The Location based Service Selection (LSS) in WSN has been well studied. Towards effective LSS, an efficient Mobility Aware Displacement Approximation (MADA-LSS) based approach is presented in this article. The model monitors the mobility of mobile device and predict the possible location at different future time stamp. According to the future time stamp, the list of service locations are identified at different possible locations. According to the possible locations and service set, the method discover set of routes to reach each of the service points. For each of the route, the method estimates Data Arrival Rate (DAR), Data Claim Rate (DCR) and Data Rate Support Measure (DRSM) for both Access Point as well as route identified. Also, the method ranks the service points according to DRSM value and estimates the Trusted Handover Measure (THM) for the routes according to IoT (Internet of Things) devices of any route. By considering both THM and DSRM values an optimal service point as well as route has been selected to perform data transmission. Also, the privacy preservation is performed by using the same set of displacement approximation scheme which selects optimal encryption based on mobility parameters and time complexity and security of different encryption schemes. The proposed method improves the performance of LSS and secure routing.