Possible to update firmware via Mesh SDK in the future?

Question

Hi, I'm testing the light control example from Mesh SDK 0.10.1. 
 Although I have received an answer about the future plans of mobile Mesh SDK from developer Hung Bui that 
 
 Out GATT bearer is under development. Unfortunately it's not available in the current SDK. But we are working on it. 
 
 I have extra questions to ask. 
 My client and I are planning to prepare a BLE mesh lighting product before April 2018. 
 In the Infocenter , I am aware that 
 
 nRF5 SDK for Mesh v0.10.0-alpha
This is an experimental release for exploring the Bluetooth low energy mesh stack on the nRF5 device family. This release is not intended for commercial use. 
 
 Since the production level of Nordic's Mesh SDK, both mobile and firmware, may or may not be released in next year's first quarter, our concern is whether to take a risk to use the alpha stage SDK. 
 This is my scenario; 
 I flash the nRF52 chips with a firmware based on the mesh SDK 0.10.1 -> 
 User uses the future mesh mobile app to update the mesh firmware 
 I know this is a bad idea for user experiences, but my client wants to prepare this product for investors really quickly. 
 Telling me about the production release date of both nRF BLE Mesh SDK and mobile SDK can help me tremendously. 
 However, the availability of a feature that updating the firmware via mobile app with mesh is my main question. 
 Will it be possible to update the mesh firmware with the mobile app in the future? 
 If so, should I add a bootloader while testing the light control example? 
 -Best Regards, MANGO

Hung Bui · Accepted Answer

Hi Mango, 
 DFU bootloader for Mesh network is already provided. Have a look here . 
 Currently, the way it work is: you have a gateway node that connects to PC via UART. And you use a tool on PC (nrfutil) to do DFU via the gateway to the whole mesh network. It take a very long time to update firmware but it can update thousand devices at the same time. 
 It's possible to modify the gateway firmware to support receiving the DFU command and image from a phone instead of UART. But it's not implemented yet, but you should be able to make one. 
 Bluetooth Mesh GATT bearer might not relate here. It could play a role for the gateway to receive image from the phone, but this can be done via normal BLE GATT as well. Note that the communication protocol when doing DFU is not Bluetooth Mesh, but a proprietary protocol that Nordic defined (the OpenMesh).