• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 50 subscribers
  • Views 409 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Max Simultaneous Advertisers and Scanners

Paulina Wegrowicz
Prodigy 50 points

We have a very large network with 100s of nodes in range which need to exchange a very small amount of data every 10s. We are comparing an established Zigbee mesh approach to one using Low Energy Bluetooth in advertising and scanning modes only.  What is the maximum number of simultaneous advertisers and scanners possible within such a network? 

  • 0
    TI__Genius 17975 points

    BLE is not great for mesh networks, but it could work for your application since the data is only sent every 10s. There are three advertising channels in BLE, and each advertising event takes a very short amount of time (~1ms or less) on a single channel.

    I would recommend doing this:

    Have advertising off by default. Every 10s when there is data to send, put the data in the advertisement and begin advertising with a fast advertisement interval (e.g. 20ms). After a few advertising events (maybe after 100ms) disabled advertising. Repeat this every 10s. The reason for allowing multiple advertising events is so that in case there was some overlap in which more than one device is advertising on the same channel at the same time, the packet will be repeated a few times.

  • 0 in reply to Willis1
    Prodigy 50 points

    My concern would be that if I have hundreds, say 500, such devices in range and they all send data via advertisement 5 times over 100ms every 10s then a receipient device in scan mode will receive 2500 such advertisements to process each 10 seconds with each sender randomly spread over 10s time. Can the BLE stack and processor keep up with that amount and rate of data, such that no readings would be lost? This amounts to 1 received advertisement every 4ms to process, and possible twice that depending on the degree of randomness. Seems a tall order. How fast can we recieve and process an advertisment on the 2540? What is the possible stack size?