nRF5340 audio CIS versus BIS maxium distance

[TueTD]

Hi team,

I setup two nrf5340 Audio DK boards in BIS mode, CIS mode (walkie talkie) and measured the longest distance the boards could synchronize the audio. After several testing times, CIS (walkie talkie) is always longer than BIS mode. 

 + BIS: around 60m.

 + CIS(Walkie Talkie): around 110m. 

I also have 2 custom board using nrf5340 chipset and i archived the same result with the same test. So my questions are:

1. Is there a difference  in BIS mode and CIS mode range?

2. Can you show me nrf5340 Audio DK's distance test results, or something similar with my test? 

I am using NCS V2.2.0 and I don't change any config related to TX_POWER.

[JONATHAN LL]

Hi,

Amanda is currently on vacation so I am taking over the case for now. 

Seems like we don't have any number so share right now, is this a urgent matter for you?

And is it a requirement that CIS and BIS has the same range? What is the criteria or use case here that needs to be achieved or is it mostly curiosity? 

Regards,
Jonathan

[TueTD]

Hi Jonathan,

In my application, I have at least 4 headsets device, 2 gateways device and a large area of device placement so BIS is a feasible choice . Therefore, I want to achieve the range as long as possible.

Both mode aren't required to have to same range. I am curious about this range difference due to the test.

The current BIS range doesn't meet my requirement so I want to achieve longer range with the BIS:

+ In firmware, because CIS has longer range so I wonder is there anything I can do to increase BIS sync range.

+ In hardware, I have to add the radio LNA/PA . 

[JONATHAN LL]

Thanks for the explanation and context. 

Currently we cant provide any good explanation and for the difference in range for CIS and BIS. 

We have entered the summer holiday season for Norway so staffing is low and tings might take some more time. 

Depending on the final design of the product a FEM/amplifier could be the way to go for you to get the desired range that you want. But cant confirm if this is needed since i cant provide any range test results as of now. 

Do you wish to achieve around 100m for BIS mode also`?

Regards,
Jonathan

[TueTD]

JONATHAN LL said:

Do you wish to achieve around 100m for BIS mode also`?

yes, I totally desire that. 

I am looking forward some numbers from you to reference even though changing in the hardware design must be taken into account to get further range in final design.