ble_app_uart is too slow for IOS,how to fix it?

[qoboty]

I use ble_app_uart of IOS,but the Tx speed is about 200B/s(send 20B for 100ms), why ? how to speed up to 20KB/s ? Thank you!

[FormerMember]

The connection interval range is defined in the Bluetooth Core Specification 4.2, vol 3, part C, chapter 12.3: 7.5 ms to 4s.