IEC 61850 has been substantially developed for substations but is seen as a key standard for all field equipment operating under both real-time and non-real time applications. It shall be possible in the future to use IEC 61850 as well to transmit Phasor Measurement Unit data and information according to IEEE C37.118 standard. Common time synchronization will be a key for many Smart Grid applications. Guidelines on how to achieve that synchronization and addressing different issues related to that synchronization are required. The IEEE 1588 standard will be a key element to achieve that synchronization.