About implementing ble and wifi coexistence on nRF7002 dk

[selfcontrol]

Hello,

I am inquiring about the development guide for the coexistence of BLE and WiFi using the nrf7002dk board. Since I have recently transitioned from the nRF5_SDK development environment to the Nordic Connect SDK, I am still getting accustomed to it, so please understand my beginner-level questions.

Board used: nRF7002dk Toolchain used: v2.6.1 SDK used: v2.6.99-cs2

The requirements are as follows: The nRF7002dk is connected to a WiFi router, It acts as a BLE Central, and when connected to a peripheral using coded PHY, The BLE UART data received from the peripheral should be sent to a server via a WiFi TCP packet.

1. What does the BLE+WiFi coexistence example from Nordic do?
2. Is it possible to connect to WiFi simultaneously while BLE is connected?
3. Can coded PHY be applied to BLE in BLE+WiFi coexistence?
4. How should I start with the BLE+WiFi coexistence example?
5. Is it feasible to implement the requirements mentioned above?
6. When using BLE and WiFi simultaneously, what are the flash and RAM sizes of the stack?

Kind regards.

[Priyanka]

Hi,

Please take a look at the WiFi Fundamentals course in the DevAcademy. Hope this helps resolve your doubts: 

https://academy.nordicsemi.com/courses/wi-fi-fundamentals/ 

Regards,

Priyanka

[selfcontrol]

Hi Priyanka,

Thank you for your response. I am studying the academic course you suggested.

Additionally, many of my questions have been resolved through the Wi-Fi: Bluetooth LE coexistence example below.
Wi-Fi: Bluetooth LE coexistence Example

However, I need to scan BLE peripherals using Coded PHY.
Does the information mentioned in the link imply that Wi-Fi coexistence is possible by using only Coded PHY without employing FEM? Or is this a different usage scenario?
Coexistence of short-range radio and other radios_Supported implementations

If it is not an issue, which parts should be modified in the ble_coex example to scan peripherals using Coded PHY on the nRF7002dk as a BLE Central?

-----------------------------------------------------------------

I successfully modified the example's peripheral.
For the central, I referred to bluetooth/central_hr_coded and BLE throughput (Central) but it didn't work well.
Here's what I tried,

[prj.conf] - Additional settings
CONFIG_BT_CTLR_PHY_CODED=y
CONFIG_BT_EXT_ADV=y
CONFIG_BT_USER_PHY_UPDATE=y

[bt_throughput_test.c] - Changes
scan_init() {
struct bt_le_scan_param scan_param = {
.type = BT_LE_SCAN_TYPE_ACTIVE,
.interval = BT_GAP_SCAN_FAST_INTERVAL,
.options = BT_LE_SCAN_OPT_CODED | BT_LE_SCAN_OPT_NO_1M,
.window = BT_GAP_SCAN_FAST_WINDOW,
};

err = bt_scan_filter_add(BT_SCAN_FILTER_TYPE_NAME, Peripheral_Name);
}
I made these changes, but,

<wrn> bt_hci_core: opcode 0x2041 status 0x01
Starting scanning failed (err -5)

I encountered this error.
------------------------------------------------------------------

Thanks & Regards,
Jeon.

[Priyanka]

Hi,
Please take a look at this ticket, where the similar error is discussed about.

selfcontrol said:

Wi-Fi coexistence is possible by using only Coded PHY without employing FEM

I am not quite sure about this and will check this internally with experts.

-Priyanka

[selfcontrol]

Hi, priyanka

First, I had already applied the solution from your ticket answer and was still getting the error.

The solution is to write it not only in prj.conf but also in child_image/hci_ipc.conf within the ble_coex source folder. This fixed the issue with applying coded PHY scan, so I'm sharing this information.

----------------------------------

Now, the question of whether this can be applied to the WIFI solution is out of my domain, and I would appreciate a response on this.

1. when you say FEM, do you mean to activate the frontend module like the link below?

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/glossary.html#term-Front-End-Module-FEM

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/device_guides/fem/index.html

2. what is the specific reason in the documentation why CODED+FEM and WIFI should not be enabled simultaneously?
- I need a detailed reason, not just a conclusion.

3. as a conclusion, is it okay to have only coded+wifi communicating simultaneously?
(When it says Wi-Fi, do you mean both 2.4Ghz and 5Ghz?)

Priyanka said:

I am not quite sure about this and will check this internally with experts.

Thank you so much I will wait for your response!

BR
Jeon.

[Priyanka]

Hi Jeon,

Before checking with the internal team, let's clarify a few things.

So you want to integrate BLE-coded PHY and wifi inside an application. Is this true? If so, then I guess it's possible you don't need to consider FEM here.

But do you want to integrate all of this? That is, BLE-coded PHY + FEM + WiFi. Then that should also be possible. Or are you asking me whether you need to consider FEM for integrating BLE-coded phy+wifi? If so, FEM is not required.

I recommend taking a look at the sample central heart rate monitor with coded phy and following the coexistence of short-range guides for editing the sample.

Regards,

Priyanka

[selfcontrol]

Hi again priyanka,

Priyanka said:

you want to integrate BLE-coded PHY and wifi inside an application. Is this true?

We are integrating BLE-coded PHY and WiFi within an application without considering FEM.

As you mentioned, we have already referred to the sample and guide, and through this, we have implemented [coded PHY] scanning while WiFi is connected.

Although the functionality is implemented, the question is, [Is it okay to perform coded PHY scanning while WiFi is connected?]

I need this operation, but I am confused about whether the content mentioned in the #supported-implementations section of the documentation affects me.

BR
Jeon.

[Priyanka]

Hi Jeon,

You should be able to perform WiFi coexistence as seen in the sample here: https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/samples/wifi/ble_coex/README.html 

Technically, you cannot have two transmitters at the same time as they might interfere with each other, but yes, it should be possible to perform coexistence.

-Priyanka

[selfcontrol]

Hi again priyanka,

Priyanka said:

You should be able to perform WiFi coexistence as seen in the sample here: https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/samples/wifi/ble_coex/README.html

Is it ok to apply Coded phy in Scan and Advertising for connecting BLE in Central and Peripheral in that sample?

If not, please let me know what difference there should be between applying Coded phy and 1M phy.

Thank you.

BR
Jeon.

[Priyanka]

Hi Jeon,

Yes, it is possible to apply Coded PHY in Scan and Advertising for connecting BLE in Central and Peripheral. But please do keep the following in mind:

Please take a look at this discussion in this ticket where a colleague of mine mentions that for the same amount of data CODED PHY will use 8 times more time to transmit.

Please also refer this ticket for details regarding the scanning window.

Also, for advertising, the .connect_if_match=1 option does not work when using coded PHY as the scanning module will try to initiate the connection with the 1M PHY .

Please also refer to this blogpost which describes further details.

-Priyanka

[selfcontrol]

Hi priyanka,

I'm not sure if my question was clearly conveyed in your response.
I apologize, but could you please clarify once more?

I am not simply asking if BLE can be changed to use Coded PHY. I am asking if there are any coexistence issues when applying Coded PHY to a BLE connection in an environment where both WiFi and BLE are used together, like in the ble_coex example, which uses BLE alongside WiFi. Clarifying this point is crucial for me.

Thank you.

BR
Jeon.

[Priyanka]

Hi Jeon,

A long as the hardware supports both, I don't see any issue in enabling both Wi-Fi and BLE coded PHY.

-Priyanka