204,847 research outputs found
Performance Analysis of Traffic and Mobility Models on Mobile and Vehicular Ad Hoc Wireless Networks
Advances in wireless communication technology and the proliferation of mobile devices enable the capa-
bilities of communicating with each other even in areas with no pre-existing communication infrastructure.
Traffic and mobility models play an important role in evaluating the performance of these communication
networks. Despite criticism and assumption from various researches on Transmission Control Protocols
(TCP), weaknesses on Mobile Ad Hoc Network (MANET), and Vehicular Ad Hoc Network (VANET).
A simulation was carried out to evaluate the performance of Constant Bit Rate, Variable Bit Rate and
Transmission Control Protocol on MANET and VANET using DSR routing protocol. CBR, VBR, and TCP
have different manufacturer operation mechanisms and these differences lead to significant performance
of CBR and VBR over TCP with better throughput and less average maximal end-to-end delay. DSR
was able to respond to link failure at low mobility which led to TCP’s performance in packets delivery
A software-defined architecture for next-generation cellular networks
In the recent years, mobile cellular networks are undergoing fundamental changes and many established concepts are being revisited. New emerging paradigms, such as Software-Defined Networking (SDN), Mobile Cloud Computing (MCC), Network Function Virtualization (NFV), Internet of Things (IoT),and Mobile Social Networking (MSN), bring challenges in the design of cellular networks architectures. Current Long-Term Evolution (LTE) networks are not able to accommodate these new trends in a scalable and efficient way. In this paper, first we discuss the limitations of the current LTE architecture. Second, driven by the new communication needs and by the advances in aforementioned areas, we propose a new architecture for next generation cellular networks. Some of its characteristics include support for distributed content routing, Heterogeneous Networks(HetNets) and multiple Radio Access Technologies (RATs). Finally, we present simulation results which show that significant backhaul traffic savings can be achieved by implementing caching and routing functions at the network edge
Breaking the entanglement barrier: Tensor network simulation of quantum transport
The recognition that large classes of quantum many-body systems have limited
entanglement in the ground and low-lying excited states led to dramatic
advances in their numerical simulation via so-called tensor networks. However,
global dynamics elevates many particles into excited states, and can lead to
macroscopic entanglement and the failure of tensor networks. Here, we show that
for quantum transport -- one of the most important cases of this failure -- the
fundamental issue is the canonical basis in which the scenario is cast: When
particles flow through an interface, they scatter, generating a "bit" of
entanglement between spatial regions with each event. The frequency basis
naturally captures that -- in the long-time limit and in the absence of
inelastic scattering -- particles tend to flow from a state with one frequency
to a state of identical frequency. Recognizing this natural structure yields a
striking -- potentially exponential in some cases -- increase in simulation
efficiency, greatly extending the attainable spatial- and time-scales, and
broadening the scope of tensor network simulation to hitherto inaccessible
classes of non-equilibrium many-body problems.Comment: Published version; 6+9 pages; 4+4 figures; Added: an example of
interacting reservoirs, further evidence on performance scaling, and extended
discussion of the numerical detail
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