Dana Chee

Self organizing IP Multimedia Subsystem

While there have been tremendous efforts to develop the architecture and protocols to support advanced Internet-based services over 3G and 4G networks, IMS is far from being deployed in a wide scale manner. Effort to create an operator controlled signaling infrastructure using IP-based protocols has resulted in a large number of functional components and interactions between those components. Thus, the carriers are trying to explore alternative ways to deploy IMS that will allow them to manage their network in a cost effective manner while offering the value-added services. One of such approaches is self organization of IMS. The self organizing IMS can enable the IMS functional components and corresponding nodes to adapt them dynamically based on the features like network load, number of users and available system resources. This paper introduces such a self organizing and adaptive IMS architecture, describes the advanced functions and demonstrates the initial results from the prototype test-bed. In particular, we show how all IMS functional components can be merged and split among different nodes as the network demand and environment change without disrupting the ongoing sessions or calls. Although it is too early to conclude the effectiveness of self organizing IMS, initial results are encouraging and it may provide additional incentives to the operators for network evolution.

Performance Analysis of Next Generation Mobility Protocols for IMS/MMD Networks

In an effort to provide seamless mobility support in IMS/MMD networks, operators need to choose a specific IP- based mobility protocol. However, there are several micro- and macro-mobility protocols available that the operators can choose from. Operators often face the challenges of selecting the appropriate mobility protocol that can provide the most cost efficient solution under a specific operating environment. Thus, it is important to analyze the effectiveness of these protocols before they are actually deployed in the IMS/MMD networks. In this paper, we analyze a number of candidate mobility protocols and conduct a performance analysis of some of these using a prototype implementation in an IPv6-based IMS/MMD testbed. These analyses provide us with some guidelines in terms of the applicability of these protocols when operators plan to deploy their IMS/MMD networks.

Loosely coupled service composition for deployment of next generation service overlay networks

In order to provide various attractive services to users, a user-centric approach such as usergenerated contents and services and a platform which can create a service easily and efficiently have been studied and designed during the past two decades. The IEEE NGSON standard has defined a functional architecture that provides advanced overlay functions for value-added services by collaboration of services with features of context awareness, dynamic adaptation and self-organizing management. Its service composition mechanism is comparable with service oriented architecture. However, due to SOAs complexity, it has not become as popular for user-generated services and contents as so-called mashup technologies, which also provide attractive and simple service creation. In this article we propose the adoption of loosely coupled service composition into the NGSON framework that can easily integrate existing communications and data services with little to no dependence on the underlying implementation and service description language details. Furthermore, the NGSON prototype supporting our proposal is presented as a proof of concept and to verify its advantages for operators, service providers, and end users.

Route optimization for Proxy Mobile IPv6 in IMS network

Localized mobility protocols are designed to address many of the drawbacks such as additional signaling and over-the-air tunnel overhead associated with global mobility protocols like Mobile IPv4 and Mobile IPv6. Proxy Mobile IPv6 is one such network controlled localized protocol defined in the IETF Although Proxy Mobile IPv6 can resolve longer binding update and tunnel overhead related issues when a mobile nodes movement is confined to a specific domain, some of the handoff-related functions and data paths between two communicating nodes still need to be optimized. The data path reduction between the communicating nodes helps to reduce one way packet delay when both nodes are under the same localized domain and the local mobility anchor point is away. The process of reducing the data path is often referred to as route optimization. Route optimization helps to reduce the delay due to media delivery that is critical for real-time application. We propose several route optimization techniques that can be applied to Proxy Mobile IPv6 to improve the efficiency of media delivery for both intra- and inter-domain movements. We select one of these proposed route optimization mechanisms and then describe the implementation details and analyze the experimental results.

A-IMS architecture analysis and experimental IPv6 testbed

Advances to IMS (A-IMS) architecture extends the existing IMS/MMD architecture currently being defined in 3GPP/3GPP2 respectively so that it can support both SIP and non-SIP-based services. We describe the key strength of A-IMS architecture, compare the benefits over MMD architecture, and then describe an enhanced MMD experimental testbed to demonstrate many of the A-IMS features. We highlight many of the functional components of the testbed that perform several operations such as signaling, location management, security, and mobility. We experiment with two different mobility management techniques and analyze the associated delays and packet loss for both 802.11 networks and PPP networks. We illustrate the service interaction between SIP-based services such as VoIP and non-SIP-based services such as IPTV. Analysis from these experimental results and testbed implementation can be useful to any service provider that plans to deploy IMS/MMD architecture over IPv6.

