Candidate Access Router Discovery Research Articles

무선랜 환경에서 서비스 연속성 지원을 위한 IMS 기반 핸드오버 지원 방안

본 논문은 단일 무선랜 인터페이스를 갖는 IMS 단말에서 서비스 연속성을 지원하기 위해 패킷 손실을 최소화하는 L3 핸드오버 지원방안을 제안한다. 기존 IMS 서비스 연속성 지원 방안은 하나의 단말 내에 존재하는 다수의 인터페이스를 통해 서로 다른 접속망을 경유하여 IMS 코어 네트워크와의 통신이 가능한 상태에서 이동성 제공이 가능하다. 하지만, 단일 인터페이스를 갖는 무선랜 단말은 동시에 하나 이상의 접속망을 통해 IMS 코어 네트워크와 통신을 할 수 없다. 제안 방안은 Candidate Access Router Discovery(CARD) 매커니즘을 이용하여 타겟 WLAN 영역에서 단말이 사용할 IP를 미리 구성하고, 서비스 연속성 서버가 단말을 대신하여 타겟 WLAN 영역에서의 L3 연결 과정 및 IMS 서버로의 등록절차를 수행한다. 이후 서비스 연속성 제공을 위해 SIP 기반의 세션 제어 메커니즘을 수행한다. 제안된 핸드오버 제공 방안의 성능 검증을 위해 기존 서비스 연속성 제공 방안과 제안 방안에 대한 핸드오버 지연(latency), 시그널링 비용(cost)을 비교 분석하였다. This paper proposes a L3 handover method to minimize packet loss for supporting service continuity to IMS Terminal which has a single WLAN interface. The existing IMS based handover solution is able to support handover between different access networks in case that a terminal has multiple interfaces. That is, WLAN terminals need multiple interfaces to connect with one or more access networks. This proposed method configures IP address for the terminal in target WLAN previously by using Candidate Access Router Discovery(CARD) mechanism. Also, in the proposed method, service continuity server performs L3 connection establishment in target WLAN and registration to IMS server instead of the terminal. And then session control mechanism based on SIP is performed to support service continuity. We analyzed handover latency and signaling cost in the proposed method and existing method to show the improved performance by the proposed method.

Design and implementation of ARIP for efficient handovers

AbstractMobile IPv6 (MIPv6), which is a protocol being standardized by Internet Engineering Task Force for global IP mobility support, is expected to have a key role for future All‐IP wireless networks. As the demands for delay sensitive multimedia applications increase, the handover latency and packet losses of MIPv6 become inadequate for these applications. Fast Handovers for Mobile IPv6 (FMIPv6) has been proposed to tackle the problem. However, FMIPv6 cannot work solely since it needs access router information for its fast handover operation. In this paper, we propose Access Router Information Protocol (ARIP), which performs a candidate access router discovery and a radio access network discovery in one protocol suite, to provide an efficient handover framework for MIPv6 and FMIPv6. ARIP is designed to cope with heterogeneous networks as well as homogeneous networks and to be closely coupled with FMIPv6 to provide the efficient handover performance. The performance evaluation of MIPv6, FMIPv6, and FMIPv6 with ARIP is performed in an actual network environment. The performance results show that FMIPv6 with ARIP can significantly improve the handover performance compared to the conventional handover approaches. Copyright © 2009 John Wiley & Sons, Ltd.

Performance evaluation of the push-mode-multicast based candidate access router discovery (PMM CARD)

In order to provide nomadic users with QoS-enabled services, advanced mobility management will prove to be of fundamental importance in the future Internet. It has been widely recognized that the basic Mobile IPv4/v6 protocols could perform poorly, especially with QoS-demanding applications. One of the main steps to achieve seamless handover is the quick discovery of the surrounding wireless coverage at each access router (AR), i.e., the discovery of IP addresses and service capabilities (SCs) of candidate access routers (CARs) to hand over to. The rapid knowledge of IP addresses allows mobile nodes (MNs) to speed-up the handover process, whereas information about SCs are important for the selection of the most appropriate wireless access (target access router, TAR) among the set of CARs, according to a given criterion (e.g., load balancing). In this paper, we first describe the candidate access router discovery (CARD) solutions proposed within the framework of the IETF SEAMOBY WG, which has inspired research in this field. Then, we propose the distributed push-mode-multicast based CARD (PMM CARD) approach and compare it with the IETF proposals. The novelty of our solution is the use of push-mode multicast transmissions, which enables an efficient distribution of CARD information within the network, together with a significant reduction in latency due to explicit queries to a remote entity. Then, we develop a theoretical model to compute the signaling burden associated with different CARD solutions. Our analysis shows that, even though the amount of signaling required to implement all CARD approaches is generally low, our approach gives a certain improvement over the IETF proposals in terms of the average signaling load. In addition, the results obtained by a simulation campaign show the effectiveness of the PMM CARD solution in terms of the time needed by ARs to discover the surrounding wireless coverage.

Target access router selection in advanced mobility scenarios

To provide nomadic users with QoS-enabled services, advanced mobility management will prove to be of fundamental importance in the future Internet. Mobile IP is the reference protocol supporting mobility at IP level. However, it has been widely recognised that it could perform poorly, especially with QoS demanding applications. In order to improve Mobile IP performance, the discovery and selection of the target access router to hand over to will play a crucial role. In this paper, we present a novel approach for Candidate Access Router Discovery and Target Access Router selection. The process is fully distributed, multicast-based, and allows timely intra and inter-access router handover, which can be either intra or inter-technology. The effectiveness of the solution to drive mobile terminal handovers has been tested by simulations.

Achieving seamless mobility in IP-based radio access networks

A handover in any IP-based mobile network is a complex procedure. Typically, it takes quite a long time before the new access router gets the parameters describing the flow states associated with an incoming mobile node. It may even be that the new access router does not have enough resources to support the rerouted flows. Thus, it is crucial to select from several candidate access routers the one that best fits the mobile node's requirements. This article describes the candidate access router discovery protocol, which can be used to select a suitable new access router. We also address the context transfer architecture that makes use of the candidate access router discovery protocol and aims to reduce the time required to recover flow descriptor parameters. Finally, we discuss how the two protocols can intemperate to achieve seamless handovers.

A Security Architecture for Mobility-Related Services

In future wireless networks, mobility-related services, such as candidate access router discovery (CARD), will play a significant role in realizing truly ubiquitous, seamless connectivity. In order...