333 research outputs found
Interworking in heterogeneous wireless networks: comprehensive framework and future trends
Interworking mechanisms are of prime importance
to achieve ubiquitous access and seamless
mobility in heterogeneous wireless networks. In
this article we develop a comprehensive framework
to categorize interworking solutions by
defining a generic set of interworking levels and
its related key interworking mechanisms. The
proposed framework is used to analyze some of
the most relevant interworking solutions being
considered in different standardization bodies.
More specifically, I-WLAN and GAN approaches
for WLAN and cellular integration, solutions
for WiMAX and 3GPP LTE/SAE interworking,
and the forthcoming IEEE 802.21 standard are
discussed from the common point of view provided
by the elaborated framework.Postprint (published version
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Ubiquitous Internet in an integrated satellite-terrestrial environment: The SUITED solution
yesThe current Internet architecture appears to
not be particularly suited to addressing the
emerging needs of new classes of users who wish
to gain access to multimedia services made available
by ISPs, regardless of their location, while
in motion and with a guaranteed level of quality.
One of the main objectives of so-called nextgeneration
systems is to overcome the limitations
of todayÂżs available Internet by adopting an
approach based on the integration of different
mobile and fixed networks. The SUITED project
moves in this direction since it aims at contributing
to the design and deployment of the global
mobile broadband system (GMBS), a unique
satellite/terrestrial infrastructure ensuring
nomadic users access to Internet services with a
negotiated QoS. A description of the main features
of the GMBS architecture, characterized
by the integration of a multisegment access network
with a federated ISP network is given in
this article. The GMBS multimode terminal is
schematically described, and an overview of the
so-called QoS-aware mobility management
scheme, devised for such a heterogeneous scenario,is provided
A Unified Mobility Management Architecture for Interworked Heterogeneous Mobile Networks
The buzzword of this decade has been convergence: the convergence of telecommunications, Internet, entertainment, and information technologies for the seamless provisioning of multimedia services across different network types. Thus the future Next Generation Mobile Network (NGMN) can be envisioned as a group of co-existing heterogeneous mobile data networking technologies sharing a common Internet Protocol (IP) based backbone. In such all-IP based heterogeneous networking environments, ongoing sessions from roaming users are subjected to frequent vertical handoffs across network boundaries. Therefore, ensuring uninterrupted service continuity during session handoffs requires successful mobility and session management mechanisms to be implemented in these participating access networks. Therefore, it is essential for a common interworking framework to be in place for ensuring seamless service continuity over dissimilar networks to enable a potential user to freely roam from one network to another. For the best of our knowledge, the need for a suitable unified mobility and session management framework for the NGMN has not been successfully addressed as yet. This can be seen as the primary motivation of this research. Therefore, the key objectives of this thesis can be stated as: To propose a mobility-aware novel architecture for interworking between heterogeneous mobile data networks To propose a framework for facilitating unified real-time session management (inclusive of session establishment and seamless session handoff) across these different networks. In order to achieve the above goals, an interworking architecture is designed by incorporating the IP Multimedia Subsystem (IMS) as the coupling mediator between dissipate mobile data networking technologies. Subsequently, two different mobility management frameworks are proposed and implemented over the initial interworking architectural design. The first mobility management framework is fully handled by the IMS at the Application Layer. This framework is primarily dependant on the IMS’s default session management protocol, which is the Session Initiation Protocol (SIP). The second framework is a combined method based on SIP and the Mobile IP (MIP) protocols, which is essentially operated at the Network Layer. An analytical model is derived for evaluating the proposed scheme for analyzing the network Quality of Service (QoS) metrics and measures involved in session mobility management for the proposed mobility management frameworks. More precisely, these analyzed QoS metrics include vertical handoff delay, transient packet loss, jitter, and signaling overhead/cost. The results of the QoS analysis indicates that a MIP-SIP based mobility management framework performs better than its predecessor, the Pure-SIP based mobility management method. Also, the analysis results indicate that the QoS performances for the investigated parameters are within acceptable levels for real-time VoIP conversations. An OPNET based simulation platform is also used for modeling the proposed mobility management frameworks. All simulated scenarios prove to be capable of performing successful VoIP session handoffs between dissimilar networks whilst maintaining acceptable QoS levels. Lastly, based on the findings, the contributions made by this thesis can be summarized as: The development of a novel framework for interworked heterogeneous mobile data networks in a NGMN environment. The final design conveniently enables 3G cellular technologies (such as the Universal Mobile Telecommunications Systems (UMTS) or Code Division Multiple Access 2000 (CDMA2000) type systems), Wireless Local Area Networking (WLAN) technologies, and Wireless Metropolitan Area Networking (WMAN) technologies (e.g., Broadband Wireless Access (BWA) systems such as WiMAX) to interwork under a common signaling platform. The introduction of a novel unified/centralized mobility and session management platform by exploiting the IMS as a universal coupling mediator for real-time session negotiation and management. This enables a roaming user to seamlessly handoff sessions between different heterogeneous networks. As secondary outcomes of this thesis, an analytical framework and an OPNET simulation framework are developed for analyzing vertical handoff performance. This OPNET simulation platform is suitable for commercial use
Performance analysis and deployment of VoLTE mechanisms over 3GPP LTE-based networks
