IoT networks allow various new types of services, such as Location-Based Services (LBS), requiring an end-to-end Quality of Service (QoS) without any interruption. However, sustaining these networks is difficult when the devices can move and vanish at any time, as they can be carried around, might run out of battery, or be turned off by users. In this paper, we propose a new programmable multitier architecture and a continuity of service protocol named ConSerN, which are based on the Software Defined Network (SDN) approach and Connected Dominating Sets (CDS) techniques. Unlike the existing solutions, the proposed mechanism considers a dynamic topology where nodes are not static from a mobility and topology point of view. Furthermore, as most of the applications using LBS need to consider the geographic position of the connected objects, we have added it in the selection process of the dynamic gateways. The performance evaluation was conducted using experimentation and emulation tools allowing scenario generations. We used three main metrics i.e. the quality of link, the number of dominant nodes and the amount of control messages. The obtained results show that the proposed solution benefits from a high number of gateways to achieve great performance in terms of overhead and quality of link.