FCC Certification Considerations¶
This section will cover important TI 15.4-Stack application changes which may be required to achieve FCC certification given a specific hardware design.
Power Limiting Table Adjustment¶
Some LaunchPad designs are known to fail FCC certifications at higher
2.4 GHz channels due to increased second harmonic transmissions. In
order to work around this issue, a power limiting table
PowerLimitTableIeee
has been initialized inside
mac_user_config.c
to help limit the maximum transmission level
for channels which are known to be affected.
/*
* For CC1352P_2_LAUNCHXL, set ch25 to 19dBm and ch26 to 15dBm
*
* For LP_CC2652RSIP, set all ch to 5dBm except for 26, set ch26 to 2dBm
*
* For LP_CC2652PSIP, set ch26 to 2dBm and set other ch to 10dBm
*/
int8_t PowerLimitTableIeee[RF_CONFIG_IEEE_PL_NO_CHANNELS] =
{
20, //20dBm max for Channel = 11
20, //20dBm max for Channel = 12
20, //20dBm max for Channel = 13
20, //20dBm max for Channel = 14
20, //20dBm max for Channel = 15
20, //20dBm max for Channel = 16
20, //20dBm max for Channel = 17
20, //20dBm max for Channel = 18
20, //20dBm max for Channel = 19
20, //20dBm max for Channel = 20
20, //20dBm max for Channel = 21
20, //20dBm max for Channel = 22
20, //20dBm max for Channel = 23
20, //20dBm max for Channel = 24
19, //19dBm max for Channel = 25
15, //15dBm max for Channel = 26
};
The example above provides the correct power limit table changes
necessary based on existing FCC certification of the LAUNCHXL-CC1352P-2,
and a comprehensive list of other affected LaunchPads is provided in the
table below. If FCC certification is desired for any of these
LaunchPads, their respective mac_user_config.c
files’s
PowerLimitTableIeee
must be modified to compensate.
LaunchPad |
Channel |
Entry |
---|---|---|
CC1352P_2_LAUNCHXL |
25, 26 |
19, 15 |
LP_CC2652RSIP |
26 |
2 |
LP_CC2652PSIP |
11-25, 26 |
10, 2 |
LP_CC2651R3SIPA |
26 |
1 |
Note
Power limitation values will vary slightly for each custom hardware design, thus caution should be taken to identify the optimal values during FCC certification and modify the table accordingly
CC1312PSIP FCC Module Certification¶
In order to re-use the FCC RF Module certification of CC1312PSIP on Sub 1GHz channels, an application using TI 15.4 stack (in Frequency Hopping mode) or TI Wi-SUN FAN stack needs to limit the transmit power to the following values. If you set the transmit power to more than the values stated in the following tables, you need to re-certify the product and will likely pass only with duty cycling.
Stack |
Tx Power |
Additional Condition |
TI 15.4 Stack |
19 dBm |
If you only use channels between 908.2-927MHz |
TI 15.4 Stack |
16 dBm |
If you include any channel between 902.2-908MHz |
Stack |
Tx Power |
Additional Condition |
TI Wi-SUN FAN Stack |
19 dBm |
If you duty cycle with 60ms out of 100ms in TX |
TI Wi-SUN FAN Stack |
17 dBm |
Without duty cycling |
If you are using other certified PHYs, you will find the limits in the following tables.
Phy |
Tx Power |
Additional Condition |
WB-DSSS All Phys |
15 dBm |
Under all conditions |
Phy |
Tx Power |
Additional Condition |
MIOTY |
20 dBm |
If you duty cycle with 60ms out of 100ms in TX |
MIOTY |
19 dBm |
Without duty cycling |
If you are using the 14 dBm port, the following table provides the maximum TX power that you can set during transmission in order to re-use the FCC RF Module certification of CC1312PSIP on Sub 1GHz channels. It is not necessary to use duty cycling or modify channel plans in this case.
Phy/Stack |
Tx Power |
TI 15.4 Stack |
12.5 dBm |
TI Wi-SUN FAN Stack |
12.5 dBm |
WB-DSSS PHYs |
12.5 dBm |
MIOTY PHYs |
12.5 dBm |