Possibilities to Optimize QoS with Next SON Versions

Background. The introduction of fifth-generation (5G) networks creates new opportunities for fast and continuous data exchange, but there are still some problems with the quality of voice services in such networks. With the rapid development of technology and the further spread of 5G, there is a need to understand the impact of key aspects of 5G on voice quality. This requires research that can systematically analyse the features of 5G networks that affect the quality of voice services. Objective. Identification of ways to improve the quality of voice services in 5G networks. Assessment of key indicators of voice service quality in 5G networks. Determination of the best option for the gradual transition to the Standalone mode and the use of VoNR technology in the fifth generation networks. Methods. Analysis of factors affecting the quality of voice services in fifth-generation networks. Analysis of well-known publications on the implementation of 5G networks. Comparison of the implementation of Non-Standalone and Standalone modes in the 5G network. Testing of the modern EVS codec, which provides an opportunity to improve the customer experience. Results. Confirmation that 5G networks can significantly improve the quality of voice services compared to previous mobile communication technologies such as 4G and 3G. Certain factors that may affect the quality of voice services and require additional attention when planning and deploying 5G networks are identified. The optimal steps for the transition to the Standalone mode and the use of VoNR technology in fifth-generation networks are determined. The main differences in the QoS architecture between LTE and 5G are identified, and the purpose of DRB flows for separating traffic types and services is established. Conclusions. It has been confirmed that 5G networks can significantly improve the quality of voice services compared to previous technologies such as 4G and 3G. This is possible due to the broadband capabilities of 5G networks, improved data transmission, low latency, the use of an advanced EVS codec and reduced response time. However, certain factors, such as network coverage, optimisation level and traffic characteristics, can affect the quality of voice services and require additional attention when planning and deploying 5G networks. The QoS management architecture consists of QoS flows, which allow separating packet assignment to flows (managed by the CN) from the assignment of DRB flows (managed by the RAN). As 5G networks are being rolled out gradually, it is important to properly integrate the 5G domain into the existing telecoms provider's network. The transition from Non-Standalone to Dual connectivity is a necessary step for the implementation of VoNR technology in Standalone mode. Using the modern EVS codec allows not only improving the customer experience, but also introducing new voice services.

Network slicing is an architectural solution that enables the future 5G network to offer a high data traffic capacity and efficient network connectivity. Moreover, software defined network (SDN) and network functions virtualization (NFV) empower this architecture to visualize the physical network resources. The network slicing identified as a multiple logical network, where each network slice dedicates as an end-to-end network and works independently with other slices on a common physical network resources. Most user devices have more than one smart wireless interfaces to connect to different radio access technologies (RATs) such as WiFi and LTE, thereby network operators utilize this facility to offload mobile data traffic. Therefore, it is important to enable a network slicing to manage different RATs on the same logical network as a way to mitigate the spectrum scarcity problem and enables a slice to control its users' mobility across different access networks. In this paper, we propose a mobility management architecture based network slicing where each slice manages its users across heterogeneous radio access technologies such as WiFi, LTE and 5G networks. In this architecture, each slice has a different mobility demands and these demands are governed by a network slice configuration and service characteristics. Therefore, our mobility management architecture follows a modular approach where each slice has individual module to handle the mobility demands and enforce the slice policy for mobility management. The advantages of applying our proposed architecture include: i) Sharing network resources between different network slices; ii) creating logical platform to unify different RATs resources and allowing all slices to share them; iii) satisfying slice mobility demands.

