864 research outputs found
Survey of Spectrum Sharing for Inter-Technology Coexistence
Increasing capacity demands in emerging wireless technologies are expected to
be met by network densification and spectrum bands open to multiple
technologies. These will, in turn, increase the level of interference and also
result in more complex inter-technology interactions, which will need to be
managed through spectrum sharing mechanisms. Consequently, novel spectrum
sharing mechanisms should be designed to allow spectrum access for multiple
technologies, while efficiently utilizing the spectrum resources overall.
Importantly, it is not trivial to design such efficient mechanisms, not only
due to technical aspects, but also due to regulatory and business model
constraints. In this survey we address spectrum sharing mechanisms for wireless
inter-technology coexistence by means of a technology circle that incorporates
in a unified, system-level view the technical and non-technical aspects. We
thus systematically explore the spectrum sharing design space consisting of
parameters at different layers. Using this framework, we present a literature
review on inter-technology coexistence with a focus on wireless technologies
with equal spectrum access rights, i.e. (i) primary/primary, (ii)
secondary/secondary, and (iii) technologies operating in a spectrum commons.
Moreover, we reflect on our literature review to identify possible spectrum
sharing design solutions and performance evaluation approaches useful for
future coexistence cases. Finally, we discuss spectrum sharing design
challenges and suggest future research directions
Techno-economic viability of integrating satellite communication in 4G networks to bridge the broadband digital divide
Bridging the broadband digital divide between urban and rural areas in Europe is one of the main targets of the Digital Agenda for Europe. Though many technological options are proposed in literature, satellite communication has been identified as the only possible solution for the most rural areas, due to its global coverage. However, deploying an end-to-end satellite solution might, in some cases, not be cost-effective. The aim of this study is to give insights into the economic effectiveness of integrating satellite communications into 4G networks in order to connect the most rural areas (also referred to as white areas) in Europe. To this end, this paper proposes a converged solution that combines satellite communication as a backhaul network with 4G as a fronthaul network to bring enhanced broadband connectivity to European rural areas, along with a techno-economic model to analyse the economic viability of this integration. The model is based on a Total Cost of Ownership (TCO) model for 5 years, taking into account both capital and operational expenditures, and aims to calculate the TCO as well as the Average Cost Per User (ACPU) for the studied scenarios. We evaluate the suggested model by simulating a hypothetical use case for two scenarios. The first scenario is based on a radio access network connecting to the 4G core network via a satellite link. Results for this scenario show high operational costs. In order to reduce these costs, we propose a second scenario, consisting of caching the popular content on the edge to reduce the traffic carried over the satellite link. This scenario demonstrates a significant operational cost decrease (more than 60%), which also means a significant ACPU decrease. We evaluate the robustness of the results by simulating for a range of population densities, hereby also providing an indication of the economic viability of our proposed solution across a wider range of areas
A Real-Time Performance Evaluation of Tightly Coupled LTE Wi-Fi Radio Access Networks
A tight coupling of LTE and Wi-Fi interfaces can be achieved by integrating them at the radio protocol stack. LTE and Wi-Fi radio level integration with IPSec tunnel (LWIP) is standardized by 3GPP in Rel-13 for tighter level of LTE-Wi-Fi interworking at IP layer. This tighter level of interworking replaces the traditional way of cellular-Wi-Fi interworking through a packet gateway and it can react to the dynamic changes in the wireless link quality. In this paper, we present a new variant of LWIP prototype that works with commercial UE (Nexus 5). The developed LWIP prototype uses OpenAirInterface (OAI) for LTE network and Cisco Access Point (AP) as Wi-Fi AP. We also present the design and implementation of LWIP prototype and interesting results for tight interworking of LTE and Wi-Fi at IP level. We have evaluated the LWIP performance with different Link Aggregation Strategies (LAS) using both UDP and TCP. We have observed that, in a highly loaded Wi-Fi channel, when LWIP employs Wi-Fi only in Downlink (WoD) LAS, then sum of individual TCP flow throughput has improved by 28% as compared to LWIP operating with Flow Split (FS) LAS. We have enumerated the challenges which has to be addressed in LWIP to reap the maximum benefits.
