Enable or disable TWT with notification

RE: Enable or disable TWT with notification

Marte Myrvold — Fri, 23 May 2025 07:35:37 GMT

Hi,

In that case, you can use this example for audio: https://github.com/charlieshao5189/nordic_wifi_opus_audio_demo, and this example for video: https://github.com/NordicPlayground/nrf70-wifi-ble-image-transfer-demo/. You will need extra hardware for both examples, but everything is listed in the README.

Best regards,
Marte

RE: Enable or disable TWT with notification

ChengQing Zhao — Thu, 22 May 2025 14:02:27 GMT

The nRF7002 device is supposed to be the one to send.

RE: Enable or disable TWT with notification

Marte Myrvold — Thu, 22 May 2025 13:52:35 GMT

Hi,

Is the nRF7002 device supposed to be the one to send or receive this traffic?

Best regards,
Marte

RE: Enable or disable TWT with notification

ChengQing Zhao — Thu, 22 May 2025 13:41:45 GMT

As described in the docs.nordicsemi.com/.../powersave.html, "The application must choose the right duration based on the traffic pattern". Therefore, I want to test different traffic patterns(video, voice, gaming, or any other real-time/unreal-time) under TWT mode. To achieve this, I want to know how to generate those different traffic patterns.

RE: Enable or disable TWT with notification

Marte Myrvold — Wed, 21 May 2025 08:00:22 GMT

Hi,

Can you clarify what you want to achieve? Do you want the device to send or receive the traffic, and do you want the traffic to be continuous, or should the device be asleep for periods of time before waking up to either receive or transmit something?

There are some unofficial demos and samples showing image transfer and audio streaming that you can find here:

These are made by Nordic employees, but have not been thoroughly tested or qualified and should be considered provided “as-is”.

Best regards,
Marte

RE: Enable or disable TWT with notification

ChengQing Zhao — Tue, 20 May 2025 03:17:47 GMT

hello， Marte Myrvold，I want to send voice traffic, game traffic, or video traffic through TWT. Do you have any examples of this？

RE: Enable or disable TWT with notification

Marte Myrvold — Wed, 11 Dec 2024 13:05:26 GMT

Hi,

Because the device is using DTIM and not listen interval. If you want the device to use listen interval as wakeup mode you must change it by sending a wakeup mode request to the AP. You can do so like this:

struct net_if *iface = net_if_get_default();
struct wifi_ps_params params = { 0 };

params.wakeup_mode = WIFI_PS_WAKEUP_MODE_LISTEN_INTERVAL;
params.type = WIFI_PS_PARAM_WAKEUP_MODE;

if (net_mgmt(NET_REQUEST_WIFI_PS, iface, &params, sizeof(params))) {
	LOG_ERR("Setting wakeup mode failed. Reason %s",
		wifi_ps_get_config_err_code_str(params.fail_reason));
	return -1;
}

Best regards,
Marte

RE: Enable or disable TWT with notification

ChengQing Zhao — Tue, 10 Dec 2024 15:22:28 GMT

no, I am not, it is the default.

so, why capture listen interval is 0x000a (10 beacon about 1 second), but the picture 3 is 100ms

are there some misunderstandings?

the code is from:

github.com/.../main.c

RE: Enable or disable TWT with notification

Marte Myrvold — Tue, 10 Dec 2024 15:08:29 GMT

Hi,

Have you configured the device to use DTIM or listen interval as wakeup mode? You can change this by sending a wakeup mode request, as described in step 5 in Lesson 6, exercise 1 - Enabling power save modes in the Wi-Fi Fundamental course.

Best regards,
Marte

RE: Enable or disable TWT with notification

ChengQing Zhao — Tue, 10 Dec 2024 14:30:49 GMT

OK, I see. As shown in the picture 1 and 2, the listen interval is 0x000a, and the beacon interval is 100ms.

The sta will wake up 10 beacons(about 1 second ) to check if AP has data buffered for it.

but why it is 100ms in the measurement of picture 3:

picture 1:

picture 2:

picture 3:

The capture package:

devzone.nordicsemi.com/.../listen-interval-.pcapng

RE: Enable or disable TWT with notification

Marte Myrvold — Tue, 10 Dec 2024 12:29:43 GMT

Hi,

[quote user="ChengQing Zhao"]How is the peak current in the picture caused？[/quote]

It is the device waking up to see if the AP sends any DTIM beacons, indicating that the AP has data buffered for it.

