# Parallel Rendezvous Strategy for Node Association in Wi-SUN FAN Networks

## TL;DR

This paper introduces a new strategy to reduce connection delays in Wi-SUN FAN networks, improving scalability and energy efficiency.

## Contribution

The Parallel Rendezvous strategy is proposed to optimize the node association process in Wi-SUN FAN networks.

## Key findings

- The PR strategy reduces association time by up to 71.22% in linear topologies.
- Energy consumption during JS1 is reduced by up to 59.56% with the proposed method.
- Improvements are observed in linear, fully connected, and mesh network topologies.

## Abstract

The Wi-SUN FAN (Wireless Smart Ubiquitous Network Field Area Network) standard facilitates large-scale connectivity among smart devices in utility networks and smart cities. Specifically designed for Low-Power and Lossy Networks (LLNs), Wi-SUN FAN supports the formation of multiple Personal Area Networks (PANs) and mesh topologies with multi-hop transmissions. However, the node association process, divided into five junction states, often results in prolonged connection times, particularly in multi-hop networks, thereby limiting network scalability and reliability. This study analyzes the factors affecting these delays, with a particular focus on Join State 1 (JS1), which relies on PAN Advertisement (PA) packets that use asynchronous communication and the trickle timer algorithm, frequently causing significant delays. To overcome this challenge in JS1, we propose the Parallel Rendezvous (PR) strategy, which forms synchronized clusters of unassociated nodes and leverages the standard’s PAN Advertisement Solicit (PAS) packets to rapidly disseminate network information. The proposed algorithm, PR Wi-SUN FAN, is evaluated through simulations in various network topologies, demonstrating notable improvements in linear, fully connected, and mesh scenarios. The most significant gains are observed in the linear topology, with reductions of up to 71.22% in association time and 59.56% in energy consumption during JS1.