WNG - Wireless Network Group
http://hdl.handle.net/2117/1080
2017-02-24T06:13:43ZCompetition: interference-aware multi-channel cross layer protocol for energy-efficient and low-delay networking
http://hdl.handle.net/2117/99753
Competition: interference-aware multi-channel cross layer protocol for energy-efficient and low-delay networking
Sierra Aiello, Guillermo; Seyfettin Demirkol, Ilker; Calveras Augé, Anna M.; Gómez Montenegro, Carlos; García Villegas, Eduard; Betzler, August
This document aims to present the general ideas and methodology that are planned to be used for the EWSN 2016 Dependability Competition by the Wireless Networks Group of Universitat Politecnica de Catalunya. We designed, developed and conducted performance tests based on the approach detailed in this extended abstract, with the target of optimizing the metrics of each of the evaluation criteria (i.e. reliability of the sent data, end-to-end latency and energy consumption). The current approach will be evaluated and improved further until the competition day.
2017-01-20T11:40:23ZSierra Aiello, GuillermoSeyfettin Demirkol, IlkerCalveras Augé, Anna M.Gómez Montenegro, CarlosGarcía Villegas, EduardBetzler, AugustThis document aims to present the general ideas and methodology that are planned to be used for the EWSN 2016 Dependability Competition by the Wireless Networks Group of Universitat Politecnica de Catalunya. We designed, developed and conducted performance tests based on the approach detailed in this extended abstract, with the target of optimizing the metrics of each of the evaluation criteria (i.e. reliability of the sent data, end-to-end latency and energy consumption). The current approach will be evaluated and improved further until the competition day.On the benefits of wireless SDN in networks of constrained edge devices
http://hdl.handle.net/2117/98164
On the benefits of wireless SDN in networks of constrained edge devices
Bestler, August; Quer, Ferran; Campus Mur, Daniel; Seyfettin Demirkol, Ilker; García Villegas, Eduard
In this paper we study the benefits of applying Software Defined Networking (SDN) to control forwarding in a network of constrained wireless edge devices. The proposed architecture is applicable to dense Small Cell deployments featuring wireless backhauling and edge computing capabilities, or to wirelessly connected sensor nodes following the fog computing paradigm. The paper introduces a novel path forwarding policy based on SDN, and presents an experimental evaluation demonstrating the benefits of the proposed policy to mitigate external interference, achieve flow balancing, and cope with CPU constrained devices.
2016-12-13T14:55:23ZBestler, AugustQuer, FerranCampus Mur, DanielSeyfettin Demirkol, IlkerGarcía Villegas, EduardIn this paper we study the benefits of applying Software Defined Networking (SDN) to control forwarding in a network of constrained wireless edge devices. The proposed architecture is applicable to dense Small Cell deployments featuring wireless backhauling and edge computing capabilities, or to wirelessly connected sensor nodes following the fog computing paradigm. The paper introduces a novel path forwarding policy based on SDN, and presents an experimental evaluation demonstrating the benefits of the proposed policy to mitigate external interference, achieve flow balancing, and cope with CPU constrained devices.Multisided patches
http://hdl.handle.net/2117/97925
Multisided patches
Pla García, Núria; Vigo Anglada, Marc; Cotrina Navau, Josep
We present a method to construct a patch of parametric surface of degree k + 1 that lls a n-sided hole, with n bigger than 2, and whose boundary coincides with a B-Spline, thus, the resulting patch can be easily connected with given B-Spline surfaces with xed continuity conditions. The method is inspired on a generic approach to construct free form surfaces, which gives a family of practical schemes to design surfaces from an arbitrary given mesh, using the di erentiable manifold theory. The input is a star shaped mesh which describes a generic n-hole and a surface in a neighborhood of the hole. The main advantages of the method are the following: arbitrary order k continuity conditions can be imposed; the involved hole can have an arbitrary number of sides and arbitrary shape (convex or not); the simplicity of the construction process gives an easy and exible method; and nally, the surface near the boundary is a B-Spline with piecewise uniform knot sequences and whose control points are vertices of the given mesh; both knot sequences and control points are easily computed. Implementation details to evaluate a surface point are given, showing that the de Boor algorithm can be exploited for efficiency.
