21 research outputs found
Traffic Convexity Aware Cellular Networks: A Vehicular Heavy User Perspective
Rampant mobile traffic increase in modern cellular networks is mostly caused
by large-sized multimedia contents. Recent advancements in smart devices as
well as radio access technologies promote the consumption of bulky content,
even for people in moving vehicles, referred to as vehicular heavy users. In
this article the emergence of vehicular heavy user traffic is observed by field
experiments conducted in 2012 and 2015 in Seoul, Korea. The experiments reveal
that such traffic is becoming dominant, captured by the 8.62 times increase in
vehicular heavy user traffic while the total traffic increased 3.04 times. To
resolve this so-called vehicular heavy user problem (VHP), we propose a cell
association algorithm that exploits user demand diversity for different
velocities. This user traffic pattern is discovered first by our field trials,
which is convex-shaped over velocity, i.e. walking user traffic is less than
stationary or vehicular user traffic. As the VHP becomes severe, numerical
evaluation verifies the proposed user convexity aware association outperforms a
well-known load balancing association in practice, cell range expansion (CRE).
In addition to the cell association, several complementary techniques are
suggested in line with the technical trend toward 5G.Comment: 15 pages, 5 figures, 1 table, to appear in IEEE Wireless
Communications Magazin
A New Handover Management Model for Two-Tier 5G Mobile Networks
There has been an exponential rise in mobile data traffic in recent times due to the increasing popularity of portable devices like tablets, smartphones, and laptops. The rapid rise in the use of these portable devices has put extreme stress on the network service providers while forcing telecommunication engineers to look for innovative solutions to meet the increased demand. One solution to the problem is the emergence of fifth-generation (5G) wireless communication, which can address the challenges by offering very broad wireless area capacity and potential cut-power consumption. The application of small cells is the fundamental mechanism for the 5G technology. The use of small cells can enhance the facility for higher capacity and reuse. However, it must be noted that small cells deployment will lead to frequent handovers of mobile nodes. Considering the importance of small cells in 5G, this paper aims to examine a new resource management scheme that can work to minimize the rate of handovers for mobile phones through careful resources allocation in a two-tier network. Therefore, the resource management problem has been formulated as an optimization issue that we aim to overcome through an optimal solution. To find a solution to the existing problem of frequent handovers, a heuristic approach has been used. This solution is then evaluated and validated through simulation and testing, during which the performance was noted to improve by 12% in the context of handover costs. Therefore, this model has been observed to be more efficient as compared to the existing model
An Efficient Uplink Multi-Connectivity Scheme for 5G mmWave Control Plane Applications
The millimeter wave (mmWave) frequencies offer the potential of orders of
magnitude increases in capacity for next-generation cellular systems. However,
links in mmWave networks are susceptible to blockage and may suffer from rapid
variations in quality. Connectivity to multiple cells - at mmWave and/or
traditional frequencies - is considered essential for robust communication. One
of the challenges in supporting multi-connectivity in mmWaves is the
requirement for the network to track the direction of each link in addition to
its power and timing. To address this challenge, we implement a novel uplink
measurement system that, with the joint help of a local coordinator operating
in the legacy band, guarantees continuous monitoring of the channel propagation
conditions and allows for the design of efficient control plane applications,
including handover, beam tracking and initial access. We show that an
uplink-based multi-connectivity approach enables less consuming, better
performing, faster and more stable cell selection and scheduling decisions with
respect to a traditional downlink-based standalone scheme. Moreover, we argue
that the presented framework guarantees (i) efficient tracking of the user in
the presence of the channel dynamics expected at mmWaves, and (ii) fast
reaction to situations in which the primary propagation path is blocked or not
available.Comment: Submitted for publication in IEEE Transactions on Wireless
Communications (TWC