The lower layers are based on G3-PLC specification. The G3-PLC data link layer is adapted for hybrid network.
The crucial part in this stack is the 6LoWPAN adaptation layer. The main goal of this layer is to optimize the transmission of IPv6 packets over low-power and noisy networks. The 6LoWPAN layer solves following tasks:
A typical 6LoWPAN network has two device types – routers and hosts. Routers can route data destined to other nodes in the 6LoWPAN network. Hosts are just end devices that are not able to route data to other devices in the network. The host may be a battery powered device that wakes up periodically to check its router for data. As the e-meters are always powered devices, for stable network configuration, all devices in ADDAX solution act as routers. The DC also acts as a border (edge) router, providing data exchange between the 6LoWPAN network and the backbone (via Ethernet or 3GPP).
The DC is responsible not only of translating (or routing) the requests coming from HES to the 6LoWPAN network, it also provides 6LoWPAN network generation and maintenance, and manages the local data exchange between devices inside the 6LoWPAN network.
Every meter has PLC or RF, or PLC+RF connectivity to other meters. The route is built hop-to-hop, selecting between the best channel. The channel selection is dynamically adjusted based on media status.
After a new e-meter is discovered in the network, the DC application first queries identification and configuration information then starts performing the tasks for data collection.
The meter may send asynchronous messages as an alarm occurs. The message is transmitted as an Event Notification to DC, then forwarded to HES or registered in DC, depending on alarm severity and configuration.
Security features are implemented at several layers.
AES-128 based encryption and authentication, defined in G3-PLC specification, is used at data link layer.
The DC also uses encryption/decryption of all input and output information at application layer. Meter-DC security architecture is based on the DLMS UA 1000-2 Ed.7.0 concepts.
AES-GCM-128 (Galois/Counter Mode with AES-128) Security Suite ID: 0 is implemented for data encryption and authentication and key transport methods.