Mobile Network Architecture Research Articles

Reliable Integrated Architecture for Heterogeneous Mobile and Wireless Networks

The major trend in next-generation or 4G wireless networks (NGWN/4G) is the coexistence of diverse but complementary architectures and wireless access technologies. In this context, an appropriate integration and interworking of existing wireless networks are crucial to allow seamless roaming across those networks. Several integrated architectures have been proposed for 3G cellular networks and wireless local area networks (WLANs) by both third generation wireless initiatives, 3GPP and 3GPP2. However, the proposed architectures have several drawbacks, the most significant being the absence of quality of service (QoS) guarantees, seamless roaming and service continuity. This paper proposes a novel architecture, called Integrated InterSystem Architecture (IISA), which enables the integration and interworking of various wireless networks and hide their heterogeneities from one another. The IISA architecture aims provisioning of guaranteed seamless roaming and service continuity across different access networks. Performance evaluation shows that IISA together with the proposed handoff management scheme provide significant gains than existing interworking architectures and mobility management protocols.

Design and Implementation of a SIP-Based Mobile and Vehicular Wireless Network With Push Mechanism

As portable devices are gaining more popularity, maintaining Internet connectivity anytime and anywhere becomes critical, particularly for mobile and vehicular networks. Network mobility (NEMO) and internet protocol mobility are gaining more and more importance. In this paper, we develop a session initiation protocol (SlP)-based mobile network architecture to support NEMO for vehicular applications. We propose to form a mobile ad hoc network (MANET) by the mobile hosts (MHs) inside a vehicle or a cluster of vehicles. The MANET is connected to the outside world via a SIP-based mobile network gateway (SIP-MNG), which is equipped with one or multiple external wireless interfaces and some internal IEEE 802.11 interfaces. The external interfaces of the SIP-MNG support Internet connectivity by aggregating user traffic to and from the Internet. In addition, exploiting the session information carried by SIP signaling, the SIP-MNG supports resource management and call admission control for the MHs. However, wireless access incurs charges, power consumption, and overhead of mobility management. So, it is desirable to allow the SIP-MNG to disconnect its external interfaces when necessary. To guarantee that users inside the mobile network will not lose any incoming request, we propose a push mechanism through short message service to wake up these wireless interfaces in an on-demand manner. We show the detailed signaling to support such a mechanism. The proposed system is fully compatible with existing SIP standards. Our real prototyping experience and some experimental results are also reported.

Hybrid mobile backbone network routing with flow control and distance awareness (MBNR-FC/DA)

The mobile backbone network (MBN) architecture has been introduced to synthesize robust, scalable and efficient mobile ad hoc wireless networks that support multimedia flows. Backbone capable nodes are dynamically elected to construct a mobile backbone (Bnet). In this article, we present a hybrid routing mechanism for such networks, identified as MBN routing with flow control and distance awareness (MBNR-FC/DA) scheme. Flows that travel a distance longer than a threshold level are routed across the Bnet. This induces a significant reduction in the route discovery control overhead, yielding a highly scalable operation. In turn, a limited span global route discovery process is invoked for routing shorter distance flows. Discovered global routes use effectively the capacity of non-backbone wireless links. Such an operation serves to upgrade the network’s throughput capacity level when the backbone network does not provide global topological covering. The hybrid routing protocol introduced and studied in this paper, also employs combined nodal congestion control and flow admission control schemes to guide admitted flows across areas that are less congested, and to avoid overloading the network. We present a centralized procedure as well as a distributed adaptive scheme for the calculation of the distance threshold level under varying traffic loading and backbone coverage conditions. We show our schemes to make efficient use of network-wide capacity resources by dynamically selecting proper distance threshold levels, yielding outstanding delay–throughput performance.

Distributed Clusterhead Architecture for Mobile Ad Hoc Networks

Mobile Ad Hoc Network (MANET) consists of dynamic topology as nodes in the network are mobile, and connected via wireless links. The nodes are grouped in clusters for the purpose of routing. Nodes within the cluster communicate directly. However, nodes communicate outside the cluster through a centralized node that is called a clusterhead. An elected clusterhead is assigned for communication with all other clusters. The centralized clusterhead can become a bottleneck and possibly cause a lower throughput for the clustering system. We propose a mechanism in which communication outside the cluster is distributed through separate clusterheads. We prove that the overall averaged throughput for the clustering system increases considerably, about doubles for our distributed number of clusterheads. We also show that the increase in overall averaged throughput is reduced by the increase in the overall averaged error rate ratio resulting from the added clusterheads. Additionally, the routing reliability to outside the cluster is increased since routes to different clusters use distinct clusterheads.

