Growing demand for the Internet of Things (IoT) applications including smart cities, healthcare systems, smart grids, and transportation systems, has enhanced the popularity of Machine-Type Communication (MTC) in 5G and 6G cellular networks significantly. Massive access is a well-known challenge in MTC that should be efficiently managed. In this paper, a grant-based massive access mechanism is introduced where time-frames are separated into two distinct parts; one for contention-based resource granting and the other for scheduled data transmission. In the contention period, we propose a novel random access mechanism where the nodes are grouped based on their distances from the Base Station (BS), and the access probability of each group member is adjusted through solving an optimization problem. In the proposed mechanism, energy efficiency, spectrum efficiency and access delay are formulated in terms of the access probability of devices using p-persistent CSMA method. Thereafter, some optimization problems are formulated to improve the energy/spectrum efficiency and access delay by adjusting the access probability of devices while regarding their delay requirements. The simulation results indicate that the proposed method is better than the previous ones considering energy efficiency, access delay, bandwidth efficiency, and scalability. Also, in the proposed method, delay-sensitive nodes experience lower access delay.

对包括智能城市，医疗保健系统，智能电网和交通运输系统在内的物联网（IoT）应用程序的需求不断增长，极大地提高了机器类型通信（MTC）在5G和6G蜂窝网络中的普及率。大规模访问是MTC中众所周知的挑战，应该对其进行有效管理。在本文中，介绍了一种基于授权的大规模访问机制，其中将时间框架分为两个不同的部分：一个用于基于竞争的资源授予，另一个用于计划的数据传输。在竞争期间，我们提出了一种新颖的随机访问机制，其中，根据节点与基站（BS）的距离对节点进行分组，并通过解决优化问题来调整每个组成员的访问概率。在拟议的机制中，能源效率，使用p-persistent CSMA方法根据设备的访问概率来制定频谱效率和访问延迟。此后，提出了一些优化问题，以通过在考虑设备延迟需求的同时调整设备的访问概率来提高能量/频谱效率和访问延迟。仿真结果表明，在能量效率，访问延迟，带宽效率和可伸缩性方面，该方法优于以前的方法。而且，在所提出的方法中，对延迟敏感的节点经历较低的访问延迟。提出了一些优化问题，以通过在考虑设备延迟需求的同时调整设备的访问概率来提高能量/频谱效率和访问延迟。仿真结果表明，在能量效率，访问延迟，带宽效率和可伸缩性方面，该方法优于以前的方法。而且，在所提出的方法中，对延迟敏感的节点经历较低的访问延迟。提出了一些优化问题，以通过在考虑设备延迟需求的同时调整设备的访问概率来提高能量/频谱效率和访问延迟。仿真结果表明，在能量效率，访问延迟，带宽效率和可伸缩性方面，该方法优于以前的方法。而且，在所提出的方法中，对延迟敏感的节点经历较低的访问延迟。