Service continuity support in self-organizing IMS networks

With the increasing interest in deploying 4G/LTE networks, IMS has a potential to be deployed in a wide scale in order to support mobile Internet and value-added services over next-generation networks. Moreover, the effort to create an operator-controlled signaling infrastructure using IP-based protocols has resulted in a large number of functional components and interactions between core networks elements. Thus, the carriers are trying to explore alternative ways to deploy IMS that will allow them to manage their network in a cost effective manner while offering rich communications services. One of such approaches is self-organization of IMS (SOIMS). The self-organizing IMS can enable the IMS functional components to adapt dynamically based on the features like network load, number of users, node failures and available system resources. This paper proposes different mechanisms to handle self-organizing IMS with usage of load balancing paradigm. The proposed solution enables topology hiding, IMS nodes failure recovery, session continuity support, and IMS scalability.

ACtive edge-Tagging (ACT): an intruder identification and isolation scheme in active networks

As client/server-based network communications becomes ever-increasingly widespread with the rapid growth of the Internet, security problems have emerged as one of the most pressing issues in the Internet community. Despite the best effort of the Internet community to minimize security problems, vulnerabilities in the network still exist, and various lapses in security have demonstrated the destruction of data integrity and resource availability in the Internet. In particular, a series of occurrences of distributed denial of service (DDoS) have proven to be a challenging issue for Internet service providers (ISPs) and content providers alike. We present a novel approach, ACtive edgeTagging (ACT), which facilitates the handling of source-spoofed attacks by effectively detecting, identifying, and isolating intrusions in the network layer. Unlike the existing solutions, ACT deals with the targeted attacks efficiently without over-bearing requirements or mandatory participation of every individual network in the Internet. ACT is particularly effective for identifying and isolating attackers employing DDoS type of intrusion schemes, and it is highly scalable and extensible as well as feasible to implement in large-scale networks such as the global Internet.

Enhanced Next-Generation Service Overlay Networks architecture

The Web Services composition paradigm has been widely used in Information Technology (IT) and Internet environments to create Web applications that both flexible and rapidly deployable. Web Services are a key way to realize Service-Oriented Architectures (SOA). In Telecom, on the other hand, the IMS (IP Multimedia Subsystem) architecture enables valued-added services composition for IP-based networks. Several ongoing efforts - referred to as “SOA for telecom” (SOA-TEL) - are attempting to merge SOA with telecom. The objective of these attempts is to enable Telecom operators and service providers to re-use existing service building blocks while building valued-added converged Web and telephony services. These services offer seamless experiences across various networks and, therefore, richer experiences, but are more complex than typical Web Services (e.g., transaction-based). The IEEE Next-Generation Service Overlay Networks (NGSON) working group is focusing on this integration and an architecture has been proposed. In addition, NGSON specifies context-aware, dynamically adaptive, and self-organizing networking capabilities. There are, however, a number of shortcomings in the NGSON architecture. This paper identifies these shortcomings and describes a possible solution. Finally, we discuss an illustrative use case scenario to help bring clarity to our proposed “enhanced” NSGON architecture.

User-transparent reconfiguration method for self-organizing IP multimedia subsystem

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.

Realizing Secure Cellular and Mobile Hot-Spot Extension to Tactical Networks

The advances of Commercial cellular networks and smart devices over the last decade have changed the way end users are communicating and connecting to each other. The soldiers in the battlefield are no exception and they would also like to have the similar experience as civilians have. Cellular networks are also providing significantly higher bandwidth at a much lower cost relative to tactical networks. However, these networks are not yet ready to be used as-is in military environment. Issues such as, frequency flexibility, operations in hostile environment, security, range extension, multicast, Push-to-Talk (PTT), and seamless session mobility that need to be addressed. Several efforts have started to look into the feasibility and deployability issues of commercial networks and devices so that they can be used as an extension to tactical networks. In recent years our focus have been addressing such issues and working closely with the US Army to fulfill the tactical requirements while hardening the technology. In this paper, we present a secure network architecture to the tactical edge that can leverage commercial cellular and ad hoc Wi-Fi networks as range extension and Android platform based smart devices fulfilling the tactical networking and security requirements. We describe our software design, implementation and recent demonstration at a Technology Readiness Levels (TRLs) - 4 and 5 in US Army Aberdeen Proving Ground, Maryland, and Fort Dix, NJ, USA.