Long Term Evolution based networks lack native support for Circuit Switched (CS) services. The Evolved Packet System (EPS) which includes the Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) and Evolved Packet Core (EPC) is a purely all-IP packet system. This introduces the problem of how to provide voice call support when a user is within an LTE network and how to ensure voice service continuity when the user moves out of LTE coverage area. Different technologies have been proposed for the purpose of providing a voice to LTE users and to ensure the service continues outside LTE networks. The aim of this paper is to analyze and evaluate the overall performance of these technologies along with Single Radio Voice Call Continuity (SRVCC) Inter-RAT handover to Universal Terrestrial Radio Access Networks/ GSM-EDGE radio access Networks (UTRAN/GERAN). The possible solutions for providing voice call and service continuity over LTE-based networks are Circuit Switched Fall Back (CSFB), Voice over LTE via Generic Access (VoLGA), Voice over LTE (VoLTE) based on IMS/MMTel with SRVCC and Over The Top (OTT) services like Skype. This paper focuses mainly on the 3GPP standard solutions to implement voice over LTE. The paper compares various aspects of these solutions and suggests a possible roadmap that mobile operators can adopt to provide seamless voice over LTE
Next generation mobile wireless hybrid network interworking architecture
It is a universally stated design requirement that next generation mobile systems will be compatible and interoperable with IPv6 and with various access technologies such as IEEE 802.11x. Discussion in the literature is currently as to whether the recently developed High Speed Packet Access (HSPA) or the developing Long Term Evaluation (LTE) technology is appropriate for the next generation mobile wireless system. However, the HSPA and the LTE technologies are not sufficient in their current form to provide ubiquitous data services. The third–generation mobile wireless network (3G) provides a highly developed global service to customers through either circuit switched or packet switched networks; new mobile multimedia services (e.g. streaming/mobile TV, location base services, downloads, multiuser games and other applications) that provide greater flexibility for the operator to introduce new services to its portfolio and from the user point of view, more services to select and a variety of higher, on-demand data rates compared with 2.5-2.75G mobile wireless system. However cellular networks suffer from a limited data rate and expensive deployment. In contrast, wireless local area networks (WLAN) are deployed widely in small areas or hotspots, because of their cost-effectiveness, ease of deployment and high data rates in an unlicensed frequency band. On the other hand, WLAN (IEEE 802.11x) cannot provide wide coverage cost-efficiently and is therefore at a disadvantage to 3G in the provision of wide coverage. In order to provide more services at high data rates in the hotspots and campus-wide areas, 3G service providers regard WLAN as a technology that compliments the 3G mobile wireless system. The recent evolution and successful deployment of WLANs worldwide has yielded demand to integrate WLANs with 3G mobile wireless technologies seamlessly. The key goal of this integration is to develop heterogeneous mobile data networks, capable of supporting ubiquitous data services with high data rates in hotspots. The effort to develop heterogeneous networks – also referred to fourth-generation (4G) mobile wireless data networks – is linked with many technical challenges including seamless vertical handovers across WLAN and 3G radio technologies, security, common authentication, unified accounting & billing, WLAN sharing (by several mobile wireless networks – different operators), consistent QoS and service provisioning, etc. This research included modelling a hybrid UMTS/WLAN network with two competent couplings: Tight Coupling and Loose Coupling. The coupling techniques were used in conjunction with EAP-AKA for authentication and Mobile IP for mobility management. The research provides an analysis of the coupling techniques and highlights the advantages and disadvantages of the coupling techniques. A large matrix of performance figures were generated for each of the coupling techniques using Opnet Modeller, a network simulation tool
Mobility and Handoff Management in Wireless Networks
With the increasing demands for new data and real-time services, wireless
networks should support calls with different traffic characteristics and
different Quality of Service (QoS)guarantees. In addition, various wireless
technologies and networks exist currently that can satisfy different needs and
requirements of mobile users. Since these different wireless networks act as
complementary to each other in terms of their capabilities and suitability for
different applications, integration of these networks will enable the mobile
users to be always connected to the best available access network depending on
their requirements. This integration of heterogeneous networks will, however,
lead to heterogeneities in access technologies and network protocols. To meet
the requirements of mobile users under this heterogeneous environment, a common
infrastructure to interconnect multiple access networks will be needed. In this
chapter, the design issues of a number of mobility management schemes have been
presented. Each of these schemes utilizes IP-based technologies to enable
efficient roaming in heterogeneous network. Efficient handoff mechanisms are
essential for ensuring seamless connectivity and uninterrupted service
delivery. A number of handoff schemes in a heterogeneous networking environment
are also presented in this chapter.Comment: 28 pages, 11 figure
The Design of Efficient Internetwork Authentication for Ubiquitous Wireless Communications
A variety of wireless technologies have been
standardized and commercialized, but no single solution is
considered the best to satisfy all communication needs due
to different coverage and bandwidth limitations. Therefore,
internetworking between heterogeneous wireless networks
is extremely important for ubiquitous and high performance
wireless communications. The security problem is
one of the major challenges in internetworking. To date,
most research on internetwork authentication has focused
on centralized authentication approaches, where the home
network participates in each authentication process. For
high latency between the home and visiting networks, such
approaches tend to be inefficient. In this paper, we describe
chained authentication, which requires collaboration between
adjacent networks without involvement of the home
network. After categorizing chained protocols, we propose
a novel design of chained authentication methods under
3G-WLAN internetworking. The experiments show that
proactive context transfer and ticket forwarding reduce the
3G authentication latency to 36.8% and WLAN EAP-TLS
latency to 23.1% when RTT between visiting and home
networks is 200 ms
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