1,355 research outputs found
Greedy-Knapsack Algorithm for Optimal Downlink Resource Allocation in LTE Networks
The Long Term Evolution (LTE) as a mobile broadband technology supports a
wide domain of communication services with different requirements. Therefore,
scheduling of all flows from various applications in overload states in which
the requested amount of bandwidth exceeds the limited available spectrum
resources is a challenging issue. Accordingly, in this paper, a greedy
algorithm is presented to evaluate user candidates which are waiting for
scheduling and select an optimal set of the users to maximize system
performance, without exceeding available bandwidth capacity. The
greedy-knapsack algorithm is defined as an optimal solution to the resource
allocation problem, formulated based on the fractional knapsack problem. A
compromise between throughput and QoS provisioning is obtained by proposing a
class-based ranking function, which is a combination of throughput and QoS
related parameters defined for each application. The simulation results show
that the proposed method provides high performance in terms of throughput, loss
and delay for different classes of QoS over the existing ones, especially under
overload traffic.Comment: Wireless Networks, 201
Resource Allocation for Energy-Efficient Device-to-Device Communication in 4G Networks
Device-to-device (D2D) communications as an underlay of a LTE-A (4G) network
can reduce the traffic load as well as power consumption in cellular networks
by way of utilizing peer-to-peer links for users in proximity of each other.
This would enable other cellular users to increment their traffic, and the
aggregate traffic for all users can be significantly increased without
requiring additional spectrum. However, D2D communications may increase
interference to cellular users (CUs) and force CUs to increase their transmit
power levels in order to maintain their required quality-of-service (QoS). This
paper proposes an energy-efficient resource allocation scheme for D2D
communications as an underlay of a fully loaded LTE-A (4G) cellular network.
Simulations show that the proposed scheme allocates cellular uplink resources
(transmit power and channel) to D2D pairs while maintaining the required QoS
for D2D and cellular users and minimizing the total uplink transmit power for
all users.Comment: 2014 7th International Symposium on Telecommunications (IST'2014
D2D-Based Grouped Random Access to Mitigate Mobile Access Congestion in 5G Sensor Networks
The Fifth Generation (5G) wireless service of sensor networks involves
significant challenges when dealing with the coordination of ever-increasing
number of devices accessing shared resources. This has drawn major interest
from the research community as many existing works focus on the radio access
network congestion control to efficiently manage resources in the context of
device-to-device (D2D) interaction in huge sensor networks. In this context,
this paper pioneers a study on the impact of D2D link reliability in
group-assisted random access protocols, by shedding the light on beneficial
performance and potential limitations of approaches of this kind against
tunable parameters such as group size, number of sensors and reliability of D2D
links. Additionally, we leverage on the association with a Geolocation Database
(GDB) capability to assist the grouping decisions by drawing parallels with
recent regulatory-driven initiatives around GDBs and arguing benefits of the
suggested proposal. Finally, the proposed method is approved to significantly
reduce the delay over random access channels, by means of an exhaustive
simulation campaign.Comment: First submission to IEEE Communications Magazine on Oct.28.2017.
Accepted on Aug.18.2019. This is the camera-ready versio
An Efficient Multi-Carrier Resource Allocation with User Discrimination Framework for 5G Wireless Systems
In this paper, we present an efficient resource allocation with user
discrimination framework for 5G Wireless Systems to allocate multiple carriers
resources among users with elastic and inelastic traffic. Each application
running on the user equipment (UE) is assigned an application utility function.
In the proposed model, different classes of user groups are considered and
users are partitioned into different groups based on the carriers coverage
area. Each user has a minimum required application rate based on its class and
the type of its application. Our objective is to allocate multiple carriers
resources optimally among users, that belong to different classes, located
within the carriers' coverage area. We use a utility proportional fairness
approach in the utility percentage of the application running on the UE. Each
user is guaranteed a minimum quality of service (QoS) with a priority criterion
that is based on user's class and the type of application running on the UE. In
addition, we prove the existence of optimal solutions for the proposed resource
allocation optimization problem and present a multi-carrier resource allocation
with user discrimination algorithm. Finally, we present simulation results for
the performance of the proposed algorithm.Comment: Under Submissio
Highly Dynamic Spectrum Management within Licensed Shared Access Regulatory Framework
Historical fragmentation in spectrum access models accentuates the need for
novel concepts that allow for efficient sharing of already available but
underutilized spectrum. The emerging Licensed Shared Access (LSA) regulatory
framework is expected to enable more advanced spectrum sharing between a
limited number of users while guaranteeing their much needed interference
protection. However, the ultimate benefits of LSA may in practice be
constrained by space-time availability of the LSA bands. Hence, more dynamic
LSA spectrum management is required to leverage such real-time variability and
sustain reliability when e.g., the original spectrum user suddenly revokes the
previously granted frequency bands as they are required again. In this article,
we maintain the vision of highly dynamic LSA architecture and rigorously study
its future potential: from reviewing market opportunities and discussing
available technology implementations to conducting performance evaluation of
LSA dynamics and outlining the standardization landscape. Our investigations
are based on a comprehensive system-level evaluation framework, which has been
specifically designed to assess highly dynamic LSA deployments.Comment: 9 pages, 5 figures, 1 table, 15 references, to appear in IEEE
Communications Magazine, Open Cal
Software-Defined and Virtualized Future Mobile and Wireless Networks: A Survey
With the proliferation of mobile demands and increasingly multifarious
services and applications, mobile Internet has been an irreversible trend.
