RT-BLE

This is the open source code for the paper accepted by IEEE INFOCOM 2023: RT-BLE: Real-time Multi-Connection Scheduling for Bluetooth Low Energy

This work is based on the RIOT OS and Apache NimBLE. This repository include the RIOT OS and the NimBLE is a third-party package of the RIOT. Our modified NimBLE can be find here. Each modification should have a comment starting with "RT-BLE:".

The main part of the RT-BLE is implemented as a system module name rt_ble. The code is located in sys/rt_ble, header file is located in sys/include/rt_ble.h

We use the Nordic nRF52840DK compatible boards. SEGGER RTT is recommended to be used as the standard output method. The makefile has already modified to use the RTT. We have a simple CMD line tool for RTT log reading and mass flash. The code may be ugly, but really useful. Hope it is helpful for you too :-)

Get started

1. First, you should install the required tool chains. Normally on Ubuntu, these two commands can install all the requirements.

sudo apt install build-essential
sudo apt install gcc-arm-none-eabi

2. Then pull this repository (The NimBLE can be automatically downloaded when you first time make any application). After this, enter the rt_ble_evaluation directory.
3. Each test has two folders, the one ended with _client should be burned to the Central node (Master), and the one ended with _server should be burned to the Peripheral node (Slave). For the first time, you should change the MAC address in main.c to the MAC address of your boards.
4. The following command can be used to make the application and then you can burn the binary file in ./bin/nrf52840dk/exp_<NAME>_<ROLE>.bin to your boards with official JLink tools or the cmd line tool mentioned above.

make TARGET=nrf52840dk all -j16

The included tests

Folder Name	Description
exp_rtble_*, exp_blex_*, exp_nf_*	This is the basic test to measure the delay of RT-BLE, BLEX and TL-BLE.
exp_rtble_critical_*, exp_blex_critical_*	This is the test to get the worst-case latency during requirement changes (enter or leave the critical mode)
exp_rtble_moveanchor_*, exp_blex_moveanchor_*	This is the test to get the connection reschedule time for RT-BLE and BLEX
exp_rtble_cap_*, exp_blex_cap_*	This is the test to get the system capacity of the RT-BLE and BLEX

For the TL-BLE, we should first measure the average retransmission time $n_f$. The result measured in our experiment setup is:

Packet Loss Rate (%)	$n_f$
0	1.0
10	1.1395
20	1.3239
30	1.5297
40	1.7577