Cost-Effective Gateway Selection Scheme for Delay-Tolerant Data Transmission in Internet of Things

Every connected smart object with sensors will be generating and transmitting data, hence a staggering amount of data needs to be collected and processed in the cloud. All these data must be sent to its application in a timely fashion. Depending on the types of application, some applications need real-time data while some can accommodate delay-tolerant data. However, although an application supports delay-tolerant data, the data still have to be sent before its delay is beyond tolerable. Our aim is to propose a mesh-type IoT gateways architecture which allows the gateways to aggregate bandwidth and provide a high-availability internet access to all the connected things. The objective of this work is to show that with the proposed architecture, IoT gateway selection scheme can be applied to reduce the WAN (Wide Area Network) data transfer cost. Data which can be delayed will be relayed to the cloud through the most cost-effective IoT gateway. We evaluated our architecture through simulations with various IoT gateway selection schemes using 3 different scenarios. Compared to direct transfer which only meets 65.8% of the data deadline, we are able to meet 98.6% of the data deadline and reduce the WAN cost by 5.74% under the normal scenario, when the average Internet connection speed is higher than the average data incoming rate.