Mobility management across converged IP-based heterogeneous access networks

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 8/2/2010.In order to satisfy customer demand for a high performance “global” mobility service, network operators (ISPs, carriers, mobile operators, etc.) are facing the need to evolve to a converged “all-IP” centric heterogeneous access infrastructure. However, the integration of such heterogeneous access networks (e.g. 802.11, 802.16e, UMTS etc) brings major mobility issues. This thesis tackles issues plaguing existing mobility management solutions in converged IP-based heterogeneous networks. In order to do so, the thesis firstly proposes a cross-layer mechanism using the upcoming IEEE802.21 MIH services to make intelligent and optimized handovers. In this respect, FMIPv6 is integrated with the IEEE802.21 mechanism to provide seamless mobility during the overall handover process. The proposed solution is then applied in a simulated vehicular environment to optimize the NEMO handover process. It is shown through analysis and simulations of the signalling process that the overall expected handover (both L2 and L3) latency in FMIPv6 can be reduced by the proposed mechanism by 69%. Secondly, it is expected that the operator of a Next Generation Network will provide mobility as a service that will generate significant revenues. As a result, dynamic service bootstrapping and authorization mechanisms must be in place to efficiently deploy a mobility service (without static provisioning), which will allow only legitimate users to access the service. A GNU Linux based test-bed has been implemented to demonstrate this. The experiments presented show the handover performance of the secured FMIPv6 over the implemented test-bed compared to plain FMIPv6 and MIPv6 by providing quantitative measurements and results on the quality of experience perceived by the users of IPv6 multimedia applications. The results show the inclusion of the additional signalling of the proposed architecture for the purpose of authorization and bootstrapping (i.e. key distribution using HOKEY) has no adverse effect on the overall handover process. Also, using a formal security analysis tool, it is shown that the proposed mechanism is safe/secure from the induced security threats. Lastly, a novel IEEE802.21 assisted EAP based re-authentication scheme over a service authorization and bootstrapping framework is presented. AAA based authentication mechanisms like EAP incur signalling overheads due to large RTTs. As a result, overall handover latency also increases. Therefore, a fast re-authentication scheme is presented which utilizes IEEE802.21 MIH services to minimize the EAP authentication process delays and as a result reduce the overall handover latency. Analysis of the signalling process based on analytical results shows that the overall handover latency for mobility protocols will be approximately reduced by 70% by the proposed scheme

Extension of MIH for FPMIPv6 (EMIH-FPMIPv6) to support optimized heterogeneous handover

Fast handover for Proxy Mobile IPv6 (FPMIPv6) can optimize the handover performance compared with PMIPv6 in terms of handover delay and packet loss. However, FPMIPv6 cannot handle heterogeneous handovers due to the lack of unified Layer 2 triggering mechanism. While Media Independent Handover (MIH) can provide heterogeneous handover support, and a lot of MIH-based integration solutions have been proposed. However, most of these solutions are based on the integration of MIH and PMIPv6, and require additional mechanisms such as L2 scanning, handover coordinator or neighbor discovery, which are out of the scope of MIH and difficult to be standardized. Furthermore, the direct integration of MIH and FPMIPv6 will cause redundant signaling cost due to the similar functions such as MIH handover commit procedure in MIH and inter-MAG (Mobility Access Gateway) tunnel setup in FPMIPv6. This paper provides a comprehensive survey on these solutions and compares each solution's functionality and characteristic, and then proposes an integration scheme based on Extension of MIH for FPMIPv6 (EMIH-FPMIPv6) to support optimized heterogeneous handover, which extends the existing MIH standard and reduces the redundant messages interaction caused by FPMIPv6 and MIH. This paper adopts the city section mobility model and heterogeneous networks model to analyze and compare the performance of EMIH-FPMIPv6 under different heterogeneous handover scenarios. The analytical results show that EMIH-FPMIPv6 is capable of reducing the handover delay and the signaling cost compared to the solution specified in MIH standard (noted as standard handover solution) and FPMIPv6. © 201

IP-Based Mobility Management and Handover Latency Measurement in heterogeneous environments