Best regards,
Marte

RE: Enable or disable TWT with notification

ChengQing Zhao — Sat, 07 Dec 2024 04:52:15 GMT

OK, thank you Marte Myrvold. So, after it goes back to sleep, How is the peak current in the picture caused？

I captured the package by the Wireshark and found that there is no package about STA, just about some AP broadcast package.

As described in the official document "This means that the STA must send a PS-Poll frame for every downlink frame, which is sub-optimal with regards to efficiency and reducing overhead control signaling."https://academy.nordicsemi.com/courses/wi-fi-fundamentals/lessons/lesson-6-wifi-fundamentals/topic/power-save-modes-2/

So, I think the peak current is caused by the "ps-poll" package, but sta nrf7002dk does not send any package. that is my question.

And I want to know the the peak current include the package detail, just like the follow picture shows. can you give me some help?

RE: Enable or disable TWT with notification

Marte Myrvold — Mon, 02 Dec 2024 14:02:44 GMT

Hi,

Since the device sent a packet, it will be awake to receive any response and ACKs from the AP. When it receives a frame from the AP informing it that the AP does not have any more data buffered for the device, it will go back to sleep.

Best regards,
Marte

RE: Enable or disable TWT with notification

ChengQing Zhao — Wed, 27 Nov 2024 11:51:22 GMT

Thank you, Marte Myrvold. The last question, as you subscribe that, in legacy power save mode, after STA receives the data, the sta will be awake to send "ps-poll", as shown in the figure, so it keeps awake, does not go to sleep, still there is no data, sta then go to sleep, right?

RE: Enable or disable TWT with notification

Marte Myrvold — Wed, 27 Nov 2024 09:53:47 GMT

Hi,

[quote user="ChengQing Zhao"]So, why does the legacy power save mode consume more power than the TWT mode when sending a package?[/quote]

Because the radio is on for a longer period of time with legacy power save mode. As is explained in the Power save modes topic in DevAcademy, with legacy power save mode, the device sends a PS poll to the AP to inform the AP that it is ready to receive data. The STA will be awake until it receives a frame from the AP with the More Data subfield set to 0, indicating that the AP does not have any more buffered data to send to the STA. In your case, this interaction seems to take 100 ms.

When it comes to TWT, you have configured the TWT interval to be 100 ms and the wake interval to be 65 ms. This means that for each TWT period, which is 100 ms, the device will be awake for 65 ms and asleep for 35 ms. It does not wait to receive a frame from the AP with the More Data subfield set to 0 before going to sleep, it goes to sleep after being awake for 65 ms, as is agreed upon with the AP. If more data is buffered on the AP, this will be sent during the next wake-up instead.

The nominal current consumption for RX is 60 mA for 2.4GHz and 56 mA for 5GHz, so the extra 35 ms that the device is awake for with legacy power save will greatly impact the average current consumption.

The best improvement of TWT is that the device can be asleep for a longer period of time than with legacy power save mode, so comparing the current consumption under the same conditions does not really show the advantages of using TWT. However, for a fairer comparison, I would recommend reducing the TWT wake interval when having such a short TWT interval, as 65 ms wake interval is rather long when the total TWT interval is 100 ms. You can change this by changing the TWT_WAKE_INTERVAL_MS or directly changing params.setup.twt_wake_interval in wifi_set_twt() instead.

I also recommend checking out the Online Power Profiler for Wi-Fi. Here, you can set the power save mode and other configurations and easily see how legacy power save mode (DTIM) compares with TWT when using different settings.

Best regards,
Marte

RE: Enable or disable TWT with notification

ChengQing Zhao — Tue, 26 Nov 2024 14:29:33 GMT

I want to compare the power consumption of TWT and legacy power save mode under the same conditions, as the legacy power save mode is 100 ms.

As you said, the legacy power save mode is 1.78mA, and TWT is 40.95mA, as shown in picture 1 and picture 2.

But when I send a package the legacy power save mode consumes more power than TWT.

as shown in picture 3 and picture 4. TWT average is 44.35mA, and the legacy power save mode is 58.31mA in 100ms.

