Energy-Efficient Dynamic RTO with Enhanced Stability for CoAP-Based IoT Networks

Area of Science:

• Computer Science
• Networking
• Internet of Things (IoT)

Background:

• The Constrained Application Protocol (CoAP) is crucial for reliable communication in resource-constrained AIoT and Wireless Sensor Networks (WSNs).
• CoAP's default retransmission timeout (RTO) mechanism struggles with volatile network conditions, leading to inefficiencies.
• Existing benchmarks like CoCoA+ and FASOR exhibit limitations such as overly conservative backoffs or retransmission storms.

Purpose of the Study:

• To propose a novel dual-adaptive Dynamic RTO algorithm for CoAP, addressing performance bottlenecks in heterogeneous IoT environments.
• To enhance the responsiveness and efficiency of CoAP's RTO mechanism under dynamic and volatile network conditions.
• To provide a scalable and resource-efficient transport-layer solution for next-generation edge-computing infrastructures.

Main Methods:

• Developed a dual-adaptive Dynamic RTO algorithm that adjusts its parameter inspection cycle (N) based on Round-Trip Time (RTT) variance.
• Scaled the tuning coefficient (α) in real-time according to packet loss indicators.
• Evaluated performance using the Gilbert-Elliott dynamic loss model across multi-hop linear and grid network topologies (1x6, 3x6, 5x6).

Main Results:

• The proposed Dynamic RTO algorithm optimized the throughput-latency trade-off, achieving a total communication time of 25.92 s in complex grid topologies.
• Demonstrated superior performance compared to CoCoA+ (14.28% improvement) and FASOR (8.89% improvement).
• Significantly reduced transmission overhead, limiting cumulative retransmissions to 59 counts under severe localized impairments.

Conclusions:

• The novel Dynamic RTO algorithm offers a scalable, resource-efficient, and empirically robust transport-layer solution for AIoT and WSNs.
• The adaptive mechanism effectively handles volatile channel conditions and optimizes communication efficiency.
• This approach establishes a foundation for improved reliability in next-generation edge-computing infrastructures.