Retransmission Policies for Efficient Communication in IoT Applications

The embedded devices that serve as the basic element for the IoT are reportedly increasing. Such devices are widely used provided that they are equipped with limited CPU, storage and battery. Some of the famous applications of IoT are online video streaming, sensing, tracking, manufacturing, smart homes and cars and many more. Most of these applications are time critical where immediate response to the input is needed in order to maintain the quality of service. Moreover, the merging of IoT with existing network architecture (and protocols) face many issues like reliability and availability of the network. The software and hardware aspects of IoT have widely been studied. On the software perspective, TCP is one of the leading protocols in the Internet. However, it creates a single connection between two devices, which decreases the availability of the Internet access to IoT devices in case of connection failure or error. A new protocol that increases the availability of the network by creating multiple connections between two devices is the SCTP (Stream Control Transmission Protocol). This paper provides the details of the use of multiple connections between two devices through SCTP. Experimentation is performed to evaluate the protocol on a multipath connection scenario where connection failures are common. The retransmission is required due to the connection failure or other errors. The results suggest that the SCTP is very suitable for the IoT devices that collaborate with the existing Internet because it re-establishes the connections quickly. The delay is measured to see the transmission delay caused by the retransmission of data. For the retransmission of the data three policies of the SCTP are compared. The experiments also conclude that the use of RTX-LOSSRATE retransmission policy of SCTP improves the transmission throughput.