A study of Sub 1GHz urban path loss models is presented in this paper. This particular frequency band provides optimal transmission characteristics for wireless communication and new WLAN standards may use the Sub 1GHz band for license-exempt data transmission in the near future. New WLAN use cases would be possible to design, such as wireless smart grid networks for meter data transmissions in urban areas. We discuss three urban propagation path loss models for carrier frequencies at 900MHz and we make statements about the performance of a proposed Sub 1GHz path loss model candidate for WLANs including a simulation study and discuss statistical shadowing effects at 900MHz. We finally validate our study with empirical MIMO OFDM measurement models from the literature.