Performance Modeling of Delayed Offloading in Mobile Wireless Environments With Failures

Mobile devices and wireless network links are sometimes unreliable and unstable owing to user mobility in mobile wireless environments. As a result, failures may occur during the offloading process, which has a huge influence on the offloading performance. Worse still, it is challenging to make high-level offloading decisions since they closely rely on an accurate predicting model, especially when encountering with offloading failures. Unfortunately, due to the high mobility and heterogeneous network environments, such a model is currently not available to researchers and practitioners. To fill that gap, this letter develops an analytical queueing model for delayed offloading systems with intermittent connectivity. We set a deadline to detect offloading failures when taking the impatient jobs and service interruptions into account. Furthermore, for different types of mobile applications, a tradeoff analysis between energy saving and latency reducing is analyzed on the basis of an energy-response time weighted product metric. The proposed offloading model can be effectively used for describing complex and realistic offloading systems with the presence of failures.