One serious concern in the ubiquitous networks is the seamless vertical handover management between different wireless technologies. To meet this challenge, many standardization organizations proposed different protocols at different layers of the protocol stack. The Internet Engineering Task Force (IETF) has different groups working on mobility at IP level in order to enhance mobile IPv4 and mobile IPv6 with different variants: HMIPv6 (Hierarchical Mobile IPv6), FMIPv6 (Fast Mobile IPv6) and PMIPv6 (Proxy Mobile IPv6) for seamless handover. Moreover, the IEEE 802.21 standard provides another framework for seamless handover. The 3GPP standard provides the Access Network and Selection Function (ANDSF) to support seamless handover between 3GPP – non 3GPP networks like Wi-Fi, considered as untrusted, and WIMAX considered as trusted networks. In this paper, we present an in-depth analysis of seamless vertical handover protocols and a handover latency comparison of the main mobility management approaches in the literature. The comparison shows the advantages and drawbacks of every mechanism in order to facilitate the adoption of the convenient one for vertical handover within Next Generation Network (NGN) environments. Keywords: Seamless vertical handover, mobility management protocols, IEEE 802.21 MIH, handover latenc

Mobility-Aware Video Streaming in MIMO-Capable Heterogeneous Wireless Networks

Multiple input and multiple output (MIMO) is a well-known technique for the exploitation of the spatial multiplexing (MUX) and spatial diversity (DIV) gains that improve transmission quality and reliability. In this paper, we propose a quality-adaptive scheme for handover and forwarding that supports mobile-video-streaming services in MIMO-capable, heterogeneous wireless-access networks such as those for Wi-Fi and LTE. Unlike previous handover schemes, we propose an appropriate metric for the selection of the wireless technology and the MIMO mode, whereby a new address availability and the wireless-channel quality, both of which are in a new wireless-access network so that the handover and video-playing delays are reduced, are considered. While an MN maintains its original care-of address (oCoA), the video packets destined for the MN are forwarded with the MIMO technique (MUX mode or DIV mode) on top of a specific wireless technology from the previous Access Router (pAR) to the new Access Router (nAR) until they finally reach the MN; however, to guarantee a high video-streaming quality and to limit the video-packet-forwarding hops between the pAR and the nAR, the MN creates a new CoA (nCOA) within the delay threshold of the QoS/quality of experience (QoE) satisfaction result, and then, as much as possible, the video packet is forwarded with the MUX. Through extensive simulations, we show that the proposed scheme is a significant improvement upon the other schemes

New Mobility Trends in Data Networks

Dizertační práce se zabývá návrhem nového algoritmu řízení handoveru v rámci protokolu Mobile IPv6, který umožní nasazení tohoto protokolu v leteckých datových sítích. Existující algoritmy řízení handoveru sice dosahují dostatečné výkonnosti v konvenčních pozemních bezdrátových sítích disponujích velkou šířkou pásma a nízkou latencí, jako jsou WiFi nebo UMTS, ale jak ukazuje tato práce, nasazení těchto algoritmů prostředí leteckých datových sítí nepřináší očekávané výhody. Analýza ukazuje, že v úzkopásmových leteckých sítích trpí tyto algoritmy řízení handoveru velkou latencí a způsobují značnou režii. Nový algoritmus řízení handoveru v MIPv6 navržený v této práci je založený na jednoduché myšlence: ''Já jsem letadlo, já vím, kam letím!'' To znamená, že pohyb letadla není náhodný, ale vysoce předvídatelný. Díky tomu je možno předvídat handovery mezi přístupovými sítěmi podél očekávané trajektorie letadla a vykonat nezbytné operace pro přípravu handoverů již na zemi, kde je letadlo připojeno k širokopásmové síti letiště. Tato dizertační práce dále uvádí porovnání existujících algoritmů řízení handoveru s nově navrženým pomocí analytické metody ohodnocení handoveru. Díky tomu je možno kvantifikovat výhody, které nový algoritmus přináší a taktéž popsat slabiny algoritmů existujících.The doctoral thesis is focused on a design of novel Mobile IPv6 handover strategy suitable for deployment in aeronautical data networks. The current handover strategies provide sufficient performance in the conventional ground networks such as WiFi or UMTS that dispose high bandwidth and low latency. However, as this thesis shows, deploying these handover strategies in aeronautical data link environment does not bring desired benefits - the handover latency is high and the related overhead gets high as well. The novel MIPv6 handover strategy presented in this thesis is based on a simple thought: ''I am an aircraft, I know where I'm flying!'' This means that the movement of the aircraft is not random, it is highly predictable. Thanks to that, inter-network handovers may be anticipated and necessary IP handover related actions can be taken in advance, while the aircraft is connected via a broadband ground link at the origination airport. The thesis also presents a comparison of the existing handover strategies with the proposed new one conducted using an analytical approach. This allows to quantify the benefits of the novel handover strategy and the drawbacks of the current ones.

