This PDF file contains the front matter associated with SPIE Proceedings Volume 6776, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.
R&D on new generation mobile network has attracted a growing interest over the
world on the background of rapid market growth for 2nd and 3rd - generation cellular
networks and wireless LANs/MANs. The National Institute of Information and
Communications Technology (NICT) has been carried out the New Generation Mobile
Network Project from April 2002 to March 2006, and has developed fundamental
technologies to enable seamless and secure integration of various wireless access
networks such as existing cellular networks, wireless LANs, home networks, intelligent
transport systems (ITS), the Beyond-3G (B3G) cellular and other wireless access
systems. From April 2006, Ubiquitous Mobile Network project focused on cognitive
radio technology and integrated seamless networking technology was started. This
paper overviews the achievement and the future plan of these projects.
In spite of the significant increase of the use of Wireless Local Area Network (WLAN) experienced in the last years, design aspects and capacity planning of the network are still systematically neglected during the network implementation. For instance, to determine the location of the access point (AP), important factors of the environment are not considered in the project. These factors become more important when several APs are installed, sometimes without a frequency planning, to cover a unique building. Faults such as these can cause interference among the cells generated by each AP.
Therefore, the network will not obtain the QoS patterns required for each service. This paper proposes a strategy to determine how much a given network can affect the QoS parameters of another network, by interference. In order to achieve this, a measurement campaign was carried out in two stages: firstly with a single AP and later with two APs using the same channel. A VoIP application was used in the experiment and a protocol analyzer collected the QoS metrics. In each stage 46 points were measured , that are insufficient for statistically characterize the environment. For expanding this data, an Artificial Neural Network (ANN) was used. After the measurement, an analysis of the results and a set of inferences were made by using Bayesian Networks, whose inputs were the experimental data, i.e., QoS metrics like throughput, delay, jitter, packet loss, PMOS and physical metrics like power and distance.
A contention-based access scheme, Distributed Coordination Function (DCF), is the basic access technology and it works as the basis for 802.11 MAC and its extensions. Using the Carrier-Sense Multiple Access with Collision Avoidance (CSMA/CA) mechanism and the Binary Exponential Backoff (BEB) mechanism, DCF can efficiently avoid multiple stations to transmit data at the same time and thus reduces the collision probability. In addition to BEB, Exponential Increase Exponential Decrease (EIED) is another well known backoff mechanism to avoid retransmission collision. In literature, many researches show that BEB algorithm may result in a poor throughput in a heavy load environment, while the EIED scheme does not perform as well as BEB under a light traffic condition. The emphasis of this paper is to address the shortcomings of the above two schemes and pose a solution to select a better random backoff timer in order to maximize the throughput under various traffic load. In this work, a novel backoff mechanism, Optimal Backoff (OB) mechanism, is proposed. OB can choose an optimal contention window according to current traffic conditions. Analytical and simulation results show that proposed Optimal Backoff mechanism always has highest throughput and lowest packet delay than those of the BEB and EIED mechanisms under both light and heavy traffic scenarios. With the deployment of the proposed OB, we believe that Wireless LAN is able to work perfectly as an extension of legacy mobile networks in t he context of upcoming Next Generation Networks.
Radio on Fiber (RoF) technologies are available to realize a universal platform for transparent forwarding various types
of wireless services under multi air interferences coexistence in a ubiquitous network environment. By applying free
space optical techniques for RoF, its concept can be extended to free space channels. This paper describes a development
project of DWDM Radio on Free Space Optics (RoFSO) system, which can realize a universal platform to quickly and
effectively provide ubiquitous wireless services for rural areas. Radio on Free Space networks using RoF, RoFSO, and
Radio on Radio (RoR) realize software definable radio networks, which is configured with the combination of Virtual
Radio Free Space Network using radio on free space networks, software definable radio gateway, wireless service over
IP, and radio agents. This paper also describes the availability of software definable radio networks for ubiquitous wireless.
