IMDEA Networks Institute Digital Repository
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Adaptive Monitoring for Mobile Networks in Challenging Environments
Get PDFThe increasing capabilities of mobile communication devices are changing the way people interconnect today. Similar trends in the communication technology domain are leading
to the expectation that data and media are available anytime and everywhere. A result is an increasing load on communication networks. In dynamic mobile networks that particularly rely on wireless communication such data requirements paired with environmental conditions like mobility or node density increase the risk of network failure. Consequently, monitoring is crucial in mobile networks to ensure reliable and efficient operation. Current
monitoring mechanisms mostly rely on a static architecture
and exhibit problems to handle the changes of mobile networks and environmental conditions over time. In this paper, an adaptive monitoring mechanism is presented to overcome these limitations. The mechanism exploits the connectivity and resource characteristics of mobile communication devices to (i) reconfigure its monitoring topology and (ii) adapt to changes of mobile networks and environmental conditions. Through evaluations we show that our proposed solution reduces the achieved relative monitoring error by a factor of six and represents a robust and reliable monitoring mechanism for these challenging environments.TRUEpu
Panel: Co-development: Processes & Technologies
No full textPanel Moderator: Ari Jouppila (Head of Development Unit Network Analytics & Control, Ericsson)
Panel Members: Antonino Albarrán (EMEA SDI Solutions Architect, Intel), Ödgard Andersson (Head of Product Development Unit Packet Core, Ericsson), Arturo Azcorra (Director, IMDEA Networks Institute), Peter López (Head of SDN Regional Engagement, Ericsson), Fabrizio Salvador (Professor of Operations Management, IE Business School Madrid)TRUEpu
Obstacle Avoidance Cell Discovery using mm-waves Directive Antennas in 5G Networks
Get PDFWith the advent of next-generation mobile devices, wireless networks must be upgraded to fill the gap between huge user data demands and scarce channel capacity. Mm-waves technologies appear as the key-enabler for the future 5G networks design, exhibiting large bandwidth availability and high data rate.
As counterpart, the small wave-length incurs in a harsh signal propagation that limits the transmission range. To overcome this limitation, array of antennas with a relatively high number of small elements are used to exploit beamforming techniques that greatly increase antenna directionality both at base station and user terminal. These very narrow beams are used during data transfer and tracking techniques dynamically adapt the direction according to terminal mobility. During cell discovery when initial synchronization must be acquired, however, directionality can delay the process since the best direction to point the beam is unknown. All space must be scanned using the tradeoff between beam width and transmission range.
Some support to speed up the cell search process can come from the new architectures for 5G currently being investigated, where conventional wireless network and mm-waves technologies coexist. In these architecture a functional split between C-plane and U-plane allows to guarantee the continuous availability of a signaling channel through conventional wireless technologies with the opportunity to convey context information from users to network.
In this paper, we investigate the use of position information provided by user terminals in order to improve the performance of the cell search process. We analyze mm-wave propagation environment and show how it is possible to take into account of position inaccuracy and reflected rays in presence of obstacles.TRUEpu
Modelling D2D communications in cellular access networks via Coupled Processors
Get PDFInvited PosterAlso in cellular networks, D2D communications provide numerous advantages. Nevertheless, modelling D2D
systems remains a complex and unsolved task. In this work, we present the first analytical study on D2D
system performance. Our approach models interdependencies among D2D and cellular transmitters in
details and achieves a conservative estimation of the stability region of D2D systems, as well as evaluates
the effects of D2D transmissions on cellular users. Furthermore, the proposed approach can easily tradeoff
performances for less complexity in a realistic application, i.e., in a proportional fairness optimization.TRUEpu
A fail safe broadcast protocol for collaborative intelligent vehicles
No full textThis paper presents a broadcast protocol that makes cooperative driving applications safer. Collaborative driving is a rapidly evolving trend in intelligent transportation system. Current communication services provided by vehicular ad-hoc network (VANET) cannot guarantee fail-safe operation.
