SBLE-iOS data collection project info

Why are we conducting this study?

We are doing research on technology that can facilitate use of public transit. In particular, we are developing a be-in-be-out (BIBO) system – a system that automatically detects whether a passenger entered a bus vehicle. Using BIBO, for example, one could be charged the correct fee, without having to purchase a ticket, tap a card, or enter data on a phone. BIBO can also be used to measure the occupancy of a bus vehicle at each time, which can be useful information for transit agencies and passengers alike.

Our BIBO system uses Bluetooth Low Energy (BLE) beacons. These are tiny devices that send a characteristic radio signal. We installed two BLE beacons in each campus shuttle bus. By receiving a signal from these beacons, the SBLE-iOS app in your iPhone can figure out that you enter the vehicle, and even detect your location in the vehicle (front, center, back).

BIBO with BLE beacons is a promising technology, but it has never been tested on a large scale. This is why we are conducting this study. The data from the BLE beacons recorded by your iPhone will be sent, along with other data, to a remote computer server. We are hoping to collect a large amount of data from many participants and in many different situations. This data will help us design more accurate, precise, and robust BIBO algorithms. Your participation in this study is crucial for this research!

What data will we collect?

After you start the app, your iPhone will "listen" for any BLE beacons installed on the campus shuttles. If it detects a signal from one or more beacons, it will transmit this data via the Internet to a remote computer server. Along with the beacon signal, your iPhone will transmit your location information (from GPS) and data from the inertial sensors of your iPhone. This data can be useful for a BIBO system to understand whether the user is actually on a moving vehicle or not.

Important things to know:

  • The BLSE-iOS app does not collect any data if the app has not been started.
  • The BLSE-iOS app only transmits information while it senses a signal from a campus shuttle BLE beacon. It does not transmit any data when it receives no signal from a BLE beacon. Unless you are on a campus shuttle bus, or in close vicinity to it, no data is transmitted.
  • The BLSE-iOS app is designed to only listen to the BLE beacons installed in the UCSC campus shuttles. Signals from other BLE beacons are neglected.

Is my data secure?

Yes! We use HTTPS (Hypertext Transfer Protocol Secure), a secure communication protocol that encrypts the connection between the mobile app on your iPhone and the remote computer when sending data. The remote computer server is password protected. Only the study investigators can access this computer.

Will you share my data, and why?

Sharing data is critical for research. We want other researchers to use this data to develop even better BIBO algorithms. We will share deauthenticated  data with other researchers. This means that the data that we will share will have no trace of your identity. Nobody will be able to figure out the identity of any of the participants in the study from the data that we will share.

What about the $150 monthly raffle?

The SBLE-iOS app will show you a leaderboard with the top power users for the month (more information here). At the end of each month, we will randomly choose one participant from the top 5 in the leaderboard. This participant will receive a $150 gift card. (Note: the raffle will be held each month from May to September of 2023.)

Where can I find more information?

Here is a video tutorial for how to use the SBLE-iOS app. If you have more questions, please contact the project leader, Professor Roberto Manduchi, at

Who wrote the app?

All credit goes to Jonathan Lam, UCSC alumnus and master software engineer.

Who is funding this research?

This research is supported by the National Science Foundation (grant No. CNS-2125279).