bandwidth and payload length of 52833

RE: bandwidth and payload length of 52833

user108933 — Tue, 07 Dec 2021 09:22:49 GMT

Hello Helen,

The occupied bandwidth of Coded PHY depends on the configuration of S. it could be either 2 or 8.

a. When S= 8, which is 1M PHY, where 8 symbols represent each data bit, so effective bandwidth 1M/8 = 125Kb
b. When S=2, which is 1M radio PHY, where 2 symbols represent each data bit; so effective bandwidth 1M/2 = 500Kb

You can look at this link to have details How to Achieve Ranges of over 1 Km using Bluetooth Low Energy (LE Coded PHY) - Novel Bits explanation.

Thanks.

Best Regards,

Kazi Afroza Sultana

RE: bandwidth and payload length of 52833

user7972 — Tue, 07 Dec 2021 00:46:56 GMT

Dear Kazi，

Thanks for your reply。

We understand the second question, and will you kindly answer the first question.

What is the "occupied bandwidth" of coded phy?Is it 2M?

We havn't found this in the core specification v5.3, where can we find explanation for this part?

Wish for your reply~

RE: bandwidth and payload length of 52833

user108933 — Mon, 06 Dec 2021 13:06:27 GMT

Hello Helen,

Thanks for your queries.

1. We have full support for S=8 (125K). SoftDevice does not have full support for S=2 (500 kbps). The application can not 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.

2. The maximum Payload length of coded phy is 20 bytes.

Payload (27) - L2CAP header(4) - ATT header (3) = 20

Hope it helps.

Best Regards,

Kazi Afroza Sultana