2016-12-09T10:50:42ZPla García, NúriaVigo Anglada, MarcCotrina Navau, JosepWe present a method to construct a patch of parametric surface of degree k + 1 that lls a n-sided hole, with n bigger than 2, and whose boundary coincides with a B-Spline, thus, the resulting patch can be easily connected with given B-Spline surfaces with xed continuity conditions. The method is inspired on a generic approach to construct free form surfaces, which gives a family of practical schemes to design surfaces from an arbitrary given mesh, using the di erentiable manifold theory. The input is a star shaped mesh which describes a generic n-hole and a surface in a neighborhood of the hole. The main advantages of the method are the following: arbitrary order k continuity conditions can be imposed; the involved hole can have an arbitrary number of sides and arbitrary shape (convex or not); the simplicity of the construction process gives an easy and exible method; and nally, the surface near the boundary is a B-Spline with piecewise uniform knot sequences and whose control points are vertices of the given mesh; both knot sequences and control points are easily computed. Implementation details to evaluate a surface point are given, showing that the de Boor algorithm can be exploited for efficiency.N-sided patches with B-spline boundaries
http://hdl.handle.net/2117/97827
N-sided patches with B-spline boundaries
Cotrina Navau, Josep; Pla García, Núria; Vigo Anglada, Marc
We present a method to construct a patch of parametric surface of
degree k+1 that fills a n-sided hole, with bigger than 2, and whose
boundary coincides with a B-Spline, thus, the resulting patch can be
easily connected with given B-Spline surfaces with fixed continuity
conditions. The method is based on the generic approach by the same
authors to con-struct free form surfaces, which gives a family of
practical schemes to design surfaces from an arbitrary given mesh,
using the differentiable manifold the-ory. The proposal uses a star
shaped mesh which describes a generic n-hole and a surface in a
neighborhood of the hole. From this mesh, a set of charts is defined,
one associated to each vertex or face of the mesh, depending on the
parity of the input parameter k. A basis function and a control point
is defined from each chart, and the surface is obtained as a
baricentric combination of the control points using the defined basis
functions. The main advantages of the method are the following:
arbitrary order k continuity conditions can be imposed; the involved
hole can have an arbitrary number of sides and arbitrary shape (convex
or not) the simplicity of the construction process gives an easy and
flexible method; and finally, the surface near the boundary is a
B-Spline with piecewise uniform knot sequences and whose control
points are vertices of the given mesh. Implementation details to
evaluate a surface point are given, showing that the de Boor algorithm
can be exploited for efficiency.
2016-12-07T10:03:03ZCotrina Navau, JosepPla García, NúriaVigo Anglada, MarcWe present a method to construct a patch of parametric surface of
degree k+1 that fills a n-sided hole, with bigger than 2, and whose
boundary coincides with a B-Spline, thus, the resulting patch can be
easily connected with given B-Spline surfaces with fixed continuity
conditions. The method is based on the generic approach by the same
authors to con-struct free form surfaces, which gives a family of
practical schemes to design surfaces from an arbitrary given mesh,
using the differentiable manifold the-ory. The proposal uses a star
shaped mesh which describes a generic n-hole and a surface in a
neighborhood of the hole. From this mesh, a set of charts is defined,
one associated to each vertex or face of the mesh, depending on the
parity of the input parameter k. A basis function and a control point
is defined from each chart, and the surface is obtained as a
baricentric combination of the control points using the defined basis
functions. The main advantages of the method are the following:
arbitrary order k continuity conditions can be imposed; the involved
hole can have an arbitrary number of sides and arbitrary shape (convex
or not) the simplicity of the construction process gives an easy and
flexible method; and finally, the surface near the boundary is a
B-Spline with piecewise uniform knot sequences and whose control
points are vertices of the given mesh. Implementation details to
evaluate a surface point are given, showing that the de Boor algorithm
can be exploited for efficiency.Towards free form surfaces
http://hdl.handle.net/2117/97654
Towards free form surfaces
Cotrina Navau, Josep; Pla García, Núria; Vigo Anglada, Marc
A theoretical approach to construct free form surfaces is presented. We
develop the conceps that arise when a free form surface is generated by
tracing a mesh, using differentiable manifold theory, and generalizing
the B-spline scheme. This approach allows to define a family of
practical schemes.
