Congestion Control for Machine-Type Communications in LTE-A Networks

Abstract

Abstract-Collecting data from a tremendous amount of Internet-of-Things (IoT) devices for next generation networks is a big challenge. A large number of devices may lead to severe congestion in Radio Access Network (RAN) and Core Network (CN). 3GPP has specified several mechanisms to handle the congestion caused by massive amounts of devices. However, detailed settings and strategies of them are not defined in the standards and are left for operators. In this paper, we propose two congestion control algorithms which efficiently reduce the congestion. Simulation results demonstrate that the proposed algorithms can achieve 20∼40% improvement regarding accept ratio, overload degree and waiting time compared with those in LTE-A.

A Hint-Based Random Access Protocol for mMTC in 5G Mobile Network

“…The configuration strategies of barring factors are intensively studied by research communities (e.g., [7]- [10]). To facilitate devices escaping from continuous congestion, [7] proposes a cooperative barring for global stabilization and access load sharing.…”

“…Based on the work [8], reference [9] introduces an iterative algorithm to update the barring factors, which yields near-optimal performance and a reduction in the total service time compared with [8]. The authors of [10] proposed two queueing model based algorithms to adjust the barring factors and backoff timers to control RA congestion. Our work differs from the above schemes in that we reserve some preambles for paged UEs to guarantee success, but still maintain the flexibility for the remaining UEs for RA process.…”

“…Reducing RA collisions has been studied through preamble allocation (e.g., [3]- [5]) and access barring (e.g., [6]- [10]). Preamble allocation schemes split RA preambles for different access purposes.…”

r-Hint: A message-efficient random access response for mMTC in 5G networks

“…If this happens, the UE needs to backoff and contend again in the next round of RACH. To increase the success probability of RA, existing work either allocates more RACHs [1]- [4] or uses Extended Access Barring (EAB) [5]- [9] to control the number of contending UEs per RACH. However, for massive MTC (mMTC) devices in an eNB, maintaining a similar success probability implies more frequent RACHs, as shown in Fig.…”

Latency Efficient Request Access Rate for Congestion Reduction in LTE MTC

“…Among others, the evolved Node B (eNB) can prevent devices from accessing the network during predefined periods [3] or can adapt the backoff interval [4]. Another efficient solution to reduce congestion in LTE-MTC lies in adapting the Request Access Rate.…”