IMPROVING SPATIAL REUSE IN MULTIHOP WIRELESS NETWORKS - A SURVEY

  • Alawieh B.
  • Assi C.
  • Mouftah H.
  • Yongning Z

In multihop wireless ad-hoc networks, the medium access control (MAC) protocol plays a key role in coordinating the access to the shared medium among wireless nodes. Currently, the distributed coordination function (DCF) of the IEEE 802.11 is the dominant MAC protocol for both wireless LANs and wireless multihop ad hoc ...

A 1-GSAMPLE/S, 15-GHZ INPUT BANDWIDTH MASTER–SLAVE TRACK-AND-HOLD AMPLIFIER IN INP DHBT TECHNOLOGY

  • Bouvier Y.
  • Godin J.
  • Konczykowska A.
  • Ouslimani A.

A fully differential master-slave track-and-hold amplifier is designed and fabricated in a 210-GHz-f T InP DHBT process. Input bandwidth of 15 GHz, total harmonic distortion lower than -39 dB and a third harmonic rejection greater than 45 dB are measured for 1 GSample/s and 4 dBm single-ended input signal. Time ...

SUM DISCRETE-RATE MAXIMIZATION WITH RATE AND POWER CONTROL IN LAYERED SPACE-TIME CODING

  • Berthet A-O
  • Layec P
  • Visoz R.

This paper generalizes the information-theoretic optimality of minimum mean square error successive interference cancellation in layered space-time coding with rate and power control. Based on this derivation, a new concept relying on partial feedback is introduced, whose core idea is to exploit an additional degree of freedom relative to the ...

MANAGING OPEX WHILE DELIVERING 1000S OF APPS

  • Mayer J.
  • Mills C.A

Rampant demand for new services and applications and the emergence of non-traditional competitors are driving CSPs to revisit their business strategies.

SEPARATE ERROR-FREE TRANSMISSION OF EIGHT CHANNELS AT 10 GB/S USING COMB GENERATION IN A QUANTUM-DASH-BASED MODE-LOCKED LASER

  • Akrout A.
  • Brenot R.
  • Guang Hua D
  • Le Gouezigou O.
  • Lelarge F.
  • Pommereau F.
  • Ramdane A.
  • Shen A.
  • Van Dijk F.

We report on comb generation at 1.55 mum using a mode-locked quantum-dash-based laser. A flat optical spectrum with a ~10-nm width consisting of eight 100-GHz-spaced channels is demonstrated. Separate error-free transmission of each channel is achieved at 10 Gb/s over 50-km-long single-mode fiber. Compared to an ideal external cavity continuous-wave ...

STUDY OF THE NOISE-REDUCTION PROBLEM IN THE KARHUNEN–LOÈVE EXPANSION DOMAIN

  • Benesty J.
  • Jingdong C
  • Yiteng H

Noise reduction, which aims at estimating a clean speech from a noisy observation, has long been an active research area. The standard approach to this problem is to obtain the clean speech estimate by linearly filtering the noisy signal. The core issue, then, becomes how to design an optimal linear ...

AN OVERVIEW OF IPTV STANDARDS DEVELOPMENT

  • Maisonneuve J.

In the last few years, IPTV has emerged as one of the major distribution and access techniques for broadband multimedia services. It is one of the primary growth areas for the telecommunications industry. However, existing IPTV systems are generally based on proprietary implementations that do not provide interoperability. Recently, many ...

WAVELENGTH CONVERSION USING SEMICONDUCTOR OPTICAL AMPLIFIERS IN DIFFERENTIAL MACH-ZEHNDER INTERFEROMETER WITH TUNABLE INPUT COUPLER

  • Bernasconi P.
  • Bhardwaj A.
  • Buhl L.
  • Legrange J.
  • Neilson D.
  • Sauer N.
  • Simsarian J.
  • Zhang L.

A monolithically-integrated wavelength converter on an InP platform with a semiconductor optical amplifier in each arm of a differential Mach-Zehnder interferometer is presented. The data input has a tunable coupler that adjusts the splitting ratio of the optical power sent to each arm. Wavelength conversion at 40 Gbit/s is demonstrated ...

HYBRID OPTICAL VECTOR MODULATOR UTILISING ALGAINAS REFLECTIVE EAMS AND HIGH INDEX-CONTRAST SILICA CIRCUIT

  • Alexandre F.
  • Buhl L.
  • Cappuzzo M.
  • Chandrasekhar S.
  • Chen Y.
  • Decobert J.
  • Dupuis N.
  • Earnshaw M.
  • Garreau A.
  • Gomez L.
  • Jany C.
  • Kazmierski C.
  • Landreau J.
  • Lee J.
  • Rasras M.

A new compact photonic-integrated modulator utilising a four-element reflective electro-absorption modulator-semiconductor optical amplifier (EAM-SOA) array and silica interferometric guide arrangement is presented. The EAM-SOA active layer consists of AlGaInAs quantum wells designed in selective area growth technology, which enables an insertion gain, and the mature silica platform provides reduced optical ...

IMPROVED OFDMA UPLINK TRANSMISSION VIA COOPERATIVE RELAYING IN THE PRESENCE OF FREQUENCY OFFSETS—PART II: OUTAGE INFORMATION RATE ANALYSIS

  • Zhongshan Z

n Part I of this paper, the ergodic information rate is derived for an orthogonal frequency-division multiplexing access (OFDMA) uplink with cooperative relaying in the presence of frequency offsets. In this part, the outage information rate of the system is analysed. Both amplify-and-forward (AF) and decode-and-forward (DF) relays are considered. ...

