3,230 research outputs found
Predicting expected TCP throughput using genetic algorithm
Predicting the expected throughput of TCP is important for several aspects such as e.g. determining handover criteria for future multihomed mobile nodes or determining the expected throughput of a given MPTCP subflow for load-balancing reasons. However, this is challenging due to time varying behavior of the underlying network characteristics. In this paper, we present a genetic-algorithm-based prediction model for estimating TCP throughput values. Our approach tries to find the best matching combination of mathematical functions that approximate a given time series that accounts for the TCP throughput samples using genetic algorithm. Based on collected historical datapoints about measured TCP throughput samples, our algorithm estimates expected throughput over time. We evaluate the quality of the prediction using different selection and diversity strategies for creating new chromosomes. Also, we explore the use of different fitness functions in order to evaluate the goodness of a chromosome. The goal is to show how different tuning on the genetic algorithm may have an impact on the prediction. Using extensive simulations over several TCP throughput traces, we find that the genetic algorithm successfully finds reasonable matching mathematical functions that allow to describe the TCP sampled throughput values with good fidelity. We also explore the effectiveness of predicting time series throughput samples for a given prediction horizon and estimate the prediction error and confidence.Peer ReviewedPostprint (author's final draft
X-TCP: A Cross Layer Approach for TCP Uplink Flows in mmWave Networks
Millimeter wave frequencies will likely be part of the fifth generation of
mobile networks and of the 3GPP New Radio (NR) standard. MmWave communication
indeed provides a very large bandwidth, thus an increased cell throughput, but
how to exploit these resources at the higher layers is still an open research
question. A very relevant issue is the high variability of the channel, caused
by the blockage from obstacles and the human body. This affects the design of
congestion control mechanisms at the transport layer, and state-of-the-art TCP
schemes such as TCP CUBIC present suboptimal performance. In this paper, we
present a cross layer approach for uplink flows that adjusts the congestion
window of TCP at the mobile equipment side using an estimation of the available
data rate at the mmWave physical layer, based on the actual resource allocation
and on the Signal to Interference plus Noise Ratio. We show that this approach
reduces the latency, avoiding to fill the buffers in the cellular stack, and
has a quicker recovery time after RTO events than several other TCP congestion
control algorithms.Comment: 6 pages, 5 figures, accepted for presentation at the 2017 16th Annual
Mediterranean Ad Hoc Networking Workshop (MED-HOC-NET
A Survey on Wireless Security: Technical Challenges, Recent Advances and Future Trends
This paper examines the security vulnerabilities and threats imposed by the
inherent open nature of wireless communications and to devise efficient defense
mechanisms for improving the wireless network security. We first summarize the
security requirements of wireless networks, including their authenticity,
confidentiality, integrity and availability issues. Next, a comprehensive
overview of security attacks encountered in wireless networks is presented in
view of the network protocol architecture, where the potential security threats
are discussed at each protocol layer. We also provide a survey of the existing
security protocols and algorithms that are adopted in the existing wireless
network standards, such as the Bluetooth, Wi-Fi, WiMAX, and the long-term
evolution (LTE) systems. Then, we discuss the state-of-the-art in
physical-layer security, which is an emerging technique of securing the open
communications environment against eavesdropping attacks at the physical layer.
We also introduce the family of various jamming attacks and their
counter-measures, including the constant jammer, intermittent jammer, reactive
jammer, adaptive jammer and intelligent jammer. Additionally, we discuss the
integration of physical-layer security into existing authentication and
cryptography mechanisms for further securing wireless networks. Finally, some
technical challenges which remain unresolved at the time of writing are
summarized and the future trends in wireless security are discussed.Comment: 36 pages. Accepted to Appear in Proceedings of the IEEE, 201
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