The question of quality of service in networks of the latest generation is studied. The impact of heterogeneous traffic on the main quality of service indicators reflecting the probability of packet loss and delivery delay over time is evaluated. A model of quality of service in information communication networks has been developed to ensure low traffic delay. Taking into account the concept of quality in information communication networks, the issue of quality of service in networks of the latest generation becomes important from the standpoint of ensuring high reliability and reliability of information transmission, which significantly affects the quality of services provided to the user. This, of course, determines the need to control various parameters of equipment and communication lines, which are determined both by the features of the transmission system and by the parameters of leased channels and tracts. The basis for determining the quality of service, as mentioned above, is the provision of the international concept of quality of service (QoS). According to the requirements of the compliance control model proposed in the concept, the approach to quality indicators is structurally related to the OSI reference model. The main advantages of modern technologies of information communication networks are undoubtedly 5G technologies, which already support such resource-intensive services as massive machine-to-machine communication, ultra-reliable communication and low-latency communication. All of them require high data transfer rates, low millisecond latency, and connectivity of millions of devices. At the same time, it is necessary to ensure a high level of quality of service (QoS), which plays an important role in 5G technologies. The proposed model makes it possible to evaluate not only the quality of service of the combined traffic flow of Internet of Things, tactile Internet, and augmented reality services, but also the delivery delay and the probability of packet loss. The simulation results showed that the parameters of the quality of service of the traffic of the Internet of Things and other modern applications differ significantly during the service of the aggregate flow. When studying the service of aggregated traffic, it was established that the probability of packet loss is higher for it than for Internet of Things traffic. In addition, this difference becomes more significant when the intensity of the incoming load increases.

Self-Organizing Networks (SONs) are being researched extensively in the existing 3G and 4G landscape primarily to facilitate a convenient yet cost-effective approach in the configuration, optimization and troubleshooting of networks. However, the existing SONs will be no match for the operational complexity of the envisioned 5G networks. The promise of 5G revolves around the premise of infinite capacity and zero latency. 5G networks are set for commercial availability by 2020 and these networks will be part of a flexible and dynamic telecom ecosystem supporting cross-domain integration and multi-RAT environments. Network Densification, Network Function Virtualization, Flexible spectrum allocation, E2E security and Massive MTC are a few of the features promised by 5G networks. With this assortment of numerous technologies, it is obvious that SONs have to evolve beyond the existing reactive paradigm without which the maintenance and management of 5G networks would prove to be a herculean task. Hence, we propose a novel Proactive SON methodology based on the Big Data framework to enable the shift in the SON paradigm. In this article we present a comprehensive Big-Data based SON framework involving innovative Machine Learning techniques which would cater to scalability and programmability of 5G networks with respect to availability, reliability, speed, capacity, security and latency.

The rapid increment of mobile device usage and the corresponding huge data volume generated afterwards, necessitated the utilisation of the 5G network spectrum. This is deployed today in terrestrial communication in a non‐stand‐alone (NSA) architectural mode; where 5G networks are supported by 4G LTE networks. Hence, the current 5G implementation with the gargantuan number of mobile subscribers, poses challenges to the choice of network Radio Access Technology (RAT) selection between 4G and 5G networks, among available multiple base‐stations to mobile (travelling) users, with respect to their location, bandwidth requirement, and mobility style. Hence, to address the scenario presented above, the authors record live signal measurements of 4G and 5G networks by a travelling user, that transversed multiple 5G NSA base stations. RAT selection implementations were carried out with support vector machine (SVM), deep neural network (DNN), and eXtreme Gradient Boosting (XGBoost) algorithms to select an appropriate RAT between 4G and 5G RATs, for effective resource allocation for travelling users’ requirements. Evaluation of results with standard classification metrics shows XGBoost with overall outstanding accuracy performance at 99.64%.

