Active queue management as quality of service enabler for 5G networks

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.5G is envisioned as the key technology for guaranteeing low-latency wireless services. Packets will be marked with QoS Flow Indicators (QFI) for different forwarding treatment. 3GPP defines the end-to-end delay limits, but leaves the QoS provisioning methods as implementation dependent. Different services with different constraints will inevitably share queues at some network entity. On the one hand, maintaining the shared queues uncongested will guarantee a rapid packet delivery to the subsequent entity. A brief sojourn time is indispensable for an on time low-latency priority traffic delivery. On the other hand, if shared queues are maintained undersized, throughput will be squandered. In this paper, we propose the use of AQM techniques in 5G networks to guarantee delay limits of QoS flows. Through the evaluation of realistic delay-sensitive and background traffic, we compare different possible solutions. We show that AQM mechanisms together with limited queues, maintain the system uncongested, which reduces drastically the delay, while effectively achieving the maximum possible throughput.Peer ReviewedPostprint (author's final draft

Chained Orchestrator Algorithm for RAN-Slicing Resource Management: A Contribution to Ultra-Reliable 6G Communications

The exponentially growing trend of Internet-connected devices and the development of new applications have led to an increase in demands and data rates flowing over cellular networks. If this continues to have the same tendency, the classification of 5G services must evolve to encompass emerging communications. The advent of the 6G Communications concept takes this into account and raises a new classification of services. In addition, an increase in network specifications was established. To meet these new requirements, enabling technologies are used to augment and manage Radio Access Network (RAN) resources. One of the most important mechanisms is the logical segmentation of the RAN, i.e. RAN-Slicing. In this study, we explored the problem of resource allocation in a RAN-Slicing environment for 6G ecosystems in depth, with a focus on network reliability. We also propose a chained orchestrator algorithm for dynamic resource management that includes estimation techniques, inter-slice resource sharing and intra-slice resource assignment. These mechanisms are applied to new types of services in the future generation of cellular networks to improve the network latency, capacity and reliability. The numerical results show a reduction in blocked connections of 38.46% for eURLLC type services, 21.87% for feMBB services, 12.5% for umMTC, 11.86% for ELDP and 11.76% for LDHMC.Spanish National Program of Research, Development, Innovation, under Grant RTI2018-102002-A-I00Junta de Extremadura under Project IB18003 and Grant GR2109

End-to-End Simulation of 5G mmWave Networks

Due to its potential for multi-gigabit and low latency wireless links, millimeter wave (mmWave) technology is expected to play a central role in 5th generation cellular systems. While there has been considerable progress in understanding the mmWave physical layer, innovations will be required at all layers of the protocol stack, in both the access and the core network. Discrete-event network simulation is essential for end-to-end, cross-layer research and development. This paper provides a tutorial on a recently developed full-stack mmWave module integrated into the widely used open-source ns--3 simulator. The module includes a number of detailed statistical channel models as well as the ability to incorporate real measurements or ray-tracing data. The Physical (PHY) and Medium Access Control (MAC) layers are modular and highly customizable, making it easy to integrate algorithms or compare Orthogonal Frequency Division Multiplexing (OFDM) numerologies, for example. The module is interfaced with the core network of the ns--3 Long Term Evolution (LTE) module for full-stack simulations of end-to-end connectivity, and advanced architectural features, such as dual-connectivity, are also available. To facilitate the understanding of the module, and verify its correct functioning, we provide several examples that show the performance of the custom mmWave stack as well as custom congestion control algorithms designed specifically for efficient utilization of the mmWave channel.Comment: 25 pages, 16 figures, submitted to IEEE Communications Surveys and Tutorials (revised Jan. 2018

Resource slicing in virtual wireless networks: a survey

New architectural and design approaches for radio access networks have appeared with the introduction of network virtualization in the wireless domain. One of these approaches splits the wireless network infrastructure into isolated virtual slices under their own management, requirements, and characteristics. Despite the advances in wireless virtualization, there are still many open issues regarding the resource allocation and isolation of wireless slices. Because of the dynamics and shared nature of the wireless medium, guaranteeing that the traffic on one slice will not affect the traffic on the others has proven to be difficult. In this paper, we focus on the detailed definition of the problem, discussing its challenges. We also provide a review of existing works that deal with the problem, analyzing how new trends such as software defined networking and network function virtualization can assist in the slicing. We will finally describe some research challenges on this topic.Peer ReviewedPostprint (author's final draft

