Konstantinos Samdanis

Traffic Offload Enhancements for eUTRAN

Local IP Access (LIPA) and Selected IP Traffic Offload (SIPTO) are two topics currently of high interest to mobile network operators. They enable data traffic offload at appropriate points in the Radio Access Network in a highly cost-efficient manner. These technologies also have the potential to greatly increase system scalability and offer operators the flexibility to cope with the growing community of smart phone users and the associated increase of mobile data traffic. This paper first introduces the main concepts behind LIPA/SIPTO and discusses the main requirements to support them. Different architecture solutions, proposed for home, enterprise and macro-cellular networks, are presented. The paper also elaborates on LIPA/SIPTO traffic handling. A DNS-based approach, offering operators a fine-grained control of LIPA/SIPTO traffic handling, is introduced. The paper then discusses different other issues pertaining to LIPA/SIPTO traffic management, SIPTO QoS support, data offload gateway selection, and service planning and deployment. Finally, the paper concentrates on recent efforts towards the support of LIPA/SIPTO service continuity.

From network sharing to multi-tenancy: The 5G network slice broker

The ever-increasing traffic demand is pushing network operators to find new cost-efficient solutions toward the deployment of future 5G mobile networks. The network sharing paradigm was explored in the past and partially deployed. Nowadays, advanced mobile network multi-tenancy approaches are increasingly gaining momentum, paving the way toward further decreasing capital expenditure and operational expenditure (CAPEX/OPEX) costs, while enabling new business opportunities. This article provides an overview of the 3GPP standard evolution from network sharing principles, mechanisms, and architectures to future on-demand multi-tenant systems. In particular, it introduces the concept of the 5G Network Slice Broker in 5G systems, which enables mobile virtual network operators, over-the-top providers, and industry vertical market players to request and lease resources from infrastructure providers dynamically via signaling means. Finally, it reviews the latest standardization efforts, considering remaining open issues for enabling advanced network slicing solutions, taking into account the allocation of virtualized network functions based on ETSI NFV, the introduction of shared network functions, and flexible service chaining.

On Multi-Access Edge Computing: A Survey of the Emerging 5G Network Edge Cloud Architecture and Orchestration

Multi-access edge computing (MEC) is an emerging ecosystem, which aims at converging telecommunication and IT services, providing a cloud computing platform at the edge of the radio access network. MEC offers storage and computational resources at the edge, reducing latency for mobile end users and utilizing more efficiently the mobile backhaul and core networks. This paper introduces a survey on MEC and focuses on the fundamental key enabling technologies. It elaborates MEC orchestration considering both individual services and a network of MEC platforms supporting mobility, bringing light into the different orchestration deployment options. In addition, this paper analyzes the MEC reference architecture and main deployment scenarios, which offer multi-tenancy support for application developers, content providers, and third parties. Finally, this paper overviews the current standardization activities and elaborates further on open research challenges.

Self-organized energy efficient cellular networks

Base stations (BSs) are the main energy expenditure elements of cellular networks, considering the high coverage requirements and the fact that the total provisioned capacity is intended to match peak hour traffic demand. In this paper, we introduce energy saving algorithms based on coordination between network elements. We introduce the notion of energy partitions - associations of powered-on and powered-off BSs - to deliver energy saving with the objective of matching offered capacity with the traffic demand in a flexible manner. Our energy saving algorithms are based on shared knowledge of load and coverage information and enable an appropriate cell reconfiguration for achieving a network-level energy saving. Through a simulation-based evaluation, we analyze the performance of centralized and distributed algorithms under different network topologies and traffic conditions, highlight the benefits and drawbacks, and provide recommendations for deployment scenarios.

Energy Efficiency Benefits of RAN-as-a-Service Concept for a Cloud-Based 5G Mobile Network Infrastructure

This paper focuses on energy efficiency aspects and related benefits of radio-access-network-as-a-service (RANaaS) implementation (using commodity hardware) as architectural evolution of LTE-advanced networks toward 5G infrastructure. RANaaS is a novel concept introduced recently, which enables the partial centralization of RAN functionalities depending on the actual needs as well as on network characteristics. In the view of future definition of 5G systems, this cloud-based design is an important solution in terms of efficient usage of network resources. The aim of this paper is to give a vision of the advantages of the RANaaS, to present its benefits in terms of energy efficiency and to propose a consistent system-level power model as a reference for assessing innovative functionalities toward 5G systems. The incremental benefits through the years are also discussed in perspective, by considering technological evolution of IT platforms and the increasing matching between their capabilities and the need for progressive virtualization of RAN functionalities. The description is complemented by an exemplary evaluation in terms of energy efficiency, analyzing the achievable gains associated with the RANaaS paradigm.