In the first phase of 5G network deployment, User Equipment (UE) will camp traditionally on LTE network. Later on, if the UE requests a 5G service, it will be made to camp simultaneously on LTE and 5G. This dual-camping is enabled through a 3GPP-standardized approach known as E-UTRAN New-Radio Dual-Connectivity (EN-DC). Unlike single-networkcamping, where poor RF conditions of only one network affect user Quality-of-Experience (QoE), in EN-DC, poor RF condition in either LTE or 5G network can be detrimental to user QoE. Sub-optimal parameter configuration to activate EN-DC can hamper retainability KPI as UE may observe increased radio link failure (RLF). While the need to maximize the EN-DC activation is obvious for 5G network maximum utility, RLF avoidance is equally important to maintain the QoE requirements. We address this problem by first using Tomek Link to counter data imbalance problem and then building an AI model to predict RLF from real network low level measurements. We then propose and evaluate an RLF risk-aware EN-DC activation scheme that draws on insights from the developed RLF prediction model. Simulation using a 3GPP-compliant 5G simulator show that compared to no-conditioning on EN-DC activation, in the evaluated cell cluster, the proposed scheme can help reduce the potential RLF instances by 99%. This RLF reduction happens at the cost of 50% reduction in EN-DC activation. This is first study to present a framework and insights for operators to optimally conFigure the EN-DC activation parameters to achieve desired trade-off between maximizing 5G sites utility and QoE.

Fifth-generation (5G) networks are evolving from special purpose-built networks to software-defined, intelligent, multipurpose networks, enabling service innovation and autonomous network operation. In this article, we present an intelligent mobile edge network based on standardized 5G network function entities and New Radio (NR) radio access networks (RANs). We propose a multitier, self-organizing network (SON) with a middle-tier SON (mSON), centralized SON (cSON), and distributed SON (dSON) to support increasing network dynamicity for different verticals and to take advantage of the latest high-layer F1 interface. This is essential to support low-latency applications and ultrahigh-reliability services. It also enables more dynamically tight interworking of 5G NR and LTE with dual connectivity, expanding initial 5G NR coverage. We analyze a lower-layer RAN split to optimize fronthaul and so further improve radio efficiency by utilizing the multitier SON among various radio nodes as well as distributed units (DUs) and centralized units (CUs). This will facilitate massive multiple-input/multiple-output (MIMO) antenna systems and accelerate centralized and virtualized RAN deployments.

With deploying LTE (Long-Term Evolution) network operators are faced with managing up to three partly overlaying network deployments of different radio access technologies (RATs), for instance, GSM, UMTS and LTE. A concerted management of all three RATs requires self-organizing networks (SON) functionalities which have become an essential part of LTE. One prominent use case is mobility robustness optimization (MRO) and, recently, inter-RAT MRO has been discussed and specified in 3GPP as part of the Rel.11 SON framework. Hereto, a network deployment scenario was assumed where the existing legacy cellular network (for instance UMTS) provides full coverage, while LTE network deployment is limited to areas with high user penetration. Consequently, 3GPP focused on two inter-RAT failure cases, namely too late handover from LTE to 3G and too early handover from 3G to LTE, where the latter case refers to a handover triggered to LTE while the quality offered there is too poor to maintain the call. All other inter-RAT handover failure cases are not considered in Rel.11. In this paper, we investigate the performance of an inter-RAT MRO algorithm based on the Rel.11 capabilities with the reduced set of key performance indicators (KPIs) being applied to deployment scenario where 3G is not ubiquitous and LTE provides better coverage in some areas. The simulation results show that the algorithm with reduced KPI set performs very well for the considered limited LTE coverage scenario, but show expected deficiencies if deployment scenario changes.

The massive growth of IoT devices and the need for digitization drive future wireless communication technologies intensively. The end-users are always demanding all kinds of network services including the time-critical and mission-critical ones. The Quality of Network Services (QoNS) of the future 5G and 6G networks are aiming to address all possible types of flexible user demands optimally. Telecom. Service Providers (TSPs) are rigorously looking for suitable network architectures that can assist them to realize such user-friendly systems. vSDN or virtualized Software Defined Network Architecture is the key technology enabler that makes such functionalities possible. In the recent paradigm shift where everything is being based on IoT, service availability and system stability are two major concerns. For keeping the quality index of the network services high, it is essential to orchestrate and deploy the network infrastructures that will provide additional and upgraded network services. Keeping these fundamental issues in mind, in this work, we have proposed a novel multi-instance deployment strategy for Controllers and Hypervisors over an actual network topology. While defining the work, our prime concern targets improving service availability within the ULL (Ultra-Low Latency) environment. Thus, we have developed a Multi-Objective Mixed Integer Linear Programming (MILP) problem for optimally placing the hypervisors and controllers over the network topology to minimize the H-plane service agreements along with propagation latency of network function demands. After analyzing the results, it can be claimed that our approach has a significant impact in improving the QoS of network parameters. The proposed model can be applied in similar time-critical relocation problems associated with UAV-assisted networks depending upon various application domains.

