nRF52840 maximum data throughput

[DJ]

How many nRF52840 chips can be used simultaneously? Can all data and advertisement channels be used at maximum capacity (2Mbps/each) to result in an overall throughput of 2Mbps*N where N is the number of nRF52840 chips < # of channels available?

Thanks

[DJ]

I have worked with nRF51822 and nRF24L01+ in the past and have written proprietary protocols to get 2 Mbps. With BLE 5.0, if running several chips chips on both sides and parallelize the stream, what is the "available bandwidth in the radio"? There are 37 data channels and 3 advertisement channels in the new BLE stack, but with hopping, it is unclear to me how many independent channels you can fit there.

[endnode]

OK, so you would like to use BLE. The channel hopping in BLE is exactly for the purpose of minimizing collisions but because BLE is very much time-dependent and these separate devices (running separate BLE stacks) would need to be in microsecond sync to be able to prevent these and have 100% of theoretical bandwidth. There is one way how to bypass the hopping and that's channel map which can be set for each device and you can limit the band down to single channel. Of course you will destroy original properties limiting collisions but if you are able to coordinate this mapping and at the same time ensure that none of assigned channels is noisy it could work. So theoretically you could get 37*1.36Mbps if you team 37 devices on each side and perfectly distribute available bandwidth...

[Roger Clark]

@endnote

Thanks. Thats higher than I thought it was. But its still not 2Mbps ;-)

[endnode]

Well if you team the devices then you should be able to get there. I'm really impressed by BT5.0 demo by Nordic but I'm struggling to decode if this is throughput on APP layer (on top of GATT) or on link layer. Should not do big difference with all the extensions (where PDU and ATT_MTU sizes are much larger then overhead) but still. I will make separate question.

[Roger Clark]

The speed is impressive, but I'm not sure whether it would be worth running multiple devices at full speed to get what you can easily get over a WiFi link.

I know that Wifi devices can take a lot of current, but I wonder if its really that much more than multple nR52's running at max speed, vs some power optimised Wifi device

And the hardware and software effort required to build a system using nRF52's, may make it uneconomic. Plus the risk of attempting to build a system with multiple devices all transmitting and receiving in very close proximity to each other could easily cause problems

Personally, not a road I would go down, unless someone was willing to pay for all the R&D knowing that the project had significant risk factors (IMHO)