In this paper, the impulsive effects on projective synchronization between the parameter mismatched neural networks with mixed time-varying delays have been analyzed. Since complete synchronization is not possible due to the existence of parameter mismatch and projective factor, a drive has been taken to achieve the weak projective synchronization of different neural networks under impulsive control strategies. Through the use of matrix measure technique and the extended comparison principle based on the formula of variation of parameters for mixed time-varying delayed impulsive systems, sufficient criteria have been derived for exponential convergence of the networks under the effects of extensive range of impulse. Instead of upper or lower bound of the impulsive interval, the concept of the average impulsive interval is applied to estimate the number of impulsive points in an interval. The concept of calculus is applied for optimizing the synchronization error bounds which are obtained because of different ranges of impulse. Finally, the numerical simulations for various impulsive ranges for different cases are presented graphically to validate the efficiency of the theoretical results.

The NGN (Next Generation Network), which can provide advanced multimedia services over an all-IP based network, has been the subject of considerable attention for several years. While there have been tremendous efforts to develop its architecture and protocols, especially for IMS, a key technology of the NGN, its wide deployment is still a long way off. However, efforts to create an advanced signaling infrastructure able to meet many requirements have resulted in a large number of functional components and interactions between these components. Thus, the carriers are trying to explore effective ways to deploy IMS while offering value-added services. As one such approach, we have proposed a self-organizing IMS. A self-organizing IMS enables IMS functional components and corresponding physical nodes to adapt dynamically and automatically based on actual conditions such as network load and available system resources while continuing IMS operation. To realize this, service continuity for users is an important requirement when a reconfiguration occurs during operation. In this paper, we propose a mechanism that will provide service continuity to users without any impact on clients by extending the SBC (Session Border Controller). Furthermore, we implement it, show its behavior and evaluate its processing time.

We propose a framework for the integration of IEEE 802.21 MIH function with an ad-hoc routing protocol to improve the performances of the ad-hoc routing protocol. In the proposed framework, MIH functions were enabled for the OLSR routing protocol: MIH events were defined and triggered for OLSR, and the OLSR operations responsive to the MIH events were implemented. We analyzed OLSR routing convergence during handover on two ad-hoc network scenarios which can manifest the typical routing behaviors of OLSR. Based on the analysis, we proposed two approaches to improve route convergence of OLSR through MIH. To capture the effects of the proposed framework, we evaluated the performances of OLSR with and without MIH through simulation and compared their performances in terms of packet drop during handover and routing control overhead. The results of the simulations showed that the performance of OLSR was significantly improved through the MIH function.

Real-time services such as VoIP and multimedia streaming are affected during a mobile's rapid handoff due to the associated delay resulting from associated handoff operations of discovery, detection, configuration, registration, media redirection, and processing at different network nodes. Redundant communication path of any signaling and media adds to the delay during session setup and media delivery. This paper highlights the overall problem associated with redundant routing in a 3GPP2-based MMD (multimedia domain) environment and proposes several mechanisms to mitigate these problems. We also compare these mechanisms and select one for existing IMS/MMD networks that use MIPv4 as the mobility protocol. We present the implementation details of the selected redundant routing mitigation technique in the experimental MMD environment and verify the effectiveness by analyzing the measurement results.

The intra-domain mobility management protocol (IDMP) has recently been proposed as a protocol for managing IP mobility within a cellular access network. The paper investigates the scalability performance of IDMP's quality of service (QoS) framework, which uses a modified form of the differentiated services (DiffServ) architecture, with a centralized bandwidth broker (BB) performing admission control and resource provisioning for different traffic classes. The theoretical analysis shows that requests for bandwidth reservation due to intra-domain mobility should be controlled to alleviate the processing burden at the BB. Accordingly, we propose a scalable bandwidth reservation scheme. By reserving the bandwidth in the trunk instead of on a per-host basis, QoS-related signaling load and handoff latency can be reduced significantly.

