A Novel Random Access Mechanism based on Realtime Access Intensity Detection The Random Access (RA) procedure in 4G LTE serves for the uplink synchronization between UE and eNB and the allocation of the channel resource for data transmission. The existing 4G LTE RA Channel (RACH) lacks the adjustment to the realtime RA traffic and suffers from preamble collision and system congestion caused by the RA request flooding, which will not meet the requirement of ubiquitous and massive connection in 5G. To better improve the system throughput and the RA success probability of RACH in the dense device network, we propose a novel congestionaware RA mechanism via a twophase process in which concurrent devices carry out a Realtime Access Intensity Detection (RAID) prior to RA preamble message. In this paper, we develop an analytical model based on stochastic geometry and derive the RA success probability of our proposed model for typical device in single RA slot. The analytical results demonstrate the improvement of our proposed RA mechanism in terms of RA success probability under heavy RA traffic. Furthermore, a large amount of simulations under homogeneous and cluster Poisson Point Process (PPP) is carried out to analyze the performance of the proposed RA mechanism in terms of the system throughput, the RA success probability, the number of retransmission and the RA delay.

Enhanced Radio Access Procedure in Sliced 5G Networks In this paper, we introduce the concept of Random Access Channel (RACH) resource slicing and investigate the performance of a sliced Radio Access Network (RAN). We consider three generic service types that the fifthgeneration (5G) wireless technology is claimed to support, and refer to them as enhanced mobile broadband (eMBB), massive machinetype communications (mMTC), and ultrareliable low latency communications (URLLC) slices. Each slice can be configured with dedicated and shared subsets of RAN and RACH resources, also known as RACH preambles. We propose an analytic framework that allows us to obtain the blocking probability of each slice in a closedform. We compare different resource allocation policies in sliced radio access system and investigate their impact on a slice performance.