FREQUENTLY ASKED QUESTIONS
|Question: In KDB 941225 mentioned the following statement:
"When SAR tests for EDGE or EGPRS mode is necessary, GMSK modulation should be used to minimize SAR measurement error due to higher peak-to-average power (PAR) ratios inherent in 8-PSK. Tests using MCS5-MCS9 should be avoided. In order to qualify for the above test reduction, the maximum burst-averaged output power for each mode GMS/GPRS/EDGE) and the corresponding multi-slot class must be clearly identified in the SAR report for each frequency band. A summary of the specific procedures applied to arrive at the final test configurations must also be included along with the test data to support the test results." My understanding can be in two approach : 1) Measure Burst-average power on GSM, then based upon multi-slot implementation, GPRS Class 8 can be calculated based upon Burst-average power (BAP) x 12.5% ; (BAP)x 25% - for Class 10; (BAP)x 50% for Class 12. This method is subject to power back-off implementation for each of device; or 2) GSM, GPRS Class 8, GPRS Class 10 and GPRS Class 12 shall be measured with BAP individually. Please let me know which approach is correct.
2. If CMU 200 base station emulator is used to establish the call. Once the call is established, CMU will report Average Burst Power (Current). Is this power should be reported ?
3. Since SAR is concerning average power ( source-based time averaging power), the measured GPRS average power shall be very closed to Peak output power x duty factor. However, if burst average power is used, it is not source-based time averaged power but very close to peak output power. Please let us know shall Burst average power or source-based time average power shall be reported for GPRS in the SAR test report.|
Response From FCC:
Question 1: You should measure the different classes individually (your second approach). Additional slots do not necessarily mean additional SAR. There might be higher power back-off for higher class operation and calculations might not sufficiently reflect operating characteristics.
Question 2: The FCC Laboratory expects to see the average power within the burst. This is quite similar to peak since GMSK is a constant amplitude modulation.
Question 3: Once the duty factor is input, the SAR system takes things into account. As long as the test set-up procedure is explained, either way is acceptable for reporting purposes.
|Question: What are equipment authorization requirements when a device with pre-existing FCCID is integrated for operating and marketing within another final product enclosure?|
--OET response sent on Jun 24 2009 11:27AM--
general remarks about module "reuse" shown below; new FCC ID filings must contain all info required by 47 CFR 2.1033(b) and/or 2.1033(c)
for RF exposure, please apply at least KDB pubs. 648474, 248227, 865664, 450824, 941225
You may use "Reply to an Inquiry Response" with present inquiry no. if there are other related equipment authorization questions (https://fjallfoss.fcc.gov/oetcf/kdb/forms/ResponseReplyEntry.cfm).
1) For a device having a modular or limited modular approval:
a) Separate from RF exposure and radiated power and/or emissions test requirements, when applicable, additional equipment authorizations are not needed when a module is used in a final product that meets all the following:
i) Final product complies with device use conditions and any grant limitations described in original and any permissive change filings under the module FCC ID
ii) Final antenna configuration(s) and use conditions comply with applicable rules, e.g., ERP / EIRP for some licensed services, 15.204 antenna-types for part 15 intentional radiator
iii) Original test data in the module FCC ID filing continues to represent characteristics of the final product containing module device
iv) Final product has FCC ID label, in accordance with applicable module policy
b) For FCCIDs with Limited Modular Approval, grantee shall evaluate radiated spurious emissions to determine whether Class I or Class permissive change is applicable for module used in different final product configurations
2) For a device not having modular approval:
a) New FCCID filing is required containing complete 2.1033 info and product-specific test results
b) Test results from the FCCID record for the non-modular-approval device cannot be re-used within the new FCCID product filing
c) The new product cannot be labelled with the existing FCCID for the non-modular device
|Question: Dear FCC:
I have forwarded your reply to all members in the CCS TCB program. We cannot come out with an universal conclusion on the assessment requirements. I would like to post my questions with specific conditions and hopefully can get your confirmation once again:
1. Class II permissive change filing by installing an approved WLAN module in a portable host
2. The portable host is laptop computer (Non-Tablet)
3. WLAN module has received single module approval.
4. WLAN TX antenna(s) is located within 20 cm separation distance thus SAR evaluation is required.
5. WLAN TX antenna(s) is not shared by any other transmitter.
6. WLAN TX antenna(s) in this portable host is the same type of antenna with less gain.
7. WLAN module is a client device and DFS evaluation is not required.
8. WLAN module is not transmitting simultaneously with other transmitter. If it does transmit simultaneously, the antenna separation distance is more than 20 cm.
9. No modification has been made on WLAN module.
If all above conditions are met, EMC evaluation is not required. In this Class II permissive change filing, only SAR test report, and all other related attachments (host user manual, host ID format, internal photos etc) are required.
The reason for me excluded the tablet computer is due to tablet computer requires X/Y/Z radiated emission tests which are not covered during stand alone module tests.
I also excluded licensed TX module due to the following review commends from FCC:
1. Output power is listed in the same units/quantity as the applicable limit (e.g., EIRP for Part 24 mobile / portable station).
a. For Part 15 devices, list only conducted output power when applicable (i.e., 15.247, 15.407).
b. For licensed devices subject to a field strength limit for the fundamental signal, indicate conducted output power if EIRP or ERP is not specified. The field strength measurement must still be compared to the field strength limit. One such example is for WMTS, 95.1115(a) where a field strength limit is specified.
