前提条件–物联网中的数据链路层通信协议
物联网(物联网)中使用了不同的网络协议,以将服务提供给网络层。在物联网中建立设备之间的通信时,我们需要通信协议。在网络协议中,LPWAN是广泛使用的流行的标准通信协议之一。
低功耗广域网(LPWAN):
LPWAN也称为低功耗广域网。这是一个无线广域网,范围从2 km到1000 km。 SigFox , LoRaWAN是LPWAN技术的示例。 LoRaWAN和SigFox均实现了远程,低功耗分配的无线数据集成。但是,LoRaWAN和SigFox是不同的技术。
1. SigFox:
SigFox使用双向功能,即一个方向为DBPSK,另一方向为GFSK。其中DBPSK代表差分二进制相移键控,而GFSK代表高斯频移键控,SigFox及其合作伙伴在塔上设置接收器,并接收来自不同设备的不同节点的数据传输。
2. LoRaWAN:
LoRaWAN是MAC层协议,专为大规模公共网络而设计。 LoRaWAN是使用Semtech的LoRa技术构建的。但是重要的是,LoRa和LoRaWAN是两个不同的事物。 LoRa和LoraWAN属于非蜂窝LPWAN无线通信网络协议。
LoRaWan和Sigfox之间的区别:
S.NO | Comparison | SigFox | LoRaWAN |
---|---|---|---|
01 | Modulation | It follows Binary pahse-shift keying modulation. | LoRaWAN follows Chirp spread spectrum modulation. |
02 | Bandwidth | In SigFox the bandwidth is 100Hz. | For LoRaWAN the bandwidth is 250KHz and 125KHz. |
03 | Maximum data rate | It can send up to 100bps . | In case of LoRaWAN the maximum data rate is 50Kbps. |
04 | Functionality | SigFox is limited bidirectional/Half-duplex | LoRaWAN is fully bidirectional/ Half-Duplex |
05 | Maximum messages/day | In SigFox the Uplink=140, Downlink =4. | In LoRaWAN this facility is Unlimited. |
06 | Maximum payload length | Uplink=12 bytes, Downlink=8 bytes. |
The maximum payload length is 243 bytes. |
07 | Range | The Range of SigFox is 10 km in urban area, 40 km in rural area. | The Range of LoRaWAN is 5 km in urban, 20 km in rural area respectively. |
08 | Interface Immunity | The interface immunity is very high in SigFox network architecture. | The interface immunity is same as in SigFox network architecture. |
09 | Authentication And Encryption | It does not support the modern Encryption Technology. | It supports (AES 128b) as Encryption Technology. |
10 | Topology | It Follows Star topology. | LoRaWAN follows Star-on-Stars topology. |