel. For more information on WDS, see WDS Bridge.

Short Guard Interval Supported — This field is available only if the selected radio mode includes 802.11n. The guard interval is the dead time, in nanoseconds, between OFDM symbols. The guard interval prevents Inter-Symbol and Inter-Carrier Interference (ISI, ICI). The 802.11n mode allows for a reduction in this guard interval from the a and g definition of 800 nanoseconds to 400 nanoseconds. Reducing the guard interval can yield a 10 percent improvement in data throughput. The client with which the WAP device is communicating must also support the short guard interval.

Choose one of these options:

• Yes — The WAP device transmits data using a 400-nanosecond guard interval when communicating with clients that also support the short guard interval. This is the default selection.

• No — The WAP device transmits data using an 800-nanosecond guard interval.

Protection — The protection feature contains rules to guarantee that 802.11 transmissions do not cause interference with legacy stations or applications. By default, protection is enabled (Auto). With protection enabled, protection is invoked if the legacy devices are within the range of the WAP device.

You can disable the protection (Off); however, the legacy clients or the WAP devices within the range can be affected by 802.11n transmissions. Protection is also available when the mode is 802.11b/g. When protection is enabled in this mode, it protects 802.11b clients and the WAP devices from 802.11g transmissions.

Beacon Interval — The interval between the transmission of beacon frames. The WAP device transmits these frames at regular intervals to announce the existence of the wireless network. The default behavior is to send a beacon frame once every 100 milliseconds (or 10 per second). Enter an integer from 20 to 2000 milliseconds. The default is 100 milliseconds.

DTIM Period — The Delivery Traffic Information Map (DTIM) period. Enter an integer from 1 to 255 beacons. The default is 2 beacons.

The DTIM message is an element included in some beacon frames. It indicates which client stations, currently sleeping in low-power mode, have data buffered on the WAP device awaiting pickup.

The DTIM period indicates how often the clients served by this WAP device should check for buffered data awaiting pickup.

The measurement is in beacons. For example, if you set it to 1, the clients check for buffered data on the WAP device at every beacon. If you set it to 10, the clients check on every 10th beacon.

Fragmentation Threshold — The frame size threshold in bytes. The valid integer must be even and in the range of 256 to 2346. The default is 2346.

The fragmentation threshold is a way of limiting the size of packets (frames) transmitted over the network. If a packet exceeds the fragmentation threshold set, the fragmentation is activated and the packet is sent as multiple 802.11 frames.

If the packet being transmitted is equal to or less than the threshold, the fragmentation is not used. Setting the threshold to the largest value (2,346 bytes, which is the default) effectively disables the fragmentation.

By default, the fragmentation is off. We recommend not using fragmentation unless you suspect the radio interference. The additional headers applied to each fragment increase the overhead on the network and can greatly reduce the throughput.

RTS Threshold — The Request to Send (RTS) Threshold value. The valid integer range must be from 0 to 65535. The default is 65535 octets.

The RTS threshold indicates the number of octets in an MPDU, below which an RTS/CTS handshake is not performed.

Changing the RTS threshold can help control the traffic flow through the WAP device. If you specify a low threshold value, the RTS packets are sent more frequently, which consumes more bandwidth and reduces the throughput of the packet. However, sending more RTS packets can help the network recover from interference or collisions that might occur on a busy network, or on a network experiencing electromagnetic interference.

Max Associated Clients — The maximum number of stations allowed to access the WAP device at any one time. You can enter an integer between 0 and 200. The default is 200 stations.

Transmit Power — A percentage value for the transmit power level for the WAP device.

The default value of Full - 100 % can be more cost-efficient than a lower percentage because it gives the WAP device a maximum broadcast range and reduces the number of access points needed.

To increase the capacity of the network, place the WAP devices closer together and reduce the value of the transmit power. This setting helps reduce overlap and interference among the access points. A lower transmit power setting can also keep your network more secure because the weaker wireless signals are less likely to propagate outside of the physical location of your network.

Some channel ranges and country code combinations have relatively low maximum transmit power. When attempting to set the transmit power to the lower ranges (for example, Medium - 25 percent or Low -12 percent), the expected drop in power may not occur, because certain power amplifiers have minimum transmit power requirements.

Frame-burst Support — Generally enabling Frame-burst support improves the radio performance in the downstream direction.

Airtime Fairness Mode — The airtime fairness (ATF) feature was implemented to address the issue of slower-data transfers throttling the higher-speed ones.

Maximum Utilization Threshold—Enter the percentage of network bandwidth utilization allowed on the radio before the WAP device stops accepting new client associations. The valid integer range is from 0 to 100 percent. The default is 0 percent. When set to 0, all new associations are allowed regardless of the utilization rate.

Fixed Multicast Rate — The transmission rate in Mbps for broadcast and multicast packets. This setting can be useful in an environment where the wireless multicast video streaming occurs, provided the wireless clients are capable of handling the configured rate.