An SPT-based topology control algorithm for wireless ad hoc networks

In this paper, we present a localized Shortest-Path-Tree (SPT) based algorithm that copes with the topology control problem in wireless ad hoc networks. Each mobile node determines its own transmission power based only on its local information. The proposed algorithm first constructs local SPTs from the initial graph, after which the total power consumption is further reduced by allowing each mobile node to search the replaceable links individually. The constructed topology ensures network connectivity, and possesses the following desirable energy-efficient features: (i) the power stretch factor is bounded and can be predetermined, (ii) the power consumption is evenly distributed among the mobile nodes, and (iii) the total power consumption is lower than that obtained by the best known algorithms. The performance improvements of the proposed algorithm are demonstrated through extensive simulations. We conclude our work with a discussion of future research directions toward more integrated mobile network architectures.

Improved implementation solution and general mobile network architecture for the interworking between MMS and streaming

AbstractThe prospects of multimedia in mobile communication depend largely on effective design of interactive multimedia applications now. Multimedia Messaging Service (MMS) and streaming are two potential multimedia applications for mobile communication. Though MMS has many advantages, a limitation is noted in MMS—an inability to handle a message requiring more space than available in a mobile terminal, as the message must be fully retrieved and stored before its presentation. Moreover, a large message can keep a recipient user waiting long for its retrieval before it is presented, causing poor user‐experience. This paper proposes a new implementation solution for the interworking between MMS and streaming to overcome the limitation. The new solution is consistent with the existing frameworks and working principles of both MMS and streaming. The new solution is compared with the previous solutions, indicating that it has considerable advantages. This paper also presents general network architecture, providing various architectural options, to accommodate the interworking in different situations. The architecture considers many practical cases, like person‐to‐person messaging, messaging involving content providers and multiple network operators, load balancing and scalability in related network servers, operational agreement between a content provider and a network operator, and using existing network infrastructure for the interworking. Copyright © 2005 John Wiley & Sons, Ltd.

QoS‐aware mobility support architecture for next generation mobile networks

AbstractProvision of quality of service (QoS) support with mobility has received impetus from the evolution that has occurred in mobile communication technologies. This is especially the main driver behind 4G/B3G networks that will enable a user to access any type of services anytime, anywhere, and anyhow. In this paper, we first review some of the state‐of‐the‐art techniques in the area of QoS and resource management based mobility. We then propose an augmented 4G/B3G architecture that addresses key limitations in the salient 4G architectures examined in the literature. Our proposed novel augmentations in mobility, QoS, and resource management schemes consolidate operation of the 4G architecture. The other defining attributes of our proposed 4G architecture are that it is open, hierarchical, layered, and modular with cross‐layer coordination and distributed network functionalities. Well‐defined message interfaces enable the layers/levels within the architecture to support cross‐layer coordination under dynamic network conditions. A signaling network that operates independent of the heterogeneous access networks in the architecture is incorporated to carry out wireless system discovery and paging. This facilitates to conserve mobile terminal's battery power. Copyright © 2005 John Wiley & Sons, Ltd.

Evaluation of a mobile IPv6-based architecture supporting user mobility QoS and AAAC in heterogeneous networks

This paper presents a Mobile IPv6-based overlay network architecture for heterogeneous environments, designed entirely based on IPv6, that aims to be implemented seamlessly irrespectively of the supporting network infrastructure. All transmission technologies are handled at the physical and data-link layers, imposing IPv6-based protocols for all higher layer communications and signaling. The architecture builds on Mobile IPv6 including improved fast handover, and integrates quality-of-service and authentication, authorization, accounting, and charging control per user. The most critical issues of the proposed architecture, mainly related to the handover process, were subject of a performance evaluation via ns-2 simulations. Finally, a field trial of the system was implemented, overlaying part of the GEANT infrastructure between Madrid and Stuttgart, which results are presented here.

An Extension of 4G Mobile Networks towards the Ubiquitous Real Space

While mobile networks have been enhanced to support a variety of mobile multimedia services such as video telephony and rich data content delivery, a new challenge is being created by the remarkable development of micro-device technologies such as micro processor-chips, sensors, and RF tags. These developments suggest the rapid emergence of the ubiquitous computing environment; computers supporting human life without imposing any stress on the users. The combination of broadband global networks and ubiquitous computing environment will lead to an entirely new class of services, which we call ubiquitous networking services. This paper discusses how to create ubiquitous service environments comparing global networking approaches which are based on fixed and mobile networks. It is shown that the mobile approach is better from service applicability and reliability viewpoints. Networking architecture is proposed which expand 4G mobile cellular networks to real space via gateways on the edges of the mobile network (i.e. mobile terminals). A new set of technical requirements will emerge via this approach, which may accelerate the paradigm shift from the current mobile network architecture and even from the Internet of today.