A Real-Time Performance Evaluation of Tightly Coupled LTE Wi-Fi Radio Access Networks | Request PDF. Available from: https://www.researchgate.net/publication/320416949_A_Real-Time_Performance_Evaluation_of_Tightly_Coupled_LTE_Wi-Fi_Radio_Access_Networks [accessed Jan 25 2018]
Architectural Challenges and Solutions for Collocated LWIP - A Network Layer Perspective
Achieving a tighter level of aggregation between
LTE and Wi-Fi networks at the radio access network (a.k.a.
LTE-Wi-Fi Aggregation or LWA) has become one of the most
prominent solutions in the era of 5G to boost network capacit
y
and improve end user's quality of experience. LWA offers
flexible resource scheduling decisions for steering user tr
affic
via LTE and Wi-Fi links. In this work, we propose a Collocated
LTE/WLAN Radio Level Integration architecture at IP layer
(C-LWIP), an enhancement over 3GPP non-collocated LWIP
architecture. We have evaluated C-LWIP performance in vari
ous
link aggregation strategies (LASs). A C-LWIP node (
i.e.
, the node
having collocated, aggregated LTE eNodeB and Wi-Fi access
point functionalities) is implemented in NS-3 which introd
uces a
traffic steering layer (
i.e.
, Link Aggregation Layer) for efficient
integration of LTE and Wi-Fi. Using extensive simulations,
we
verified the correctness of C-LWIP module in NS-3 and evaluat
ed
the aggregation benefits over standalone LTE and Wi-Fi netwo
rks
with respect to varying number of users and traffic types. We
found that split bearer performs equivalently to switched b
earer
for UDP flows and switched bearer outperforms split bearer in
the case of TCP flows. Also, we have enumerated the potential
challenges to be addressed for unleashing C-LWIP capabilit
ies.
Our findings also include WoD-Link Aggregation Strategy whi
ch
is shown to improve system throughput by 50% as compared to
Naive-LAS in a densely populated indoor stadium environmen
t
Performance analysis and deployment of VoLTE mechanisms over 3GPP LTE-based networks
Long Term Evolution based networks lack native support for Circuit Switched (CS) services. The Evolved Packet System (EPS) which includes the Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) and Evolved Packet Core (EPC) is a purely all-IP packet system. This introduces the problem of how to provide voice call support when a user is within an LTE network and how to ensure voice service continuity when the user moves out of LTE coverage area. Different technologies have been proposed for the purpose of providing a voice to LTE users and to ensure the service continues outside LTE networks. The aim of this paper is to analyze and evaluate the overall performance of these technologies along with Single Radio Voice Call Continuity (SRVCC) Inter-RAT handover to Universal Terrestrial Radio Access Networks/ GSM-EDGE radio access Networks (UTRAN/GERAN). The possible solutions for providing voice call and service continuity over LTE-based networks are Circuit Switched Fall Back (CSFB), Voice over LTE via Generic Access (VoLGA), Voice over LTE (VoLTE) based on IMS/MMTel with SRVCC and Over The Top (OTT) services like Skype. This paper focuses mainly on the 3GPP standard solutions to implement voice over LTE. The paper compares various aspects of these solutions and suggests a possible roadmap that mobile operators can adopt to provide seamless voice over LTE
Adaptive Control of IoT/M2M Devices in Smart Buildings using Heterogeneous Wireless Networks
With the rapid development of wireless communication technology, the Internet
of Things (IoT) and Machine-to-Machine (M2M) are becoming essential for many
applications. One of the most emblematic IoT/M2M applications is smart
buildings. The current Building Automation Systems (BAS) are limited by many
factors, including the lack of integration of IoT and M2M technologies,
unfriendly user interfacing, and the lack of a convergent solution. Therefore,
this paper proposes a better approach of using heterogeneous wireless networks
consisting of Wireless Sensor Networks (WSNs) and Mobile Cellular Networks
(MCNs) for IoT/M2M smart building systems. One of the most significant outcomes
of this research is to provide accurate readings to the server, and very low
latency, through which users can easily control and monitor remotely the
proposed system that consists of several innovative services, namely smart
parking, garden irrigation automation, intrusion alarm, smart door, fire and
gas detection, smart lighting, smart medication reminder, and indoor air
quality monitoring. All these services are designed and implemented to control
and monitor from afar the building via our free mobile application named Raniso
which is a local server that allows remote control of the building. This
IoT/M2M smart building system is customizable to meet the needs of users,
improving safety and quality of life while reducing energy consumption.
Additionally, it helps prevent the loss of resources and human lives by
detecting and managing risks.Comment: Accepted in IEEE Sensors Journa
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