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97
Pre-Authenticated Fast Handoff in a Public Wireless LAN Based on IEEE 802.1x Model
- IEEE 802.1x Model,” IFIP TC6 Personal Wireless Communications 2002 (To Appear
, 2002
"... With the popularity of portable devices, public Internet access service using wireless LAN has been started in many countries. In the public wireless LAN network, since re-authentication latency during handoff affects the service quality of multimedia applications, minimizing authentication latency ..."
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Cited by 43 (0 self)
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With the popularity of portable devices, public Internet access service using wireless LAN has been started in many countries. In the public wireless LAN network, since re-authentication latency during handoff affects the service quality of multimedia applications, minimizing authentication latency is very important in order to support real-time multimedia applications on the wireless IP network. In this paper, we proposed a fast handoff scheme using the predictive authentication method based on IEEE 802.1x model. In our scheme, a mobile host entering an area of an access point (AP) performs authentication procedures for a set of multiple APs instead of the current AP. Multiple APs are selected using a Frequent Handoff Region (FHR) selection algorithm considering users' mobility patterns and their service classes. Since a mobile host is authenticated for FHR in advance, the handoff latency due to the reauthentication can be minimized. Simulation results show that the proposed scheme is more efficient than other schemes in terms of delay.
Bandwidth aggregation for real-time applications in heterogeneous wireless networks
- IEEE TOMC
"... Abstract—A variety of wireless interfaces are available for today’s mobile user to access Internet content. When coverage areas of these different technologies overlap, a terminal equipped with multiple interfaces can use them simultaneously to improve the performance of its applications. In this pa ..."
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Cited by 37 (0 self)
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Abstract—A variety of wireless interfaces are available for today’s mobile user to access Internet content. When coverage areas of these different technologies overlap, a terminal equipped with multiple interfaces can use them simultaneously to improve the performance of its applications. In this paper, we motivate the advantages that can be had through simultaneous use of multiple interfaces and present a network layer architecture that enables diverse multiaccess services. In particular, we explore in depth one such service provided by the architecture: Bandwidth Aggregation (BAG) for real-time applications. An important aspect of the architecture when providing BAG services for real-time applications is the scheduling algorithm that partitions the traffic onto different interfaces such that the QoS requirements of the application are met. We propose one such algorithm Earliest Delivery Path First (EDPF), that ensures packets meet their playback deadlines by scheduling packets based on the estimated delivery time of the packets. We show through analysis that EDPF performs close to an idealized Aggregated Single Link (ASL) discipline, where the multiple interfaces are replaced by a single interface with same aggregated bandwidth. A prototype implementation and extensive simulations carried using video and delay traces show the performance improvement BAG with EDPF scheduling offers over using just the Highest Bandwidth Interface (HBI) and other scheduling approaches based on weighted round robin. Index Terms—Network architecture and design, video, scheduling, algorithm/protocol design and analysis, implementation, simulation. æ 1
Modeling and analysis of an efficient multicast mechanism for UMTS
- IEEE Transactions on Vehicular Technology
, 2005
"... Abstract—This paper proposes a multicast mechanism for the universal mobile telecommunication system (UMTS). Our scheme relies on establishing multicast tunnels throughout the network that allow multicast packets to be transferred in an optimal manner on shared links toward multiple destinations. We ..."
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Cited by 35 (0 self)
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Abstract—This paper proposes a multicast mechanism for the universal mobile telecommunication system (UMTS). Our scheme relies on establishing multicast tunnels throughout the network that allow multicast packets to be transferred in an optimal manner on shared links toward multiple destinations. We describe the mechanisms of the scheme in establishing and maintaining the multicast tunnels, managing multicast groups, executing location updates, and performing multicast packet forwarding. As a result of dynamically delivering multicast packets to the downstream nodes that are serving multicast users on a per-packet basis, the multicast mechanism is able to respond well to group dynamics as well as to subscriber mobility. The mechanism also requires little state at intermediate network nodes and can be implemented with only minimal modifications to existing UMTS protocols. Based on a cost analysis in comparison with three related schemes for one-to-many packet delivery, we show that our mechanism performs well under various user distributions. Index Terms—Mobility management (MM), mobile networks, multicast, universal mobile telecommunication system (UMTS). APN BG
Dynamic Hierarchical Mobility Management Strategy for Mobile IP Networks
- IEEE Journal on Selected Areas in Communications
, 2004
"... Abstract—One of the major challenges for the wireless network design is the efficient mobility management, which can be addressed globally (macromobility) and locally (micromobility). Mobile Internet protocol (IP) is a commonly accepted standard to address global mobility of mobile hosts (MHs). It r ..."
