1,997 research outputs found
Millimeter-wave Evolution for 5G Cellular Networks
Triggered by the explosion of mobile traffic, 5G (5th Generation) cellular
network requires evolution to increase the system rate 1000 times higher than
the current systems in 10 years. Motivated by this common problem, there are
several studies to integrate mm-wave access into current cellular networks as
multi-band heterogeneous networks to exploit the ultra-wideband aspect of the
mm-wave band. The authors of this paper have proposed comprehensive
architecture of cellular networks with mm-wave access, where mm-wave small cell
basestations and a conventional macro basestation are connected to
Centralized-RAN (C-RAN) to effectively operate the system by enabling power
efficient seamless handover as well as centralized resource control including
dynamic cell structuring to match the limited coverage of mm-wave access with
high traffic user locations via user-plane/control-plane splitting. In this
paper, to prove the effectiveness of the proposed 5G cellular networks with
mm-wave access, system level simulation is conducted by introducing an expected
future traffic model, a measurement based mm-wave propagation model, and a
centralized cell association algorithm by exploiting the C-RAN architecture.
The numerical results show the effectiveness of the proposed network to realize
1000 times higher system rate than the current network in 10 years which is not
achieved by the small cells using commonly considered 3.5 GHz band.
Furthermore, the paper also gives latest status of mm-wave devices and
regulations to show the feasibility of using mm-wave in the 5G systems.Comment: 17 pages, 12 figures, accepted to be published in IEICE Transactions
on Communications. (Mar. 2015
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
Secure Communications in Millimeter Wave Ad Hoc Networks
Wireless networks with directional antennas, like millimeter wave (mmWave)
networks, have enhanced security. For a large-scale mmWave ad hoc network in
which eavesdroppers are randomly located, however, eavesdroppers can still
intercept the confidential messages, since they may reside in the signal beam.
This paper explores the potential of physical layer security in mmWave ad hoc
networks. Specifically, we characterize the impact of mmWave channel
characteristics, random blockages, and antenna gains on the secrecy
performance. For the special case of uniform linear array (ULA), a tractable
approach is proposed to evaluate the average achievable secrecy rate. We also
characterize the impact of artificial noise in such networks. Our results
reveal that in the low transmit powerregime, the use of low mmWave frequency
achieves better secrecy performance, and when increasing transmit power, a
transition from low mmWave frequency to high mmWave frequency is demanded for
obtaining a higher secrecy rate. More antennas at the transmitting nodes are
needed to decrease the antenna gain obtained by the eavesdroppers when using
ULA. Eavesdroppers can intercept more information by using a wide beam pattern.
Furthermore, the use of artificial noise may be ineffective for enhancing the
secrecy rate.Comment: Accepted by IEEE Transactions on Wireless Communication
- …