Configurable Antenna Diversity

The wireless SonicWall security appliances employ dual 5 dBi antennas running in diversity mode. The default implementation of diversity mode means that one antenna acts as a transmitting, and both antennas act as potential receiving antenna. As radio signals arrive at both antennas on the secure wireless appliance, the strength and integrity of the signals are evaluated, and the best received signal is used. The selection process between the two antennas is constant during operation to always provide the best possible signal. To allow for external (higher gain uni-directional) antennas to be used, antenna diversity can be disabled.

The SonicWall NSA 220 and 250M wireless security appliances employ three antennas. The Antenna Diversity is set to Best by default, this is the only setting available for these appliances.

The Antenna Diversity setting determines which antenna the wireless security appliance uses to send and receive data. You can select:

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Best—This is the default setting. When Best is selected, the wireless security appliance automatically selects the antenna with the strongest, clearest signal. In most cases, Best is the optimal setting.
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1—Select 1 to restrict the wireless security appliance to use antenna 1 only. Facing the rear of the appliance, antenna 1 is on the left, closest to the console port. You can disconnect antenna 2 when using only antenna 1.
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2—Select 2 to restrict the wireless security appliance to use antenna 2 only. Facing the rear of the appliance, antenna 2 is on the right, closest to the power supply. You can disconnect antenna 1 when using only antenna 2.