QoE-driven LTE Downlink Scheduling for Multimedia Services

The significant growth in multimedia services and traffic (e.g. VoIP, video streaming and video gaming) in current and emerging mobile networks including the latest 4G Long-Term Evolution (LTE) networks and the rising user expectation for high Quality of Experience (QoE) for these services have posed real challenges to network operators and service providers. One of the key challenges is how to bring multimedia services to the end-user over resource-constrained mobile networks with a satisfactory QoE. Cost-effective solutions are needed for network operators to improve the bandwidth usage of these mobile networks. Therefore, scheduling schemes are of extreme importance in LTE, where scheduling algorithms are responsible for the overall efficiency of resource allocation in an LTE system. The aim of the project is to develop novel QoE-driven scheduling algorithms for improving system capacity in delivering multimedia services over downlink 3GPP LTE. This is to move away from traditional QoS-driven scheduling schemes to a QoE-driven scheme which guarantee end-user satisfaction in resource allocation. The main contributions of the thesis are threefold: 1. Performance of several existing scheduling algorithms for VoIP applications was evaluated thoroughly in terms of QoE metric (i.e. MOS), instead of QoS metrics (e.g. packet loss and delay). Using QoE metrics instead of QoS ones will facilitate the development of QoE-driven scheduling schemes in order to achieve optimised end-user experiences or optimised mobile system capacity. 2. A novel QoE-driven LTE downlink scheduling scheme for VoIP application was developed to maximize the number of users per cell at an acceptable MOS score. The proposed scheme achieved significant improvement in cell capacity at an acceptable quality (75% compared to MLWDF, and 250% compared to PF and EXP-PF in all three lower speed scenarios considered). 3. A QoE-driven LTE downlink scheduling scheme for multiservice multimedia applications was developed to improve the cell capacity with satisfactory QoE for both VoIP and video streaming services. The proposed algorithm performed well in a pedestrian scenario increasing cell capacity to double for video stream with ‘Rapid Movement’ (RM) content. For ‘Medium Movement’ (MM) video content, the capacity was increased about 20% compared to MLWDF and by 40% compared to EXP-PF. In a vehicular scenario, the proposed scheme managed to enhance the cell capacity for MM video stream case. The project has led to three publications (IEEE Globecom’12 – QoEMC Workshop, IEEE CCNC’15 and IEEE MMTC E-letter/May-2015). A journal paper is in preparation.The Public Authority for Applied Education and Training , Kuwai

Environmental Policy Formation and the Tax Treatment of Citizen Interest Groups

With increasing technological advancements more sophisticated mobile devices are being used by end-users. Third generation (3G) mobile communication systems such as Universal Mobile Telecommunication System (UMTS) are not able to satisfy the rising demand for higher throughputs and low latencies. New standards based on Orthogonal Frequency Division Multiplexing (OFDM), such as Long Term Evolution (LTE) and Worldwide Interoperability for Microwave Access (WiMAX), have been proposed and are currently being integrated into existing mobile networks all over the world. LTE specifications are being finalized within the 3rd Generation Partnership Project (3GPP) with the ambitious goals of increased spectral efficiency and end user throughput. Despite the introduction of several high data rate services, voice communication is still an essential part of the overall wireless wide area cellular communication market. In LTE, the core network is purely packet switched, thus voice is transmitted entirely using a Voice over Internet Protocol (VoIP). Like its predecessor standards it is desired that a large number of simultaneous VoIP calls be supported in LTE, while satisfying the desired Quality of Service (QoS) demands. This thesis examines issues related to VoIP capacity for LTE. One of the key challenges is the limited number of schedulable voice packets per sub frame. The main goal of this thesis is to quantify the impact of this limitation. After describing basic LTE concepts, a detailed description of the control channel resource limitations for the scheduling of voice packets is presented. Consequences of these limitations are explained systematically by presenting the problem in a wider context. Simulation results were obtained using the openWNS Simulator, an event driven system level simulation platform developed at the Communication Networks Research Group (ComNets), RWTH Aachen University Germany. Results are presented showing the impact of different scheduling strategies on VoIP capacity. These results illustrate how the limited control channel resources, specifically the Physical Downlink Control Channel (PDCCH) resources, affect the total number of schedulable VoIP user audio media streams.Med ökande tekniska framsteg mer avancerade mobila enheter som används av slutanv ändarna. Tredje generationens (3G) mobila kommunikationssystem såsom Universal Mobile Telecommunication System (UMTS) inte kan tillgodose den ökande efterfrågan på högre genomströmning och låga latenser. Nya standarder som bygger på Orthogonal Frequency Division Multiplexing (OFDM), såsom Long Term Evolution (LTE) och Worldwide Interoperability för Microwave Access (WiMAX), har föreslagits och håller på att integreras I befintliga mobilnät över hela världen. LTE specifikationer håller på att färdigställas inom 3rd Generation Partnership Project (3GPP) med de ambitiösa målen om ökad spektral effektivitet och slutanvändare genomstr ömning. Trots införandet av flera tjänster av hög datahastighet, är röstkommunikation fortfarande en väsentlig del av den totala Wireless Wide Area cellulär kommunikation marknaden. I LTE är kärnnätet rent paketförmedlande därmed röst överförs helt och hållet med hjälp av en Voice over Internet Protocol (VoIP). Precis som sina föregångare standarder är det önskvärt att ett stort antal samtidiga VoIP samtal få stöd i LTE, samtidigt som det uppfyller önskade Quality of Service (QoS) krav. Denna avhandling undersöker frågor relaterade till VoIP kapacitet för LTE. En av de viktigaste utmaningarna är det begränsade antalet schemaläggningsbart röst paket per sub ram. Det huvudsakliga målet med denna avhandling är att kvantifiera effekterna av denna begränsning. Efter att ha beskrivit de grundläggande LTE begrepp, är en detaljerad beskrivning av de resurser kontroll kanal begränsningar för schemaläggning av röst paket presenteras. Konsekvenser av dessa begränsningar förklaras systematiskt genom att presentera problemet i ett större sammanhang. Simulering resultat erhölls med hjälp av openWNS Simulator, en händelse driven systemnivå simulering som utvecklats vid Communication Networks Research Group (ComNets), RWTH Aachen University Tyskland. Resultat presenteras som visar effekterna av olika schemaläggning strategier för VoIP kapacitet. Dessa resultat illustrerar hur de begränsade kontroll kanalresurser, särskilt fysiskt Downlink (PDCCH) resurser, påverkar det totala antalet schemaläggningsbart VoIP användare ljud mediaströmmar