When Auto is selected, the WAP device chooses the best rate for the associated clients. The range of valid values is determined by the configured radio mode.

Legacy Rate Sets — Rates are expressed in megabits per second.

The Supported Rate Sets indicate the rates that the WAP device supports. You can check multiple rates. The WAP device automatically chooses the most efficient rate based on the factors such as error rates and the distance of client stations from the WAP device.

The Basic Rate Sets indicate the rates that the WAP device advertises to the network for the purposes of setting up communication with other access points and client stations on the network. It is generally more efficient to have a WAP device broadcast a subset of its supported rate sets.

Broadcast/Multicast Rate Limiting — Multicast and broadcast rate limiting can improve overall network performance by limiting the number of packets transmitted across the network.

By default, this feature is disabled. Until you enable this feature, these fields are disabled:

• Rate Limit — The rate limit for multicast and broadcast traffic. The limit should be greater than 1, but less than 50 packets per second. Any traffic that falls below this rate limit will always conform and be transmitted to the appropriate destination. The default and maximum rate limit setting is 50 packets per second.

• Rate Limit Burst — An amount of traffic, measured in bytes, which is allowed to pass as a temporary burst even if it is above the defined maximum rate. The default and maximum rate limit burst setting is 75 packets per second.

Spectrum Analysis Mode— The Spectrum Analysis Mode status can be one of the following:

• Dedicated Spectrum Analyzer—In dedicated mode, the radio is used for spectrum analysis for more than 10% of the time and the client connections may work but are not guaranteed.

• Hybrid Spectrum Analyzer—In hybrid mode, client connections are guaranteed but degradation is expected throughout.

• 3+1 Spectrum Analysis— In 3+1 mode, clients connect to 3x3 chains, while spectrum analysis is done on 1x1 chain.

• Disabled—The default is Disabled

VHT Features — The purpose of this feature is to enabled/disable Broadcom specific extensions in VHT for Broadcom-to-Broadcom links. VHT feature enables support for 256QAM VHT rates not specified by the 802.11 ac Draft. The rates are all VHT LDPC mode, MCS 9 Nss 1 20Mhz, MCS 9 Nss 2 20Mhz, MCS 6 Nss 3 80Mhz. The VHT feature is supported for 802.11 ac PHY.

TSPEC Violation Interval — In the TSPEC Violation Interval field, enter the time interval in seconds for the WAP device to report associated clients that do not adhere to mandatory admission control procedures. The reporting occurs through the system log and SNMP traps. Enter a time from 0 to 900 seconds. The default is 300 seconds.

TSPEC Mode — Regulates the overall TSPEC mode on the WAP device. By default, the TSPEC mode is off. The options are:

• On — The WAP device handles TSPEC requests according to the TSPEC settings that you configure on the Radio page.

• Off — The WAP device ignores TSPEC requests from client stations.

TSPEC Voice ACM Mode — Regulates mandatory admission control (ACM) for the voice access category. By default, TSPEC Voice ACM mode is off. The options are:

• On — A station is required to send a TSPEC request for bandwidth to the WAP device before sending or receiving a voice traffic stream. The WAP device responds with the result of the request, which includes the allotted medium time if the TSPEC was admitted.

• Off — A station can send and receive the voice priority traffic without requiring an admitted TSPEC. The WAP device ignores voice TSPEC requests from client stations.

TSPEC Voice ACM Limit — The upper limit on the amount of traffic that the WAP device attempts to transmit on the wireless medium using a voice AC to gain access. The default limit is 20 percent of total traffic.

TSPEC Video ACM Mode — Regulates mandatory admission control for the video access category. By default, TSPEC Video ACM mode is off. The options are:

• On — A station is required to send a TSPEC request for bandwidth to the WAP device before sending or receiving a video traffic stream. The WAP device responds with the result of the request, which includes the allotted medium time if the TSPEC was admitted.

• Off — A station can send and receive video priority traffic without requiring an admitted TSPEC; the WAP device ignores video TSPEC requests from client stations.

TSPEC Video ACM Limit — The upper limit on the amount of traffic that the WAP device attempts to transmit on the wireless medium using a video AC to gain access. The default limit is 15 percent of total traffic.

TSPEC AP Inactivity Timeout — The amount of time for a WAP device to detect a downlink traffic specification as idle before deleting it. The valid integer range is from 0 to 120 seconds and the default is 30 seconds.

TSPEC Station Inactivity Timeout — The amount of time for a WAP device to detect an uplink traffic specification as idle before deleting it. The valid integer range is from 0 to 120 seconds and the default is 30 seconds.

TSPEC Legacy WMM Queue Map Mode — Check Enable to enable the intermixing of legacy traffic on queues operating as ACM. By default, this mode is off.