scholarly journals Preamble Design and Collision Resolution in a Massive Access IoT System

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 250
Author(s):  
Ailing Zhong ◽  
Zhidu Li ◽  
Ruyan Wang ◽  
Xingjie Li ◽  
Boren Guo
Keyword(s):  
Detection Probability ◽  
Success Probability ◽  
Random Access ◽  
Future Internet ◽  
Collision Probability ◽  
Collision Resolution ◽  
Simulation Experiments ◽  
Access Channel ◽  
Resolution Scheme ◽  
Random Access Channel

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.

scholarly journals Adaptive Access Class Barring Method for Machine Generated Communications

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Jaesung Park ◽  
Yujin Lim
Keyword(s):  
Success Probability ◽  
Access Network ◽  
Random Access ◽  
Original Method ◽  
Collision Probability ◽  
Data Traffic ◽  
Coverage Area ◽  
Access Channel ◽  
Communication Devices ◽  
A Cell

Cellular network is provisioned to serve traffic demands generated by human being. The random access channel used for nodes to compete for a connection with an eNB is limited. Even though machines generate very small amount of data traffic, the signaling channel of a network becomes overloaded and collisions occur to fail the access if too many MTC (Machine Type Communication) devices attempt to access network. To tackle the issue, 3GPP specifies an access class barring but leaves a specific algorithm as an implementation issue. In this paper, we propose an adaptive access barring method. Generally, an eNB does not know the number of MTC devices in its coverage area. Thus, it is difficult to control the barring factor by predicting the number of MTC devices in a service area of a cell. On the contrary, we control the barring factor based on the prediction of access intensity which can be measured at an eNB. Simulation results show that since the proposed method can manipulate the barring factor autonomously according to the access intensity, it is superior to the original method in terms of the access success probability and the collision probability.

scholarly journals Exploiting the Capture Effect to Enhance RACH Performance in Cellular-Based M2M Communications

2017 ◽  
Author(s):  
Jonghun Kim ◽  
Jaiyong Lee
Keyword(s):  
Positive Impact ◽  
Success Probability ◽  
Random Access ◽  
Network System ◽  
Capture Effect ◽  
M2m Communication ◽  
Access Channel ◽  
Random Access Channel ◽  
Analysis Models ◽  
The Internet Of Things

Cellular-based machine-to-machine (M2M) communication is expected to facilitate services for the Internet of Things (IoT). However, because cellular networks are designed for human users, they have some limitations. Random access channel (RACH) congestion caused by massive access from M2M devices is one of the biggest factors hindering cellular-based M2M services because the RACH congestion causes random access (RA) throughput degradation and connection failures to the devices. In this paper, we show the possibility exploiting the capture effects, which have been known to have a positive impact on the wireless network system, on RA procedure for improving the RA performance of M2M devices. For this purpose, we analyze an RA procedure using a capture model. Through this analysis, we examine the effects of capture on RA performance and propose a Msg3 power-ramping (Msg3 PR) scheme to increase the capture probability (thereby increasing the RA success probability) even when severe RACH congestion problem occurs. The proposed analysis models are validated using simulations. The results show that the proposed scheme, with proper parameters, further improves the RA throughput and reduces the connection failure probability, by slightly increasing the energy consumption. Finally, we demonstrate the effects of coexistence with other RA-related scheme through simulation result.

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

Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 508
Author(s):  
Alaa Omran Almagrabi ◽  
Rashid Ali ◽  
Daniyal Alghazzawi ◽  
Abdullah AlBarakati ◽  
Tahir Khurshaid
Keyword(s):  
Poisson Process ◽  
Random Access ◽  
Communication Technologies ◽  
Channel Access ◽  
Access Channel ◽  
Machine Type Communications ◽  
Equal Chance ◽  
Random Access Channel ◽  
Access Mechanisms

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.

scholarly journals Multiple Slot Reservation for Rapid Data Traffic Transmission in the Satellite Random Access Channel

2015 ◽  
Vol 40 (10) ◽  
pp. 1889-1899 ◽  
Author(s):  
Yun-sung Lee ◽  
Jin-seok Lee ◽  
Jae-sung Lim ◽  
Hyung-won Park ◽  
Hong-jun Noh
Keyword(s):  
Random Access ◽  
Data Traffic ◽  
Access Channel ◽  
Random Access Channel

scholarly journals Optimization of 5G Accessibility in Non Standalone and Standalone Mode

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Admission Control ◽  
Random Access ◽  
Resource Control ◽  
Radio Resource ◽  
Access Channel ◽  
Different Types ◽  
Random Access Channel

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.

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