19,059 research outputs found
Throughput Analysis for Wireless Networks with Full-Duplex Radios
This paper investigates the throughput for wireless network with full-duplex
radios using stochastic geometry. Full-duplex (FD) radios can exchange data
simultaneously with each other. On the other hand, the downside of FD
transmission is that it will inevitably cause extra interference to the network
compared to half-duplex (HD) transmission. In this paper, we focus on a
wireless network of nodes with both HD and FD capabilities and derive and
optimize the throughput in such a network. Our analytical result shows that if
the network is adapting an ALOHA protocol, the maximal throughput is always
achieved by scheduling all concurrently transmitting nodes to work in FD mode
instead of a mixed FD/HD mode or HD mode regardless of the network
configurations. Moreover, the throughput gain of using FD transmission over HD
transmission is analytically lower and upper bounded.Comment: 4 figure
Improved Handover Through Dual Connectivity in 5G mmWave Mobile Networks
The millimeter wave (mmWave) bands offer the possibility of orders of
magnitude greater throughput for fifth generation (5G) cellular systems.
However, since mmWave signals are highly susceptible to blockage, channel
quality on any one mmWave link can be extremely intermittent. This paper
implements a novel dual connectivity protocol that enables mobile user
equipment (UE) devices to maintain physical layer connections to 4G and 5G
cells simultaneously. A novel uplink control signaling system combined with a
local coordinator enables rapid path switching in the event of failures on any
one link. This paper provides the first comprehensive end-to-end evaluation of
handover mechanisms in mmWave cellular systems. The simulation framework
includes detailed measurement-based channel models to realistically capture
spatial dynamics of blocking events, as well as the full details of MAC, RLC
and transport protocols. Compared to conventional handover mechanisms, the
study reveals significant benefits of the proposed method under several
metrics.Comment: 16 pages, 13 figures, to appear on the 2017 IEEE JSAC Special Issue
on Millimeter Wave Communications for Future Mobile Network
Design and Optimal Configuration of Full-Duplex MAC Protocol for Cognitive Radio Networks Considering Self-Interference
In this paper, we propose an adaptive Medium Access Control (MAC) protocol
for full-duplex (FD) cognitive radio networks in which FD secondary users (SUs)
perform channel contention followed by concurrent spectrum sensing and
transmission, and transmission only with maximum power in two different stages
(called the FD sensing and transmission stages, respectively) in each
contention and access cycle. The proposed FD cognitive MAC (FDC-MAC) protocol
does not require synchronization among SUs and it efficiently utilizes the
spectrum and mitigates the self-interference in the FD transceiver. We then
develop a mathematical model to analyze the throughput performance of the
FDC-MAC protocol where both half-duplex (HD) transmission (HDTx) and FD
transmission (FDTx) modes are considered in the transmission stage. Then, we
study the FDC-MAC configuration optimization through adaptively controlling the
spectrum sensing duration and transmit power level in the FD sensing stage
where we prove that there exists optimal sensing time and transmit power to
achieve the maximum throughput and we develop an algorithm to configure the
proposed FDC-MAC protocol. Extensive numerical results are presented to
illustrate the characteristic of the optimal FDC-MAC configuration and the
impacts of protocol parameters and the self-interference cancellation quality
on the throughput performance. Moreover, we demonstrate the significant
throughput gains of the FDC-MAC protocol with respect to existing half-duplex
MAC (HD MAC) and single-stage FD MAC protocols.Comment: To Appear, IEEE Access, 201
Thwarting Selfish Behavior in 802.11 WLANs
The 802.11e standard enables user configuration of several MAC parameters,
making WLANs vulnerable to users that selfishly configure these parameters to
gain throughput. In this paper we propose a novel distributed algorithm to
thwart such selfish behavior. The key idea of the algorithm is for honest
stations to react, upon detecting a selfish station, by using a more aggressive
configuration that penalizes this station. We show that the proposed algorithm
guarantees global stability while providing good response times. By conducting
a game theoretic analysis of the algorithm based on repeated games, we also
show its effectiveness against selfish stations. Simulation results confirm
that the proposed algorithm optimizes throughput performance while discouraging
selfish behavior. We also present an experimental prototype of the proposed
algorithm demonstrating that it can be implemented on commodity hardware.Comment: 14 pages, 7 figures, journa
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