The bluetooth mesh self-setup smart lighting solution is a new smart home solution, it can directly use the smart phone bluetooth to connect to all the smart nodes if the smart phone signal reachs one.
Bluetooth mesh network introduction:
the bluetooth mesh network is a self-build up network by bluetooth node, the nodes in the signal coverage can be found automatically and extend the network range by its signal coverage
Bluetooth mesh Advantage:
1.Quick self set up, join the network when it is powered on, no routing can road caculating need
2.Can be acceed by smart phone or controller directly, the gateway is not necessary
3.High Security, data is encrypt with LES, Net name + passord security
4.Long distance,broadcasting communcation,it can be controled if in the broadcasting coverage.
5.Collision detection to avoid network message flooding
6.Effective node status update
7.Multiple device control,group control support
disadvantage:
1.Network frame capacity is limited to 30 bytes
Introduction about shiningintl Bluetooth Mesh system
1.Bluetooth mesh Stack introduction
the stack includes three levels in architeture: the core lib, the source, the application , please look at the picture below
2.shiningintl mesh network set up communication
Mesh network is built up step by step with the broadcasting, if evey node will rebroadcast the package it received, then the network will be blocked by large amount message
In order to avoid the broadcasting storm, we needs to calculate the times of rebroadcasting, to limit how many times the messange can be broadcasting,it means when frame is broadcasting, the sno. Will be counted once, it will be discarded when it grow up to meet the limitation, for example if the limitation is 4, when the messange received with the sno. Is 4, it will not be broacasting again.
3.Implementation of Mesh Network Communication Packet
Every node can only be assigned to 8 group, the network group id shoud be within8000-fffe,
Shiningintl Bluetooth mesh Operation procedure
Operation procedure- 1
the general connection procudure is: scanning -> connecting–> login –> login ok–>control CDM
1.Scanning:
Light advanced messange include local name and vender ID as the filter for app scaning
2.connecting:
After build up connection,report all service and register service property UUID
3.login
Login needs to ceritify the netname and password(both 16bytes)
AEC ectryption private key produce. The encryption bases on the two 16bytes of netname and password to generate a 16 bytes .this 16 bytes private key will be exchanged with the other
4.login ok
Login is to certifythe name and password
5.start CDM control
Operation procedure- 2
1 encryption between smart phone and bluetooth mesh node
①Master send out netname + password,slaver matchs the netname and password of himself
②Master will generate an random encryption according to netname and password
③Master will send the random encryption private keey to slaver
④ slaver generate a random private key after receiving the key from master,and return to the master
⑤ two side to generte an SK based on netname + passwor +random key + rrandom key
⑥This SK will be used for the later communcation
⑦If the connection broken, it will go through this above procedure
2 encryption between mesh node and mesh node
Communication between Mesh nodes will be encryped, the encryption is LTK
When the master changes the name of node , it also change the LTK.
Ltk is only the private key for mesh network, it doesn’t matter with the ble communication
Device type
sensor and other:
–Light switches
–Dimmers
–Sensors
controller:
–Remote controls
–Gateway
light device:
–Light bulbs/Strips
–Light fixtures