Time sychronization in BLE communication

[Ziyao Zhou]

Hi

I am developing some nodes that all using BLE in nordic chip, I want each node get some data at the same time and send to one central device, the central device can fuse the same time data together and send to a computer to do some process. I am not sure about the sychronization, the timeliness of data is important, could you give me some advice? I can only think about the time stamp.

[Hieu]

Hello Ziyao,

This highly depends on the data rate and number of nodes, requirement for latency and packet losses.
Below I list a few potential technologies and some relevant overviews. You can use this as a starting point and look further into each technology to see which suits your need best.

• Periodic Advertising with Response
  • Precise/strict packet timing, no timestamp needed, as data can only be transferred in specific timeslot.
  • Packet losses possible.
  • Limited throughput.
  • Reference time synchronization might not be necessary, but also possible thanks to strict packet schedule.
• BLE Connection
  • No timing guaranteed at application layer, timestamp needed.
  • Packet losses not possible, the connection itself is terminated in case of loss.
  • High throughput. 
  • Reference time synchronization might be a challenge. Refer: BLE Time Synchronization between devices
• Bluetooth Mesh with Time Models
  • No timing guaranteed at application layer, timestamp needed.
  • Packet losses possible.
  • Limited throughput.
  • Time Models provide a mean for reference time synchronization.

Hieu

[Ziyao Zhou]

Thank you so much for your reply!