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Cited by 33 (1 self)
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Abstract—One of the major challenges for the wireless network design is the efficient mobility management, which can be addressed globally (macromobility) and locally (micromobility). Mobile Internet protocol (IP) is a commonly accepted standard to address global mobility of mobile hosts (MHs). It requires the MHs to register with the home agents (HAs) whenever their care-of addresses change. However, such registrations may cause excessive signaling traffic and long service delay. To solve this problem, the hierarchical mobile IP (HMIP) protocol was proposed to employ the hierarchy of foreign agents (FAs) and the gateway FAs (GFAs) to localize registration operations. However, the system performance is critically affected by the selection of GFAs and their reliability. In this paper, we introduce a novel dynamic hierarchical mobility management strategy for mobile IP networks, in which different hierarchies are dynamically set up for different users and the signaling burden is evenly distributed among the network. To justify the effectiveness of our proposed scheme, we develop an analytical model to evaluate the signaling cost. Our performance analysis shows that the proposed dynamic hierarchical mobility management strategy can significantly reduce the system signaling cost under various scenarios and the system robustness is greatly enhanced. Our analysis also shows that the new scheme can outperform the Internet Engineering Task Force mobile IP hierarchical registration scheme in terms of the overall signaling cost. The more important contribution is the novel analytical approach in evaluating the performance of mobile IP networks. Index Terms—Mobile IP (MIP), mobility management, roaming, wireless networks. I.
Performance Issues with Vertical Handovers - Experiences from GPRS Cellular and WLAN hot-spots Integration
- in Proc. IEEE PerCom
, 2004
"... Interworking heterogeneous wireless access technologies is an important step towards building the next generation, all-IP wireless access infrastructure. In this paper, we present an experimental study of inter-network mobility between GPRS Cellular and 802.11b-based WLAN hot-spots, and analyse its ..."
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Cited by 27 (5 self)
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Interworking heterogeneous wireless access technologies is an important step towards building the next generation, all-IP wireless access infrastructure. In this paper, we present an experimental study of inter-network mobility between GPRS Cellular and 802.11b-based WLAN hot-spots, and analyse its impact on active transport TCP flows. Our experiments were conducted over a loosely-coupled, Mobile IPv6-based, GPRS-WLAN experimental testbed. Detailed analysis from packet traces of inter-network (vertical) handovers reveals a number of performance bottlenecks. In particular, the disparity in the round trip time and bandwidth offered by GPRS and WLAN networks, and presence of deep buffers in GPRS, can aggravate performance during vertical handovers. This paper summerizes the practical experiences and challenges of providing transparent mobility in heterogeneous environments.
P-MIP: Paging Extensions for Mobile IP
- ACM Mobile Networks and Applications
, 2002
"... As the number of Mobile IP users grows, so will the signalling overhead associated with Internet mobility management in the core IP network. ..."
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Cited by 27 (1 self)
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As the number of Mobile IP users grows, so will the signalling overhead associated with Internet mobility management in the core IP network.
Efficient Micro-Mobility using Intra-domain Multicast-based Mechanisms (MM)
, 2001
"... One of the most important metrics in the design of IP mobility protocols is the handover performance. Handover occurs when a mobile node changes its network point-ofattachment from one access router to another. If not performed efficiently, handover delays, jitters and packet loss directly impact an ..."
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Cited by 22 (2 self)
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One of the most important metrics in the design of IP mobility protocols is the handover performance. Handover occurs when a mobile node changes its network point-ofattachment from one access router to another. If not performed efficiently, handover delays, jitters and packet loss directly impact and disrupt applications and services. With the Internet growth and heterogeneity, it becomes crucial to design efficient handover protocols that are scalable, robust and incrementally deployable. The current Mobile IP (MIP) standard has been shown to exhibit poor handover performance. Most other work attempts to modify MIP to slightly improve its efficiency, while others propose complex techniques to replace MIP. Rather than taking these approaches, we instead propose a new architecture for providing efficient and smooth handover, while being able to co-exist and inter-operate with other technologies. Specifically, we propose an intra-domain multicast-based mobility architecture, where a visiting mobile is assigned a multicast address to use while moving within a domain. Efficient handover is achieved using standard multicast join/prune mechanisms. Two approaches are proposed and contrasted. The first introduces the concept proxy-based mobility, while the other uses algorithmic mapping to obtain the multicast address of visiting mobiles. We show that the algorithmic mapping approach has several advantages over the proxy approach, and provide mechanisms to support it. Network simulation (using NS-2) is used to evaluate our scheme and compare it to other major approaches to micromobility; hierarchical mobile IP and seamless handover. Results show that our scheme, although simpler, outperforms the other schemes in over 94% of the scenarios, and provides, on average, handover p...
