Is there any Firmware Over-The-Air service implemented with Mbed and BLE Cordio ?
Kinda. It’s still in development. Mbed OS used to have it, but it only worked on nordic devices that also used the proprietary softdevice. Follow this issue for more details: Service Proposal: FOTAService · Issue #46 · ARMmbed/mbed-os-experimental-ble-services · GitHub