Wireless technology offers flexibility and mobility that enables users to access to any service including voice call, anytime, anywhere with any device. Transferring call or session across devices is also made possible with today's session management protocol such as SIP, provided the user knows the contact information of the target device. In this paper, we propose a method which simplifies the transfer of session across devices whereby the target device is automatically selected based on its proximity to the active source device. Such automation is enabled with the use of a customised Location Server that performs location estimation of all registered devices using the RSSI-based triangulation method. Our proposed method successfully eliminated the error-prone manual intervention on the selection of target device during the transfer, and achieved a small average error of 0.21 meter.