Proc. SPIE 6776, A novel fair queuing algorithm for hybrid wired/wireless architecture with wireless compensation to provide end-to-end quality of service support, 677607 (10 September 2007); doi: 10.1117/12.735366
We proposed novel hybrid FSO/RF architecture1 to provide broadband wireless access to end users. To provide quality
of service (QoS) bounds for different types of traffic(voice, video and data) we proposed some fair queuing algorithms2,3
,but because of the hybrid wired and wireless links there can be certain times allocated to a host when that host is unable
to transmit data because of wireless link errors. These wireless link errors are location dependent and bursty. The
channel errors can occur from multi-path fading, shadow fading or interference from another device. In this paper we
proposed a novel fair queuing algorithm to provide end to end QoS bounds to the end users for the proposed architecture
.The algorithm provide QoS bounds for Ethernet traffic in the wired domain as well as in wireless domain with
compensation for wireless link errors. Scheduler maps priorities and weights for QoS of the Ethernet traffic into wireless
MAC. By supporting existing Ethernet traffic QoS parameters 4-7, scheduler avoids the need to redefine QoS parameters
for wireless channel. By simulations and analysis we proved that the algorithm guarantees (1) delay and throughput for
error-free flows, (2) short term fairness among error-free flows, (3) long term fairness among errored and error-free
flows,(4) graceful degradation for leading flows and graceful compensation for lagging flows. Each connection QoS is
guaranteed by calculating bounds on delay and reserving the Bandwidth (BW).
Arbitrarily-shaped ultrashort pulse waveforms could be synthesized with optimized high-resolution zero-dispersion pulse
shaping system. The system and optimized parameters are analyzed and discussed. It is shown that the optimized pulse
shaping system could resolve frequency components of ultrashort pulse and avoid spatial shaping of individual
frequency components. The specified shaped pulses are generated through our optimized system, which can potentially
improve the performance of optical wireless communication system.
Home users are in need for broadband communications access, globally. Broadband over power-lines
transmission has advanced throughout the last decade, and it is going to be a mature last-mile access in near
Meanwhile, indoor optical wireless communications (optical WiFi) through lighting LEDs has been
It is shown that a combination of these two techniques provides an efficient way of fulfilling the premise of
broadband access for home networking, while providing efficient and low-cost lighting.
Local communities and governments are taking various steps to fight the so-called "digital divide" between well served
urban communities and undeserved areas. In order to make broadband access available to these under served areas,
several technical solutions are available with the capacity to provide high speed Internet access, video, telephony
services, etc. This paper presents a cost-model and a tool for the evaluation of broadband access technologies (xDSL,
HFC, FTTx, WiMAX, PLC and satellite), and compares two technologies: FTTx and WiMAX. Our tool compares these
different access technologies in different scenarios, and examining the capital expense and deployment of building
access networks with the same requisite performance using each technology. The cost model is limited to the access part
of the network. The results obtained by our evaluation tool give the possibility to compare several BB access
technologies, and support the decision about which is the better technological solution for a given scenario
The Multimedia-over-Coax Alliance (MoCA) standard is rapidly emerging as the de-facto standard in North
America for multimedia home networking. This is driven by the desire to have digital content from various
sources such as DVRs, audio devices and PCs reliably available anywhere in the home using the in-home
existing coaxial cable wiring. The MoCA technology coexists with other services at the home such as cable
TV, cable modem, and satellite services. This technology achieves MAC throughputs exceeding 100 Mb/s in
97% of all outlets in the home with no changes to the home coax infrastructure, and with packet error rates
less than 10-5, and with an average latency of less than 3.5 milliseconds based on extensive field trial results.
For the last 500,000 years, progress of human civilization has been linked to exploration of electromagnetic spectrum.
Photonic devices progressed from torches to candles, from gas lamps to electric bulbs, and finally to visible, infrared,
and UV lasers and light emitting diodes. Electronic devices, such as High Electron Mobility Transistors and
Heterojunction Bipolar Transistors, reached into the sub-terahertz range. The terahertz range (0.3 THz to 30 THz) is in
between the spectral ranges dominated by electronic and photonic device. In this paper, we review applications of
terahertz technology for space exploration and data communications.
