CC2564 BLE FCC 15.249

Weiren Tee

Other Parts Discussed in Thread: CC2564, CC2564MODN

Hi TI Folks,

Sorry, I am very new to the FCC and got a bit confused. Therefore could some experienced Engineers advise on the below question?

With regards to the FCC 15.249, there is a criteria of Electric Field of less than 50mV/m @ 3m. But from calculation, using the lowest power setting of 0dBm from the CC2564, the Electric Field is greater than 50mV/m(around 60++).

How can we pass FCC 15.249? (use attenuation circuit to reduce the output power?)

If with the lowest power setting we are facing such violation in the FCC 15.249, it is still meaningful to have high power settings?

Please find below extract from :

http://processors.wiki.ti.com/index.php/CC256x_FCC_Certification_Guide under

White paper from bluetooth.org on LE testing: https://www.bluetooth.org/docman/handlers/downloaddoc.ashx?doc_id=237781

10.3 FCC 15.249

Another FCC study was the filing of Bluetooth LE under FCC 15.249. These rules allow for flexibility in implementing low power short-range radio systems. The rules do not restrict frequency band usage as much as in FCC 15.247. In line with FCC 15.249, the system may either be frequency hopping or stationary. The problem is that although Bluetooth LE is considered a low duty cycle system, the allowable transmission power would be too limited. The output power limits for the FCC 15.249 are:

• Maximum average transmission power -1.25 dB (radiated measurement)

• Maximum peak power +18.75 dBm (peak field strength of any emission shall not exceed the maximum permitted average limits by more than 20 dB under any condition of modulation.)

The measurement setup defined in ANSI C63.4-1992 (shown in Figure 1), decreases the calculated average radiated power from the device. The maximum allowed field intensity at a distance of 3 meters is 50 mV/m. There are two reasons why the actual output power is less than a direct conversion from the field strength to the conducted power.

• The measurement is performed to strongest polarization and direction. Non-directional applications must therefore assume an average antenna gain in their link budget calculations; therefore 2-4dBs are lost depending on antenna pattern.

• Measurement shall be performed with a reflective floor. Maximum signal can be 6 dB more than direct signal alone.

Thus, due to ground plane reflection and antenna, the average radiated power can be only ~-10 dBm

Thank you very much.

Regards,

Weiren

over 10 years ago

0 Sundeep Javvaji over 10 years ago

TI__Mastermind 32615 points

Hi,

For Both CC256xQFN and CC2564MODN, we are only FCC 15.247 certified and not FCC 15.249.
https://apps.fcc.gov/eas/GetApplicationAttachment.html?id=1963171
https://apps.fcc.gov/eas/GetApplicationAttachment.html?id=2228841

0 Weiren Tee over 10 years ago in reply to Sundeep Javvaji

Expert 1100 points

Hi Sundeep,

Thanks for your reply.

May I double check with you. Is FCC 15.249 necessary for CC256X so that it can design in and sell as a product globally?
If not, may I know what is the reason for not certifying the CC256X for FCC 15.249?

As for the links provided, I received the following error message "You are not authorized to access this page.". Could you attached or email me the files?

Please pardon me on my ignorance for the FCC certification for BLE. I hope this will be useful to those who new to this arena. Thanks

Regards,
Weiren

0 Sundeep Javvaji over 10 years ago in reply to Weiren Tee

TI__Mastermind 32615 points

Hi,

No, we have also removed the link to the " White paper from bluetooth.org on LE testing ", from our wiki.

I hope this post will answer your question http://e2e.ti.com/support/wireless_connectivity/f/660/p/385487/1362575

You can get the links I have provided From FCC wiki (below)-> FCC ID section (click on the links --> FCC ID: Z64-CC256XEM. and Z64-2564N) --> test report.
http://processors.wiki.ti.com/index.php/CC256x_FCC_Certification_Guide

0 Weiren Tee over 10 years ago in reply to Sundeep Javvaji

Expert 1100 points

Hi Sundeep,

Thanks for your guidance and information provided.

From the link provided, is the conclusion that, if CC256X were to be qualifed under FCC 15.259, it will fail?

From http://www.ti.com/lit/an/swra048/swra048.pdf ,
I found an interesting table(Table 7. under section 2.4 Operation in the 2.4–2.4835 GHz Band)

The limits given in sections 15.247 and 15.249 for the 2.4–2.4835 GHz band are summarized in Table 7("Transmit Power Limits for the 2.4–2.4835 GHz Band).

The "Transmit Power Limits for the 2.4–2.4835 GHz Band" limit for "Frequency hopping" transmission type and "Digitally spread" transmission type is not defined.

And from what i recently read, FCC classified BLE as Frequency-hopping spread spectrum(FHSS) (ref:http://en.wikipedia.org/wiki/Bluetooth_low_energy)

From the above information, can i conclude and say that BLE does not need fall under the scope of FCC 15.259 thus there is no need to qualify BLE for FCC 15.259?

PS: Any qualification expert can help on this? I need a definite answer to advise my customer. Thanks

Regards,
Weiren

0 Miguel over 10 years ago in reply to Weiren Tee

TI__Mastermind 23565 points

Hi Weiren,
Your last description is correct. BLE falls onto FCC 15.247 category. At the beginning of BLE, it was not clear if it would fall under FCC 15.249 or FCC 15.247 and hence some confusion. But you should use FCC 15.247 now.
~Miguel

0 Weiren Tee over 10 years ago in reply to Miguel

Expert 1100 points

Hi Miguel,

Thank you very much for your confirmation. :)

Regards,
Weiren

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CC2564 BLE FCC 15.249