2016-12-01T18:18:08ZCotrina Navau, JosepPla García, NúriaVigo Anglada, MarcA theoretical approach to construct free form surfaces is presented. We
develop the conceps that arise when a free form surface is generated by
tracing a mesh, using differentiable manifold theory, and generalizing
the B-spline scheme. This approach allows to define a family of
practical schemes.Multi-beam zooming: an enabler for energy efficient 5G networks
http://hdl.handle.net/2117/97544
Multi-beam zooming: an enabler for energy efficient 5G networks
Molluru, S. K.; Seyfettin Demirkol, Ilker; Wei-Ho, Chung
The demand for electrical power is growing tremendously, which poses grand challenges to modern energy systems. The telecommunications industry takes a significant part in the global power consumption. In this work we introduce the multi-beam zooming concept as a new perspective to the energy-efficient 5G network, where the multibeam
zooming technique incorporates the beam zooming and multi-beam beamforming methods. This approach enables multiple beams to be casted on different users with adjustable amplitudes of individual beams based on user locations obtained using PRS in LTE. We developed an LTE simulation framework to quantitatively evaluate the
advantages of the multi-beam zooming approach in terms of the power savings. Using the realistic mobility traces, we analyze the effect of crucial system setting of antenna tapering method and its effect on the potential power savings achievable at the base stations.
2016-11-30T15:44:19ZMolluru, S. K.Seyfettin Demirkol, IlkerWei-Ho, ChungThe demand for electrical power is growing tremendously, which poses grand challenges to modern energy systems. The telecommunications industry takes a significant part in the global power consumption. In this work we introduce the multi-beam zooming concept as a new perspective to the energy-efficient 5G network, where the multibeam
zooming technique incorporates the beam zooming and multi-beam beamforming methods. This approach enables multiple beams to be casted on different users with adjustable amplitudes of individual beams based on user locations obtained using PRS in LTE. We developed an LTE simulation framework to quantitatively evaluate the
advantages of the multi-beam zooming approach in terms of the power savings. Using the realistic mobility traces, we analyze the effect of crucial system setting of antenna tapering method and its effect on the potential power savings achievable at the base stations.Free form surfaces
http://hdl.handle.net/2117/95949
Free form surfaces
Cotrina Navau, Josep; Pla García, Núria
A method to construct continuous order k surfaces of arbitrary
topological type by tracing a mesh that represents a 2-manifold is
presented. The presented approach constructs the surface from a
collection of pieces which overlap, using the known technology of
manifolds. The surface is built from the given mesh and two arbitrary
input parameters, k and n. The value of k gives the continuity of the
resulting surface and n controls the local influence of the vertices
of the mesh. The presented scheme generalizes the B-spline approach
in terms of manifolds. The surface that arises from regular zones of
the mesh is a tensorial product B-spline surface. For the rest, that
is, the irregular zones, the surface has the following good
properties: it is k continuous, affine invariant, the convex hull
property is guaranteed, and it has local control. The algorithm is
simple and efficient in time and space.
2016-11-09T12:52:04ZCotrina Navau, JosepPla García, NúriaA method to construct continuous order k surfaces of arbitrary
topological type by tracing a mesh that represents a 2-manifold is
presented. The presented approach constructs the surface from a
collection of pieces which overlap, using the known technology of
manifolds. The surface is built from the given mesh and two arbitrary
input parameters, k and n. The value of k gives the continuity of the
resulting surface and n controls the local influence of the vertices
of the mesh. The presented scheme generalizes the B-spline approach
in terms of manifolds. The surface that arises from regular zones of
the mesh is a tensorial product B-spline surface. For the rest, that
is, the irregular zones, the surface has the following good
properties: it is k continuous, affine invariant, the convex hull
property is guaranteed, and it has local control. The algorithm is
simple and efficient in time and space.Has time come to switch from duty-cycled MAC protocols to wake-up radio for wireless sensor networks?
http://hdl.handle.net/2117/91114
Has time come to switch from duty-cycled MAC protocols to wake-up radio for wireless sensor networks?
