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Low Power RF & Wireless Connectivity
CC2560 hopping sequence for Japan
We are using the CC256x for regular Bluetooth and are looking for the settings to obtain RF regulatory compliance in Japan. We think that the command 6.1.56 HCI_VS_Set_PLL_Mode (0xFD23) in SWRU193D - Bluetooth Vendor Specific HCI Commands.pdf may do this but it's not clear what the settings should be or if anything else needs to be configured. Can you please tell us what should be done to reduce the number of hop frequencies so the CC256x can be used in Japan ? <<
a) We are using the CC2564
b) The patch load is WL127xL_BT_Service_Pack_1.9_BLE_AddOn.txt
c) Stonestreet Stack
The frequency range used for Bluetooth in Japan is 2472 to 2497 MHz with 23 1-MHz RF channels. The VS_Set_Frequency_Mode 0xFF06, 00, 00 command should also be used.
Given our maximum output power (12dBm/16mW), we don’t have any problems to comply with the Spectral Power Density limit set by TELEC. See below.
Japan Regulatory Specs:
Spectrum Availability: 2,400-2,483.5MHz
Spectral Power Density Limits:
- 2400-2427 MHz and 2470.75-2483.5 <=10mW/MHz
- 2427 - 2470.75 MHz <= 3mW/MHz
BT spread BW is 70Mhz for 79 channels hopping and 18MHz for 20 channels hopping which is Nmin (minimum hop) in AFH. Therefore, worst case is set for 20 channels with a spread BW of 18Mhz, which gives an antenna power in our case of 16mW/18MHz, 0.88mW/MHz. This is less than power limit of 3mW/MHz and also satisfies the tolerance of antenna power defined by TELEC, -80% to +20%.
I ran the command VS_Set_Frequency_Mode (0xFF06) with parameters 00,00 and then checked the frequency range usage again. It still seems to be using the US range (2400-2483.5).
I'm not sure if we are missing anything here. Can you comment on this?
Also, it's my understanding that even though it may meet the PSD requirements, we still need to use the reduced hopping frequency range in order to inter-operate with BT devices in Japan.
I'll attach a picture of the Spectrum Analyzer plot that shows the usage of the US range.
As discussed in the thread above, there is no need to reduce the number of hopping frequencies for Japan to comply with regulatory purposes. Regarding interoperability, the AFH map is provided during connection so it should not be a problem. Could you provide more information on why you think it is needed?
This request originally started with me, I think, and I apologize for the confusion. LSR is supporting us and asked a question that we did not pose precisely enough.
I had asked a question about a request that a certification lab in Japan had made of us a couple of years ago for an older product of ours. The lab wanted to limit the frequencies used for hopping during a modulated constant transmit test mode to a range from 2431 - 2450 MHz.
I believe that they were running Wifi simultaneously and for whatever reason they wanted us to limit our transmissions to that range. We never really got a justification at the time for why they needed that specific range, but the radio that we were using had a diagnostic mode that let us limit hopping to an arbitrary channel set. We wanted the certification to go smoothly, so we complied and that was that.
Now that we're integrating cc256x radios into our next design, we'd like to be able to implement this feature so that we can use the same test lab as smoothly as the last product went.
We are booting the radio and executing HCI_VS_DRPb_Tester_Packet_TX_RX in its 79 frequency hopping mode for most labs that want to test modulated transmission with hopping. Since the only choices available are single channel or 79 frequencies, we wondered if there was a way to program the radio to limit its hopping specifically to 2431 - 2450 MHz.
Thank you, and again, sorry for the confusion.
And as a final follow up, we didn't realize that we could intermix standard bluetooth HCI commands with vendor-specific commands, and expect the standard ones to be honored. So, we used normal HCI commands to limit the AFH hop channel set and turn off classification before starting HCI_VS_DRPb_Tester_Packet_TX_RX in 79-frequencies hopping mode. That did the trick.
Could you clarify what commands are needed and what order to issue them in order to reduce the channel set?
Are these all the commands needed:
Those commands are used to set manual classification for the AFH Channel Map. However, it will depend on the role, Master or Slave, to decide if the Channel Map will be used. Master is the one controlling the Channel Map.
What are you trying to achieve?
We are trying to figure out how to reduce the channel set to 23 channels (0-22) for Japan to meet these requirements:
Uplink (UL) operating band BS receive UE transmit
Downlink (DL) operating band BS transmit UE receive
FUL_low – FUL_high
FDL_low – FDL_high
BT 2.1 EDR
US& Korea: 2402 MHz – 2480 MHz (ch 0-78) incls guard band
Japan: 2471 MHz – 2497 MHz (ch 0-22) incls guard band
US & Korea: 2402 MHz – 2480 MHz (ch 0-78)
Japan: 2471 MHz – 2497 MHz (ch 0-22)
Could you point me to the specific section in the ARIB STD-T66 specs that mandate this restriction please?
Still waiting on this information from the customer. I will post when I get it.
It turns out the table I provided in the earlier post is out of date. Our customer has confirmed the BT frequency band for Japan is 2400MHz – 2483.5MHz. Based on this, I don't think there is anything that needs to be changed with the CC2564. Can you verify that?
Nothing else is needed. I was surprised they were still talking about a ~10 years old legacy limitation ;)
Thanks for the information.
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