Wireless relay is a kind of device that receives signals from other station and generate own signals accordingly. In the next generation mobile communication system, a so called decode-forward wireless relay will be deployed. This kind of relay has simplified protocol stacks and can decode received signal. After base-band processing, it generate new version of signal for transmitting. According to complexity of protocol stacks, this kind of relay can perform error control, power control, channel measure, interference mitigation and even handover. This paper introduce wireless relay impact on communication system, deployment scenarios, related techniques and progress of related standardization and research.