# Effect of payload size on goodput when message segmentations occur for wireless networks: Case of packet corruptions recovered by stop-and-wait protocol

## TL;DR

This paper analyzes how payload size impacts goodput in wireless networks with message segmentation and packet loss, deriving an exact analytical model that accounts for variable packet sizes and bit-error conditions.

## Contribution

It introduces an exact analytical model for goodput considering variable packet sizes due to segmentation, improving upon previous constant-size assumptions.

## Key findings

- Constant packet-size assumption is invalid at low bit-error rates.
- Goodput curves are concave in payload size at high bit-error rates.
- Longer bit-error bursts reduce the concavity of goodput curves.

## Abstract

This paper investigates the effect of payload size on goodput for wireless networks where packets created from a message through a segmentation function are lost due to bit errors and they are recovered by a stop-and-wait protocol. To achieve this, we derive the exact analytical form of goodput using the analytical form of a packet-size distribution, given a message-size distribution and a payload size. In previous work, the packet sizes are assumed to be constant, which are payload size plus header size, although actual segmented packets are not constant in size. Hence, this constant packet-size assumption may be not justified for goodput analysis. From numerical results, we show that the constant packet-size assumption is not justified under low bit-error rates. Furthermore, we indicate that the curves of goodput are concave in payload size under high bit-error rates. In addition, we show that the larger mean bit-error burst length yields less concave curves of goodput.