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Survey on energy consumption entities on mobile phone platform
No full textThe full degree of freedom in mobile systems heavily
depends on the energy provided by the mobile phone’s batteries.
Their capacity is in general limited and for sure not keeping pace as
the mobile devices are crammed up with new functionalities. The
discrepancy of Moore’s law, offering twice the processing power at
least each second year, and the development in batteries, which did
not even double over the last decade, makes a shift in researchers’
way of designing networks, protocols, and the mobile device itself.
The bottleneck to take care of in the design process of mobile systems
is not only the wireless data rate, but even more the energy limitation
as the customers ask for new energy-hungry services, e.g., requiring
faster connections or even multiple air interfaces, and longer
standby or operational times of their mobile devices at the same time.
In this survey, the energy consuming entities of a mobile device such
as wireless air interfaces, display, mp3 player and others are
measured and compared. The presented measurement results allow
the reader to understand what the energy hungry parts of a mobile
device are and use those findings for the design of future mobile
protocols and applications. All results presented in this work and
further results are made public on our web pageTRUEpu
Feasibility of floating content service for context aware applications
Get PDFContext aware applications encompass an ever-expanding set of applications that make use of a combination of restricted spatio-temporal locality and mobile communications to deliver a variety of services to the user. The communication requirements for such applications significantly differ from ordinary applications and opportunistic communications can play a role for such applications because they naturally incorporate context.
In this work we chose to analyze the complex interplay
between context information, communication technologies, and
context aware applications, by studying the feasibility of a context aware communication service called floating content as a support for context aware mobile applications. In order to complement our performance study, we considered a specific context aware application belonging to family of ”social proximity sensing” which can be implemented via floating content.
We analyzed the suitability of the floating content technique for such an application, and analyzed the main performance bounds at the communication level by means of simulations. The analysis revealed that floating content service can be used only for the applications that are used in areas having high user density.Telematics EngineeringUniversidad Carlos III de Madrid, Spainpu
New Insights from the Analysis of Free Flow Vehicular Traffic in Highways
Get PDFBuilding vehicular networks in roads and highways
is a challenging research topic with a large number of applications ranging from the prevention of traffic jams and car collisions to efficient route planning. Analyzing the distance between vehicles in roads is a key factor in, e.g., designing vehicular networks protocols or planning a supporting infrastructure to improve connectivity. This work proposes a Gaussian-exponential mixture model to
characterize the time distance between vehicles in a highway
lane, based on measurements collected at different locations in several highways of the city of Madrid. The model arises from the observed behavior that some vehicles travel very close together, like in a burst mode, showing Gaussian inter-arrival times, while other vehicles are isolated, showing exponentially distributed inter-arrival times. The experiments show that such a Gaussian exponential
mixture model accurately characterizes inter-vehicle times as observed from real traces.TRUEpu
Analytical Characterization of Failure Recovery in REAP
Get PDFThis paper characterizes analytically the performance of REAchability Protocol (REAP), a network layer end-to-end recovery protocol for IPv6. REAP was developed by the IETF SHIM6 Working Group as part of its multihoming solution. The behavior of REAP is governed by a small number of parameters: three timers, a simple characterization of the application traffic, and the communication delay. The key figure of merit of REAP performance is the time to recover from a path failure as seen by the upper layers, figure
that cannot be trivially obtained, despite the apparent simplicity of this reachability protocol. In this paper we provide upper bounds for the recovery time of REAP for different deployment scenarios, applying these analytical results to two interesting case studies, TCP and VoIP traffic.TRUEpu
The Shim6 architecture for IPv6 multihoming
Get PDFThe Shim6 architecture enables IPv6 multihoming without compromising the scalability of the global routing system by using provider aggregatable addresses. To do so, hosts use different addresses as locators for data packet transmission, but present the same source and destination identifier pair to transport and upper layers. The components of this architecture are the Shim6 entity, which maps and tra nslates upper-layer identifiers and locators for remote hosts; the Shim6 protocol, which exchanges mapping information between two hosts that communicate; and the REAP protocol, which monitors the existing unidirectional paths and finds new valid locator combinations in case of failure. To protect against new vulnerabilities this architecture may introduce compared to IPv6, Shim6 hosts use either cryptographically generated addresses or hash-based addressesTRUEpu
Is Content Publishing in BitTorrent Altruistic or Profit Driven?