So, why does the legacy power save mode consume more power than the TWT mode when sending a package?

picture 1 (the legacy power mode ):

picture 2 (TWT mode ):

picture 3 (the legacy power mode with send a package):

picture 4 (the TWT mode with send a package):

The code is from lesson 6/wifi fund_1ess6uexer2, and put the button 2 to send a "hello"

package. the high peak power in Figure 3 and Figure 4 is caused by the package. the code change is as:

static void button_handler(uint32_t button_state, uint32_t has_changed)
{
	uint32_t button = button_state & has_changed;

	/* STEP 5.1 - Call wifi_set_twt() to enable or disable TWT when button 1 is pressed. */
	if (button & DK_BTN1_MSK) {
		wifi_set_twt();
	}

	/* STEP 5.2 - Enable or disable sending packets during TWT awake when button 2 is pressed.
	 */
	if (button & DK_BTN2_MSK) {
		send_packet();
	}
}

RE: Enable or disable TWT with notification

Marte Myrvold — Tue, 26 Nov 2024 13:45:12 GMT

Hi,

Why are you setting the TWT interval to 100 ms? With your current configurations, the device will only be asleep for 35 ms for each TWT service period since the wake interval is 65 ms and the TWT interval (wake + sleep) is 100 ms. This will result in a higher current consumption than when using legacy power save mode. Can you try increasing the TWT interval to see if you get the same behavior?

Best regards,
Marte

RE: Enable or disable TWT with notification

ChengQing Zhao — Mon, 25 Nov 2024 12:16:10 GMT

Oh, i am so sorry that i modify the twt interval 100ms.

The nRF Connect SDK is v2.7.0.

devzone.nordicsemi.com/.../nordic-TWT.pcapng

RE: Enable or disable TWT with notification

Marte Myrvold — Mon, 25 Nov 2024 10:08:59 GMT

Hi,

Can you share the sniffer log as a pcap file?

It seems like TWT is not set up correctly based on this log:

[00:01:15.231,933] <inf> Lesson6_Exercise2: TWT interval: 0 s (100000 us)

For some reason, TWT is set up with a TWT interval of 0.1 seconds, which could explain the high current consumption. If you have not made any changes to the code, then the interval should be 7 seconds.

Also, which version of the nRF Connect SDK are you using?

Best regards,
Marte

RE: Enable or disable TWT with notification

ChengQing Zhao — Sat, 23 Nov 2024 16:53:51 GMT

I captured the package by wireshark, the track is shown in figure below, I tried to analyze the reason for the peak.

I think the peak is caused by the "QoS null function" package.

do you think it is reasonable or not?

RE: Enable or disable TWT with notification

ChengQing Zhao — Thu, 21 Nov 2024 15:27:20 GMT

The log is:

> wifi_cred auto_connect
wifi_cred auto_connect
[00:00:36.831,787] <inf> wifi_mgmt_ext: Connection requested
[00:00:41.863,525] <inf> Lesson6_Exercise2: Network connected
[00:00:41.864,288] <inf> Lesson6_Exercise2: Connected to server
[00:00:41.864,288] <inf> Lesson6_Exercise2: Press button 1 on your DK to enable or disable TWT
[00:00:41.865,753] <inf> Lesson6_Exercise2: Successfully sent message: Hello from nRF70 Series! 0
[00:00:42.865,936] <inf> Lesson6_Exercise2: Data received from the server: (Hello from nRF70 Series! 0)
[00:01:15.183,654] <inf> Lesson6_Exercise2: -------------------------------
[00:01:15.183,685] <inf> Lesson6_Exercise2: TWT operation TWT setup requested
[00:01:15.183,715] <inf> Lesson6_Exercise2: -------------------------------
[00:01:15.231,750] <inf> Lesson6_Exercise2: TWT response: TWT accept
[00:01:15.231,781] <inf> Lesson6_Exercise2: == TWT negotiated parameters ==
[00:01:15.231,781] <inf> Lesson6_Exercise2: TWT Dialog token: 1
[00:01:15.231,781] <inf> Lesson6_Exercise2: TWT flow ID: 1
[00:01:15.231,811] <inf> Lesson6_Exercise2: TWT negotiation type: TWT individual negotiation
[00:01:15.231,842] <inf> Lesson6_Exercise2: TWT responder: true
[00:01:15.231,872] <inf> Lesson6_Exercise2: TWT implicit: true
[00:01:15.231,903] <inf> Lesson6_Exercise2: TWT announce: false
[00:01:15.231,903] <inf> Lesson6_Exercise2: TWT trigger: false
[00:01:15.231,933] <inf> Lesson6_Exercise2: TWT wake interval: 65 ms (65024 us)
[00:01:15.231,933] <inf> Lesson6_Exercise2: TWT interval: 0 s (100000 us)
[00:01:15.231,933] <inf> Lesson6_Exercise2: ===============================
[00:01:15.232,574] <inf> Lesson6_Exercise2: TWT sleep state: sleeping
[00:01:15.333,343] <inf> Lesson6_Exercise2: TWT sleep state: awake

