When a disaster strikes, communication infrastructure such as cellular network may get destroyed, which makes rescue operations more challenging. Short range-based opportunistic communications using daily mobile devices such as smartphones present a promising solution to support infrastructure failure. In a previous work, we have proposed COPE, a cooperative opportunistic alert diffusion solution useful for trapped survivors during disasters to ease and speed up their rescue and assistance. It targets to maintain mobile devices alive as long as possible for a maximum network coverage until reaching proximate rescuers. COPE leverage mobile devices that come with multiple network technologies and aims to perform a systematic network interface selection. We have implemented a proof-of-concept of COPE for android smart-phones using two network technologies: Bluetooth and Wi-Fi. This work presents a benchmark analysis of performances of smartphones based on COPE. Testing experiments have been carried out to measure the performance of smartphones in terms of energy consumption, clock synchronization and transmission range. We believe that such experimental results can support technological choices for rescue operations but also for many other applications relying on smartphone performances.