This paper describes the session initiation protocol (SIP) based mobility in IPv6 and its performance in our laboratory testbed. For real-time mobile multimedia communication, we use SIP for signaling protocol as well as for supporting terminal mobility. While performance study for real-time mobile communication refers to several factors and their measurements, we analyze here only the handoff delay due to node mobility. In particular, we are interested to examine the delay incurred when a mobile node moves to a new link and perform the duplicate address detection (DAD) and router selection, and analyze the delay in each case. We notice that the IPv6 Linux implementation provides substantial amount of delay during node movement, which severely affects the performance of real-time applications. Therefore, we modify the Linux kernel and compare with the unaltered one. Finally, we conclude that a faster handoff is achievable in SIP based terminal mobility with intelligent modifications to unaltered Linux kernel.

The intra-domain mobility management protocol (IDMP) has been proposed as a protocol for managing IP mobility within a cellular access network. This paper evaluates the performance of IDMP's quality of service (QoS) framework, which uses a modified form of the differentiated services architecture, with a centralized bandwidth broker performing admission control and resource provisioning for different traffic classes. While experimental results demonstrate that our IDMP-based QoS mechanism is able to support differential performance guarantees for mobile users with fairly low latency overheads, analytical derivations show that this QoS support can be achieved with only a marginal increase in the signaling cost.

In an effort to realize wireless Internet telephony and multimedia streaming in a highly mobile environment a testbed emulating a wireless Internet has been built. This allows the setting up of multimedia calls between IP mobiles and integration between IP and PSTN end-points in a wireless environment. Different functionalities and components involved with the wireless Internet streaming multimedia have been prototyped and experimented in the testbed. These include signaling, registration, dynamic binding, location management as well as supporting the QoS features for the mobile users. This paper describes some of the components of the testbed and highlights the experiences while building this testbed which could be beneficial to some who plan to build a similar testbed to realize several features and capabilities of Mobile Wireless Internet, before actually bringing to the market.

We present our implementation of TeleMIP, a two-level architecture for IP-based mobility management. TeleMIP essentially uses an intra-domain mobility management protocol (IDMP) for managing mobility within a domain, and mobile IP for supporting inter-domain (global) mobility. Unlike other proposed schemes for intra-domain mobility management, IDMP uses two care-of addresses for mobility management. The global care-of address is relatively stable and identifies the mobile node's current domain, while the local care-of address changes every time the mobile changes subnets and identifies the mobile's current point of attachment. The paper describes our TeleMIP implementation based on enhancements to the Stanford University mobile IP Linux code and presents performance results obtained through experiments on our test-bed. Finally, we use analysis to accurately quantify the savings in signaling overhead obtained when TeleMIP is used in environments where mobiles change subnets relatively rapidly.

Abstract This paper considers three applications—VoIP, mobile Web access and mobile server‐based data transfers—and evaluates the applicability of various IP‐based mobility management mechanisms. We first survey the features and characteristics of various IP mobility protocols, such as MIPv4, MIPv6, MIP‐RO, SIP, CIP, HAWAII, MIP‐RR and IDMP, and then evaluate their utility on an application‐specific basis. The diversity in the mobility‐related requirements ensures that no single mobility solution is universally applicable. We recommend a hierarchical mobility architecture. The framework uses our Dynamic Mobility Agent (DMA) architecture for managing intra‐domain mobility and multiple application‐based binding protocols for supporting inter‐domain mobility. Thus, we recommend SIP as the global binding protocol for VoIP applications and MIPv4/MIPv6 as the global binding mechanism for the mobile server scenario. Copyright © 2001 John Wiley & Sons, Ltd.

We compare various existing approaches for locating roaming users and providing continuous connectivity in quasi-dynamic networks in which the movement is much more restricted than in ad-hoc networks. However, there are frequent host movements combined with occasional major topology changes (e.g., whole network is changing their point of attachment or getting disconnected). The higher dynamics causes many proposed mobility solutions including basic Mobile IP (which work well in environments limited to host mobility), perform poorly. Based on some qualitative comparisons, we suggest which approaches are the best to handle mobility in quasi-dynamic networks.