Hierarchical Sensor Network
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:
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the network might have many nodes (thousands, or more);
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a node might be a cheap device with limited processing capability and transmission bandwidth;
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a node might connect/disconnect to/from the SN at any time;
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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.