Self Organized Network Management Functions for Energy Efficient Cellular Urban Infrastructures

Energy efficiency is a significant requirement for the design and management of mobile networks and has recently gained substantial attention from both network operators and the research community. The general concept of energy saving management aims to match the capacity offered by operators to the actual demand at given times and geographic areas. This paper introduces the notion of energy partition, an association of powered-on and powered-off BSs to deliver network-level energy saving. It then elaborates how such concept is applied to perform energy re-configuration to flexibly re-act to load variations encouraging none or minimal extra energy consumption. A simulation-based study evaluates the performance of the proposed algorithms under different network topologies and traffic conditions, highlights the benefits and drawbacks, and provides recommendations for deployment scenarios.

Energy-Efficient D2D Discovery for Proximity Services in 3GPP LTE-Advanced Networks: ProSe Discovery Mechanisms

Device-to-device (D2D) communications facilitate promising solutions for service optimization and spectrum/capacity efficiency in the Third-Generation Partnership Project (3GPP) networks. A key enabler for D2D communications and proximity services (ProSe) is the device discovery process. Currently, many aggressive peer discovery methods discussed in 3GPP could induce high energy consumption. Therefore, a critical objective in efficient D2D proximity service deployments is how to prolong the battery life time of user equipments (UEs) by managing discovery cycles intelligently. In this article, D2D discovery mechanisms discussed in the 3GPP are studied in terms of energy consumption aspects. In particular, we consider an efficient D2D discovery mechanism that takes advantage of the concept of proximity area (P-Area), a dynamic geographical region wherein UEs activate their D2D capabilities. The mechanism enables UEs to perform D2D discovery procedures only when there is a high probability to find other UEs subscribed to the same service. The energy consumption profiles of various discovery mechanisms are evaluated using simulations, and the results indicate that significant energy savings can be obtained using the considered discovery mechanism.

Dynamic energy-aware network re-configuration for cellular urban infrastructures

Energy saving management aims to match the capacity offered by operators to the actual traffic demand at off-peak times when the network load under-utilizes the maximum capacity dimension. Such a process is relatively complex in cellular infrastructures since mobility and user activity patterns may create load fluctuations. This paper introduces energy-aware network re-configuration methods to flexibly re-act to load variations encouraging none or minimal extra energy consumption. A simulation-based study evaluates the performance of the proposed schemes considering the network service quality and energy cost.

Towards supporting highly mobile nodes in decentralized mobile operator networks

There is a general trend towards the decentralization of mobile operator networks. Such network decentralization will not be efficient without rethinking mobility management schemes, particularly for users moving for a long distance and/or at a high speed (e.g., vehicles). To support such highly mobile users, this paper introduces a data anchor gateway relocation method based on user mobility, history information, and user activity patterns. The performance of the proposed schemes is evaluated through simulations and encouraging results are obtained.

Supporting Highly Mobile Users in Cost-Effective Decentralized Mobile Operator Networks

Due to the tremendous increase in mobile data traffic, there is a general trend toward the decentralization of mobile operator networks, at least to a certain extent. This shall be further facilitated with the virtualization of mobile network functions and the enabling of mobile cloud networking, whereby mobile networks are created on demand and in a flexible manner. Mobile network decentralization will not be efficient without rethinking mobility management schemes, particularly for users moving for a long distance and/or at a high speed (e.g., vehicles and bullet trains). To support such highly mobile users, this paper introduces: 1) a data anchor gateway (GW) relocation method based on user mobility, history information, and user activity patterns, and 2) a handover management policy that selects a target base station or evolved Node B (eNB) in a way to minimize mobility anchor GW relocation. The performance of the proposed schemes is evaluated via Markov model-based analysis and through simulations. Encouraging results are obtained, validating the design objectives of the scheme.