Powerline communications interface in CSMA/CA-networks

The utilization of existing powerlines for communication purposes opens many possibilities, which can be advantageous for a wide range of field bus applications. Known home automation solutions have low transmission speeds (e.g. EIB, LON) or works with other packet-oriented communication techniques (OFDM- or TDMA-based technologies). Networks with CSMA/CA access (e.g. SCAN) requires minimized signal delay times because this delay limits the possible transmission speed. CAN systems can be used for real-time applications and are especially time-critical. They work with bit-oriented arbitration mechanisms and are composed of protocol frames (acknowledge-flag set from other bus nodes in the same frame). Therefore, the maximum delay time on the transmission and receive path must be smaller than a half bit time. This hard timing requirement causes big problems during the realization of CAN powerline transceivers. Another requirement beside the global goal of real-time capability is the development of cost- and expenditure-minimized transceivers.