Carlos A. Astudillo

The impact of massive machine type communication devices on the access probability of human-to-human users in LTE networks

Machine-type Communication (MTC) enables devices to exchange information in an autonomous way without human intervention. Hence, new applications can be developed benefiting from a richer awareness of the surrounding environment. However, the deployment of MTC over cellular networks creates new challenges to the contention-based Random Access (RA) procedure as well as to resource allocation for MTC devices with low impact on Human-to-Human (H2H) services. In this paper, we analyze the impact of massive number of MTC devices on traditional H2H users in Long Term Evolution (LTE) network. We compare the performance of three Radio Access Network (RAN) overload control schemes proposed by the 3rd Generation Partnership Project (3GPP) for the contention-based RA procedure in this network. Results derived via simulation show that the access probability of Human-type Communication (HTC) users can be jeopardized by the large number of MTC devices. Therefore, enhanced mechanisms for the contention-based RA procedure in LTE network need to be investigated in order to support the expected large number of MTC devices and the traditional H2H users in the same infrastructure.

LTE time-domain uplink scheduler for QoS provisioning

This paper introduces a novel time-domain (TD) LTE uplink scheduler called Z-Based QoS Scheduler (ZBQoS) which is fully standard-compliant. The ZBQoS scheduler provides Quality of Service (QoS) requirements, supporting delay bound and guaranteed rate even when the network is heavily loaded. We evaluate the proposed scheduler under heterogeneous traffic and compare its performance to that of another TD scheduler, called Bandwidth and QoS Aware (BQA), recently proposed. Simulation results show that ZBQoS scheduler reduces significantly delay of real-time traffic, while it is able to maintain lower packet loss ratio (PLR), when compared with the performance of the BQA scheduler which greatly surpasses the recommended PLR value under heavily loaded scenarios.

Allocation of Control Resources for Machine-to-Machine and Human-to-Human Communications Over LTE/LTE-A Networks

The Internet of Things (IoT) paradigm stands for virtually interconnected objects that are identifiable and equipped with sensing, computing, and communication capabilities. Services and applications over the IoT architecture can take benefit of the long-term evolution (LTE)/LTE-Advanced (LTE-A), cellular networks to support machine-type communication (MTC). Moreover, it is paramount that MTC do not affect the services provided for traditional human-type communication (HTC). Although previous studies have evaluated the impact of the number of MTC devices on the quality of service (QoS) provided to HTC users, none have considered the joint effect of allocation of control resources and the LTE random-access (RA) procedure. In this paper, a novel scheme for resource allocation on the packet downlink (DL) control channel (PDCCH) is introduced. This scheme allows PDCCH scheduling algorithms to consider the resources consumed by the random-access procedure on both control and data channels when prioritizing control messages. Three PDCCH scheduling algorithms considering RA-related control messages are proposed. Moreover, the impact of MTC devices on QoS provisioning to HTC traffic is evaluated. Results derived via simulation show that the proposed PDCCH scheduling algorithms can improve the QoS provisioning and that MTC can strongly impact on QoS provisioning for real-time traffic.

The Random Access Procedure in Long Term Evolution Networks for the Internet of Things

Network connectivity is a key issue in the realization of IoT, and LTE cellular technology is the most promising option for the provisioning of such connectivity. However, in LTE networks, a large number of IoT devices trying to access the medium can overload the RAN. In this article, we review the LTE random access procedure and its support for IoT applications. We also assess the performance of the RAN overload control schemes proposed by 3GPP, taking into consideration the interaction between the random access procedure and packet downlink control channel resource allocation.

Impact of M2M traffic on human-type communication users on the LTE uplink channel

The worldwide markets for Machine-type Communication (MTC) over cellular networks are expected to grow in the incoming years. However, since MTC is quite different than existing Human-type Communication (HTC), it poses significant challenges to the cellular networks. Large number of MTC devices are anticipated to be operating in the future Long Term Evolution (LTE) networks, bringing several service requirements. The LTE standard suffers from excessive Physical Downlink Control Channel (PDCCH) overhead associated with the radio resource allocation method for small, sporadic traffic per terminal which is the nature of Machine-to-Machine (M2M) traffic. The rigid Quality of Service (QoS) support framework of LTE for voice and data services also fails to address specific QoS requirements of M2M traffic. This paper focuses on describing the impact of M2M traffic on the performance of the HTC users in LTE Frequency Division Duplexing (FDD) uplink. Simulation results show the impact of M2M traffic on the performance of different types of Human-to-Human (H2H) services (Voice-over-IP (VoIP), video and CBR), when using a QoS-aware packet scheduling. Although MTC in LTE networks impacts HTC, the utilization of a semi-persistent scheduling scheme to VoIP traffic can reduce such impact.

LTE scheduler for LTE/TDM-EPON integrated networks

This paper introduces a novel LTE uplink scheduler called Hybrid Z-Based QoS Scheduler (HZBQoS), a fully standard-compliant LTE scheduler designed to operate in ONU-eNB devices of integrated LTE/TDM-EPON networks. The HZBQoS scheduler provides delay bound and guaranteed rate even when the backhaul and mobile network are heavily loaded. We evaluated the proposed scheduler under heterogeneous traffic and compared its performance to that of another LTE uplink scheduler, called Z-Based QoS Scheduler (ZBQoS), which does not take into account the variability of the backhaul link capacity. Simulation results show that HZBQoS is able to provide QoS requirements in the integrated network and outperforms the ZBQoS scheduler.

Allocation of control resources with preamble priority awareness for human and machine type communications in LTE-Advanced networks

In this paper, we introduce the Preamble Priority-Aware (PPA) Packet Downlink Control Channel (PDCCH) resources allocation algorithm to provide Quality of Service (QoS) differentiation in the Random Access (RA) procedure of the LTE-Advanced technology. The PPA algorithm uses the preamble priority defined by the RA procedure and Radio Access Network (RAN) overload control schemes to make scheduling decisions. Results derived via simulation show that the proposed PDCCH algorithm significantly increases the chance of accessing the network as well as reducing random-access delays for user equipment employing prioritized preamble sequences. Thus, the proposed algorithm provides enhanced QoS support to prioritized users during intense RA attempts.

PM²PLS: Integrating Proxy Mobile IPv6 and MPLS in Wireless Access Networks

This paper proposes a handover scheme supporting Multi-Protocol Label Switching (MPLS) in a Proxy Mobile IPv6 (PMIPv6) domain that improves the mobility and gives Quality of Service (QoS) and Traffic Engineering (TE) capabilities in a mobile MPLS access network. The proposed scheme takes advantage of both PMIPv6 and MPLS. PMIPv6 was designed to provide Network-based Localized Mobility Management (NETLMM) to a Mobile Node (MN), therefore, the MN does not perform any mobility related signaling, while MPLS is used as an alternative tunnel technology between the Mobile Access Gateway (MAG) and the Local Mobility Anchor (LMA) by replacing the IP-in-IP tunnels with Label Switched Path (LSP) tunnels. It can also be integrated with other Quality of Service (QoS) architectures as the Differentiated Services (DiffServ) one or the Integrated Services (IntServ) one. In this study, we used MATLAB to perform an analysis to evaluate the impact of introducing MPLS technology in PMIPv6 domain based on handover latency and this was compared with PMIPv6 and a PMIPv6/MPLS integration. We proved that the proposed scheme can obtain better handover performance than other proposed schemes.