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Displaying 101 - 125 of 125

Multiple Description Video Coding over Multiple Path Routing Networks

August 1, 2006
Author(s)
Shaoshuai Gao, Hamid Gharavi
This paper presents a multiple description (MD) video-coding scheme, which uses interlaced high signal to noise ratio (H-SNR) and low signal to noise ratio (L-SNR) coded frames to produce two bit-streams. At the decoder, when both bit-streams are received

Multi-Path Multi-Channel Routing Protocol

July 24, 2006
Author(s)
Hamid Gharavi
In this paper we present a DSR-based multi-path Routing protocol, which has been developed for transmission of Multiple Description Coded (MDC) packets in wireless ad-hoc network environments. The protocol is designed to eliminate co-channel interference

Multi-path Multi-Channel Routing Protocol

July 1, 2006
Author(s)
Bo Yan, Hamid Gharavi
In this paper we present a DSR-based multi-path Routing protocol, which has been developed for transmission of Multiple Description Coded (MDC) packets in wireless ad-hoc network environments. The protocol is designed to eliminate co-channel interference

Power Control in Multihop CSMA

June 1, 2006
Author(s)
Hamid Gharavi, Bo Yan
We have implemented a quantum key distribution (QKD) system with polarization encoding at 850 nm over 1 km of optical fiber. The high-speed management of the bit-stream, generation of random numbers and processing of the sifting algorithm are all handled

Control Based Mobile Ad-hoc Networks For Video Communications

May 1, 2006
Author(s)
Hamid Gharavi
This paper presents a feedback control scheme for transmission of video signals over mobile ad-hoc channels. The scheme is a combination of cross-layer (local) feedback and receiver feedback. The receiver feedback is based on the real time transport

Group-Based Ad-hoc Network for Multimedia Communications

October 1, 2005
Author(s)
K Ban, Hamid Gharavi
This paper is concerned with evaluating ad-hoc networks for group-oriented tactical operations. For such operations, a cellular-based ad-hoc network architecture has been constructed for real-time multimedia communications. To assess the suitability of

Real-time Applications for Sensor Networks

April 1, 2005
Author(s)
Hamid Gharavi
We have implemented a quantum key distribution (QKD) system with polarization encoding at 850 nm over 1 km of optical fiber. The high-speed management of the bit-stream, generation of random numbers and processing of the sifting algorithm are all handled

Ad-hoc Network Systems and Applications

November 1, 2004
Author(s)
Hamid Gharavi
We have implemented a quantum key distribution (QKD) system with polarization encoding at 850 nm over 1 km of optical fiber. The high-speed management of the bit-stream, generation of random numbers and processing of the sifting algorithm are all handled

Rate Adaptive Video Transmission Over Ad-Hoc Networks

September 1, 2004
Author(s)
Hamid Gharavi, K Ban
In mobile ad-hoc network environments where the network topology is expected to change considerably, providing reliable video communications is a challenging task. This paper is mainly concerned with developing a packet control mechanism to reduce bursts

A Link-Level Simulator of the CDMA2000 Reverse-Link Layer

August 1, 2003
Author(s)
Hamid Gharavi, R Wyatt-Millington, F Chin, K Ban
This paper presents the design and implementation of a simulation model for the cdma2000 reverse link. The model includes all the radio configurations and their corresponding data rates in accordance with the IS-2000 specifications. The paper first

A Link-Level Simulator of the cdma2000 Reverse-Link Physical Layer

August 1, 2003
Author(s)
Hamid Gharavi, F Chin, K Ban, R Wyatt-Millington
The cdma2000 system is an evolutionary enhancement of the IS-95 standards which support 3G services defined by the International Telecommunications Union(ITU). cdma2000 comes in two phases: 1XRTT and 3XRTT (1X and 3X indicatesthe number of 1.25 MHz wide

Multihop Sensor Network Design for Wideband Communications

August 1, 2003
Author(s)
Hamid Gharavi, K Ban
This paper presents a master/slave cellular based mobile ad-hoc network architecture for multihop multimedia communications. The proposed network is based on a new paradigm for solving the problem of cluster-based ad-hoc routing when utilizing existing

Master-Slave Cluster Based Multihop Ad-hoc Networking

December 1, 2002
Author(s)
Hamid Gharavi, K Ban
This paper presents a master-slave cluster based mobile ad-hoc network architecture for multihop communications using the IEEE 802.11 system. The proposed architecture is a mixture of two different types of networks: managed (master-and-slave) and ad-hoc

Video Transmission for 3G Mobile Communication Systems

June 1, 2002
Author(s)
Hamid Gharavi, K Ban
This paper presents the design and implementation of a mobile ad-hoc network for video communications. The network architecture is based on cluster-to-cluster operation using IEEE 802.11b FHSS (Frequency Hopping Spread Spectrum). FHSS is considered to

IEEE 802.11 FHSS Receiver Design for Multihop Sensor Application

May 1, 2002
Author(s)
K Ban, Hamid Gharavi
This paper presents a receiver design for IEEE 802.11 FHSS (Frequency-Hopping Spread-Spectrum) wireless local area network systems. 802.11 FHSS systems support two basic data rates. 1 Mbps and 2 Mbps systems employ 2GFSK (Gaussian Frequency Shift Keying)

Video Transmission for Multi-Hop Networks Using IEEE 802.11 FHSS

May 1, 2002
Author(s)
K Ban, Hamid Gharavi
In many applications such as construction, manufacturing, ground robotic vehicles, and rescue operations, there are many issues that necessitate the capability of transmitting digital video and that such transmissions should be performed wirelessly and in

Pilot-Assisted 16-Level QAM for Wireless Video

February 1, 2002
Author(s)
Hamid Gharavi
This paper presents a twin-class transmission system for narrowband radio access channels suitable for handheld video phone and multimedia portable PC applications. The transmission system is comprised of a hierarchical 16-QAM modulation technique and a

Video Transmission for Multi-Hop Networks Using IEEE 802.11 FHSS

January 1, 2002
Author(s)
K Ban, Hamid Gharavi
In many applications such as construction, manufacturing, ground robotic vehicles, and rescue operations, there are many issues that necessitate the capability of transmitting digital video and that such transmissions should be performed wirelessly and in

Video Transmission for Third Generation Mobile Communication Systems

December 1, 2001
Author(s)
Hamid Gharavi
This paper presents a method of transmitting video over the cdma2000 mobile systems. In this method, the video bit-stream, after splitting, is transmitted via the supplemental channels of the cdma2000 reverse link. The method takes advantage of the direct

CDMA2000 Reverse-Link Simulation Model Design and Evaluation

July 1, 2001
Author(s)
Hamid Gharavi, R Wyatt-Millington, F Chin
This paper presents the design and implementation of a simulation model for the cdma2000 reverse link. The model includes all the radio configurations and their corresponding data rates in accordance with the IS-2000 specifications. The paper first

Guest Editorial Article (Foreword)

October 1, 1999
Author(s)
Hamid Gharavi, L Hanzo
This article provides a short overview of past and present advancements in mobile communication systems, as well as identifying major challenges for the future generation of wireless technologies. Its main objective is to scan the special issue of the

Receiver Sensitivity in CSMA Networks

Author(s)
B Yan, Hamid Gharavi
This paper aims at improving the power efficiency of the CSMA/CA protocol for transmission of multimedia information over multihop wireless channels. Using a distance dependent propagation model, we present a power control scheme, which is based on the