A method and system for controlling discontinuous reception in a mobile device in a wireless communications network that supports voice-over-internet-protocol and that uses an automatic repeat-request method, like a hybrid automatic repeat-request method, uses autonomous DRX control after initial VoIP traffic setup. The buffer unit includes stacked NMOS transistors. The housing body and the at least one battery are connected to each other via a male-female engagement device. The retainer mechanism includes a moveable keeper member on the end member. Transaction costs are estimated for each investment institution relative to the cost benchmarks.