NEMA - ANSI C12/IEC 62056-8-20
Electricity Metering Data Exchange – The DLMS/COSEM Suite Part 8-20: Mesh Communication Profile for Neighbourhood Networks
|Publication Date:||1 January 2019|
This part of IEC 62056 specifies a DLMS/COSEM communication profile that can be used in a smart metering system in which the Neighbourhood Networks (NN) are mesh networks.
This profile may be considered as an adaptation and extension of the UDP/IP communication profile specified in IEC 62056-9-7:2013. As in that standard, the PHY and MAC layers are out of the Scope.
This Technical Specification specifies a number of features essential to the efficient operation of a large scale AMI using mesh NNs. These features include:
• identification of the DLMS/COSEM client and server participating in an application association (AA) with their system title, so that this identification does not change when the IP address of the server changes;
• a mechanism to inform the client of the binding between the server's system title and its current IP address(es);
• the use of the DLMS/COSEM UDP based transport layer, that allows keeping DLMS/COSEM AAs open for long periods, while the device may leave and join the mesh NN and/or its IP address may change;
• DLMS/COSEM application layer and application process level security features that can be used in a mesh environment;
• a mechanism to organize servers to one or more groups based on various conditions, so that the requests can be broadcasted to all devices attached to the mesh network, but only those servers belonging to the group carry out the request and respond;
• a mechanism that allows to send the response to a request in designated time windows and with a randomized delay.
• the use of a specific UDP port that allows efficient UDP header compression.
The Scope of this communication profile specification is restricted to aspects concerning the use of communication protocols in conjunction with the COSEM data model and the DLMS/COSEM application layer. Any project specific definitions of data structures and data contents may be provided in project specific companion specifications.