Seamless LTE-WiFi Architecture for Offloading the Overloaded LTE with Efficient UE Authentication

Nowadays a cellular network suffers from a data traffic load in a metropolitan area due to the enormous number of mobile devices connectivity. Therefore, the users experience many issues because of a congestion and overload at an access network such as low throughput, long latencies and network outages. Current network operator’s solutions, such as capping data usage and throttling a connection speed, have a negative effect on the user satisfaction. Therefore, alternative solutions are needed such as Access Point (AP)-based complementary network. In this paper, we use WiFi as a complementary network to Long-Term Evolution (LTE). We propose a seamless network architecture between LTE and WiFi networks, by utilizing the packet gateway (P-GW) as an IP flow anchor between LTE and WiFi to maintain a seamless connectivity. The proposed architecture has two new components, Access Network Query Protocol-Data Server (ANQP-DS) and Access Zone Control (AZC), to WiFi core network for managing UE authentication and balancing the load of UEs between APs. Finally, we demonstrate and validate the effectiveness of our proposed idea over other prior approaches based on comparison with a current handover and Extensible Authentication Protocol-Authentication and Key Agreement (EAP-AKA) mechanisms in the literature through simulations

An Efficient Resource Management Mechanism for Network Slicing in LTE Network

The proliferation of mobile devices and user applications has continued to contribute to the humongous volume of data traffic in cellular networks. To surmount this challenge, service and resource providers are looking for alternative mechanisms that can successfully facilitate managing network resources in a more dynamic, predictive and distributed manner. New concepts of network architectures such as Software Defined Network (SDN) and Network Function Virtualization (NFV) have paved the way to move from static to flexible networks. They make networks more flexible (i.e. network providers capable of on-demand provisioning), easily customizable and cost effective. In this regard, network slicing is emerging as a new technology built on the concepts of SDN and NFV. It splits a network infrastructure into isolated virtual networks and allows them to manage resources allocation individually based on their requirements and characteristics. Most of the existing solutions for network slicing are computationally expensive because of the length of time they require to estimate the resources required for each isolated slice. In addition, there is no guarantee that the resource allocation is fairly shared among users in a slice. In this paper, we propose a Network Slicing Resource Management (NSRM) mechanism to assign the required resources for each slice in an LTE network, taking into consideration resources isolation between different slices. In addition, NSRM aims to ensure isolation and fair sharing of distributed bandwidths between users belonging to the same slice. In NSRM, depending on requirements, each slice can be customized (e.g. each can have a different scheduling policy)

A large-scale R-matrix calculation for electron-impact excitation of the Ne2+^{2+} O-like ion

The five J$\Pi$ levels within a $np^2$ or $np^4$ ground state complex provide an excellent testing ground for the comparison of theoretical line ratios with astrophysically observed values, in addition to providing valuable electron temperature and density diagnostics. The low temperature nature of the line ratios ensure that the theoretically derived values are sensitive to the underlying atomic structure and electron-impact excitation rates. Previous R-matrix calculations for the Ne$^{2+}$ O-like ion exhibit large spurious structure in the cross sections at higher electron energies, which may affect Maxwellian averaged rates even at low temperatures. Furthermore, there is an absence of comprehensive excitation data between the excited states that may provide newer diagnostics to compliment the more established lines discussed in this paper. To resolve these issues, we present both a small scale 56-level Breit-Pauli (BP) calculation and a large-scale 554 levels R-matrix Intermediate Coupling Frame Transformation (ICFT) calculation that extends the scope and validity of earlier JAJOM calculations both in terms of the atomic structure and scattering cross sections. Our results provide a comprehensive electron-impact excitation data set for all transitions to higher $n$ shells. The fundamental atomic data for this O-like ion is subsequently used within a collisional radiative framework to provide the line ratios across a range of electron temperatures and densities of interest in astrophysical observations.Comment: 17 pages, 8 figure

Effective Rheology of Bubbles Moving in a Capillary Tube

We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

Seamless Mobility Management in Heterogeneous 5G Networks: A Coordination Approach among Distributed SDN Controllers

The major objective of evolution towards 5G networks is to support increasing number of end devices with stringent latency and high bandwidth requirements. Software Defined Networking (SDN) and Network Function Virtualization (NFV) are paving the way in supporting such requirements of 5G networks. In this paper, we propose a seamless mobility management for the users when they move from a SDN controller coverage to another in 5G heterogeneous networks. Our proposed solution utilizes the key-value Distributed Hash Table (DHT) to catch users’ mobility in a distributed SDN controller to address scability and seamlessness, where mobile device may join and leave between different associated SDN controllers. The proposed solution allows to select an appropriate AP with cooperation of mobile devices and controllers, so that network performance can be maximized and users’ demand can be met in a dynamically changing of network condition. The performance evaluated using OMNeT++ simulator imparts that the solution introduced in this paper can successfully reduce handover latency around 50% compared to the conventional mobility management solutions