We present a fail safe broadcast protocol (FSBP) that resides between the cooperative driving applications and VANET to make the cooperative driving applications work in a safer way. The protocol uses synchronized clocks with the help of GPS to schedule the broadcast transmissions of the participants. Electing not to transmit at a scheduled time is a unique message that cannot be lost because of a noisy or lost communication channel. This message is used to abort a collaborative operation and revert to an autonomous driving mode, similar to the current
generation of intelligent vehicles, in which a vehicle protects itself. We describe a particular, simple protocol that uses a token passing mechanism. We specify the protocol as a finite state machine and use probabilistic verification to verify the protocol. This is the first formal verification of a multi-party broadcast protocol.TRUEpu
Anticipatory Quality-Resource Allocation for Multi-User Mobile Video Streaming
Get PDFMobile video delivery forms the largest part of the traffic in cellular networks. Thus optimizing the resource allocation to satisfy a user's quality of experience is becoming paramount in modern communications. This paper belongs to the line of research known as anticipatory networking that makes use of prediction of wireless capacity to improve communication performance. In particular, we focus on the problem of optimal resource allocation for steady video delivery under maximum average quality constraints for multiple users. We formulate the problem as a piecewise linear program and provide a heuristic algorithm, which solution is close to optimal. Based on our formulation we are now able to trade off minimum video quality, average quality and offered network capacity.pu
Enhancing Wireless local area Networks by leveraging Diverse Frequency Resources
Get PDFIn this thesis, signal propagation variations, that are experience over the frequency resources of IEEE 802.11 Wireless Local Area Networks (WLANs) are studied. It is found that exploitation of these variations can improve several aspects of wireless communication systems. To this aim, frequency varying behavior is addressed at two different levels.
First, the intra-channel scale is considered, i.e. variations over the continuous frequency block that a device uses for a cohesive transmission. Variations at this level are well known but cur- rent wireless systems restrict to basic equalization techniques to balance the received signal. In contrast, this work shows that more fine grained adaptation to these differences can accomplish throughput and connection range gains.
Second, multi-frequency band enabled devices that access widely differing frequency re- sources in the millimeter wave range as well as in the microwave range are analyzed. These devices that are expected to follow the IEEE 802.11ad specification experience intense propaga- tion variations over their frequency resources. Thus, a part of this thesis revises, the theoretical specification of the IEEE 802.11ad standard and complements it by a measurement study of first generation millimeter wave devices. This study reveals deficiencies of first generation millime- ter wave systems, whose improvement will pose new challenges to the protocol design of future generation systems. These challenges are than addressed by novel methods that leverage from frequency varying propagation characteristics.
The first method, improves the beam training process of millimeter wave networks, that need highly directional, though electronically steered, transmissions to overcome increased free space attenuation. By leveraging from omni-directional signal propagation at the microwave bands, efficient direction interference is utilized to provide information to millimeter wave interfaces and replace brute force direction testing. Second, deafness effects at the millimeter wave band, which impact IEEE 802.11 channel access methods are addressed. As directional communication on these bands complicates sensing the medium to be busy or idle, inefficiencies and unfairness are implied. By using coordination message exchange on the legacy Wi-Fi frequencies with omni- directional communication properties, these effects are countered. The millimeter wave bands can thus unfold their full potential, being exclusively used for high speed data frame transmission.Telematics EngineeringUniversidad Carlos III de Madrid, Spainpu
Lightweight Mobile Bandwidth Availability Measurement
Get PDFMobile data traffic is increasing rapidly and wireless spectrum is becoming a more and more scarce resource. This makes it highly important to operate the mobile network efficiently. In this paper we are proposing a novel lightweight measurement technique that can be used as a basis for advanced resource optimization algorithms to be run on mobile phones. Our main idea leverages an original packet dispersion based, technique to estimate both per user capacity and asymptotic dispersion rate. This allows passive measurements using only existing mobile traffic. Our technique is able to efficiently filter outliers introduced by mobile network schedulers. In order to verify the feasibility of our measurement technique, we run a week-long measurement campaign spanning two cities in two countries, different radio technologies, and covering all times of the day. The campaign demonstrates that our technique is effective even if it is provided only with a small fraction of the exchanged packets of a flow. The only requirement for the input data is that it should consist of a few consecutive packets that are gathered periodically. This makes the measurement algorithm a good candidate for inclusion in OS libraries to allow for advanced resource optimization and application-level traffic scheduling, based on current and predicted future user capacity.TRUEpu
