A system and method for resource utilization in a constrained sensor gateway for transfer of data in terms of the bandwidth and energy available to transfer data. The system includes a processor in communication with the constrained sensor gateway, which includes an application layer protocol and which is in communication with a communication network, and a memory coupled to the processor. The memory includes a network condition detection module configured to detect a network condition of the constrained sensor gateway, and an adaption module configured to determine a reliability score. The application layer protocol of the constrained sensor gateway adapts a reliability level based on the reliability score determined by the adaption module, which enables better utilization of the bandwidth and energy to transfer data. The reliability level may pertain to a reliable mode, or a non-reliable mode of communication for transferring data.