IMPROVED OFDMA UPLINK TRANSMISSION VIA COOPERATIVE RELAYING IN THE PRESENCE OF FREQUENCY OFFSETS—PART I: ERGODIC INFORMATION RATE ANALYSIS

  • Zhongshan Z

In this two-part paper, we evaluate ergodic and outage information rates in an orthogonal frequency-division multiple access (OFDMA) uplink with amplify-and-forward (AF) and decode-and-forward (DF) relays in the presence of frequency offsets. Each node plays the roles of the source node and the relay, simultaneously, but on different subcarriers. In ...

LP MOCVD GROWTH OF INALN/GAN HEMT HETEROSTRUCTURE: COMPARISON OF SAPPHIRE, BULK SIC AND COMPOSITE SICOPSIC SUBSTRATES FOR HEMT DEVICE APPLICATIONS

  • Chartier E.
  • Delage S.
  • Di Forte Poisson M.
  • Di Persio J.
  • Magis M.
  • Morvan E.
  • Oualli M.
  • Sarazin N.
  • Tordjman M.

In this paper we report on low-pressure metalorganic vapour deposition of InAlN/GaN heterostructures grown on different substrates (Sapphire, bulk SiC, composite SiCopSiC) for HEMT applications, and on first device performances obtained with these heterostructures. Optimisation of the crystal growth on each kind of substrate has led to InAlN/GaN HEMT heterostructures ...

THE STRUCTURE OF INALN/GAN HETEROSTRUCTURES FOR HIGH ELECTRON MOBILITY TRANSISTORS

  • Bejerano Y.

In the investigated InAlN/GaN layers, it is shown that the surface morphology and the crystallinity of the alloy critically depend on the In composition. Atomic force microscopy analysis points out that step flow growth is not easily attained in this system. When the InAlN or AlN interlayer thickness is increased, ...

EXPERIMENTAL EVALUATION OF THE DIVERSITY PERFORMANCE FOR A DVB-SH MOBILE TERMINAL

  • Dussauby E
  • Duval R

This article presents measurements performed with test infrastructures for digital TV broadcasting (DVB-SH standard).The objective is to determine the diversity performance of a mobile terminal integrating two orthogonally polarized antennas in various sites. The performance evaluation is based on a narrow band analysis of the propagation channel.

TAKING THE SKELETONS OUT OF THE CLOSETS: A SIMPLE AND EFFICIENT TOPOLOGY DISCOVERY SCHEME FOR LARGE ETHERNET LANS

  • Bejerano Y.

We propose a simple and efficient algorithmic solution for discovering the physical topology of large, heterogeneous Ethernet LANs that may include multiple subnets as well as uncooperative network elements, like hubs. Our scheme utilizes only generic MIB information and does not require any hardware or software modification of the underlying ...

OFDMA UPLINK FREQUENCY OFFSET ESTIMATION VIA COOPERATIVE RELAYING

  • Tellambura C
  • Zhongshan Z
  • Zou Wei

Frequency offset estimation for an orthogonal frequency-division multiple access (OFDMA) uplink for amplify-and-forward (AF) relays and a new type of relay (R) called decode-and-compensate-and-forward (DcF) relays are studied. Multiple relays are considered, and the relay with the best S rarr R channel is chosen to perform re-transmission, where S and ...

180-GHZ GAIN-BANDWIDTH PRODUCT BACK-SIDE-ILLUMINATED GAINAS–ALINAS APDS

  • Achouche M.
  • Carpentier D.
  • Decobert J.
  • Lagay N.
  • Pommereau F.
  • Rouvie A.

This letter presents a comparative study of GaInAs-AlInAs avalanche photodiodes with different absorption layer thicknesses. Simulations concerning dark current and frequency response have been carried out to study the influence of the vertical structure on functional characteristics. Fabricated devices achieved gain-bandwidth product GtimesB as high as 180 GHz combined with ...

ANALYTICAL MODEL FOR HIERARCHICAL CACHE OPTIMIZATION IN IPTV NETWORK

  • Krogfoss B.
  • Sofman L.

In an IPTV network, video on demand and other video services generate large amount of unicast traffic from video hub office (VHO) to subscribers and, therefore, require additional bandwidth and equipment resources in the network. To reduce this traffic and overall network cost, a portion of the video content (the ...

CELL BREATHING TECHNIQUES FOR LOAD BALANCING IN WIRELESS LANS

  • Bejerano Y.
  • Seung-Jae H

Maximizing network throughput while providing fairness is one of the key challenges in wireless LANs (WLANs). This goal is typically achieved when the load of access points (APs) is balanced. Recent studies on operational WLANs, however, have shown that AP load is often substantially uneven. To alleviate such imbalance of ...

DISTORTION MINIMIZATION IN GAUSSIAN LAYERED BROADCAST CODING WITH SUCCESSIVE REFINEMENT

  • Erkip E.
  • Goldsmith A.
  • Gundunz D
  • Ng C.

A transmitter without channel state information wishes to send a delay-limited Gaussian source over a slowly fading channel. The source is coded in superimposed layers, with each layer successively refining the description in the previous one. The receiver decodes the layers that are supported by the channel realization and reconstructs ...