QOE-ORIENTED MULTIMEDIA DELIVERY ALGORITHM FOR E-LEARNING IN NEXT GENERATION WIRELESS NETWORKS
Authors: Muntean Vasile horia , Otesteau Marius 
Published: February 2023

During the last years, many research efforts in e-learning were focused on developing new content delivery algorithms able to improve the quality of the learning process from content distribution point of view. This is a pressing problem as an increasing number of users are accessing learning content from mobile devices via wireless networks. E-learning involves multiple activities (i.e. web browsing, video and audio streaming, interactive voice calls and ftp background traffic exchange) and various applications that are generating a rich traffic mix. Managing traffic flows is a difficult problem, especially when they are delivered over wireless networks. This is because wireless technologies have limited radio resources and are highly susceptible of being affected by environmental factors, traffic load, number of clients and their mobility patterns. Additionally delivering multimedia traffic with large bandwidth requirements and high sensitivity to loss and delay variations in these wireless environments at high quality levels constitutes significant challenge. Moreover if the end goal is learning and involves users with various profiles, there is an important pressure in developing excellent adaptive solutions to distribute the multimedia content.
The paper will describe in detail a novel solution for adaptive multimedia content delivery over wireless networks, the Dynamic Quality-Oriented Adaptation Scheme (DQOAS) which focuses on mobile e-learning. The proposed algorithm concentrates on performing multimedia content management in accordance with end-user learning profile, including their preferences and network conditions. By using DQOAS the end-user quality of experience (QoE) during learning process is improved, as shown in previous papers that investigates the benefits of the algorithm when IEEE802.11 networks are used. The paper presents also the behavior of DQOAS for multimedia content delivery in next generation networks, and in particular over Long Term Evolution (LTE) networks.
LTE is an all-IP network technology standardised by the 3rd Generation Partnership Project (3GPP) in Release 8 which uses new multiple access schemes on the air interface. Orthogonal Frequency Division Multiple Access (OFDMA) is used in the downlink and Single Carrier Frequency Division Multiple Access (SC-FDMA) is employed in the uplink to fulfil all the ambitious requirements for data rate, spectrum efficiency, latency, and capacity. Another important technique used is Multiple Input Multiple Output (MIMO) that involves using multiple transmitters and receivers to achieve higher bit rates and improved coverage. An important aspect in LTE is Quality of Service (QoS) support. The 3GPP QoS concept is based on traffic differentiation and prioritization of data flows, using network-initiated bearers in conjunction with simple QoS profiles based on QoS Class Identifiers (QCI). This paper proposes a new QoS delivery parameter mapping which complements LTE QoS class mapping, most beneficial for the case of e-learning traffic mix, in order to obtain higher end-user QoE levels when used in conjunction with DQOAS. The proposed solution improves the overall QoE for the end-user.
The paper will be structured as follows. Section II will present the technical aspects and the studies performed by researchers regarding LTE QoS parameters and scheduling in case of traffic mix connections for both downlink and uplink. Section III will describe the DQOAS algorithm. Section IV will present the functioning of the algorithm followed by test results in section V. Conclusions will be drawn in section VI.