Advanced Radio Settings

To configure advanced radio settings

1. Toggle the Enable Short Slot Time option on the DEVICE | Internal Wireless > Advanced page to increase performance if you do not expect 802.11b traffic. 802.11b is not compatible with a short slot time. This setting is disabled by default.
2. From the Antenna Rx Diversity drop-down menu, select which antenna the wireless security appliance uses to send and receive data. For more information about antenna diversity, refer to Configurable Antenna Diversity. The default is Best.

3. From the Transmit Power drop-down menu, select:

   • Full Power to send the strongest signal on the WLAN. For example, select Full Power if the signal is going from building-to-building.
   • Half (-3 dB) is recommended for office-to-office within a building.
   • Quarter (-6 dB) is recommended for shorter distance communications.
   • Eighth (-9 dB) is recommended for shorter distance communications.
   • Minimum is recommended for very short distance communications.
4. From the Preamble Length drop-down menu, select Short or Long. Short is recommended for efficiency and improved throughput on the wireless network, but is not supported by 802.11b. The default is Long.

5. Specify the Fragmentation Threshold (bytes). The minimum is 256; the maximum is 2346, and the default is 2346.

   You can fragment wireless frames to increase reliability and throughput in areas with RF interference or poor wireless coverage. Lower threshold numbers produce more fragments. Increasing the value means that frames are delivered with less overhead, but a lost or damaged frame must be discarded and retransmitted.

6. Specify the request-to-send (RTS) threshold in the RTS Threshold (bytes) field. The minimum is 1, the maximum is 2347, and the default is 2346.

   This field sets the threshold for a packet size (in bytes) at which a RTS is sent before packet transmission. Sending an RTS ensures that wireless collisions do not take place in situations where clients are in range of the same access point, but might not be in range of each other. If network throughput is slow or a large number of frame retransmissions is occurring, decrease the RTS threshold to enable RTS clearing.

7. Specify the DTIM (Delivery of Traffic Indication Message) interval in the DTIM Interval field. The minimum is 1, the maximum is 256, and the default is 1.

   For 802.11 power-save mode clients of incoming multicast packets, the DTIM interval specifies the number of beacon frames to wait before sending a DTIM. Increasing the DTIM Interval value allows you to conserve power more effectively.

8. Enter the number of seconds for client association in the Association Timeout (seconds) field. The default is 300 seconds, and the allowed range is from 60 to 36000 seconds. If your network is very busy, you can increase the timeout by increasing the number of seconds in this field.
9. Enter the Maximum Client Associations for each access point using this profile. The minimum value is 1; the maximum is 128, and the default is 128. This setting limits the number of stations that can connect wirelessly at one time.
10. From the Data Rate drop-down menu, select the speed at which the data is transmitted and received. Best automatically selects the best rate available in your area given interference and other factors. Or you can manually select a data rate from the options that range from 1 Mbps to 54 Mbps.

11. From the Protection Mode drop-down menu, select the protection mode: None, Always, or Auto.

    Protection can decrease collisions, particularly where you have two overlapping access points. However, it can slow down performance. Auto is probably the best setting, as it engages only in the case of overlapping access points.

12. Choose the Protection Rate from the drop-down menu: 1 Mbps, 2 Mbps, 5 Mbps, or 11 Mbps. The protection rate determines the data rate when protection mode is on. The slowest rate offers the greatest degree of protection, but also the slowest data transmission rate.

13. From the Protection Type drop-down menu, select the type of handshake used to establish a wireless connection: CTS-only (default) or RTS-CTS.

    802.11b traffic is only compatible with CTS.

14. Click Accept to apply your changes. Click Restore Default Settings to return to the default settings.