Oller, Joaquim; Seyfettin Demirkol, Ilker; Casademont Serra, Jordi; Paradells, Josep; Gamm, Gerd Ulrich; Reindl, Leonhard Michael
Duty-cycled Medium Access Control (MAC) protocols certainly improve the energy efficiency of wireless networks. However, most of these protocols still suffer from severe degrees of overhearing and idle listening. These two issues prevent optimum energy usage, a crucial aspect in energy-constrained wireless networks such as wireless sensor networks (WSNs). Wake-up radio (WuR) systems drastically reduce these problems by completely switching off the nodes' microcontroller unit (MCU) and main radio transceiver until a secondary, extremely low-power receiver is triggered by a particular wireless transmission, the so called wake-up call. Unfortunately, most WuR studies focus on theoretical platforms and/or custom-built simulators. Both these factors reduce the associated usefulness of the obtained results. In this paper, we model and simulate a real, recent, and promising WuR hardware platform developed by the authors. The simulation model uses time and energy consumption values obtained in the laboratory and does not rely on custom-built simulation engines, but rather on the OMNET++ simulator. The performance of the WuR platform is compared to four of the most well-known and widely employed MAC protocols for WSN under three real-world network deployments. The paper demonstrates how the use of our WuR platform presents numerous benefits in several areas, from energy efficiency and latency to packet delivery ratio and applicability, and provides the essential information for serious consideration of switching duty-cycled MAC-based networks to WuR.
2016-10-26T14:06:17ZOller, JoaquimSeyfettin Demirkol, IlkerCasademont Serra, JordiParadells, JosepGamm, Gerd UlrichReindl, Leonhard MichaelDuty-cycled Medium Access Control (MAC) protocols certainly improve the energy efficiency of wireless networks. However, most of these protocols still suffer from severe degrees of overhearing and idle listening. These two issues prevent optimum energy usage, a crucial aspect in energy-constrained wireless networks such as wireless sensor networks (WSNs). Wake-up radio (WuR) systems drastically reduce these problems by completely switching off the nodes' microcontroller unit (MCU) and main radio transceiver until a secondary, extremely low-power receiver is triggered by a particular wireless transmission, the so called wake-up call. Unfortunately, most WuR studies focus on theoretical platforms and/or custom-built simulators. Both these factors reduce the associated usefulness of the obtained results. In this paper, we model and simulate a real, recent, and promising WuR hardware platform developed by the authors. The simulation model uses time and energy consumption values obtained in the laboratory and does not rely on custom-built simulation engines, but rather on the OMNET++ simulator. The performance of the WuR platform is compared to four of the most well-known and widely employed MAC protocols for WSN under three real-world network deployments. The paper demonstrates how the use of our WuR platform presents numerous benefits in several areas, from energy efficiency and latency to packet delivery ratio and applicability, and provides the essential information for serious consideration of switching duty-cycled MAC-based networks to WuR.On-demand sensor node wake-up using solar panels and visible light communication
http://hdl.handle.net/2117/91077
On-demand sensor node wake-up using solar panels and visible light communication
Carrascal, Carolina; Seyfettin Demirkol, Ilker; Paradells, Josep
To significantly reduce, or eliminate completely, the energy waste caused by the standby (idle) mode of wireless sensor nodes, we propose a novel on-demand wake-up system, which allows the nodes to be put into sleep mode unless their activation is truly necessary. Although there have been many studies proposing RF-based wake-up radio systems, in this work, we develop the first visible light communication (VLC)-based wake-up system. The developed system can extend the existing VLC systems and can be exploited to derive new application areas such as VLC tags. The system uses an off-the-shell indoor solar panel as receptor device of the wake-up signal as well as for energy harvesting purposes, through which it is able to harvest enough energy for its autonomous work. The design, implementation details and the experimental evaluation results are presented, which include flickering characterization and wake-up range evaluations. The results show that the developed system achieve reasonable wake-up distances for indoor environments, mainly where the use of VLC systems are considered.
