Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

Sigurd — Tue, 14 Aug 2018 14:18:03 GMT

[quote userid="73265" url="~/f/nordic-q-a/19716/is-ble_gap_phy_coded-using-the-s-2-or-the-s-8-coding/143697"]When both applications are configured with BLE_GAP_PHY_CODED, the one using S140_nrf52_5.0.0-2.alpha reaches a farther point than the one using S140_nrf52_6.1.0. (S140v5 is about twice more efficient than S140v6).[/quote]

You mean that you are getting better range with the 5.0.0-2-alpha?

Please make sure that you are using nRF52840 DK version 1.0.0 (nRF52840 production silicon) when testing the S140 v6.1.0.

[quote userid="73265" url="~/f/nordic-q-a/19716/is-ble_gap_phy_coded-using-the-s-2-or-the-s-8-coding/143697"]From these results, I am wondering if S140_nrf52_6.1.0. uses the S=2 coding scheme and if so, is there a way to configure the S=8 coding scheme like in the S140_nrf52_5.0.0-2.alpha ?[/quote]

S140 V6.1 can receive both S=2 and S=8, but it will only send S=8 when configured with BLE_GAP_PHY_CODED. That means that you are already using S=8 when sending data between 2 nRF52840 devices.

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

cedric pi — Fri, 10 Aug 2018 09:52:21 GMT

Hi,

The S140_nrf52_6.1.0 release notes document says that this SoftDevice supports S=2 coding scheme since version 6.0.0. It also says that version 5.0.0-2.alpha supports S=8 coding scheme only.

I use two applications to perform some tests. The first application is using nRF5_SDK14.2.0 and the SoftDevice S140_nrf52_5.0.0-2.alpha while the second one is using nRF5_SDK15.0.0 and the SoftDevice S140_nrf52_6.1.0.

When both applications are configured with BLE_GAP_PHY_1MBPS (set using sd_ble_phy_request function, checked using BLE_GAP_EVT_PHY_UPDATE event), the disconnection appears at the same point.

When both applications are configured with BLE_GAP_PHY_CODED, the one using S140_nrf52_5.0.0-2.alpha reaches a farther point than the one using S140_nrf52_6.1.0. (S140v5 is about twice more efficient than S140v6).

From these results, I am wondering if S140_nrf52_6.1.0. uses the S=2 coding scheme and if so, is there a way to configure the S=8 coding scheme like in the S140_nrf52_5.0.0-2.alpha ?

Regards,

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

Sigurd — Fri, 25 May 2018 08:13:30 GMT

Hi,

The S140 version 6.0.0 SoftDevice does not have full support for S=2 (500 kbps). The application cannot select S=2, so all packets are transmitted using S=8 when Coded PHY is used. However, the nRF can receive both S=2 and S=8 coded packets from the peer.

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

l_kamp — Fri, 25 May 2018 08:02:16 GMT

Sorry to warm up this old topic, but is it possible now to use S=2 on an NRF52840 with SoftDevice S140? I looked at the API but can only find the BLE_GAP_PHY_CODED PHY, no way to specify S=2 or S=8.

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

Sigurd — Thu, 21 Sep 2017 13:26:41 GMT

Hi Christian,

We are still working on the implementation of S=2. It will probably be released together with the production variants of the nRF52840 in Q4 2017.

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

Christian — Thu, 21 Sep 2017 13:19:10 GMT

Hi,

Is there any update on the implementation of S=2 in the Soft Device?

Sorry if this is the wrong place to ask

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

Sigurd — Tue, 16 May 2017 12:59:22 GMT

Yes, that should be possible.

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

Luke — Fri, 12 May 2017 08:40:41 GMT

Thanks, i found the examples \peripherals\radio\receiver and transmitter, where I can do just what I want. It si possible to send and receive single packets. With the modifications: devzone.nordicsemi.com/.../ it is also possible to run the 125 kBit BLE5.0 mode

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

Sigurd — Thu, 11 May 2017 14:55:51 GMT

Note that BLE all communication is reliable, the link layer will ensure all packets are received, and in the correct order. Only a link loss will stop this. Unfortunately, there is no API to check the link quality itself. However, you can see a “pause” in the terminal printing flow when a packet must be retransmitted.

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

Luke — Wed, 10 May 2017 08:51:16 GMT

The ATT_MTU Throughput Example is very good! But is there a possiblity to see the link quality? For example it would be interesting how many packets had to be resent. Now I can only take the ellapsed time and throughput to conclude on the quality of the link

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

Luke — Wed, 10 May 2017 06:57:58 GMT

I would like to select a specific (non advertising) channel and send packets from one nRF52840-PDK to the other and counting the received packets. If the devices are connected over the GATT profiles I do not have so much control over the lower layers... Thanks I will have a look into the Throughput Example anyway

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

Sigurd — Tue, 09 May 2017 15:05:40 GMT

If you have 2 nRF52840-PDK you can use the ATT_MTU Throughput Example for that. What do you mean by "Connected mode is not the best option"? You will need to connect 2 devices(1 master/ 1 slave) to test the throughput.

Also take a look at this blog post here: devzone.nordicsemi.com/.../

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

Luke — Tue, 09 May 2017 14:55:16 GMT

Thanks for the quick answer! Is there any example code to send packets (simple rx/tx) in the 125kBit(BLE_GAP_PHY_CODED) mode? I would like to test the percentage of throughput in difficult environment. Connected mode is not the best option to test that.

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

Sigurd — Tue, 09 May 2017 12:59:23 GMT

Bluetooth 5 specifies 3 new PHYs:

S=2, S=8 and 2Mbps.

If you want high speed you need to use the 2Mbps, and you if you want the longest range(4x longer) you should use S=8(BLE_GAP_PHY_CODED). S=2 is currently not supported by the SoftDevice, but we will hopfully add support for S=2 soon.

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

Luke — Tue, 09 May 2017 12:15:31 GMT

Hey, And how do I configure the S=2 (500 kbit/s)?

RE: Is BLE_GAP_PHY_CODED using the S=2 or the S=8 coding?

Sigurd — Wed, 15 Feb 2017 11:50:43 GMT

Hi,

The BLE_GAP_PHY_CODED option enables S=8 coding (125 kbit/s), this is the option that will give you the longest range.