No full textBitTorrent is the most popular P2P content delivery application where individual users share various type of content
with tens of thousands of other users. The growing popularity of BitTorrent is primarily due to the availability of valuable content without any cost for the consumers. However,
apart from required resources, publishing (sharing) valuable
(and often copyrighted) content has serious legal implications for users who publish the material (or publishers). This
raises a question that whether (at least major) content publishers behave in an altruistic fashion or have other incentives such as !nancial. In this study, we identify the content
publishers of more than 55K torrentsin two major BitTorrent
portals and examine their behavior. We demonstrate that a
small fraction of publishers is responsible for 67% of the
published content and 75% of the downloads. Our investigationsreveal that these major publishersrespond to two different pro!les. On the one hand, antipiracy agencies and malicious publishers publish a large amount of fake !les to protect copyrighted content and spread malware respectively.
On the other hand, content publishing in BitTorrent is largely
driven by companies with !nancial incentives. Therefore, if
these companies lose their interest or are unable to publish
content, BitTorrent traf!c/portals may disappear or at least
their associated traf!c will be signi!cantly reduced.TRUEpu
Rope ladder routing: Position-based multipath routing for wireless mesh networks
Get PDFE-ISBN: 978-1-4244-7263-5, ISBN: 978-1-4244-7264-2 (Print)
DOI: 10.1109/WOWMOM.2010.5534994In this paper, we present a novel multipath structure
called rope-ladder which combines the advantages of path, node and link protection schemes. We also propose a position-based multipath routing protocol in order to efficiently construct ropeladders in wireless networks. By design, the paths which are constructed by our protocol are closely together which allows to quickly switch back and forth between them in cases of node or link failures. Hence, the size of loss gaps (i.e. the number of consecutively lost packets) can be minimized. Previous works
mostly confine themselves to overall packet loss comparisons.
However, the loss gap size is crucial to ensure high quality for gap-sensitive traffic like voice flows. Our multipath structure can also tolerate failures of multiple consecutive nodes on the primary path, and has a superior path diversity and path lifetime compared to even perfect braids. We evaluate the performance of our protocol using analysis and simulationsTRUEpu
Integrated Routing and Addressing for Improved IPv4 and IPv6 Coexistence
Get PDFWe claim that the slow deployment of IPv6 seen so
far is related with the complete decoupling with IPv4 regarding to routing and addressing. In this paper we propose Integrated Routing and Addressing (InRA), a new solution to allow IPv6 to integrate with IPv4 routing and addressing in order to decrease management cost during the coexistence period, and speed up IPv6 deployment. Addressing and routing integration are achieved by the use of a new address format derived from IPv4 address assignment, and the use of a new type of encapsulation
allowing packets to be forwarded according to the most detailed information known by a router (InRA or IPv4).TRUEpu
Optimal Configuration of 802.11e EDCA for Real-Time and Data Traffic
Get PDFThe enhanced distributed channel access (EDCA) mechanism of the IEEE 802.11e standard provides quality-ofservice (QoS) support through service differentiation by using different medium-access-control (MAC) parameters for different stations. The configuration of these parameters, however, is still an open research challenge, as the standard provides only a set of fixed recommended values that do not take into account the current wireless local area network (WLAN) conditions and, therefore, lead to suboptimal performance. In this paper, we propose a novel algorithm for EDCA that, given the throughput and delay requirements of the stations that are present in the WLAN, computes the optimal configuration of the EDCA parameters. We first present a throughput and delay analysis that provides the mathematical foundation upon which our algorithm is based.
This analysis is validated through simulations of different traffic sources (both data and real time) and EDCA configurations. We then propose a mechanism to derive the optimal configuration of the EDCA parameters, given a set of performance criteria for throughput and delay. We assess the effectiveness of the configuration provided by our algorithm by comparing it against 1) the recommended values by the standard, 2) the results from an exhaustive search over the parameter space, and 3) previous configuration proposals, which are both standard and nonstandard compliant. Results show that our configuration outperforms
all other approaches.TRUEpu