Shervin Erfani

Review: Survey of multipath routing protocols for mobile ad hoc networks

This survey investigates multipath routing protocols for mobile ad hoc networks (MANETs). The main objectives of multipath routing protocols are to provide reliable communication and to ensure load balancing as well as to improve quality of service (QoS) of MANETs. These multipath protocols are broadly classified into five categories based on their major goals. The goals are to improve delay, provide reliability, reduce overhead, maximize network life and support hybrid routing. Multipath routing protocols address issues such as multiple paths discovery and maintaining these paths. Issues, objectives, performances, advantages and disadvantages of these protocols are investigated and summarized. A checklist is provided as a guideline so that a network designer can choose an appropriate multipath routing protocol to meet the networks application objectives.

A multipath routing survey for mobile ad-hoc networks

Mobile ad hoc networks (MANETs) pose particular challenges in terms of Quality of Service (QoS) and performance. This is due to the effect of numerous parameters such as; bandwidth and power constrains, delays, security issues, etc. On the there hand, the degree of freedom enables the wireless mobile nodes to enter and leave the network dynamically. The latter offers redundant paths and dynamic coverage. Particular attention is given to the multipath transmission capability as well as load balancing to have efficient routing possible for heavy multimedia traffics. In this paper, the issues of multipath routing in MANETs are surveyed and performances of such MANETs are compared to discuss the application of multipath routing and its effects on different layers to support QoS.

Frequency analysis of linear time-varying systems

This paper outlines a solution technique developed for frequency-domain analysis and synthesis of linear time-varying (LTV) systems. By an application of two-sided Laplace transform and two-dimensional Laplace Transform (2DLT), in general, the frequency-domain techniques are developed, which facilitate the analysis or synthesis of variable and adaptive systems. The significant advantage of the frequency analysis and synthesis over the time-domain techniques is clear.

Frequency analysis of linear time-varying systems: a new perspective

This paper extends the application of Laplace transform as a frequency-domain tool of linear time-invariant (LTI) systems to the analysis and synthesis of linear time-varying (LTV) systems. It is shown that the LTV system input and output are related to each other by their bi-frequency transfer function H (s1, s2). This is the two-dimensional Laplace transform (2DLT) of the unit-impulse response of the system. The LTI systems and other transformation techniques can be considered as special cases of this general method. On the basis of the results presented in this paper, applicability of the Laplace transform to linear ordinary differential equations (ODE) as well as general linear systems is verified. This is on the contrary to a hitherto-known belief that confined the use of Laplace transform to LTI systems only

On properties of double laplace transformation for analysis of linear time-varying systems

Properties of double (or two-dimensional) Laplace transform (2DLT) for analysis of linear time-varying (LTV) systems are explored. The one-dimensional to two-dimensional expansion formulas, as well as the two-dimensional to one-dimensional reduction formulas, are outlined. The merit of the proposed technique for frequency analysis of LTV systems is demonstrated.

Mobile-IP MPLS-based networks

The Internet backbone has been enjoying the great many advantages of multi-protocol label switching (MPLS) for quite sometimes, as well as in wireless applications. The employment of MPLS in mobile services and applications was not noticeable until the beginning of the year 2000. However researches began extensive efforts to extend the MPLS capability to the wireless access networks. This is particularly important when quality of service (QoS) became a major issue. In this paper we provide an overview of the MPLS-based mobile-IP management including label switched path set up, packet forwarding, and handoff/handover processing. This investigation further reveals the improvement of handoff/handover procedures and depending on the structure and capacities of these schemes, traffic with variety of bandwidth requirements could be routed with minimal interruption/packet-loss. The research also includes the integrity of peer-to-peer communications covering multi-layer communication requirements. Future work involves in investigation of buffer-system failure and its effect on the traffic-loss. This includes thorough investigation using mathematical tools and practical investigation using proper simulation and testbed environments

A note of frequency-domain characterization of linear time-varying networks

The extension of the Laplace transform techniques for characterization of linear time-varying (LTV) networks is presented. The proposed two-dimensional Laplace transform (2DLT) can be used as a framework for analysis and synthesis of LTV networks and systems that exhibit a circular symmetry property.

Frequency-domain realization of linear time-varying systems by two-dimensional Laplace transformation

The objective of this paper is to extend application of Laplace-Carson transform (LCT) to the realization of linear time-varying (LTV) systems. We propose using the unilateral and bilateral two-dimensional Laplace transform (2DLT) for realization of LTV systems, which exhibit a circular symmetry. Application of two-dimensional Laplace and Fourier transforms to LTV systems results in a bifrequency realization. In particular, it is shown that the 2DLT of LTV systems is, in fact, a Hankel transform of order zero.

A framework for implementing IPSec functional architecture

We provide a framework for implementing IPSec security services in a well-structured functional architecture based on a layered functional architecture for network security management [1]. The proposed architecture is modular, and supports open standards and interfaces, and implements the security services of IPSec as an integrated solution under a unified security management system.

Laplace transform approach to analysis and synthesis of bessel type linear time-varying systems

Two-dimensional Laplace transform (2DLT) is applied as a powerful analysis and synthesis tool for linear time-varying networks resulting in Bessel type linear ordinary differential equations. In this sense a parallel and more powerful closed-form solution (compared to traditional transforms) is obtained which is analogous to that in which one-dimensional Laplace transform is used for linear time-invariant (LTI) systems.