先决条件——物联网中的数据链路层协议
1. 罗拉旺：
LoRaWAN 属于 MAC 层协议，适用于大规模公共区域网络。 LoRaWAN 是使用 Semtech 的 LoRa 技术创建的。 LoRa 和 LoraWAN 属于非蜂窝无线通信网络协议。它遵循 chirp 扩频调制(CSS 调制)。
2. 窄带物联网：
NB-IoT也称为窄带物联网，被公认为物联网的无线通信。 NB-IoT 属于 LPWAN(低功耗广域网)类别，能够连接需要少量数据、低带宽和长电池寿命的设备。
NB-IoT 是一种适用于物联网设备和应用的窄带无线电技术，需要以低成本实现远距离无线连接，并且分别使用很少的功率来延长电池寿命。
LoRaWAN 和 NB-IoT 的区别：
| COMPARISON | LORAWAN | NB-IoT |
|---|---|---|
| Modulation | LORAWAN uses chirp spread spectrum modulation. | NB-IoT uses Quadrature phase shift keying modulation. |
| Frequency | It uses 868MHz in Europe, 915MHz in North America, 433MHz in Asia (Unlicensed ISM bands). | It uses Licensed LTE frequency Bands. |
| Bandwidth | LORAWAN has 250KHz and 125KHz bandwidth. | NB-IoT has 200KHz bandwidth. |
| Maximum message/day | Maximum Message it can send per day is unlimited. | In this technology maximum message/day is also unlimited. |
| Maximum Data Rate | The maximum data rate in case of LoRaWAN is 50Kbps. | The maximum data rate in case of NB-IoT is 200Kbps. |
| Maximum Payload Length | In LORAWAN, the maximum payload length is 243bytes. | In NB-IoT, the maximum payload length is 1600bytes. |
| Range | The Range of LoRaWAN is 5 km in urban, 20 km in rural area. | The Range of NB-IoT is 1 km in urban, 10 km in rural area. |
| Interference Immunity | Interference immunity in case of LORAWAN is very high. | Interference immunity in case of NB-Iot is Low. |
| Authentication and Encryption | It supports AES 128b as encryption technique . | It supports LTE encryption technique. |
| Adaptive Data Rate | LORAWAN supports Adaptive Data Rate (ADR). | It does not support Adaptive Data Rate (ADR). |