756 research outputs found
Cost-Effective Cache Deployment in Mobile Heterogeneous Networks
This paper investigates one of the fundamental issues in cache-enabled
heterogeneous networks (HetNets): how many cache instances should be deployed
at different base stations, in order to provide guaranteed service in a
cost-effective manner. Specifically, we consider two-tier HetNets with
hierarchical caching, where the most popular files are cached at small cell
base stations (SBSs) while the less popular ones are cached at macro base
stations (MBSs). For a given network cache deployment budget, the cache sizes
for MBSs and SBSs are optimized to maximize network capacity while satisfying
the file transmission rate requirements. As cache sizes of MBSs and SBSs affect
the traffic load distribution, inter-tier traffic steering is also employed for
load balancing. Based on stochastic geometry analysis, the optimal cache sizes
for MBSs and SBSs are obtained, which are threshold-based with respect to cache
budget in the networks constrained by SBS backhauls. Simulation results are
provided to evaluate the proposed schemes and demonstrate the applications in
cost-effective network deployment
Traffic Steering in B5G Sliced Radio Access Networks.
In 5G and beyond wireless systems, Network Slicing (NS) feature will enable the coexistence of extremely different services by splitting the physical infrastructure into several logical slices tailored for a specific tenant or application. In sliced Radio Access Networks (RANs), an optimal traffic sharing among cells is key to guarantee Service Level Agreement (SLA) compliance while minimizing operation costs. The configuration of network functions leading to that optimal point may depend on the slice, claiming for slice-aware traffic steering strategies. This work presents the first data-driven algorithm for sliceaware traffic steering by tuning handover margins (a.k.a.
mobility load balancing). The tuning process is driven by a novel indicator, derived from connection traces, showing the imbalance of SLA compliance among neighbor cells per slice. Performance assessment is carried out with a system-level simulator implementing a realistic sliced RAN offering services with different throughput, latency and reliability requirements. Results show that the proposed algorithm improves the overall SLA compliance by 9% in only 15 minutes of network activity compared to the case of not steering traffic, outperforming two legacy mobility load balancing approaches not driven by SLA
Competition for Partners: Strategic Games in Wholesale International Roaming
High international roaming prices have puzzled and occupied analysts and regulators for quite a time. While on the retail side the problem seems to be well understood, and the high margins can be justified using Ramsey pricing logic, on the wholesale side the picture is not so clear. Recent contributions find reasons for regulation based on the existence of random traffic and on the bilateral nature of the wholesale deals, which raise the equilibrium prices even when operators can choose a preferred network. This paper intends to investigate whether or not those concerns are justified. This is done by modelling the bilateral roaming negotiations and extending the current models, assuming that home operators (the ones with a retail contract with the customer in its country of residence) can decide not only their preferred network in each visited country, but also the distribution of their outbound traffic among the visited operators. We find that when traffic steering is perfect the wholesale market is competitive, and that the lower prices are passed on to end users through competition for retail customers. The bilateral nature of international roaming wholesale deals is actually an additional source of competition on the retail market for mobile services because the roaming out traffic (the traffic of an operator's retail customers abroad) and the roaming in traffic (the traffic of foreign customers that an operator is able to attract) are directly linked. --
Self-Sustaining Caching Stations: Towards Cost-Effective 5G-Enabled Vehicular Networks
In this article, we investigate the cost-effective 5G-enabled vehicular
networks to support emerging vehicular applications, such as autonomous
driving, in-car infotainment and location-based road services. To this end,
self-sustaining caching stations (SCSs) are introduced to liberate on-road base
stations from the constraints of power lines and wired backhauls. Specifically,
the cache-enabled SCSs are powered by renewable energy and connected to core
networks through wireless backhauls, which can realize "drop-and-play"
deployment, green operation, and low-latency services. With SCSs integrated, a
5G-enabled heterogeneous vehicular networking architecture is further proposed,
where SCSs are deployed along roadside for traffic offloading while
conventional macro base stations (MBSs) provide ubiquitous coverage to
vehicles. In addition, a hierarchical network management framework is designed
to deal with high dynamics in vehicular traffic and renewable energy, where