A Geo-Located Web Services Architecture for next generation mobile networks

As many geo-located web services will be deployed in the future, the mobile clients will be interested in locating a specific application server based on requirements such as proximity, service cost per location area, bandwidth and server utilisation rate. This paper presents a middleware system named GLWSA (Geo-Located Web Services Architecture) that aims at satisfying these requirements as well as a thematic factorisation of common location functions used to get position of mobile clients. A GLWSA supports a set of GLWSMs (Geo-Located Web Services Manager) distributed over the mobile network. It defines protocols to discover and inform a Supplier Application Server (SAS) to migrate the service execution (of a specific client) to the nearest SAS based on the client's location. This architecture is suitable to assist mobile clients in the discovering geo-located web services process and to maintain the service execution closest to their location context.

A two-tier heterogeneous mobile Ad Hoc network architecture and its load-balance routing problem

The mobile ad hoc network (MANET) has attracted a lot of interest recently. However, most of the existing works have assumed a stand-alone MANET. In this paper, we propose a two-tier, heterogeneous...

Design and analysis of location management schemes for a new light-weight wireless network

With the advances in low-cost wireless networking products, researchers and providers are looking at various alternate approaches to mobile communications that can provide low-cost services, and are easy to set up. These approaches are to coexist with traditional Cellular Networks. To this end, we propose a novel light-weight mobile communication network architecture called Cell-Hopping. Cell-hopping has only base stations interconnected by wireless inter-basestation links (WIBLs) as the network infrastructure. WIBLs support all routing and switching in cell-hopping networks, obviating the need for costly core networks. However, lack of core networks make location management more challenging because: (i) location databases cannot be maintained in the core, (ii) database update consumes precious wireless resource, (iii) signalling can not be supported by the core (no core) among disjoint segments of the network. Consequently, approaches which minimise or eliminate database updates are more suitable for Cell-hopping networks. We provide a primary scheme for location management in Cell-hopping and analytically show the scalability problem. To address the scalability problem, we propose a location caching scheme to be used with the primary scheme. In the caching scheme, tuning the cache timer value is most crucial for the success of the scheme because the timer is the most important control parameter. We present analysis of the location caching scheme, and provide a closed-form expression for the optimum timer value for the location cache entry based on user mobility parameter. Using numerical examples, we show that the signalling cost can be reduced by as much as 80% for reasonable message-to-mobility (MMR) values. Conversely, incorrectly selected timer values can nullify benefits of using the location caching scheme.

Third-generation mobile network architectures for the Universal Mobile Telecommunications System (UMTS)

Mobile telecommunications is the fastest growing sector of the telecommunications industry, with second-generation systems being implemented with great success all over the world. Spectrum limitations and various technical limitations of second-generation systems have led some regions to develop concepts for a third-generation mobile system. Planned to begin operation at the start of the next millennium, third-generation systems are currently the subject of research and development and standardization by the International Telecommunication Union (ITU) and regional standards bodies. This paper addresses the market for third-generation services and several technical issues of network architectures for the Universal Mobile Telecommunications System (UMTS). We place particular emphasis on the collaborative research activity conducted in Europe since 1988, funded by the European Commission. One of their major research projects is Radio Independent Broadband on Wireless (RAINBOW), which is investigating the feasibility of a UMTS network infrastructure based on the concept of radio dependence/independence. This UMTS network infrastructure can support both second- and third-generation multiple air interface standards. Lucent is a major partner in this collaborative research effort, providing the Global System for Mobile Communications (GSM) radio interconnection to the asynchronous transfer mode (ATM)-based network infrastructure of the RAINBOW demonstrator.

Fast network synchronization

Much of the popularity of mobile computing and handheld devices can be attributed to their ability to deliver information to users on a seamless basis. Periodic synchronization of data between various devices is an enabling technology for this computing paradigm and an essential feature of any effective mobile and heterogeneous network architecture. We propose a peer-to-peer synchronization algorithm based on recent information-theoretic advances [3] and demonstrate an implementation of that algorithm through an improved PC-PDA synchronizer.

The European project trust—reconfigurable terminals and supporting networks

To date, research into reconfigurable mobile communications has predominantly focussed on the software radio concept, and specifically on the hardware technologies required to move physical layer processing into a programmable environment [1, 2, 3]. Although an interesting and necessary challenge, this only represents a fraction of the overall support and technology required to realise the potential of the concept. Other necessary developments include network/terminal cooperation for seamless inter-standard handoff, QoS management for software download and reconfiguration, a secure software download mechanism, terminal software and mobile radio network architecture supporting terminal reconfiguration, management for software downloads, configuration management, capability negotiation, radio resource management and spectrum allocation policies etc… This paper describes results from the EuropeanIst Trust (Transparently Reconfigurable UbiquitouS Terminal) [4] project concerning user and operator requirements, the proposed overall system environment, security issues, concerted radio resource management, and expected time frame for the development of reconfigurable terminals.