Mobilenat: A new technique for mobility across heterogeneous address spaces
- MONET
, 2005
"... We propose a new network layer mobility architecture called MOBILENAT to efficiently support micro and macro-mobility in and across heterogeneous address spaces common in emerging public networks. The key ideas in this architecture are as follows: (1) Use of two IP addresses – an invariant virtual I ..."
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Cited by 16 (4 self)
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We propose a new network layer mobility architecture called MOBILENAT to efficiently support micro and macro-mobility in and across heterogeneous address spaces common in emerging public networks. The key ideas in this architecture are as follows: (1) Use of two IP addresses – an invariant virtual IP address for host identification at the application layer and an actual routable address at the network layer that changes due to mobility. Since physical address has routing significance only within a domain, it can be a private address and therefore, does not deplete the public IP address resource. (2) New DHCP enhancements to distribute the two addresses. (3) A new signaling element called Mobility Manager (MM) that uses Middlebox Communication (MIDCOM) framework to signal the changes in packet processing rules to the Network Address Translators (NATs) in the event of node mobility. Our proposal does not require any modifications to the access networks and can seamlessly co-exist with the existing Mobile IP mechanisms and therefore, can be used to provide seamless mobility across heterogeneous wireline and wireless networks. We report implementation details of a subset of our ideas in a testbed with Windows XP clients and Linux based NATs. I.
An End-to-End Multipath Smooth Handoff Scheme for Stream Media
- IEEE Journal on Selected Areas in Communications
, 2004
"... In the near future, wide variety of wireless networks will be merged into the Internet and allow users to continue their application with higher degree of mobility. In such environment, multimedia applications, which require smooth rate transmission, will become more popular. There are two main reas ..."
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Cited by 16 (0 self)
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In the near future, wide variety of wireless networks will be merged into the Internet and allow users to continue their application with higher degree of mobility. In such environment, multimedia applications, which require smooth rate transmission, will become more popular. There are two main reasons that cause difficulties in the smooth transmission of stream media application when a user roams around the wireless mobile networks: 1) packets may get lost due to the re-routing caused by handoffs; 2) due to the disparity in the amount of available bandwidth among wireless cells, handoffs may cause congestion. We propose an end-to-end multi-path transmission scheme that provides a comprehensive solution for the smooth handoffs of stream media. In the proposed scheme, multiple paths are acquired during the handoff period to reach a single mobile node. Multi-layer encoding technique is applied to make the stream media more adaptive to the heterogeneous network environment with different bandwidths. Protection of more important video layer through duplicated transmission is carefully designed for smooth handoff using multiple paths. The performance of the proposed multi-path handoff scheme is evaluated and compared with existing schemes through extensive simulations. The simulation results show that the proposed scheme improves the throughput and quality for stream media application during the handoff. Cost of the proposed scheme is also carefully evaluated in terms of transmission efficiency.
Multicast-based Mobility: A Novel Architecture for Efficient Micro-Mobility
, 2002
"... Handover performance is very important when evaluating IP mobility protocols. If not performed efficiently, handover delays, jitters and packet loss directly impact application performance. We propose a new architecture for providing efficient handover, while being able to co-exist with other proto ..."
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Cited by 15 (1 self)
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Handover performance is very important when evaluating IP mobility protocols. If not performed efficiently, handover delays, jitters and packet loss directly impact application performance. We propose a new architecture for providing efficient handover, while being able to co-exist with other protocols. We propose a paradigm for multicast-based micro mobility (M&M), where a visiting mobile is assigned a multicast address to use while moving within a domain. The multicast address is obtained using algorithmic mapping, and handover is achieved using multicast join/prune mechanisms. This study outlines a framework for the design and evaluation of micro-mobility protocols. We define a suite of protocols (called CAR-set) to enable multiple access routers to receive traffic for the mobile node. By changing the number of such routers, timing and buffering parameters, the protocol may be fine-tuned for specific technologies (e.g., 802.11) and handover scenarios. Extensive NS-2 simulations are used to compare M&M to other micro-mobility schemes- CIP and HAWAII. For proactive handover scenarios, our results show that M&M and CIP show lower handover delay and packet reordering than HAWAII. M&M, however, handles multiple border routers in a domain, where CIP fails. Also, for scenarios of reactive handover and coverage gaps M&M clearly outperforms CIP and HAWAII.
