在整合式WiMAX/WLAN網路中具QoS感知無縫換手之RSVP延展方法

RSVP Extensions for Seamless Handoff with QoS Aware in Integrated WiMAX/WLAN Networks

魏曉明(Shiao-Ming Wei)

指導教授 ： 王能中 ； 謝政勳

朝陽科技大學/資訊學院/資訊工程系/碩士(2009年)

摘要

在不久的未來，未來的網路將會是異質性。像是全球互通微波存取(WiMAX)和無線區域網路(WLAN)可以各自結合彼此優點，覆蓋範圍及資料傳輸速率在混合式網路系統的基礎上。因此，提供服務品質(QoS)連接無縫式(Seamless)換手(Handoff)在WLAN與WiMAX環境是很重要的議題。然而，在目前的無線網路環境中，許多無線行動裝置使用者在具移動性(Mobility)的狀態下使用即時性服務(如聲音、視訊會議及影像等)時，會面臨跨越網路的服務邊界而進入另外一個網路的服務區域（這機制我們稱之為換手Handoff 或Handover）之時，因此引發新資源之需求，但也往往因無法取得所需之網路資源而造成嚴重的延遲或甚至造成連結的中斷。在本論文中，我們提出一個在異質無線網路環境中，以服務品質(QoS)感知RSVP方法達到使用即時性服務之服務品質(QoS)保證之方法。提出方法基於整合在WiMAX與WLAN網路中，具服務品質(QoS)感知移動架構以保證一定的服務品質(QoS)。在本論文中，藉由行動節點的移動和訊號強度執行預先換手(Pre-handoff)而選擇網路。在另一方面，假如換手(Handoff)觸發了網路擁塞，行動節點依據擁塞控制服務品質(QoS)參數而將會執行換手(Handoff)。我們提出的方法可以有效降低封包傳輸因換手(Handoff)時需重新繞路連線所造成的的延遲(Delay)時間和換手阻塞率在異質無線網路。

關鍵字

WiMAX ； 服務品質 ； WLAN ； 異質無線網路 ； 換手

並列摘要

In the near future, future network environments will be heterogeneous. The hybrid networks based on systems such as WiMAX (Worldwide Interoperability for Microwave Access) and WLAN (Wireless Local Access Networks) can combine their respective advantages on coverage and data rates. Therefore, it is a significant issue of how to provide seamless handoff for QoS connections in WLAN and WiMAX environments. However, in the wireless networks we use today, many mobile users still cannot obtain the network resources they need when employing the real-time services like voice, video conferences, video IP phone, and so forth while handoff occurs, and it causes a serious delay or even the break of the link. Thus, our approach is proposed to guarantee the QoS with QoS aware RSVP in heterogeneous wireless networks. The proposed scheme is based on QoS aware mobility architecture to guarantee a certain QoS in integrated WiMAX and WLAN networks. In this paper, the network selection is ignited by mobility of MS and pre-handoff is performed based on signal strength. On ther other hand, if the selection is triggered by the congestion, we will perform the handoff based on congestion controlling delay according to the QoS parameters. Our proposed scheme of resource pre-reservation can reduce the delay time of re-routing while handoff occurs and handoff blocking rate in the heterogeneous wireless networks efficiently.

並列關鍵字

Handoff ； heterogeneous wireless networks ； WiMAX ； quality of service ； WLAN

參考文獻

[3] ATM Forum, Traffic Management Specification version 4.0, March 1996.

[11] IEEE Std 802.16-2004. IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems, October 2004.

[12] J. N. Al-Karaki and A. E. Kamal, “End-to-End Support for Statistical Quality of Service in Heterogeneous Mobile Ad Hoc Networks,” Computer Communications, pp. 2119-2132, November 2005.

[13] R. Braden and L. Zhang, “Resource ReSerVation Protocol (RSVP) - version 1 Functional Specification,” RFC 2205, September 1997.

[14] Y.-W. Chen, I.-H. Peng, and S.-T. Guan, “Dynamic Bandwidth Management for Handoffs with RSVP in 802.16/WLAN Environment,” Advanced Information Networking and Applications Workshops, Vol. 2, pp. 243-248, May 2007.