• State Verified Answer
  • Locked Locked
  • Replies 20 replies
  • Subscribers 69 subscribers
  • Views 3347 views
  • Users 0 members are here
Attachments (0)
Nordic Case Info
  • Case ID: 284319
Options
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

BLE Throughput

kai19960504

Hi All,

As far as I know , BLE Thrughput is basically set around a few parameters => 1. NRF_SDH_BLE_GAP_DATA_LENGTH

                                                                                                                            2. NRF_SDH_BLE_GATT_MAX_MTU_SIZE

                                                                                                                            3. NRF_SDH_BLE_GAP_EVENT_LENGTH

My question is => Does the value of NRF_SDH_BLE_GAP_EVENT_LENGTH represent the packets that can be sent in each connection interval?

According to this table : 

If the event length equal 7.5ms,does it mean that it can transmit 6 packets?

Best regards,

Kai

Parents
  • 0

    Hi,

    The event length is a Bluetooth concept. A connection event occurs every connection interval, and the duration of it is defined by the event length. During the event length, packets can be exchanged. If the event length is as long as the connection interval, packets can be exchanged more or less continuously. This maximises throughput.

    If the event length equal 7.5ms,does it mean that it can transmit 6 packets?

    Yes and no. If you cant fit 6 packets, then yes. If you can fit more, then you can send more. There is no defined maximum. Note that the documentation you refer to is for an old SoftDevice. More recent SoftDevice versions does not have this bandwidth configuration, but instead just allows you to configure the event length, using NRF_SDH_BLE_GAP_EVENT_LENGTH  as you have found.

  • 0 in reply to Einar Thorsrud

    Hi Einar,

    Here is my sdk_config.h setting

    Now NRF_SDH_BLE_GAP_EVENT_LENGTH  is 6,so my packet will transfer total 6ms?

  • 0 in reply to kai19960504

    It means that you have 6 ms that you can spend to transfer packets, but there is no need to spend the entire 6 ms (though that is not a very long time). You can also send several short packets or a single long. Here you don't use data length extension, so you can send several short packets. This is handled by the Bluetooth stack though, so you cannot do anything other than to try to send as much data a possible so that the stack always has more data to send.

  • 0 in reply to Einar Thorsrud

    Could you please provide the latest S132 SPEC?

    Else question is 1 packet have 20byte,how long will that packet take?

  • 0 in reply to kai19960504
    kai19960504 said:

    Could you please provide the latest S132 SPEC?

    https://infocenter.nordicsemi.com/topic/struct_nrf52/struct/s132.html

    kai19960504 said:
    Else question is 1 packet have 20byte,how long will that packet take?

    Which exact time are you after here? If this is 20 payload bytes, you would see about 272 us on air. The SIG has a page which may be interesting for you: How Fast Can It Be?

Reply Children
Related