Talal Al-Kharobi

Comparative Performance Study for Integrated 3G/WLAN Networks Using Mobile IP, SIP, and m-SCTP Protocols

The 3rd Generation Partnership Project (3GPP) has adopted an interworking architecture between Universal Mobile Telecommunication System (UMTS) and Wireless Local Area Networks (WLANs). This architecture imposes a set of security requirements on subscribers connecting from within interworked WLANs to be able to access their 3G home packet-switched services. Providing seamless handoff and session continuity of ongoing communication is a critical task in UMTS/WLAN integrated networks. However, the 3GPP does not specify how mobility can be supported. This paper provides a performance evaluation for the three candidate solutions: Mobile IP (MIP), Session Initiation Protocol (SIP), and mobile Stream Control Transmission Protocol (mSCTP) that may be used to provide session continuity in the integrated network. The vertical handoff delay figure is analyzed using simulations for different WLAN speeds and its major components due to the involved signaling procedures are quantified. The results are derived from our developed OPNET based simulation model that accounts for the detailed prescribed signaling procedures as per the related standards and Request for Comments (RFCs) documents, and the main network entities in the adopted architecture. The presented analysis provides insight into the potential performance bottlenecks in the integrated network. Major findings of the work show that the security related signaling and the signaling pertaining to obtaining a new Internet Protocol (IP) address, each contribute about 40% of the total delay for all the three solutions. Enhancements targeting these procedures will help reduce the overall delay while supporting seamless handoff between the two networks.

Characterization of Vertical Handoff Delay for Mobile IP Based 3G/WLAN Integrated Networks

optimizations. In this paper, we present a side-by-side performance evaluation and comparisons of the UMTS to WLAN handoff delay that results from using each configuration in the lately adopted UMTS/WLAN interworking architecture by 3GPP. In addition, we analyze the delay components due to 3GPP security and Internet protocol integration requirements. Simulation results show that under low network loading all configurations yield similar performances. However, Mobile IP with IPv6 configuration is more sensitive for network loads and wireless access speeds. In fact, it produces the highest delay figures at high load. Moreover, 3GPP security procedures contribute to more than 60% of the handoff delay for all the configurations.

Analysis of Handoff Delay Components for Mobile IP-Based 3GPP UMTS/WLAN Interworking Architecture

The integration of the widely spread 3rd Generation (3G) Universal Mobile Telecommunication System (UMTS) with the Wireless Local Area Networks (WLANs) has recently attracted considerable attention. However, addressing seamless and transparent handoff during mobility between these networks is still the biggest challenge to overcome. This paper evaluates the components of the handoff delay for the 3GPP UMTS/WLAN interworking architecture. We analyze the handoff delay components due to security procedures, Dynamic Host Configuration Protocol (DHCP), Mobile IP, and the one-way or data transfer delay. This study utilizes a simulation model comprised of network of queues to model the integrated networks at the packet level taking into account both signaling traffic and background loads. Simulation results show that the handoff delay component due to security procedures is the dominant relative to other components under the considered network parameters. In addition, results also reveal that this former component specifically, and the total handoff delay in general, are very sensitive to background load in the network.

A Novel Dual-Mode User Equipment Design and Enhanced Gateway Selection Algorithm for B3G Networks

As wireless Internet applications are proliferating and becoming the main driver for the exploding growth of wireless access technologies, integrating third generation (3G) systems with Wi-Fi networks allows combining the strengths of these two technologies. In this paper, we present a novel design for a dual-mode user equipment (UE) model that supports both 3G and Wi-Fi access and provide one implementation using the OPNET simulation tool. The proposed UE model should be capable of supporting all the integrated network architectures depending on the deployment scenario. The modular model is equipped with two air-interface modules that allow communication with 3G and Wi-Fi networks, but the rest of the protocol stack is the standard IP protocol stack to satisfy the compatibility requirement. The design also includes needed functionalities to support vertical handoff across the two networks. The paper also presents an example algorithm that may be implemented into the proposed UE for enhanced gateway selection.

New neural networks based on Taylor series and their research

This paper is Mining in the essence of neural networks, and constructing 4 types of neural networks: (1) to construct a neural network based on Taylor series; (2) to construct a Taylor component neural network which brings in a Radial Basis Function neuron as a prefix; (3) to construct a Fourier component neural network.Because of the relationships between these functions, the Taylor component NN and the Fourier component NN can be called Gauss series NN equivalently; (4) to construct a Gauss series Clustering neural network and to prove its equivalence with RBF NN in a limit situation.The development of new types of neural Networks is playing an important role either to promote deepening study of neural networks theory or to provide new methods for applications.

Design of an augmented telerobotic stereo vision system and associated security concerns

A telerobotic stereo vision system is used to extend operators eye-hand motion co-ordination to a distance and has been used in many applications. One of the most critical problems of such system is communication delay that leads to teleoperation instability. This problem can be minimized by using Augmented Reality (AR) concepts of superimposing virtual objects onto the real video image of the workspace to create a simulation plan in the local machine. This facilitates trial and error increasing task safety with reduced network interactions. In this paper, a detailed model to augment a given stereo vision system with AR is presented. At first, a six DOF 3D graphical arm is designed and then superimposed onto the video image using camera calibration and registration methods. Motion activation algorithms are developed and interfaces are designed to facilitate task simulations. Data transmission security and integrity over the network are also discussed. The system is implemented using Microsoft .NET with Visual C# and DirectX 9 to augment a stereo vision system comprising of a PUMA-560 robot operating over a LAN.