2016-10-25T18:21:15ZCarrascal, CarolinaSeyfettin Demirkol, IlkerParadells, JosepTo significantly reduce, or eliminate completely, the energy waste caused by the standby (idle) mode of wireless sensor nodes, we propose a novel on-demand wake-up system, which allows the nodes to be put into sleep mode unless their activation is truly necessary. Although there have been many studies proposing RF-based wake-up radio systems, in this work, we develop the first visible light communication (VLC)-based wake-up system. The developed system can extend the existing VLC systems and can be exploited to derive new application areas such as VLC tags. The system uses an off-the-shell indoor solar panel as receptor device of the wake-up signal as well as for energy harvesting purposes, through which it is able to harvest enough energy for its autonomous work. The design, implementation details and the experimental evaluation results are presented, which include flickering characterization and wake-up range evaluations. The results show that the developed system achieve reasonable wake-up distances for indoor environments, mainly where the use of VLC systems are considered.A practical framework for 802.11 MIMO rate adaptation
http://hdl.handle.net/2117/86345
A practical framework for 802.11 MIMO rate adaptation
Deek, Lara; García Villegas, Eduard; Belding, Elizabeth; Lee, Sung-Ju; Almeroth, Kevin
The emergence of MIMO antennas and channel bonding in 802.11n wireless networks has resulted in a huge leap in capacity compared with legacy 802.11 systems. This leap, however, adds complexity to optimizing transmission. Not only does the appropriate data rate need to be selected, but also the MIMO transmission technique (e.g., Spatial Diversity or Spatial Multiplexing), the number of streams, and the channel width. Incorporating these features into a rate adaptation (RA) solution requires a new set of rules to accurately evaluate channel conditions and select the appropriate transmission setting with minimal overhead. To address these challenges, our contributions in this work are two-fold. First, we propose a practical link metric that accurately captures channel conditions in MIMO 802.11n environments, and we call this metric diffSNR. Using diffSNR captured from real testbed environments, we build performance models that accuractely predict link quality in 95.5% of test cases. Practicality and deployability are guaranteed with diffSNR as it can be measured on all off-the-shelf MIMO WiFi chipsets. Second, we propose ARAMIS (Agile Rate Adaptation for MIMO Systems), a standard-compliant, closed-loop RA solution that jointly adapts rate and bandwidth, and we utilize the diffSNR-based 802.11n performance models within ARAMIS's framework. ARAMIS adapts transmission rates on a per-packet basis; we believe it is the first closed-loop, 802.11 RA algorithm that simultaneously adapts rate and channel width. We have implemented ARAMIS with diffSNR on Atheros-based devices and deployed it on our 15-node testbed. Our experiments show that ARAMIS accurately adapts to a wide variety of channel conditions with negligible overhead. Furthermore, ARAMIS outperforms existing RA algorithms in 802.11n environments with up to a 10-fold increase in throughput. (C) 2015 Elsevier B.V. All rights reserved.
2016-04-28T10:35:31ZDeek, LaraGarcía Villegas, EduardBelding, ElizabethLee, Sung-JuAlmeroth, KevinThe emergence of MIMO antennas and channel bonding in 802.11n wireless networks has resulted in a huge leap in capacity compared with legacy 802.11 systems. This leap, however, adds complexity to optimizing transmission. Not only does the appropriate data rate need to be selected, but also the MIMO transmission technique (e.g., Spatial Diversity or Spatial Multiplexing), the number of streams, and the channel width. Incorporating these features into a rate adaptation (RA) solution requires a new set of rules to accurately evaluate channel conditions and select the appropriate transmission setting with minimal overhead. To address these challenges, our contributions in this work are two-fold. First, we propose a practical link metric that accurately captures channel conditions in MIMO 802.11n environments, and we call this metric diffSNR. Using diffSNR captured from real testbed environments, we build performance models that accuractely predict link quality in 95.5% of test cases. Practicality and deployability are guaranteed with diffSNR as it can be measured on all off-the-shelf MIMO WiFi chipsets. Second, we propose ARAMIS (Agile Rate Adaptation for MIMO Systems), a standard-compliant, closed-loop RA solution that jointly adapts rate and bandwidth, and we utilize the diffSNR-based 802.11n performance models within ARAMIS's framework. ARAMIS adapts transmission rates on a per-packet basis; we believe it is the first closed-loop, 802.11 RA algorithm that simultaneously adapts rate and channel width. We have implemented ARAMIS with diffSNR on Atheros-based devices and deployed it on our 15-node testbed. Our experiments show that ARAMIS accurately adapts to a wide variety of channel conditions with negligible overhead. Furthermore, ARAMIS outperforms existing RA algorithms in 802.11n environments with up to a 10-fold increase in throughput. (C) 2015 Elsevier B.V. All rights reserved.