Many broadband services are based on multimedia applications, such as voice over internet protocol (VoIP), video conferencing, video on demand (VoD), and internet protocol television (IPTV). The combination "triple-play" is often used with IPTV. It simply means offering voice, video and data. IPTV and others services uses digital broadband networks such as ADSL2+ (Asymmetric Digital Subscriber Line) and VDSL (Very High Rate DSL) to transmit the data. We have formulated a MDP (Markov Decision Process) for a triple-play transmission on DSL environment. In this paper, we establish the relationship between DSL transmission characteristics and its finite-state Markov model for a triple-play transmission system. This relationship can be used for a resource management for multimedia applications delivered through a broadband infrastructure. The solution to our optimization problem can be found using dynamic programming (DP) techniques, such as value iteration and its variants. Our study results in a transmission strategy that chooses the optimal resource allocation according the triple-play traffic requirements, defined in technical report TR-126 (Triple-Play Services Quality of Experience Requirements) from DSL Forum, minimizing quality of service (QoS) violations with respect to bandwidth. Three traffic classes (video, audio, and best effort internet data) are defined and analyzed. Our simulation results show parameters like as blocking probability for each class, link utilization and optimal control policies. The MDP-based approach provides a satisfactory way of resource management for a DSL system.
The increasing trend of triple play traffic transmission (voice, video and data) over internet is a worldwide phenomenon.
However, to get a satisfactory communication, we need study the process on end-the-end way. Into regions with little
infrastructure of telecommunications, one of the concerns is about used technologies of access. This work presents an
analysis based on an IPTV (Television Internet Protocol) transmission generated on two combined technologies of
access, PLC (PowerLine Communications) and ADSL2+ (Asymmetric Digital Subscriber Line), using a combination of
electric network and telephony infrastructure, called of pDSL. This technology is a viable combination for regions with
poor infrastructure of telecommunications. The results are evaluated with intention to present the viability of this kind of
the telecommunication environment and with a simulation for extrapolation study.
WDM based passive optical network (PON) upgrades current TDM based PON at the architecture, protocol and
dynamic bandwidth allocation algorithms to provide higher bandwidth in the access networks. Various Dynamic
Wavelength and Bandwidth Allocation algorithms for WDM-PON have been studied. These DWBA algorithms exploit
both inter-channel and intra-channel statistical multiplexing in order to achieve better performance, especially when the
load on various channels is not symmetric. However, these algorithms let all ONUs share all wavelengths equally, and
decouple bandwidth allocation from the wavelength assignment, which may cause bandwidth fragmentation across
different wavelengths, and these algorithms further strictly limit the ONUs only to use one wavelength per allocation
cycle, hence, leading to the underutilized network performance. To overcome the above limitation, we propose an
enhanced dynamic wavelength and bandwidth allocation (EDBA) algorithm, which integrates wavelength assignment
with bandwidth allocation process. We use extensive simulation to compare the performance of EDBA to another
DWBA algorithm in 3.
Interest is high among residential customers and businesses for advanced, broadband services such as fast Internet
access, electronic commerce, video-on-demand, digital broadcasting, teleconferencing and telemedicine. In order to
satisfy such growing demand of end-customers, access technologies such as fiber-to-the-home/building (FTTH/B) are
increasingly being deployed. Carriers can reduce maintenance costs, minimize technology obsolescence and introduce
new services easily by reducing active elements in the fiber access network. However, having a passive optical network
(PON) also introduces operational and maintenance challenges. Increased diagnostic monitoring capability of the
network becomes a necessity as more and more fibers are provisioned to deliver services to the end-customers. This
paper demonstrates the clear advantages that large 3D optical MEMS switches offer in solving these access network
problems. The advantages in preventative maintenance, remote monitoring, test and diagnostic capability are
highlighted. The low optical insertion loss for all switch optical connections of the switch enables the monitoring,
grooming and serving of a large number of PON lines and customers. Furthermore, the 3D MEMS switch is transparent
to optical wavelengths and data formats, thus making it easy to incorporate future upgrades, such higher bit rates or
DWDM overlay to a PON.
