Interference management for smart grid communication under cognitive wireless network

Wireless communication in smart grid is a typical scenario of Machine-to-Machine (M2M) communication. For a smart grid communication system, the requirements for stability, security and reliability are more strict than those for other M2M applications. Interference management is one of the key challenges to ensure the wireless system working with stability and reliability. The interferences may come from the existed SCADA (Supervisory Control and Data Acquisition) system, or some unknown devices using the same spectrum band occasionally. In this paper, we propose a novel mechanism for a WiMAX based system to manage various in-band interferences under cognitive environment, which are meaningful when there is no dedicated spectrum resource assigned for the new system or at the stage for system evolution from narrow band to broadband. We design the periodical sensing (PS) process during the normal wireless communication to obtain the realtime interference information and define the cross layer message between PHY and MAC to deliver the interference information to downlink and uplink respectively. Based on the time and frequency domain analysis for PS data, we classify received interferences into several types and execute corresponding management methods to reduce the influences caused by interferences. Through the field test in two cities, it proves that the interference management mechanism we proposed is effective.