Multi-slot allocation protocols for massive IoT devices with small-size uploading data

The emergence of Internet of Things applications introduces new challenges such as massive connectivity and small data transmission. In traditional data transmission protocols, an ID (i.e., IP address or MAC address) is usually included in a packet so that its receiver is able to know who sent the packet. However, this introduces the big head-small body problem for light payload. To address this problem, the Hint protocols have been proposed. The main idea is to 'encode' information in a tiny broadcast Hint message that allows devices to 'decode' their transmission slots. Thus, it can significantly reduce transmission and contention overheads. In this letter, we extend eHint to support multi-slot data transmissions. Several efficient protocols are proposed. Our simulation results validate that the protocols can significantly increase the number of successfully transmitted devices, channel utilization, and payload of transmitted devices compared with eHint.