Real-Time Applications in Smart Grids Using Internet Communications:: Latency Issues and Mitigations

The Smart Grid will be a geographically widespread system, with real-time applications spanning large distances. To deploy real-time applications traditionally Industrial networks designed to specification are used. Since the Smart Grid will be geographically widespread and consist of many devices there is a great economic gain by utilizing the Internet as its communication network.This thesis presents literature describing problems with congestion, bufferbloat and active queue management in today's Internet. Additionally existing solutions and mitigations to these problems are presented and discussed. In addition, two end-user last mile links connected to the Norwegian Internet are characterized in terms of delay and passive traffic measurements. One link utilizes fiber to the home and one utilizes Asymmetric Digital Subscriber Line (ADSL) technology. The characterization results show evidence of both bufferbloat and lack of active queue management in the ADSL link. The characterization results provide no conclusive evidence of neither bufferbloat nor active queue management in the fiber to the home link.The guaranteed timely delivery problem over an Internet path has been analysed. This leads to recommendations on minimizing latency at the end-user based on the discussion on existing solutions and the characterization experiments performed