What will the range be with a ble 5 server, but iphone with Bluetooth 4

[Renix]

If I used a nrf52840 bluetooth5 as a server, but customers have iPhones with Bluetooth 4.x on, will the range still be 2x or 4x, as stated by BT SIG?

Did Nordic test the range with Bluetooth 4.x phone?

I do not have a nrf52840 board yet.

I currently have 132 10040 nrf5283 device on my board, but the distance / range is not enough for the application. So I thought perhaps BLE5 will do the trick?

Any advise appreciated

[endnode]

Yes, if you are at the edge of Rx sensitivity (= "weak signal") then some packets get lost and because BLE has 100% link layer reliability these packets will be re-transmitted until they go through or link is terminated. Now termination can be caused by two factors: either higer-level application will ask for it because it stops getting data and decides that link is lost or by relying on Link Layer low-level time-out which has value typically agreed during connection (aka "Supervision Timeout"). Note that Supervision Timeout used by phones is very much device type/vendor specific a vary widely (Android devices using values from 1 to 20s) but iPhones specifically are using very short value of 0.5~1s. So if you would be on Android you might get less terminations of the link because of temporarily week signal (but long retry cycles) while with iOS devices you might be out of luck.

[endnode]

(all that assuming that it's not your mobile app who kills the connection because it's impatient and few lost packets scare it too much...)

[RK]

If you're fighting range issues consider equipping the non-mobile piece with a proper antenna. The original nordic nrf51 dev boards used to ship with a small whip antenna and the range extension you get with that was dramatic. Doesn't help if both bits need to be mobile of course.