Unceasingly developed and deeply exploited along with the software system, the variety of middlewares becomes
more and more, they mutually affect each other in the complex way. These middlewares, because of the complex
of the origin, are not extremely credible. So, before using these middlewares, we must understand the security
features of them, for instance, the secret data cannot be leaked in the network. But, it is very difficult to confirm
whether these middlewares have good security feature. The paper designs the encapsulations, which let these
middlewares run under secure environment, and it provides the control of good granularity among the
middlewares, the middleware and other system resources. The main part of this paper is to research the expression
methods of the encapsulations, and we state and verify the security through these methods. This paper uses
box-πcalculus to describe several kinds of encapsulations, and discuss the security that each encapsulation could
The Brazilian Amazon has sui generis characteristics that affect strongly the communication technologies, such as high humidity and temperature. These characteristics cause impact in the existent infrastructure, especially in twisted-pair copper lines. At the moment, new services are based on multimedia applications, as voice over internet protocol (VoIP), video on demand (VoD), and internet protocol television (IPTV). Such services use digital broadband networks such as ADSL2+ (Asymmetric Digital Subscriber Line) to transmit the data. Broadband services require data rates which can only be achieved by using relatively high spectrum frequencies. At high frequencies the DSL signal is more susceptible to external noise sources, such as radio frequency interference and impulsive noise. For this purpose, an experimental setup has been built at UFPA that consists of noise generator, traffic generator, real cables, modems and DSLAM (digital subscriber line access multiplexer). This paper aims at characterizing how the noise impacts on triple play services for a broadband system using a DSL loop on Amazon environment. The objective of the noise impact experimentation is to observe the behavior of a DSL system under more realistic but controlled line conditions. Metrics as lost packet, jitter, latency, and throughput are used to characterize the triple play service in a DSL loop under the noise impact. Through the real experiments and controlled loop conditions, this paper allow identify, from application level point of view, how robust DSL system is in respect to noise occurrence. Additionally, it is described a methodology for noise impact measurements using a DSL system.
This paper describes Sequence Time Domain Reflectometry (STDR) and Spread Spectrum Time Domain Reflectometry (SSTDR), which utilizes concepts from direct sequence spread spectrum communications, as a technique
for detecting impedance mismatches in telephone lines (twisted pair). The aim of this paper is to present methodologies for characterizing a subscriber loop, which is used for Digital Subscriber Line (DSL) technology, based
on STDR and SSTDR tests. Those tests enable the TDR functionality to be incorporated into a DSL transceiver integrated circuit eliminating the need for costly test equipment. In addition to the cost savings, the
characteristics of the STDR and SSTDR offer improved spectral compatibility, interference immunity and fault
xDSL systems are widely used nowadays. Services such as VDSL2 can achieve high bitrates over copper wires.
The usage of dynamic spectrum management techniques (DSM) can result in even better bitrates, through
mitigation of crosstalk, the worst interference in such systems. This tutorial surveys the recent progress in DSM,
covering the main algorithms and optimization concepts used by then.
Data collection is the most important stage in network forensics; but under the resource constrained situations, a good
evidence collection mechanism is required to provide effective event collections in a high network traffic environment.
In literatures, a few network forensic tools offer MSN-messenger behavior reconstruction. Moreover, they do not have
classification strategies at the collection stage when the system becomes saturated. The emphasis of this paper is to
address the shortcomings of the above situations and pose a solution to select a better classification in order to ensure the
integrity of the evidences in the collection stage under high-traffic network environments. A system-awareness decision
classifier (SADC) mechanism is proposed in this paper. MSN-shot sensor is able to adjust the amount of data to be
collected according to the current system status and to keep evidence integrity as much as possible according to the file
format and the current system status. Analytical results show that proposed SADC to implement selective collection (SC) consumes less cost than full collection (FC) under heavy traffic scenarios. With the deployment of the proposed SADC mechanism, we believe that MSN-shot is able to reconstruct the MSN-messenger behaviors perfectly in the context of upcoming next generation network.
This paper presents a model to treat the problem of process scheduling within a computer network using a fuzzy
inference system. The scheduling system implemented, simulated in the Network Simulator, acts in two particularly
points: first defining the discard priority for the applications according to its characteristics; and further, to redefine their
transfer rate, also considering its particularities; thus providing fitting transfer rates for the applications and, with it,
means for Quality of Service.