Question about ESL

RE: Question about ESL

Hieu — Wed, 01 Nov 2023 13:42:28 GMT

Thanks a lot for correcting me and further detailed answer, Lorenzo Amicucci .

RE: Question about ESL

Victor A — Mon, 30 Oct 2023 11:25:53 GMT

Thank you so much for your answer

RE: Question about ESL

Lorenzo Amicucci — Mon, 30 Oct 2023 11:19:56 GMT

ESL Payload in the response package is always from one single ESL. Each ESL can reply (on a specific response slot) with one or more TLVs.
So, what happens if you have multiple ESL devices in the same group, and they have received a command for which they need to reply to?
Each ESL needs to understand which response slot is assigned to it. This is regulated in "5.3.1.4.2 Allocation of response slots to ESLs" in ESL profile. Then it will prepare the ESL Payload (it can have one or more TLV from the same ESL), encrypt it with its own response key, and then send it to the AP in the right response slot.
Basically, each ESL responds independently from the others. ESL profile/service make sure responses do not overlap.

RE: Question about ESL

Lorenzo Amicucci — Mon, 30 Oct 2023 11:11:58 GMT

About your point 3:
Group_ID is included in the ESL payload when AP sends data.

Section 5.3.1.3 in ESL Profile: "A synchronization packet in which the Group_ID field has the value N shall be transmitted in a Periodic Advertising with Responses subevent with the subevent number N; therefore, the Group_ID maps to a specific Periodic Advertising with Responses subevent."

RE: Question about ESL

Victor A — Thu, 26 Oct 2023 01:40:14 GMT

I also want to ask you a question, that is, how the PAwR's response package is sent to the AP when there are multiple devices.

The following figure shows the format of the response packet, for example, a TLV represents an ESL device. The response is transmitted from ESL0 to ESL1, and then transmitted to ESL2 for merging and encrypting the response packets, and then sent to the AP, or the AP directly receives the response packets of the three ESL012 devices, and then merges and encrypts them?

and If ESL1 does not receive a subevent, or the ESL1 response packet is not received by the AP, what will be the response packet TLV1 content received by the AP

RE: Question about ESL

Victor A — Thu, 26 Oct 2023 01:21:32 GMT

No, it's just that I found out that all of the subevents written in the ESL Profile spec. or other documents were sent in order, so I have questions about this

RE: Question about ESL

Hieu — Wed, 25 Oct 2023 13:29:16 GMT

I don't find any requirements about GroupID order in the ESL Profile spec. I also don't think it's reasonable that the PAwR packets must address groups in order. After all, there will be scenarios where some tags need to be updated more often than others.

I have asked internally to be sure.

Do you have any scenario in mind that raises this question?

RE: Question about ESL

Victor A — Wed, 25 Oct 2023 01:22:18 GMT

Thank you very much for your answer.I will be looking forward to your reply.

RE: Question about ESL

Hieu — Tue, 24 Oct 2023 19:25:45 GMT

Hi Victor,

[quote user=""]1.The AP device will synchronize many ESL device or connect them. My question is can the AP device connect any ESL and broadcast any PAwR packet and receive the PAwR response packet at the same time?[/quote]

Yes. The AP device can keep an ACL connection with an ESL tag while maintaining PAwR traffic with other tags.

[quote user=""]2.Is the AP need to connect to every ESL in every period?[/quote]

No, it does not need to connect to every ESL in every period.

[quote user=""]3.Is the Gourp ID must be broadcast in order(like 1->2->3->4) or it can be customized(like 1->2->4->1).[/quote]

I will have to look up on this. I will get back to you with an answer within one or two days.

Hieu