Question regarding the transfer speed of the BLE on nrf52832 using nordic uart service

[Rajat]

Hi Everyone

I have been trying to send a text file(reading from SD card) , The size of the file is 2MB. 
I am using softdevice s132 for nrf52832 to transfer the text file via the Bluetooth to the Android application(nrf Connect). 
I am able to transmit the file to the nrf connect app , but the problem is that the transfer is too slow , it gives me an average speed of around 20KBPS , which is very less for our application.

What  i would like to know is 
1. Is there any specification of the softdevice which i should enable to receive the maximum throughput(or atleast 3/4th of it). 
2. Is it related to the service that i am using , I am using Nordic Uart Service. 

Here are the settings that i have been using
PHY - LE 1M for both Tx and Rx
Here is a log file , i am attaching , if that helps.

5001.Log 2020-10-07 12_34_02.txt

[Turbo J]

Your 20KB/sec actually sound quite good. I am getting only roughly 4.5 KB/sec on older (Bluetooth 4.0) android devices that don't properly support changing ATT MTU.

You can request a "high priority" connection (= low connection latency) on android via

BluetoothGatt.requestConnectionPriority (BluetoothGatt.CONNECTION_PRIORITY_HIGH);

but at 20KB/sec you probably did that already.