Mobility management across converged IP-based heterogeneous access networks

In order to satisfy customer demand for a high performance “global” mobility service, network operators (ISPs, carriers, mobile operators, etc.) are facing the need to evolve to a converged “all-IP” centric heterogeneous access infrastructure. However, the integration of such heterogeneous access networks (e.g. 802.11, 802.16e, UMTS etc) brings major mobility issues. This thesis tackles issues plaguing existing mobility management solutions in converged IP-based heterogeneous networks. In order to do so, the thesis firstly proposes a cross-layer mechanism using the upcoming IEEE802.21 MIH services to make intelligent and optimized handovers. In this respect, FMIPv6 is integrated with the IEEE802.21 mechanism to provide seamless mobility during the overall handover process. The proposed solution is then applied in a simulated vehicular environment to optimize the NEMO handover process. It is shown through analysis and simulations of the signalling process that the overall expected handover (both L2 and L3) latency in FMIPv6 can be reduced by the proposed mechanism by 69%. Secondly, it is expected that the operator of a Next Generation Network will provide mobility as a service that will generate significant revenues. As a result, dynamic service bootstrapping and authorization mechanisms must be in place to efficiently deploy a mobility service (without static provisioning), which will allow only legitimate users to access the service. A GNU Linux based test-bed has been implemented to demonstrate this. The experiments presented show the handover performance of the secured FMIPv6 over the implemented test-bed compared to plain FMIPv6 and MIPv6 by providing quantitative measurements and results on the quality of experience perceived by the users of IPv6 multimedia applications. The results show the inclusion of the additional signalling of the proposed architecture for the purpose of authorization and bootstrapping (i.e. key distribution using HOKEY) has no adverse effect on the overall handover process. Also, using a formal security analysis tool, it is shown that the proposed mechanism is safe/secure from the induced security threats. Lastly, a novel IEEE802.21 assisted EAP based re-authentication scheme over a service authorization and bootstrapping framework is presented. AAA based authentication mechanisms like EAP incur signalling overheads due to large RTTs. As a result, overall handover latency also increases. Therefore, a fast re-authentication scheme is presented which utilizes IEEE802.21 MIH services to minimize the EAP authentication process delays and as a result reduce the overall handover latency. Analysis of the signalling process based on analytical results shows that the overall handover latency for mobility protocols will be approximately reduced by 70% by the proposed scheme.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Mobility management in IP-Based Networks