Ubiquitous access to information anywhere, anytime and anyhow is a main feature of the upcoming 4G mobile communication networks, which will interconnect existing and future networks via common IP core. 4G networks are termed, therefore, as All-IP and are expected to provide higher bandwidth than currently obtained from 3G networks at lower costs. One of the main challenges arising while deploying these networks is the guarantee of fast and smooth mobility support for customers so that seamless functionality for ongoing applications can be guaranteed. As the mobility in heterogeneous network environments is becoming more complex to be handled by Mobile Nodes (MNs), network-based mobility management solutions are of major interest. Such solutions are currently being developed by the IETF working group NETLMM. The basic idea is to develop a new modular mobility management architecture that better accommodates any changes in technologies while reducing the complexity of the MN's stack software. The well-known proposal of the NETLMM working group is Proxy MIPv6 (PMIPv6), which tries to support mobility without involving MNs. This paper analyzes this proposal and evaluates it compared to the well-known Fast MIPv6 (FMIPv6) protocol in different radio access technologies. The comparison has been achieved with respect to the experienced handoff latency, resulting handoff interruption time and expected number of dropped packets per handoff. This analysis takes the dropping of control messages into account and has been done using mathematical models developed for both protocols. The obtained results show that the best performance can be seen by FMIPv6 in predictive mode. Access technology affects significantly the handoff interruption time. PMIPv6 performs almost comparable to FMIPv6 in reactive mode using a fast radio access technology. However, for slower radio access technologies, PMIPv6 performs better than FMIPv6 in reactive mode. PMIPv6 shows more robustness against control messages dropping than FMIPv6. Similar results are noticed with respect to the expected number of dropped packets per handoff. A main property of PMIPv6 is that there is no remarkable impact of radio access technologies on the number of dropped packets per handoff for downlink traffic.

With the recent advent of 4G LTE networks, there has been increasing interest to better understand the performance and power characteristics, compared with 3G/WiFi networks. In this paper, we take one of the first steps in this direction.Using a publicly deployed tool we designed for Android called 4GTest attracting more than 3000 users within 2 months and extensive local experiments, we study the network performance of LTE networks and compare with other types of mobile networks. We observe LTE generally has significantly higher downlink and uplink throughput than 3G and even WiFi, with a median value of 13Mbps and 6Mbps, respectively. We develop the first empirically derived comprehensive power model of a commercial LTE network with less than 6% error rate and state transitions matching the specifications. Using a comprehensive data set consisting of 5-month traces of 20 smartphone users, we carefully investigate the energy usage in 3G, LTE, and WiFi networks and evaluate the impact of configuring LTE-related parameters. Despite several new power saving improvements, we find that LTE is as much as 23 times less power efficient compared with WiFi, and even less power efficient than 3G, based on the user traces and the long high power tail is found to be a key contributor. In addition, we perform case studies of several popular applications on Android in LTE and identify that the performance bottleneck for web-based applications lies less in the network, compared to our previous study in 3G [24]. Instead, the device's processing power, despite the significant improvement compared to our analysis two years ago, becomes more of a bottleneck.

