SWRU455M February 2017 – October 2020 CC3120 , CC3120MOD , CC3130 , CC3135 , CC3135MOD , CC3220MOD , CC3220MODA , CC3220R , CC3220S , CC3220SF , CC3230S , CC3230SF , CC3235MODAS , CC3235MODASF , CC3235MODS , CC3235MODSF , CC3235S , CC3235SF
The Antenna Diversity feature lets the device select the best antenna for a specific connection. Choosing the best antenna is applied according to the configured mode. There are four operational modes available according to the device part. Table 5-13 illustrates the supported mode per the device type.
For more information on device types, refer to Table 2-1.
Mode | Description | CC3120/CC3220 | CC3x35/CC3x30 |
---|---|---|---|
Antenna1 | Use the first antenna only | + | + |
Antenna2 | Use the second antenna only | + | + |
Automatic | Automatic antenna selection during connection only | - | + |
Manual | Manual antenna selection while connected | + | - |
CC3120 and CC3220 parts support Antenna Diversity starting from service pack v3.10.0.5.
The automatic mode which is available only on CC3x35 and CC3x30 parts is active only during connection. When connecting to an AP, a scan command is issued internally on both antennas and the best antenna is chosen according to the RSSI level. This antenna is used for the entire connection with the selected AP (meaning no dynamic switch between antennas is done during connection). The mode is configurable by the user. By default, the feature is enabled.
While the feature is enabled:
The manual mode which is available only on CC3120 and CC3220 parts is active after a connection with an AP is established. Unlike the automatic mode where the entire implementation is in the NWP, the manual mode is controlled by the host processor application. This mode provides two additional APIs for setting and getting the desired antenna. The host application makes the decision according to the best RSSI level.
In manual mode, there is additional optional API to set a user trigger based on RSSI level. This API is used in case the user would like the host application to wake up only when the operational antenna is degraded below a predefined value. This feature serves two advantages, the first is power saving when periodic host application wake ups are not required, and the second is real time responsiveness so the host application is notified immediately on degraded antenna link.
While manual mode is enabled: