Multiband Massive Channel Random Access in Ultra-Reliable Low-Latency Communication

Abstract

Ultra-Reliable Low-Latency Communication (URLLC) is challenging due to its extremely higher reliability requirement with stringent short latency packet transmission. In order to overcome this reliability and latency bound, a communication access scheme needs to assure almost error-free and high speed packet transmission. In this paper, a new multiple-access scheme-Orthogonal Frequency-Subcarrier-based Multiple Access (OFSMA)-is proposed with URLLC's high requirement adaptation. In this scheme, the packet diversity concept is incorporated to achieve the expected packet transmission reliability and a diverse number of the duplicated packet are processed with a set of operations and transmitted over randomly selected orthogonal subcarrier frequency channels. Performances of the OFSMA system are measured in terms of applying several numbers of frequency bands, a massive number of subcarrier channels, a different number of packet duplications, and a diverse rate of traffic arrival conditions. We determined the minimum number of subcarrier channels requirement to satisfy the reliability of 99.999% for different packet duplication in presence of different frequency bands. The reliability response for a fixed number of subcarrier channels is evaluated for different frequency band conditions. Finally, the air interface latency of the OFSMA system is measured for single packet uplink transmission and compared with that of a traditional OFDMA system. The performance results in terms of reliability and latency express that the OFSMA scheme can assure the expected reliability and latency defined by URLLC.

Signal Propagation Through the Inside of Robot Leg for Non-wired Robot System

“…In order to manage the transmission between different wireless sensors, the hybrid scheme is proposed which combines with OFSMA [11] and waveguide in Figure. Basically, there are three kinds of sensors in a robot system: general sensors, video sensors, and audio sensors.…”

“…Nowadays, Robots are combined with many different components and connected with many cables [4]. One of the famous robotic topics is how to remove the wire inside Figure 1.2.1: A typical humanoid robot with a large number of audio, video and general sensors [9]. robots.…”

“…Before transmitting a packet, the transmitter will duplicate the packet, and choose a random frequency subcarrier to transmit the packet. Among the duplicate packet, if one packet is successfully received by the receiver, the transmission is regarded as successful transmission and the receiver discard the other replicated copies of the same packets [9].…”

Machine Learning Enables Radio Resource Allocation in the Downlink of Ultra-Low Latency Vehicular Networks

“…Rich works have explored the realization and improvement of URLLC network performance from the following three aspects: (1) Some focus on enhancing existing technologies [5], such as HARQ [6]- [8], radio access [9], code [10], MIMO [11], grant-free [12]- [14], NOMA [15], short packet transmission [16]. (2) Some restructure the network architecture by introducing fog computing and distributed network technologies, then optimize the uplink and downlink transmission, offloading, and online learning issues to reduce latency [17]- [19].…”