# Enhancing Block-Wise Transfer with Network Coding in CoAP

## TL;DR

This paper proposes integrating network coding into CoAP's block-wise transfer to reduce retransmissions and transfer time in lossy IoT networks, demonstrating significant improvements in efficiency.

## Contribution

It introduces a novel combination of network coding with CoAP's block-wise transfer to minimize retransmissions in lossy environments.

## Key findings

- Up to 5 times fewer block retransmissions at maximum blocksize and 50% loss probability.
- Reduced transfer time due to fewer retransmissions.
- Effective in various blocksize configurations.

## Abstract

CoAP (Constrained Application Protocol) with block-wise transfer (BWT) option is a known protocol choice for large data transfer in general lossy IoT network environments. Lossy transmission environments on the other hand lead to CoAP resending multiple blocks, which creates overheads. To tackle this problem, we design a BWT with network coding (NC), with the goal to reducing the number of unnecessary retransmissions. The results show the reduction in the number of block retransmissions for different values of blocksize, implying the reduced transfer time. For the maximum blocksize of 1024 bytes and total probability loss of 0.5, CoAP with NC can resend up to 5 times less blocks.