I do not change the code from the Lesson 6/wifi fund_1ess6uexer2:https://github.com/NordicDeveloperAcademy/wifi-fund/blob/main/lesson6/wififund_less6_exer2_solution/src/main.c

Is it due to a negotiation process in TWT, but why does it appear so regularly？

RE: Enable or disable TWT with notification

Marte Myrvold — Thu, 21 Nov 2024 14:56:31 GMT

Hi,

Can you share what you are setting the TWT parameters to in your code, and share the application log from the device?

Best regards,
Marte

RE: Enable or disable TWT with notification

ChengQing Zhao — Wed, 20 Nov 2024 13:55:21 GMT

Thank you, Marte Myrvold. Your guidance is detailed and easy to understand.

I still have questions, as shown in the picture, TWT mode and DTIM mode. How is the peak in the image caused in TWT mode?

RE: Enable or disable TWT with notification

Marte Myrvold — Tue, 19 Nov 2024 12:08:50 GMT

Hi,

This is due to how the exercise is implemented in such a way that it only sends a message during the awake state when TWT is enabled:

static void twt_mgmt_event_handler(struct net_mgmt_event_callback *cb, uint32_t mgmt_event,
				   struct net_if *iface)
{
	switch (mgmt_event) {
	/* STEP 3.2.1 - Upon a TWT event, call handle_wifi_twt_event() to handle the response */
	case NET_EVENT_WIFI_TWT:
		handle_wifi_twt_event(cb);
		break;
	/* STEP 3.2.2 -	Upon TWT sleep state event, inform the user of the current sleep state.
	 * When the device is in the awake state, send a packet to the server and check for any
	 * received packets if sending packets is enabled. */
	case NET_EVENT_WIFI_TWT_SLEEP_STATE:
		int *twt_state;
		twt_state = (int *)(cb->info);
		LOG_INF("TWT sleep state: %s", *twt_state ? "awake" : "sleeping");
		if ((*twt_state == WIFI_TWT_STATE_AWAKE) & sending_packets_enabled) {
			send_packet();
			receive_packet();
		}
		break;
	}
}

If you want to be able to send packets when TWT is not enabled, you can call the function to send the packet directly in the button_handler() or schedule that it should be called. This code snippet shows how to call it directly in the button_handler():

static void button_handler(uint32_t button_state, uint32_t has_changed)
{
	uint32_t button = button_state & has_changed;

	/* STEP 5.1 - Call wifi_set_twt() to enable or disable TWT when button 1 is pressed. */
	if (button & DK_BTN1_MSK) {
		wifi_set_twt();
	}

	/* STEP 5.2 - Enable or disable sending packets during TWT awake when button 2 is pressed.
	 */
	if (button & DK_BTN2_MSK) {
		send_packet();
	}
}

If you want to schedule it, you can take a look at the TWT example here: https://github.com/martelmy/NCS_examples/blob/main/wifi/twt_provisioning_demo. In this example, pressing button 2 will schedule a ping that will either be sent immediately when TWT is not enabled or during the next wakeup when TWT is enabled. You can use work queue to schedule the UDP packet in the DevAcademy exercise in a similar way.
Please note that this example is not official and should be considered provided “as-is”.

Best regards,
Marte

RE: Enable or disable TWT with notification

ChengQing Zhao — Mon, 18 Nov 2024 18:14:24 GMT