The Internet of Things Still Has a Gateway Problem

Abstract

As the Internet of Things (IoT) has grown more prevalent, the gateway has become a critical linchpin of IoT network architectures. To bring constrained embedded devices online, Bluetooth Low Energy (BLE) has proven to be particularly popular for the low power sensors and actuators pervasive in the consumer IoT market. And yet, the gateways that facilitate cloud connectivity for such devices incur burdensome time, cost, and unreliability. This problem persists because current gateways conflate many application-specific functions, which continues to fuel the trend of requiring separate expensive, custom, and over-provisioned solutions for each brand or class of device to establish reliable network connectivity. One route to address the problem is the over-provisioned gateways at the heart of Apple and Google's smart home offerings. Another approach involves adding ephemeral gateway functions on pervasive connected devices like smartphones. In this paper, we explore a third approach that strips the gateway down to its bare essentials and eliminates the rest. We test the approach on the Espressif ESP32, a $3 microcontroller that contains built-in Wi-Fi and BLE radios, with a deployment of low-power IoT devices, evaluating the performance, drawbacks, and tradeoffs. Our results suggest that this is a promising technique for cost-sensitive applications with low deployment densities and aggregate data rates, but more capable design points may be preferred as these assumptions are relaxed.