As mobile Internet applications supporting real-time communications services are pervasively used, traffic patterns in mobile networks have changed significantly. New mobile Internet applications differ from traditional applications such as web browser and FTP in that they need always-on connectivity and generate a large amount of signaling traffic. The traffic patterns of these new mobile applications lead to frequent change of radio resource control states between connected and idle in the user equipment, consuming device battery power and causing excessive signaling overhead. The growth in signaling has resulted in a traffic surge that has attracted the attention of mobile network operators. In this article, we first explore traffic composition in a 3G network and show that chatty applications such as instant messenger and social network services contribute to the frequent change of radio states. We then describe the mechanism behind the surge in signaling traffic and describe the disastrous outcome when an application server failure and recovery occurs. Lastly, we discuss some remedies to reduce the application signaling traffic and network load in 3G and LTE networks. These remedies include development of network-aware smart applications that consider the mobile network characteristics and introduction of push notification services. We also present related future work and our research directions.

This thesis work presents an architectural design of a system to bring non-repudiation concept into the IP based digital voice conversations (VoIP) in LTE and UMTS networks, using electronic signatures, by considering a centralized approach. Moreover, functionalities and technical methods to support such a system are researched. Last but not least, ways to introduce this system as a public and commercial service are discussed. Non-repudiation concept provided by electronic signatures and related cryptographic functions, as introduced in this study, allow using digital records of these voice conversations as legally binding statements or proofs likewise and even instead of traditional wet signatures. The system is designed as a subsystem to IMS based 3G and 4G networks and maximum compatibility with current configurations, components and interfaces of these networks is intended. On the other hand non-repudiation is achieved by special signature, storage and verification units located in the IMS core network. Voice data is proposed to be processed in MRF unit of the IMS. Additionally, a USSD/USSI based special solution to initiate these signed calls is developed. According to the proposed scheme; during a signed call, two unidirectional voice streams originating from two parties of the call, which are transferred in IP and UDP encapsulated RTP packages, are received by the signature unit and interweaved using their arrival times, so that they become a unified stream. Signature unit generates hashes of groups of received packages and signs them using PKI algorithms and applying hash/signature chaining to increase integrity protection and to empower non-repudiation. Then, it forwards packages and signature information to the storage unit. Storage unit keeps all the call records, signature data and metadata of these calls. Verification unit later gathers relevant data from the storage unit...

The net neutrality principle, also known as Open Internet, states that users should have equal access to all Internet content and that Internet Service Providers (ISPs) should not practice differentiated treatment on any of the Internet traffic. While net neutrality aims to restrain any kind of discrimination, it also provides exemption for a certain category of Internet traffic known as specialized services (SS), by allowing the ISP to dedicate part of the resources for the latter. In this work, we shed light on this particular case by comparing five Radio Access Technology (RAT) selection policies in heterogeneous wireless networks where SS traffic and Internet Access Services (IAS) traffic are carried. The studied policies include a non-net-neutral revenue-maximizing policy used as reference policy, and four other net-neutral policies with and without exemption to SS traffic. The results show that, even though, as expected, integrating net neutrality regulation within RAT selection policies can lead to a decrease in the generated revenue, a properly designed net-neutral policy will not only be able to reduce this decrease in revenue but also can maintain a similar level of social benefit in terms of the number of users admitted to the system.

At present, single wireless technology cannot meet all the demands of mobile users, and owing to such requirements, like Quality of Service (QoS) provision, efficiency, mobility, and cost, it is very prominent to incorporate diverse wireless technologies. Moreover, it is necessary to establish an efficient handover approach that allows mobile nodes (MN) to continuously move between different wireless networks that overlap with each other. A plethora of handover decision approaches have been developed in various literatures but, they are monolithic in nature and thus result in high computational cost and misbalancing of the network. In order to mitigate handover price owing to the densification of the network, an efficacious handover model is established for providing handover in Fifth Generation (5G) network. The proposed approach is mainly comprised of four components, namely the Network Quality of Service (NQ) module, User Preference (UP) module, power module and Decision System (DS) module. Here, the contribution of DS module is to make decisions on whether to offer handover in 5G network or not and the decision is selected based on proposed optimizations, such as Crow Search Algorithm (CSA) and Sun Flower Optimization (SFO), separately. However, the proposed CSA has obtained the maximum received power of - 93.706, throughput of 708.910, and USR of 0.647.