Existing sensors and actuators, that can be used in an AAL (ambient assisting living) environment, work on het- erogeneous network protocols, e.g., WiFi, Bluetooth, EIB/KNX and Zigbee. For a given sensor/actuator, the choice of its underlying communication protocol is optimized according to its bandwidth and/or energy needs. However, integrating sensors/actuators of heterogeneous network protocols into an AAL system arises interoperability problems. In this paper, we present MPIGate, a multi-protocol gateway and interface for assisted living applications. Besides its multiple communication drivers for supporting the different protocols, MPIGate also proposes a database for storing the last updated sensor data as well as an user interface for both transparent data access and easy application development. MPIGate has been deployed in a smart home technical test bed at our LORIA labs. We presents some first results and discuss the lessons learnt.