1. Introduction
Regarding Thread implementation, each node forming the 802.15.4 network can act with different roles: Leader, Router, End device or Sleepy End Device (SED). A special role named Border Router allow the Thread nodes to access the outside world through an end-to-end IPv6 connection. A Thread Border Router (i.e., Thread BR) connects a Thread network to other IP-based networks, such as Wi-Fi or Ethernet. A Thread network requires a Border Router to connect to other networks. It is basically a bridge between Thread network and a Wi-Fi or ethernet interface.
| OpenThread Border Router |
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A Thread Border Router minimally supports the following functions:
- Bidirectional IP connectivity between Thread and Wi-Fi/Ethernet networks.
- Bidirectional service discovery via mDNS (on a Wi-Fi/Ethernet link).
- Thread-over-infrastructure that merges Thread partitions over IP-based links.
- External Thread Commissioning (for example, a mobile phone) to authenticate and join a Thread device to a Thread network.
2. OpenThread Border Router (OTBR) Setup
The border router is based on a Raspberry Pi (RPi) loaded with OTBR and a Dory acting as RCP (Radio co-processor). The RCP is controlled by the RPi as a remote Radio and all commands and data packets are send from RPi to RCP and vice versa. OTBR includes:
- Bridge ethernet/WiFi to Thread
- Open Thread stack (above MAC)
- Local web server to server Web pages thru WiFi AP
OTBR comes in Raspberry Pi image which embeds a list of services.