content caching, energy management and traffic steering are jointly
investigated to optimize the service capability of SCSs with balanced power
demand and supply in different time scales. Case studies are provided to
illustrate SCS deployment and operation designs, and some open research issues
are also discussed.Comment: IEEE Communications Magazine, to appea
SDN/NFV-enabled satellite communications networks: opportunities, scenarios and challenges
In the context of next generation 5G networks, the satellite industry is clearly committed to revisit and revamp the role of satellite communications. As major drivers in the evolution of (terrestrial) fixed and mobile networks, Software Defined Networking (SDN) and Network Function Virtualisation (NFV) technologies are also being positioned as central technology enablers towards improved and more flexible integration of satellite and terrestrial segments, providing satellite network further service innovation and business agility by advanced network resources management techniques. Through the analysis of scenarios and use cases, this paper provides a description of the benefits that SDN/NFV technologies can bring into satellite communications towards 5G. Three scenarios are presented and analysed to delineate different potential improvement areas pursued through the introduction of SDN/NFV technologies in the satellite ground segment domain. Within each scenario, a number of use cases are developed to gain further insight into specific capabilities and to identify the technical challenges stemming from them.Peer ReviewedPostprint (author's final draft
Fixed-Mobile Convergence in the 5G era: From Hybrid Access to Converged Core
The availability of different paths to communicate to a user or device
introduces several benefits, from boosting enduser performance to improving
network utilization. Hybrid access is a first step in enabling convergence of
mobile and fixed networks, however, despite traffic optimization, this approach
is limited as fixed and mobile are still two separate core networks
inter-connected through an aggregation point. On the road to 5G networks, the
design trend is moving towards an aggregated network, where different access
technologies share a common anchor point in the core. This enables further
network optimization in addition to hybrid access, examples are userspecific
policies for aggregation and improved traffic balancing across different
accesses according to user, network, and service context. This paper aims to
discuss the ongoing work around hybrid access and network convergence by
Broadband Forum and 3GPP. We present some testbed results on hybrid access and
analyze some primary performance indicators such as achievable data rates, link
utilization for aggregated traffic and session setup latency. We finally
discuss the future directions for network convergence to enable future
scenarios with enhanced configuration capabilities for fixed and mobile
convergence.Comment: to appear in IEEE Networ
Experimental Evaluation of SDN-Controlled, Joint Consolidation of Policies and Virtual Machines
Middleboxes (MBs) are ubiquitous in modern data centre (DC) due to their crucial role in implementing network security, management and optimisation. In order to meet network policy's requirement on correct traversal of an ordered sequence of MBs, network administrators rely on static policy based routing or VLAN stitching to steer traffic flows. However, dynamic virtual server migration in virtual environment has greatly challenged such static traffic steering. In this paper, we design and implement Sync, an efficient and synergistic scheme to jointly consolidate network policies and virtual machines (VMs), in a readily deployable Mininet environment. We present the architecture of Sync framework and open source its code. We also extensively evaluate Sync over diverse workload and policies. Our results show that in an emulated DC of 686 servers, 10k VMs, 8k policies, and 100k flows, Sync processes a group of 900 VMs and 10 VMs in 634 seconds and 4 seconds respectively
A QoE-driven traffic steering algorithm for LTE Networks
Due to the huge increase in traffic and services in mobile networks, network management has changed its main focus from Quality of Service (QoS) to a Quality of Experience (QoE) perspective. In addition, SON (Self Organizing Networks) techniques have been developed to automate network management, being load balancing a key use case. Load balancing aim is to balance the traffic among adjacent cells. This balance is expected to decrease the overall blocking ratio, thus increasing the total carried traffic in the network. Nevertheless, these techniques may fail when QoE perspective is considered. In this work, a novel QoE balancing algorithm is proposed to reach QoE equilibrium in a realistic LTE network with different services. The proposed balancing approach is tested and compared with classical techniques by means of simulations.Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tech
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