Mobile IPv6網路上動態及負載平衡之階層式行動管理

A Dynamic and Load-Balanced Hierarchical Mobility Management Scheme in Mobile IPv6 Networks

蔡莉文(Li-wen Tsai)

指導教授 ： 賴國華

元智大學/資訊學院/資訊工程學系/碩士(2004年)

摘要

行動管理是無線網路中最重要的議題之一，由於cell面積縮小（為使頻寬能充分再利用）及異質性網路的重疊，換手（handoff）的機率因此提高。藉由區分inter-domain和intra-domain可減少Binding Update訊息，然而當高速行動節點（Mobile Node）數量增加時，部份集中及固定式架構中的節點將無法負荷，形成系統運作上的瓶頸。
我們提出一個分散式行動管理方案，為了減少Binding Update訊息，動態地依照每一個行動節點的移動形成一個專有的2層式Mobility Anchor Point（MAP）階層，並且依往來資料流量、移動性等因素估算之成本決定其MAP階層範圍，以達到最佳化。另外，以此2層式MAP階層的特性，利用先前已註冊的on-line care-of address（LCoA），提前來向Home Agent註冊，以縮短換手所需時間。
我們分別以一些較簡單的分析比較及在ns-2系統上的模擬實驗來作成效評估，結果顯示這方案對高速行動節點的表現良好，Binding Update的成本減少近30%，當行動節點離它的Home Network較遠時，這改善更達50%。然而，對閒置或低行動性的節點，因在2層式階層的額外處理，它造成較多成本。

並列摘要

Mobility management is one of the most important issues for wireless networks. Because of the shrinking cells and overlapped heterogeneous networks, the probability of handoff becomes higher. By differentiating inter-domain and intra-domain, signaling load can be reduced. However, some entities in a centralized and fixed scheme are burdened with processing load when number of mobile nodes grows.
We propose a distributed mobility management scheme which forms a two-level hierarchy of mobility anchor points for each mobile node according to its movements in order to reduce the signaling for binding updates. The size of the hierarchy is optimized dynamically per the estimated cost which is affected by its mobility, traffic load and some other factors. It also utilizes the two-level hierarchy to reduce handoff latency. Mobile node does a global binding update, registering the previous registered on-link care-of address to home agent, and a local binding update concurrently.
The proposed scheme is evaluated by a simplified analytical model and simulation tool, ns-2. The results show that it performs well for high mobile nodes. The reduction in cost of binding update is close to 30%. The improvement is remarkable, around 50%, when they are far away from their home networks. However, it costs more than Hierarchical Mobile IPv6 due to the extra processing cost in the two-level hierarchy when mobile node is idle or in low mobile rate.

並列關鍵字

Mobile IPv6 ； Handoff Latency ； Micro-mobility ； Binding Update

參考文獻

[Akyil 04a] Ian F. Akyildiz, J. Xie, and S. Mohanty, “A survey of mobility management in next-generation all-IP-based wireless systems,” IEEE Wireless Communications, August 2004, pp. 16-28

[Akyil 04b] Ian F. Akyildiz and Wenye Wang, “The Predictive User Mobility Profile Framework for Wireless Multimedia Networks,” IEEE/ACM Transactions on Networking (TON), Vol. 12, No. 6, December 2004, pp. 1021-1035.

[Bandai 03] M. Bandai and I. Sasase, “A Load Balancing Mobility Management for Multilevel Hierarchical Mobile IPv6 Networks,” Proc. IEEE PIMRC 2003

[Beau 02] R. Beaubrun et al., ”Global roaming management in the next-generation wireless systems,” ICC 2002 - IEEE International Conference on Communications, Vol. 25, No. 1, April 2002, pp. 2070-2074.

[Camp 00] A. T. Campbell et al., “Design, Implementation, and Evaluation of Cellular IP,” IEEE Personal Communications, August 2000, pp. 42-49.