Analysis of Uplink Scheduling for Haptic Communications

While new mechanisms and configurations of the 5G radio are offering step forward in delivery of ultra-reliable low latency communication services in general, and haptic communications in particular, they could inversely impact the remainder of traffic services. In this paper, we investigate the uplink access procedure, how different advances in this procedure enhance delivery of haptic communication, and how it affects the remainder of traffic services in the network. We model this impact as the remainder of service, using stochastic network calculus. Our results show how best the tradeoff between faster or more resource efficient uplink access can be made depending on the rate of haptic data, which is directly relevant to the application domain of haptic communication.Comment: 8 pages, 14 figures, conference pape

Reliable and Low-Latency Fronthaul for Tactile Internet Applications

With the emergence of Cloud-RAN as one of the dominant architectural solutions for next-generation mobile networks, the reliability and latency on the fronthaul (FH) segment become critical performance metrics for applications such as the Tactile Internet. Ensuring FH performance is further complicated by the switch from point-to-point dedicated FH links to packet-based multi-hop FH networks. This change is largely justified by the fact that packet-based fronthauling allows the deployment of FH networks on the existing Ethernet infrastructure. This paper proposes to improve reliability and latency of packet-based fronthauling by means of multi-path diversity and erasure coding of the MAC frames transported by the FH network. Under a probabilistic model that assumes a single service, the average latency required to obtain reliable FH transport and the reliability-latency trade-off are first investigated. The analytical results are then validated and complemented by a numerical study that accounts for the coexistence of enhanced Mobile BroadBand (eMBB) and Ultra-Reliable Low-Latency (URLLC) services in 5G networks by comparing orthogonal and non-orthogonal sharing of FH resources.Comment: 11pages, 13 figures, 3 bio photo

Latency Bounds of Packet-Based Fronthaul for Cloud-RAN with Functionality Split

The emerging Cloud-RAN architecture within the fifth generation (5G) of wireless networks plays a vital role in enabling higher flexibility and granularity. On the other hand, Cloud-RAN architecture introduces an additional link between the central, cloudified unit and the distributed radio unit, namely fronthaul (FH). Therefore, the foreseen reliability and latency for 5G services should also be provisioned over the FH link. In this paper, focusing on Ethernet as FH, we present a reliable packet-based FH communication and demonstrate the upper and lower bounds of latency that can be offered. These bounds yield insights into the trade-off between reliability and latency, and enable the architecture design through choice of splitting point, focusing on high layer split between PDCP and RLC and low layer split between MAC and PHY, under different FH bandwidth and traffic properties. Presented model is then analyzed both numerically and through simulation, with two classes of 5G services that are ultra reliable low latency (URLL) and enhanced mobile broadband (eMBB).Comment: 6 pages, 7 figures, 3 tables, conference paper (ICC19

An SDR-Based Experimental Study of Reliable and Low-Latency Ethernet-Based Fronthaul with MAC-PHY Split

Cloud-Radio Access Network (RAN) is one of the architectural solutions for those mobile networks that aim to provide an infrastructure that satisfies the communication needs of a wide range of services and deployments. In Cloud-RAN, functions can be flexibly split between central and distributed units, which enables the use of different types of transport network. Ethernet-based fronthaul can be an attractive solution for Cloud-RAN. On the one hand, the deployment of Ethernet-based fronthaul enables Cloud-RAN to provide more diverse, flexible and cost-efficient solutions. On the other hand, Ethernet-based fronthaul requires packetized communication, which imposes challenges to delivering stringent latency requirements between RAN functionalities. In this paper, we set up a hardware experiment based on Cloud-RAN with a low layer split, particularly between medium access control and the physical layer. The aim is to demonstrate how multi-path and channel coding over the fronthaul can improve fronthaul reliability while ensuring that: (i) latency results meet the standard requirements; and (ii) the overall system operates properly. Our results show that the proposed solution can improve fronthaul reliability while latency remains below a strict latency bound required by the 3rd Generation Partnership Project for this functional split

Decentralized federated learning methods for reducing communication cost and energy consumption in UAV networks

Unmanned aerial vehicles (UAV) or drones play many roles in a modern smart city such as the delivery of goods, mapping real-time road traffic and monitoring pollution. The ability of drones to perform these functions often requires the support of machine learning technology. However, traditional machine learning models for drones encounter data privacy problems, communication costs and energy limitations. Federated Learning, an emerging distributed machine learning approach, is an excellent solution to address these issues. Federated learning (FL) allows drones to train local models without transmitting raw data. However, existing FL requires a central server to aggregate the trained model parameters of the UAV. A failure of the central server can significantly impact the overall training. In this paper, we propose two aggregation methods: Commutative FL and Alternate FL, based on the existing architecture of decentralised Federated Learning for UAV Networks (DFL-UN) by adding a unique aggregation method of decentralised FL. Those two methods can effectively control energy consumption and communication cost by controlling the number of local training epochs, local communication, and global communication. The simulation results of the proposed training methods are also presented to verify the feasibility and efficiency of the architecture compared with two benchmark methods (e.g. standard machine learning training and standard single aggregation server training). The simulation results show that the proposed methods outperform the benchmark methods in terms of operational stability, energy consumption and communication cost.Comment: 13 pages, 7 figure

Challenges and Opportunities for Designing Tactile Codecs from Audio Codecs

Haptic communications allows physical interaction over long distances and greatly complements conventional means of communications, such as audio and video. However, whilst standardized codecs for video and audio are well established, there is a lack of standardized codecs for haptics. This causes vendor lock-in and thereby greatly limits scalability, increases cost and prevents advanced usage scenarios with multi-sensors/actuators and multi-users. The aim of this paper is to introduce a new approach for understanding and encoding tactile signals, i.e. the sense of touch, among haptic interactions. Inspired by various audio codecs, we develop a similar methodology for tactile codecs. Notably, we demonstrate that tactile and audio signals are similar in both time and frequency domains, thereby allowing audio coding techniques to be adapted to tactile codecs with appropriate adjustments. We also present the differences between audio and tactile signals that should be considered in future designs. Moreover, in order to evaluate the performance of a tactile codec, we propose a potential direction of designing an objective quality metric which complements haptic mean opinion scores (h-MOS). This, we hope, will open the door for designing and assessing tactile codecs

Business Case and Technology Analysis for 5G Low Latency Applications

A large number of new consumer and industrial applications are likely to change the classic operator's business models and provide a wide range of new markets to enter. This article analyses the most relevant 5G use cases that require ultra-low latency, from both technical and business perspectives. Low latency services pose challenging requirements to the network, and to fulfill them operators need to invest in costly changes in their network. In this sense, it is not clear whether such investments are going to be amortized with these new business models. In light of this, specific applications and requirements are described and the potential market benefits for operators are analysed. Conclusions show that operators have clear opportunities to add value and position themselves strongly with the increasing number of services to be provided by 5G.Comment: 18 pages, 5 figure

Using energy criteria to admit flows in a wired network

Admission control in wired networks has been traditionally used as a way to control traffic congestion and guarantee quality of service. Here, we propose an admission control mechanism which aims to keep the power consumption at the lowest possible level by restricting the more energy-demanding users. This work relies on the fact that power consumption of networking devices, and of the network as a whole, is not proportional to the carried traffic, as would be the ideal case [1]. As a result some operating regions may be more efficient than others and ”jumps” may arise in power consumption when new traffic is added in the network. The proposed mechanism aims to keep power consumption in the lowest possible power consumption level, hopping to the next level only when necessary