Unfortunately, the current mobile and wireless network (MWN) faces a series of
pressing challenges caused by the inherent design. In this paper, we extend two
latest and promising innovations of Internet, software-defined networking and
network virtualization, to mobile and wireless scenarios. We first describe the
challenges and expectations of MWN, and analyze the opportunities provided by
the software-defined wireless network (SDWN) and wireless network
virtualization (WNV). Then, this paper focuses on SDWN and WNV by presenting
the main ideas, advantages, ongoing researches and key technologies, and open
issues respectively. Moreover, we interpret that these two technologies highly
complement each other, and further investigate efficient joint design between
them. This paper confirms that SDWN and WNV may efficiently address the crucial
challenges of MWN and significantly benefit the future mobile and wireless
network.Comment: 12 pages, 3 figures, submitted to "Mobile Networks and Applications"
(MONET
QoS and Coverage Aware Dynamic High Density Vehicle Platooning (HDVP)
In a self-driving environment, vehicles communicate with each other to create
a closely spaced multiple vehicle strings on a highway, i.e., high-density
vehicle platooning (HDVP). In this paper, we address the Cellular Vehicle to
Everything (C-V2X) quality of service (QoS) and radio coverage issues for HDVP
and propose a dynamic platooning mechanism taking into account the change of
coverage condition, the road capacity, medium access control (MAC) and spectrum
reuse while at the same time guaranteeing the stringent QoS requirements in
terms of latency and reliability.Comment: 5 pages, 9 figures, accepted by VTC Fall 201
Distributed Learning for Channel Allocation Over a Shared Spectrum
Channel allocation is the task of assigning channels to users such that some
objective (e.g., sum-rate) is maximized. In centralized networks such as
cellular networks, this task is carried by the base station which gathers the
channel state information (CSI) from the users and computes the optimal
solution. In distributed networks such as ad-hoc and device-to-device (D2D)
networks, no base station exists and conveying global CSI between users is
costly or simply impractical. When the CSI is time varying and unknown to the
users, the users face the challenge of both learning the channel statistics
online and converge to a good channel allocation. This introduces a multi-armed
bandit (MAB) scenario with multiple decision makers. If two users or more
choose the same channel, a collision occurs and they all receive zero reward.
We propose a distributed channel allocation algorithm that each user runs and
converges to the optimal allocation while achieving an order optimal regret of
O\left(\log T\right). The algorithm is based on a carrier sensing multiple
access (CSMA) implementation of the distributed auction algorithm. It does not
require any exchange of information between users. Users need only to observe a
single channel at a time and sense if there is a transmission on that channel,
without decoding the transmissions or identifying the transmitting users. We
demonstrate the performance of our algorithm using simulated LTE and 5G
channels
Performance and Energy Conservation of 3GPP IFOM Protocol for Dual Connectivity in Heterogeneous LTE-WLAN Network
For the 5th Generation (5G) networks, Third Generation Partnership Project
(3GPP) is considering standardization of various solutions for traffic
aggregation using licensed and unlicensed spectrum, to meet the rising data
demands. IP Flow Mobility (IFOM) is a multi access connectivity
solution/protocol standardized by the Internet Engineering Task force (IETF)
and 3GPP in Release 10. It enables concurrent access for an User Equipment (UE)
to Heterogeneous Networks (HetNets) such as Long Term Evolution (LTE) and IEEE
802.11 Wireless Local Area Network (WLAN). IFOM enabled UEs have multiple
interfaces to connect to HetNets. They can have concurrent flows with different
traffic types over these networks and can seamlessly switch the flows from one
network to the other. In this paper, we focus on two objectives. First is to
investigate the performance parameters e.g. throughput, latency, tunnelling
overhead, packet loss, energy cost etc. of IFOM enabled UEs (IeUs) in HetNets
of LTE and WLAN. We have proposed a novel mechanism to maximize the throughput
of IeUs achieving a significant throughput gain with low latency for the IeUs.
We have explored further and observed a throughput energy trade off for low
data rate flows. To address this, we also propose a smart energy efficient and
throughput optimization algorithm for the IeUs, resulting in a substantial
reduction in energy cost, while maintaining the high throughput at lower
latency and satisfying the Quality of Service (QoS) requirements of the IeUs.Comment: 12 pages, 15 figures, journa
Scalable RAN Virtualization in Multi-Tenant LTE-A Heterogeneous Networks (Extended version)
Cellular communications are evolving to facilitate the current and expected
increasing needs of Quality of Service (QoS), high data rates and diversity of
offered services. Towards this direction, Radio Access Network (RAN)
virtualization aims at providing solutions of mapping virtual network elements
onto radio resources of the existing physical network. This paper proposes the
Resources nEgotiation for NEtwork Virtualization (RENEV) algorithm, suitable
for application in Heterogeneous Networks (HetNets) in Long Term
Evolution-Advanced (LTE-A) environments, consisting of a macro evolved NodeB
(eNB) overlaid with small cells. By exploiting Radio Resource Management (RRM)
principles, RENEV achieves slicing and on demand delivery of resources.
Leveraging the multi-tenancy approach, radio resources are transferred in terms
of physical radio Resource Blocks (RBs) among multiple heterogeneous base
stations, interconnected via the X2 interface. The main target is to deal with
traffic variations in geographical dimension. All signaling design
considerations under the current Third Generation Partnership Project (3GPP)
LTE-A architecture are also investigated. Analytical studies and simulation
experiments are conducted to evaluate RENEV in terms of network's throughput as
well as its additional signaling overhead. Moreover we show that RENEV can be
applied independently on top of already proposed schemes for RAN virtualization
to improve their performance. The results indicate that significant merits are
achieved both from network's and users' perspective as well as that it is a
scalable solution for different number of small cells.Comment: 40 pages (including Appendices), Accepted for publication in the IEEE
Transactions on Vehicular Technolog
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