Technology Day 2014

Hierarchical Sensor Network

1 Introduction

The current technology lacks in providing network protocols which really support scalability, heterogeneity and dynamic changes. For this reason we designed a Sensor Network specifically conceived to work with cheap boards and sensors, and based on some easy-to-meet assumptions:

  • the network might have many nodes (thousands, or more);

  • a node might be a cheap device with limited processing capability and transmission bandwidth;

  • a node might connect/disconnect to/from the SN at any time;

  • each node might have different sensors.

2 Logical Structure of the Project

The Hierarchical Sensor Network works on three logical levels based on TCP/IP Stack Protocols.

  • Physical Layer (UART,Wireless);
  • Network Layer (CHNP);
  • Application Layer.

Thanks to the Centralized Hierarchical Network Protocol, the network layer protocol, the network has the following properties:

  • Scalable;
  • Efficient;
  • Heterogeneous;
  • Hot-Pluggable;
  • Reliable.

3 Network Hierarchical Topology

 

4 Implementation

Each Network Element has been implemented on various devices by using:

  • Physical and Wireless connections,
  • C Program Language;
  • FreeRTOS;

The portability is guaranteed from implementation level separation and all operational levels higher than strictly physical are completely hardware-independent. Only a small hardware-dependent implementation has to be replaced.