Mobile communication networks experience a tremendous development clearly evident from the wide variety of new applications way beyond classical phone services. The tremendous success of the Internet along with the demand for always-on connectivity has triggered the development of All-IP mobile communication networks. Deploying these networks requires, however, overcoming many challenges. One of the main challenges is how to manage the mobility between cells connecting through an IP core in a way that satisfies real-time requirements. This challenge is the focus of this dissertation. This dissertation delivers an in-depth analysis of the mobility management issue in IP-based mobile communication networks. The advantages and disadvantages of various concepts for mobility management in different layers of the TCP/IP protocol stack are investigated. In addition, a classification and brief description of well-known mobility approaches for each layer are provided. The analysis concludes that network layer mobility management solutions seem to be best suited to satisfy the requirements of future All-IP networks. The dissertation, therefore, provides a comprehensive review of network layer mobility management protocols along with a discussion of their pros and cons. Analyses of previous work in this area show that the proposed techniques attempt to improve the performance by making constraints either on access networks (e.g. requiring a hierarchical topology, introducing of intermediate nodes, etc.) or mobile terminals (e.g. undertaking many measurements, location tracking, etc.). Therefore, a new technique is required that completes handoffs quickly without affecting the end-to-end performance of ongoing applications. In addition, it should place restrictions neither on access networks nor on mobiles. To meet these requirements, a new solution named Mobile IP Fast Authentication protocol (MIFA) is proposed. MIFA provides seamless mobility and advances the state of the art. It utilizes the fact that mobiles movements are limited to a small set of neighboring subnets. Thus, contacting these neighbors and providing them in advance with sufficient data related to the mobiles enable them to fast re-authenticate the mobiles after the handoff. The dissertation specifies the proposal for both IPv4 and IPv6. The specification of MIFA considers including many error recovery mechanisms to cover the most likely failures. Security considerations are studied carefully as well. MIFA does not make any restrictions on the network topology. It makes use of layer 2 information to optimize the performance and works well even if such information is not available.In order to analyze our new proposal in comparison to a wide range of well-known mobility management protocols, this dissertation proposes a generic mathematical model that supports the evaluation of figures such as average handoff latency, average number of dropped packets, location update cost and packet delivery cost. The generic model considers dropped control messages and takes different network topologies and mobility scenarios into account. This dissertation also validates the generic mathematical model by comparing its results to simulation results as well as results of real testbeds under the same assumptions. The validation proves that the generic model delivers an accurate evaluation of the performance in low-loaded networks. The accuracy of the model remains acceptable even under high loads. The validation also shows that simulation results lie in a range of 23 %, while results of real testbeds lie in a range of 30 % of the generic model?s results. To simplify the analysis using the generic mathematical model, 4 new tools are developed in the scope of this work. They automate the parameterization of mobility protocols, network topologies and mobility scenarios. This dissertation also evaluates the new proposal in comparison to well-known approaches (e.g. Mobile IP, Handoff-Aware Wireless Access Internet Infrastructure (HAWAII), etc.) by means of the generic mathematical model as well as simulation studies modeled in the Network Simulator 2. The evaluation shows that MIFA is a very fast protocol. It outperforms all studied protocols with respect to the handoff latency and number of dropped packets per handoff. MIFA is suitable for low as well as high speeds. Moreover, there is no significant impact of the network topology on its performance. A main advantage of MIFA is its robustness against the dropping of control messages. It remains able to achieve seamless handoffs even if a dropping occurs. The performance improvement is achieved, however, at the cost of introducing new control messages mainly to distribute data concerning mobile terminals to neighbor subnets. This results in more location update cost than that resulting from the other mobility management protocols studied. Due to excluding any constraints on the network topology, MIFA generates the same packet delivery cost as Mobile IP and less than other protocols.An additional focus of this dissertation is the development of an adaptive eLearning environment that personalizes eLearning contents conveying the topics of this dissertation depending on users? characteristics. The goal is to allow researchers to quickly become involved in research on mobility management, while learners such as students are able to gain information on the topics without excess detail. Analyses of existing eLearning environments show a lack of adaptivity support. Existing environments focus mainly on adapting either the navigation or the presentation of contents depending on one or more selected users? characteristics. There is no environment that supports both simultaneously. In addition, many user characteristics are disregarded during the adaptivity process. Thus, there is a need to develop a new adaptive eLearning environment able to eliminate these drawbacks. This dissertation, therefore, designs a new Metadata-driven Adaptive eLearning Environment (MAeLE). MAeLE generates personalized eLearning courses along with building an adequate navigation at run-time. Adaptivity depends mainly on providing contents with their describing metadata, which are stored in a separate database, thus enabling reusing of eLearning contents. The relation between the metadata that describe contents and those describing learners are defined accurately, which enables a dynamic building of personalized courses at run-time. A prototype for MAeLE is provided in this dissertation as well