Communications hub, border-router or Gateway links low power hardware to the outside world
- Network
Wifi/Ethernet
Low Power Wide Area Networks
Low power IPv6 networks
Stars
Meshes
应用层协议：
-
MQTT
Designed to be smaller packets & less overhead than HTTP
Messages are published to a broker
Clients subscribe to data streams
e.g. topic temperature
应用层协议；无损，双向连接，使用TCP/IP，大小2bytes-256MB
两种网络实体：消息代理（message broker）与客户端（client） -
MQTT-SN MQTT-SN uses UDP
-
Constrained Application Protocol (CoAP)
longer battery life
as familiar as HTTP
Low memory footprint
A more modern lightweight design than MQTT
Prefers UDP
应用层协议：使用UDP，可轻松转换HTTP，信息最小4bytes
- JSON and CBOR
LPWAN：
-
LoRa
Low data rate simple low level links 0.3 – 50 kbit/s data rates
物理层协议：双向通信，端到端安全性，可移动性，低功率，低比特率，抗干扰，长距离， -
LoRaWAN
配套的网络层，Mac层协议
Wide area low power network using gateways -
NB-IoT - Narrowband-IoT
200 kbps
IEEE 802.15.4
- Zigbee
歇性数据传输 - 6LoWPAN
IPv6 packets over 802.15.4 networks TCP/IP - Matter
