Massive IoT Access for 6G

The Internet-of-Things (IoT) revolution has triggered the need of  massive connectivity for billions of devices requiring a system capacity  which is far beyond the current network designs that can be supported.  This emerging requirement has reshaped the society and industry in  pursuing efficient communication paradigm. In particular, massive  machine-type communications (mMTC) will be a prime driver for enabling  the vision of scalable IoT with heterogeneous applications, where the  massive access is of paramount importance. This book discusses important  massive IoT scenarios and the key technical requirements of the  corresponding massive access. We review the state-of-the-art IoT  standards and mMTC solutions, and summarize the limitations of the  existing schemes from the perspectives of the network architecture,  random access procedure, and multiple access techniques. Here, we  specify the massive access challenges and reveal that the facilitation  of MTC invokes a dramatically different access scheme from current ones  mainly designed for human-centric communications. Moreover, we propose  several promising massive access solutions to overcome the limitations,  where sufficient theoretical model and algorithm design guidance are  provided. Besides, detailed simulation and engineering implementation  methods are also included.