A mobile agent-based active network architecture for intelligent network control

The innovation and evolution of network technologies and services to enhance network functionality have traditionally encountered the problems of backward-compatibility and standardization. To resolve the related issues, active networks have been introduced to enable specific customization of network functionality without the lengthy standard-mediated committee processes. In this paper, we exploit the capability of mobile agent technology to construct an active network architecture. We argue that the mobile agent can be a building block for specific network customizations, and introduction of new network functionality. Both integrated and discrete operational models of network customizations can be supported in our prototype implementation. For the service development and deployment, an abstract service structure and a service loading mechanism are presented. Furthermore, we provide an agent management/control mechanism and devise a service management/control mechanism, which is either not available or incomplete in the other related work. The proposed architecture allows new service introduction, and as a result, achieves improved network functionality.

Master-slave cluster-based multihop ad-hoc networking

A master-slave cluster-based mobile ad-hoc network architecture for multihop communications using the IEEE 802.11 system is presented. The proposed architecture is a mixture of two different types of networks: managed (master-and-slave) and ad-hoc (star). In this architecture, the participating nodes in each cluster communicate with each other via their respective access points (APs), which operate as mobile base stations. A network architecture is presented where APs can be utilised to communicate with other APs in an ad-hoc manner.

Mobile IP-DECT internetworking architecture supporting IMT-2000 applications

Realistic realization and mass acceptance of mobile data services require networking architectures offering acceptable quality of service and attractive tariffs. A novel strategy for this goal is maximum integration of popular data networking standards and their infrastructure into wireless networks. This article discusses a Mobile IP-based network architecture to provide IP services in DECT to support IMT-2000 applications. DECT offers micromobility within multicell subnets, while Mobile IP supports macromobility between multicell subnets. Incorporating Mobile IP into the DECT handoff mechanism in this way extends DECT micromobility with IP macromobility. Also, utilizing fast, seamless DECT handoff management reduces Mobile IP handoff delay to circumvent TCP throughput degradation during handoff and reduce frequency of Mobile IP signaling over the ether to conserve spectral efficiency. This feature seamlessly unifies DECT with the global Internet. Seamless integration of DECT with the Internet is crucial due to the continuing phenomenal popularity of the Internet and wireless communications, and ubiquity of DECT systems. To achieve the above DECT/IP interworking efficiently, the architecture introduces a network entity called a DECT service switching point, which is an extended DECT central control fixed part. DECT network-level services are mapped onto those of the IETF integrated services architecture to maintain QoS provided by DECT in the backbone Internet. Mobile Resource Reservation Protocol, an extended RSVP tailored to mobile networking, is adopted to provide the needed signaling in IntServ. The proposed architecture preserves traditional non-IP based services such as PSTN voice.

An Internet infrastructure for cellular CDMA networks using mobile IP

The CDMA community, under the umbrella of the 3rd Generation Partnership Project 2, has embarked on a standardization effort for wireless data based on mobile IP. Important issues addressed include the link layer interface to a mobile IP foreign agent; how link-layer mobility interacts with IP-layer mobility; how virtual private network services will be supported; and how to provide authentication, authorization, and accounting in a cellular mobile IP environment. Members of 3GPP2 are also active in the Internet Engineering Task Force's mobile IP, ROAMOPS, and AAA working groups. Based on our experiences in this effort, this article gives an overview of the issues we have encountered in standardizing a mobile IP-based network architecture in a cellular telephony environment, including current points of contention, and gives a summary of the current state of the standards.

Enhanced privacy and authentication for the global system for mobile communications

The Global System for Mobile Communications (GSM) is widely recognized as the modern digital mobile network architecture. Increasing market demands point toward the relevancy of security-related issues in communications. The security requirements of mobile communications for the mobile users include: (1) the authentication of the mobile user and Visitor Location Register/Home Location Register; (2) the data confidentiality between mobile station and Visitor Location Register, and the data confidentiality between Visitor Location Register and Visitor Location Register/Home Location Register (VLR/HLR); (3) the location privacy of mobile user. However, GSM does not provide enough security functions to meet these requirements. We propose three improved methods to enhance the security, to reduce the storage space, to eliminate the sensitive information stored in VLR, and consequently to improve the performance of the system. Proposed methods include an improved authentication protocol for the mobile station, a data confidentiality protocol, and a location privacy protocol. The merit of the proposed methods is to improve but not to alter the existing architecture of the system. Furthermore, this study also performs computational and capacity analyses to evaluate the original GSM system and proposed approaches on a comparative basis.