2. Conducted output power can be listed for devices where measurements can be made at the antenna connector, and subject to the conditions below. The conducted output power listed must be the same type (i.e., peak, average) as defined by the applicable rule part. Indicate ?Power listed is conducted? on the grant.
a. Allowed for devices authorized without specific antenna(s), e.g., 24E base-station tower-mounted antennas. Also allowed for licensed service module and module-like devices without specified antennas used in mobile and fixed RF exposure conditions.
b. Allowed for module-like devices authorized with specific antennas (i.e., built-in antenna) subject to radiated power limits (e.g., 24E integral-antenna PCMCIA). List conducted power on line-item and radiated power in grant note.
c. Not allowed for final products authorized with specific antennas, e.g., 22H, 24E handsets and laptops.
Please help to review above statement. If my understanding is not correct, please feel free to let me know.
Response From FCC:
For EMC evaluation, if you have considered all rules, policies and grant conditions(which appears you have done here) and in your engineering judgement EMC emissions is not affected, it would be reasonable to conclude that EMC testing is not required. If so, you would neet to document your justification and conclusion in lieu of an EMC test report. Please note that the device always needs to comply and the FCC may request tests to be performed and submitted to verify compliance or may perform testing in certain circumstances for pre or post grant sampling.
|Question: During December 2007 TCB/FCC monthly conference call, the following statement was given by FCC during KDB 616217 and KDB 178919 discussion
4) Other general considerations
a) EMC evaluation is not required to be submitted if the following conditions are met.
i) The transmitters do not share a common antenna
ii) The transmitters do not coordinate transmissions
iii) The transmitters do not transmit simultaneously
However, in KDB 178919, the following statement is given:
3. When a Class II permissive change is filed for either EMC or RF exposure (RFE) purposes, an EMC test report or RFE evaluation is required, regardless of whether EMC or the RFE levels have degraded.*
Question: When an approved WLAN module is installed in the laptop computer and antenna(s) are installed at display section, TCB shall assess RF exposure compliance based upon KDB 616217. If after the assessment, SAR evaluation is required but complies with above three EMC conditions, shall such WLAN module also be tested per EMC requirement?
Response From FCC:
This is one consideration listed and it is not based on whether or not SAR evaluation is required. This assumes there are no changes to any of the devices. However, all applicable rules and requirements must be considered for each device in the final configuration when there are any changes such as hardware changes, applicable grant conditions changes, device configuration changes, RF safety changes, HAC (if applicable), DFS(if applicable) etc..
|Question: Dear FCC:
On April 15, 2008, FCC modified form 731 to include section for modular approval (single/split, limited). While certifying Part 22/24 WWAN data modem module, shall TCB use the indication of modular approval for licensed transmitter?
Response From FCC:
The answer is yes. Even though the modular rules and policies apply to non-licensed devices, we do grant modular approvals on a case by case basis for licensed devices and we do need the FCC Form 731 module box checked
|Question: Can a Part 15 transmitter such as an 802.11b/g or a UNII device allow users or professional installers to set the country code to ensure compliance, if the user manual contains the following statement: " WARNING: Select only the country in which you are using the device. Any other selection will make the operation of this device illegal?"
FCC Response/ KDB 594280:
No. A Part 15 device cannot have the ability to be configured by end users or professional installers to operate in any way except as granted. Selecting country codes or frequencies, power or grant conditions for different regulatory domains is not permitted as noted in Section 15.202 of the rules. All master devices as defined in Section 15.202 must operate within the authorized bands, and cannot have the ability to be configured for other countries.
All devices meeting the definition of a client as specified in Section 15.202 may have the ability to operate on other regulatory domain frequencies if it is under control of (automatically associates with) a certified master device. In this case, the "WARNING" statement mentioned above would not serve any purpose since frequency selection, power or grant conditions would be automatic, and regulatory domain selection would not be permitted.
Many devices referred to by the WiFi industry as client devices may not meet the definition of a Section 15.202 client and must be limited to operating as master devices on US frequencies, and within the grant conditions. To qualify as a Section 15.202 client, a device cannot initiate, or be configured to initiate, any transmission for any reason on non US frequencies, or on frequencies not authorized for use. This includes probes, beacons, and ad hoc mode transmissions. Only if all features and functions that utilize initiating transmissions are within the frequencies as granted can the device be authorized as a Section 15.202 client device. These devices can then automatically associate and operate on non US frequencies when outside of the US, under the control of a foreign master device authorized on other regulatory domain frequencies.
Based upon section 2.933, the original grantee can issue the authorization to another grantee to create new FCC ID number if no modification has been made. The following question is related to section 2.933 procedure: Grantee-A is the original grantee received the grant of equipment authorization. Grantee-B would like to market this certified device under different grantee code thus requested Grantee-A to issue the authorization to Grantee-B to establish new FCC ID number under under Grantee Code-B. By following 2.933 procedure, Grantee-B received new FCC ID number under its grantee code.
Question : Can Grantee-B issue authorization to Grantee-C by using section 2.933 procedure so Grantee-C can establish new FCC ID number under Grantee Code-C?
Grantee B can authorize Grantee C to submit a filing under the Change in ID rules ? Section 2.933. The filing submitted by Grantee C must refer to the filing submitted by Grantee B. In addition, the grantee should submit a Cover Letter Exhibit that includes a statement that Grantee B acknowledges the Change in FCC ID, and a statement declaring that the device continues to comply with the applicable Commission rules and standards.