Network packet

Wireless sensor network

Transmission Control Protocol

Internet layer

Internet Protocol

Embedded system

Layer (electronics)

User Datagram Protocol

Protocol stack

Operating system

The Internet

Computer science

MQTT

Hypertext Transfer Protocol

Computer network

Organic chemistry

Internet of Things

Transport layer

Chemistry

Message queue

Software deployment

Application layer

Sensors

The IoT protocols used for data transfer in the application layer, namely the Constraint Application Protocol (CoAP) and Message Queue Telemetry Transport (MQTT) have dependencies to the transport layer. The choice of transport, Transmission Control Protocol (TCP) or the User Datagram Protocol (UDP), on the other hand, has an impact on the Internet of Things (IoT) application level performance, especially over a wireless medium. Furthermore, we touch upon the impact of different security solutions. The motivation of this work is to look at the impact of the protocol stack on performance over a narrowband IoT (NB-IoT) link. The use case studied is infrequent small reports sent from the sensor device to a central cloud storage over a last mile radio access link. We find that while CoAP/UDP based transport performs consistently better both in terms of latency, coverage, and system capacity, MQTT/TCP also works when the system is less loaded.

Impact of CoAP and MQTT on NB-IoT System Performance