Need support for PAwR using ncs2.5.0

RE: Need support for PAwR using ncs2.5.0

Hung Bui — Wed, 28 Feb 2024 09:25:42 GMT

I see. As I said you don't have to stop PAwR to establish a direct connection to one of the scanner.
Please try to capture a sniffer trace. Make sure you enable security on both sides, central and peripheral.

RE: Need support for PAwR using ncs2.5.0

Hemanth B — Wed, 28 Feb 2024 09:10:18 GMT

Hi Hung Bui,

At present, I am working with one scanner if this is working fine, need to test with multiple scanners (nearly 12-15). Project is like sensing library whenever we have large amount of data that needs to transfer.

RE: Need support for PAwR using ncs2.5.0

Hung Bui — Wed, 28 Feb 2024 08:57:44 GMT

Hi Hemanth,
If you are having only one scanner, why doing PAwR ?

You will establish a connection between the two at some point, why not just make a connection with a long latency and switch to short latency when you need to transfer large amount of data.

RE: Need support for PAwR using ncs2.5.0

Hemanth B — Wed, 28 Feb 2024 08:49:25 GMT

In our setup, we operate with a single scanner. After the synchronization process with PAwR, we disconnect the connection. We only establish a connection when we have the file available for transmission. 500KB of data need to send one scanner (Central to peripheral). after the connection establishment able to transfer 500KB of data. only issue is security exchange fail.

At the moment, we don't have access to the sniffer setup. I will share the log in a while.

RE: Need support for PAwR using ncs2.5.0

Hung Bui — Wed, 28 Feb 2024 08:38:19 GMT

Hi Hemanth,

Could you give more detail on the data you need to exchange ? 500kB need to be sent from the advertiser to all the scanners or the other way around ?

Please be aware that you can establish a connection when you are doing PAwR, you don't have to stop the periodic advertising. Please refer to the blog.

Please show the full log, the log you provided has some part covered.

Also please try capture a sniffer trace.

RE: Need support for PAwR using ncs2.5.0

Hemanth B — Wed, 28 Feb 2024 07:19:22 GMT

Hi,

In our project, we need to transmit a significant amount of data, roughly around 500KB. To initiate this process, we utilize PAwR to verify the availability of the file. If the file is indeed accessible, we halt the periodic advertisement and transition to connectable advertisement mode. Although we succeed in establishing a connection, encountering failure arises during the security exchange phase.

Could you please provide assistance in troubleshooting this problem?

Security mode details Security mode1 level2.

bt_conn_set_security(conn, BT_SECURITY_L2);

Screen Shot:

Prj.conf file:

CONFIG_SERIAL=y

CONFIG_UART_ASYNC_API=y

CONFIG_BT=y

CONFIG_BT_EXT_ADV=y

CONFIG_BT_PER_ADV=y

CONFIG_BT_PERIPHERAL=y

CONFIG_BT_SMP=y

CONFIG_BT_DEVICE_NAME="BLE"

#CONFIG_BT_MAX_CONN=2

CONFIG_BT_PER_ADV_SYNC_TRANSFER_SENDER=y

CONFIG_BT_PER_ADV_RSP=y

CONFIG_BT_REMOTE_INFO=y

CONFIG_BT_SETTINGS=y

CONFIG_FLASH=y

CONFIG_FLASH_PAGE_LAYOUT=y

CONFIG_FLASH_MAP=y

CONFIG_NVS=y

CONFIG_SETTINGS=y

CONFIG_HEAP_MEM_POOL_SIZE=2048

CONFIG_DK_LIBRARY=y

CONFIG_BT_SMP_APP_PAIRING_ACCEPT=y

CONFIG_BT_SMP_ALLOW_UNAUTH_OVERWRITE=y

Regards,

Hemanth

RE: Need support for PAwR using ncs2.5.0

Hung Bui — Thu, 22 Feb 2024 12:47:37 GMT

Hi Hemanth,
PAwR doesn't have security covered. The Encrypted Advertising Data is what you need. You would need to implement it on top of the PaWR. I would suggest to take a look at the ESL (electronic shelf label) profile where PAwR and EAD is combined.
We have some example code of ESL here: https://github.com/NordicPlayground/nrf-esl-bluetooth

RE: Need support for PAwR using ncs2.5.0

Hemanth B — Thu, 22 Feb 2024 10:24:09 GMT

Hi Hung Bui,

Thank you for the update. now understand the concept, I will implement according to application need. I have one more question: is it possible to set security for PAwR? looking for Security mode1 level2.

RE: Need support for PAwR using ncs2.5.0

Hung Bui — Thu, 22 Feb 2024 08:27:18 GMT

Hi Hemanth,
The design of PaWR is that one advertiser can serve thousand of scanner simultaneously. For that there is no live tracking on of each scanner if they are active or receive the subevent advertising packet or not.

To be able to detect if a scanner is alive or not, the advertiser would need to poll them and wait for the response in the subevent response. The implementation is up to the application to choose how often the advertiser should poll and how the polling should work. You would need to decide an interval when the scanner should send a packet to the advertiser, either periodically or by a request from the advertiser.

RE: Need support for PAwR using ncs2.5.0

Hemanth B — Thu, 22 Feb 2024 06:00:02 GMT

Hi Hung Bui,

Thank you for the update. I now understand how to synchronize periodic advertisement and receive responses from the scanner. I have a question: if the scanner disconnects, how will the advertiser be informed of the sync lost?

RE: Need support for PAwR using ncs2.5.0

Hung Bui — Thu, 15 Feb 2024 14:29:57 GMT

Hi Hemanth,

It's possible to send data from the scanner/tag back to the advertiser/gateway. You would need to use a subevent response slot to send data back.
I'm not so sure calling bt_le_per_adv_set_info_transfer() from the scanner is the correct way to do. You should call the function from the advertiser instead.

Have you tried to test with our sample in the SDK, for example periodic_adv_rsp&periodic_sync_rsp and periodic_adv_conn&periodic_sync_conn.

I have made a blog here that might be useful for you: Periodic Advertising with Responses (PAwR): A practical guide

In the blog I provided an example that the tags send data about temperature value back to the gateway.