## 1 Introduction
The SMV and MMS data models are used for sampled measured values and manufacturing message specification, respectively. In addition to communications over the data layer (horizontal communications), the routable communication protocols (vertical communications), such as routable GOOSE (R-GOOSE), for internetworking communications over the network layer (Internet Protocol (IP) layer) has been defined by IEC 61850-90-5. This communication is also time sensitive and should be highly reliable and completed over a 10 ms time span including the network topology convergence. However, communication over the network layer using the Internet Protocol (IP) deals with many limits because they were not built for these types of communications which are highly sensitive in terms of reliability, delivery order, and communication latency. The R-GOOSE message, along with its applications in distribution automation, were described in detail in [11], where authors demonstrated the difference between GOOSE and R-GOOSE message and their data models and features. However, a proper communication middleware was not introduced, and network issues were not addressed. The applications of DDS in smart grids were evaluated in [12]. For example, DDS was used to improve smart grids communications by addressing the interoperability between different protocols such as DNP3 and MODBUS. However, it did not consider and address interoperability issued related to the IEC 61850 and routable communications. To route a GOOSE message over the WAN, adaptors are needed for configuration and interface with various equipment which use their own communication protocols such as Modbus, DNP3, IEC 61850, etc. For this purpose, by considering the formats which are described by data profiles, adaptors convert data and send them over MQTT, DDS, or AMQP communication protocols [13]. In this reference, the GOOSE message is translated to the OPC by the user agent (UA) to be transmitted over the WAN. However, this reference did not map the GOOSE data model over a DDS data object. In [14], a mechanism was introduced to deploy the IEC 61850 routable sample values (R-SV) and routable GOOSE (R-GGOSE) messages for reliable data transfer of Phasor measurement units (PMUs) over the WAN to facilitate the communication for wide-area monitoring, protection and control (WAMPAC). But the application of a broker-less communication middleware for fast and reliable data delivery was not presented. In [15], the DDS was deployed as a communication backbone for SAS. The process of mapping different communication traffics (GSE, SMV) into DDS data object were described properly. However, network issues, routing service, and end-to-end delay for routable communication over the WAN were not addressed. For a successful routable communication over the WAN that meets the maximum acceptable latency, network traffic management is needed. Usually, tunneling techniques could help to manage traffics between networks. Nowadays, by creating the 5G networks, a specific slice can be allocated for delay sensitive messages and, for example, slice isolation can help with managing the traffic as mentioned in [16]. This reference categorizes the different message types used in distribution grid protection and control from the standard defined by IEC 61850 and maps onto the three major groups of 5G use cases. It is worth mentioning that the 5G can address the end-to-end delay challenge in the substation-to-substation communication, however utilizing DDS in addition to the 5G can get the maximum benefit of the 5G network. DDS provides low latency scalable communication middleware, in addition to flexible and extensive Quality of service (QoS) profiles which can be applied to individual data types instead of applying QoS to the whole stream or protocol in addition to QoS profiles, DDS binary encoding, and data filtering reduce the network bandwidth. Mapping GOOSE messages to DDS provides a solution that can be deployed using current technology and migrates it easily to the 5G when it becomes available.