Machine To Machine Overlay Network Over Random Access Channel Of LTE For Smart City

The purpose of this dissertation work is to investigate the perspective of the application areas of machine to machine (M2M) communications specifically to build smart city. To have ubiquitous coverage over the city, we consider cellular infrastructure. We propose a M2M overlay network over the physical random access channel (PRACH) of LTE. Based on this architecture, we conduct a case study in a vehicular context and proposed a non-priority CSMA/CA based vehicular M2M (VM2M) overlay networks. The overlay architecture is implemented using a dedicated subset of preambles at the physical layer, and a carrier sense multiple access with collision avoidance (CSMA/CA) mechanism similar to the one used in IEEE 802.15.4 at the medium access control (MAC) layer. We evaluate the performance and interaction of regular human to human (H2H) traffic and VM2M traffic, in particular, the impact of RACH resource configuration and preamble format (PF) in large cells. We have shown that the proposed LTE based VM2M architecture is better suited for smart city scenarios with higher vehicular speed and larger distances without sacrificing performance of H2H traffic. To transmit priority messages with high data rate and more reliably, we also propose a novel priority based CSMA/CA machine to machine (PM2M) overlay network over LTE. The PM2M overlay‘s MAC is more sophisticated with priorities. The architecture is same in the physical layer with dedicated preambles and in MAC layer priority based CSMA/CA is used, which is similar to the one of IEEE 802.15.6. Finally, We propose an analytical model to evaluate the impact of error in the MAC layer of overlay networks during sensing the medium. We develop a 3 dimensional Discrete Time Markov chain (DTMCs) in order to model the backoff procedure of CSMA/CA mechanism with backoff error. We investigated the capacity of PM2M networks for with and without considering backoff error. We have shown that overlay network allows fair coexistence of PM2M and H2H traffic. To validate our scheme we compare the proposed approach with a reference approach. By performance evaluation, we have shown that PM2M overlay out performs compared with reference approach.

Machine To Machine Overlay Network Over Random Access Channel Of LTE For Smart City

The purpose of this dissertation work is to investigate the perspective of the application areas of machine to machine (M2M) communications specifically to build smart city. To have ubiquitous coverage over the city, we consider cellular infrastructure. We propose a M2M overlay network over the physical random access channel (PRACH) of LTE. Based on this architecture, we conduct a case study in a vehicular context and proposed a non-priority CSMA/CA based vehicular M2M (VM2M) overlay networks. The overlay architecture is implemented using a dedicated subset of preambles at the physical layer, and a carrier sense multiple access with collision avoidance (CSMA/CA) mechanism similar to the one used in IEEE 802.15.4 at the medium access control (MAC) layer. We evaluate the performance and interaction of regular human to human (H2H) traffic and VM2M traffic, in particular, the impact of RACH resource configuration and preamble format (PF) in large cells. We have shown that the proposed LTE based VM2M architecture is better suited for smart city scenarios with higher vehicular speed and larger distances without sacrificing performance of H2H traffic. To transmit priority messages with high data rate and more reliably, we also propose a novel priority based CSMA/CA machine to machine (PM2M) overlay network over LTE. The PM2M overlay‘s MAC is more sophisticated with priorities. The architecture is same in the physical layer with dedicated preambles and in MAC layer priority based CSMA/CA is used, which is similar to the one of IEEE 802.15.6. Finally, We propose an analytical model to evaluate the impact of error in the MAC layer of overlay networks during sensing the medium. We develop a 3 dimensional Discrete Time Markov chain (DTMCs) in order to model the backoff procedure of CSMA/CA mechanism with backoff error. We investigated the capacity of PM2M networks for with and without considering backoff error. We have shown that overlay network allows fair coexistence of PM2M and H2H traffic. To validate our scheme we compare the proposed approach with a reference approach. By performance evaluation, we have shown that PM2M overlay out performs compared with reference approach.

A Poisson Process-Based Random Access Channel for 5G and Beyond Networks

The 5th generation (5G) wireless networks propose to address a variety of usage scenarios, such as enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC). Due to the exponential increase in the user equipment (UE) devices of wireless communication technologies, 5G and beyond networks (B5G) expect to support far higher user density and far lower latency than currently deployed cellular technologies, like long-term evolution-Advanced (LTE-A). However, one of the critical challenges for B5G is finding a clever way for various channel access mechanisms to maintain dense UE deployments. Random access channel (RACH) is a mandatory procedure for the UEs to connect with the evolved node B (eNB). The performance of the RACH directly affects the performance of the entire network. Currently, RACH uses a uniform distribution-based (UD) random access to prevent a possible network collision among multiple UEs attempting to access channel resources. However, in a UD-based channel access, every UE has an equal chance to choose a similar contention preamble close to the expected value, which causes an increase in the collision among the UEs. Therefore, in this paper, we propose a Poisson process-based RACH (2PRACH) alternative to a UD-based RACH. A Poisson process-based distribution, such as exponential distribution, disperses the random preambles between two bounds in a Poisson point method, where random variables occur continuously and independently with a constant parametric rate. In this way, our proposed 2PRACH approach distributes the UEs in a probability distribution of a parametric collection. Simulation results show that the shift of RACH from UD-based channel access to a Poisson process-based distribution enhances the reliability and lowers the network’s latency.

Preamble Design and Collision Resolution in a Massive Access IoT System

How to support massive access efficiently is one of the challenges in the future Internet of Things (IoT) systems. To address such challenge, this paper proposes an effective preamble collision resolution scheme to sustain massive random access (RA) for an IoT system. Specifically, a new sub-preamble structure is first proposed to reduce the preamble collision probability. To identify different devices that send the same preamble to the gNB on the same physical random access channel (PRACH), a multiple timing advance (TA) capturing scheme is then proposed. Thereafter, an RA scheme is designed to sustain massive access and the performance of the scheme is studied analytically. Finally, the effectiveness of the proposed RA scheme is validated by extensive simulation experiments in terms of preamble detection probability, preamble collision probability, RA success probability, resource efficiency and TA capturing.

Optimization of 5G Accessibility in Non Standalone and Standalone Mode

In this paper, we have analyzed and developed different types of algorithms related to 5G accessibility procedures for Non Standalone (NSA) and Standalone (SA) mode. The 5G accessibility depends on 5G radio parameters of each procedure, such as contention based Random access (CBRA), contention free random access (CFRA), Radio admission control (RAC), Radio resource control (RRC) and Radio bearer reconfiguration. The random access procedure for NSA is similar to SA mode. The goal is to improve the accessibility by optimizing timers and tune the main 5G radio parameters related to Random access channel (RACH), RRC reconfiguration and RAC procedures.