The 4G wireless network is proposed to integrate various radio access technologies into a common network known as open wireless architecture (OWA), this has led to the idea of cooperative user location estimation, in this paper we have proposed a cooperative TDoA/RSS/TDoA user location estimation method which uses information from two different Radio Access Networks (RANs) as the long range (LR) data via Time Difference of Arrival (TDoA) method with the combination of short range (SR) data from connection between MSs using Received Signal Strength (RSS) method. Results from simulations show that the information used as LR data from the second RAN provides great advantages and enhances the accuracy of user location estimation.