Trillions of nodes for 5G!?

With the rapid development of internet of things (IoT) with various low-cost machine type communications (MTC) devices, intelligent wearable devices, vehicular sensors and environmental sensors etc, it's anticipated that trillions of wireless nodes in IoT with diversified applications and services may come to life in the fifth generation wireless communication system (5G). These devices, however, may not be handled efficiently by the current wireless communication networks, which were not designed for frequent small data packets and simultaneous massive accesses. In this paper, a novel aggregator based MTC communication architecture is proposed, where the aggregators function as MTC gateways towards the cellular network, combining connections of masive devices into single connection. Correspondingly, based on the aggregated packet characteristics and data relay modes, the aggregators will request for aggregator specific radio resource control (RRC) mechanism. Simply put, always available connectivity is desired for contiguous packets with low latency, while coordinated transmission among multiple aggregators are preferred for packets with larger delay tolerance. Through various analysis and numerical results, MTC communication with aggregators are expected to bring much improved signaling efficiency, thus handling the gigantic pressure on 5G network design from the potential trillions of MTC devices.