Key Specifications

SMETS defines the technical capabilities required of smart metering equipment. SMETS1 covers the earlier generation of devices, with additional requirements governing how those devices and their communications are supported through DCC. SMETS2 defines the later generation of gas and electricity meters and associated devices, including their physical, functional, interface, data, testing and certification requirements. The two generations can support comparable services, but their underlying device behaviour and communications are handled differently.

Sets out supporting requirements for delivering DCC services to SMETS1 devices. It describes how applicable DUIS service requests are fulfilled through equivalent processing steps, while Appendix AM - Annex A Device Model Variations to Equivalent Steps Matrix identifies device-model variations that can affect those steps.

CHTS defines the minimum requirements for the DCC-provided Communications Hubs that support the SMETS2 architecture. It covers communications, routing, buffering, security, interfaces, data handling, testing and certification, including the Communications Hub Function and Gas Proxy Function. These hubs connect SMETS2 devices on the premises’ Home Area Network to DCC Systems. SMETS1 devices use separate SMETS1 communications and service-processing arrangements rather than being treated as GBCS-native SMETS2 devices.

DUIS defines the technical interface through which authorised Users exchange service requests, responses and alerts with DCC for both SMETS1 and SMETS2 devices. For SMETS2, DCC converts applicable DUIS requests into GBCS device commands and returns GBCS-based responses or alerts. For SMETS1, DUIS applies with explicit variations: equivalent processing is defined by the SMETS1 Supporting Requirements and related service-processing rules, with outcomes returned using SMETS1-specific response and alert structures.

GBCS defines the interoperable device-message layer used by SMETS2 equipment and Communications Hubs. It specifies how commands, responses, alerts and Home Area Network messages are formatted, protected and processed using technologies such as DLMS/COSEM, Zigbee Smart Energy and ASN.1. GBCS does not directly govern communications with SMETS1 devices; the equivalent SMETS1 behaviour required for DCC services is defined through the SMETS1 Supporting Requirements and associated processing rules.

MMC defines how device response and alert data is presented to DCC Users. For SMETS2, it maps meaningful information from the technical GBCS Payload Format into structured XML aligned with DUIS. For SMETS1, corresponding MMC response structures and data definitions apply to countersigned SMETS1 responses and alerts, subject to specific SMETS1 variations. MMC therefore provides a broadly consistent output model for Users while preserving the different underlying processing paths used by SMETS1 and SMETS2 devices.