# Packet Throughput Analysis of Static and Dynamic TDD in Small Cell Networks

## TL;DR

This paper presents an analytical comparison of static and dynamic TDD in small cell networks, showing that D-TDD improves downlink throughput while S-TDD benefits uplink, with results validated by simulations.

## Contribution

The paper introduces a stochastic geometry and queuing theory-based framework for analyzing and comparing static and dynamic TDD performance in small cell networks.

## Key findings

- D-TDD outperforms S-TDD in downlink throughput.
- S-TDD has better uplink performance.
- D-TDD offers significant gains in asymmetric traffic scenarios.

## Abstract

We develop an analytical framework for the perfor- mance comparison of small cell networks operating under static time division duplexing (S-TDD) and dynamic TDD (D-TDD). While in S-TDD downlink/uplink (DL/UL) cell transmissions are synchronized, in D-TDD each cell dynamically allocates resources to the most demanding direction. By leveraging stochastic geom- etry and queuing theory, we derive closed-form expressions for the UL and DL packet throughput, also capturing the impact of random traffic arrivals and packet retransmissions. Through our analysis, which is validated via simulations, we confirm that D-TDD outperforms S-TDD in DL, with the vice versa occurring in UL, since asymmetric transmissions reduce DL interference at the expense of an increased UL interference. We also find that in asymmetric scenarios, where most of the traffic is in DL, D-TDD provides a DL packet throughput gain by better controlling the queuing delay, and that such gain vanishes in the light-traffic regime.