Rate-Splitting Enabled Multi-Connectivity in Mixed-Criticality Systems

The enormous quality of service (QoS) demands posed by mission-critical use-cases of future 5G/6G wireless communication raise the need for resource-efficient highly reliable and low latency connectivity solutions. Multi-connectivity is considered a promising yet resource demanding approach to enhance reliability. In this work, we study the potential of the rate-splitting multiple access (RSMA) framework as an efficient way to enable uplink multi-connectivity for data transmissions with particularly high reliability requirements. Mapping high-criticality data onto the common stream allows it to be decoded at multiple access points (APs), which enhances reliability, while the private stream is utilized to serve applications with less stringent requirements. We propose a criticality-aware RSMA-based transmission scheme with short blocklength coding and derive an iterative power allocation algorithm by means of successive convex approximation (SCA). The proposed scheme is shown to achieve an expanded stability rate region compared to two baseline schemes. Moreover, it turns out to be less impacted by short blocklength while leading to substantial rate gains, particularly in the high SNR regime.Comment: 6 pages, 4 figures, submitted to IEEE ICC 202

Integration of LoRa Wide Area Network with the 5G Test Network

Abstract. The global communication network is going through major transformation from conventional to more versatile and diversified network approaches. With the advent of virtualization and cloud technology, information technology (IT) is merging with telecommunications to alter the conventional approaches of traditional proprietary networking techniques. From radio to network and applications, the existing infrastructure lacks several features that we wished to be part of 5th Generation Mobile Networks (5G). Having a support for large number of applications, Internet of Things (IoT) will bring a major evolution by creating a comfortable, flexible and an automated environment for end users. A network having the capability to support radio protocols on top of basic networking protocols, when blended with a platform which can generate IoT use cases, can make the expectations of 5G a reality. Low Power Wide Area Network (LPWAN) technologies can be utilized with other emerging and suitable technologies for IoT applications. To implement a network where all the technologies can be deployed virtually to serve their applications within a single cloud, Network Functions Virtualization (NFV) and Software Defined Network (SDN) is introduced to implement such a networking possibility for upcoming technologies. The 5G Test Network (5GTN), a testbed for implementing and testing 5G features in real time, is deployed in virtual platform which allows to add other technologies for IoT applications. To implement a network with an IoT enabler technology, LoRa Wide Area Network (LoRaWAN) technology can be integrated to test the feasibility and capability of IoT implications. LoRaWAN being an IoT enabler technology is chosen out of several possibilities to be integrated with the 5GTN. Using MultiConnect Conduit as a gateway, the integration is realized by establishing point to point protocol (PPP) connection with eNodeB. Once the connection is established, LoRa packets are forwarded to the ThingWorx IoT cloud and responses can be received by the end-devices from that IoT cloud by using Message Queuing Telemetry Transport (MQTT) protocol. Wireshark, an open source packet analyser, is then used to ensure successful transmission of packets to the ThingWorx using the 5GTN default packet routes

General QoS-Aware Scheduling Procedure for Passive Optical Networks

Increasing volume, dynamism, and diversity of access traffic have complicated the challenging problem of dynamic resource allocation in passive optical networks. We introduce a general scheduling procedure for passive optical networks, which optimizes a desired performance metric for an arbitrary set of operational constraints. The proposed scheduling has a fast and causal iterative implementation, where each iteration involves a local optimization problem followed by a recursive update of some status information. The generality of the platform enables a proper description of the diverse quality of service requirements, while its low computational complexity makes agile tracking of the network dynamism possible. To demonstrate its versatility and generality, the applications of the scheme for service-differentiated dynamic bandwidth allocation in time- and wavelength-division-multiplexed passive optical networks are discussed. To further reduce the computational complexity, a closed-form solution of the involved optimization in each iteration of the scheduling is derived. We directly incorporate transmission delay in the scheduling and show how the consumed power is traded for the tolerable amount of transmission delay. Furthermore, a 50% power efficiency improvement is reported by exploiting the inherent service diversity among subscribers. The impact of service prioritization, finite buffer length, and packet drops on the power efficiency of the scheme are also investigated