以IEEE 802.11無線區域網路為基礎的無線熱點越來越普遍，用來提供無線網際網路使用者不同的資料服務。而以發展中的IEEE 802.16 (WiMAX)系列家族為基礎的無線都會網路技術，可望用來作為WLAN熱點的背後支援之解決方法。
WLAN與WMAN之整合網路可取其各別優勢以提供高品質的傳輸服務。不同無線網路系統之間的無縫換手相對就變得有需要，而且要將其QoS機制與換手程序整合也具一定困難度。
IEEE 802.21 MIH為發展中的網路標準，它可以讓包括802與非802系列之異質網路間的換手及互通性可以實行。這個協定定義了提供連結層更有智能的方法，以及給上層其他相關的網路資訊，以使得異質媒介間的換手達最佳化。
本論文提出以IEEE 802.21 MIH為基礎的機制，使用於IEEE 802.11無線區域網路以及IEEE 802.16無線都會網路之間的無縫換手。我們提出的以MIH支援垂直換手方法可針對兩種不同使用情境。經由模擬實驗證明，本方法可以減少因為換手所造成的系統負載以及提供無線網際網路使用者服務不中斷。

Wireless hotspots based on IEEE 802.11 wireless LAN (WLAN) have become very popular for providing different data services to wireless Internet users. The evolving family of IEEE 802.16 -based wireless metropolitan area network (WMAN) technologies is a promising solution to provide backhaul support for WLAN hotspots.
The integrated network of WLAN and WMAN can take advantage of them to offer high quality of service (QoS). Seamless handover between different wireless systems is possible while the Internet’s QoS mechanisms are difficult to integrate into the handover procedures.
IEEE 802.21 Media Independent Handover (MIH) is developing standards to enable handover and interoperability between heterogeneous network types including both 802 and non 802 networks. This protocol defines method to provide the related network information and link layer intelligence to the upper layers for optimizes handovers between heterogeneous media.
In this thesis, we propose a scheme to make seamless handover between IEEE 802.11 WLAN and IEEE 802.16 WMAN based on IEEE.21 MIH. We propose the method to support vertical handover using MIH for two different scenarios. According to the simulation results, this proposal can decrease system overhead caused by handover and provides service continuity for wireless Internet users.

中文摘要	I
Abstract	II
List of Figures	V

1	Introduction	1
2	Related Work	6
2.1	IEEE Standards for Wireless Networks	8
2.1.1	IEEE 802.11(WLAN/Wi-Fi)	9
2.1.2	IEEE 802.16 (WMAN/WiMAX)	10
2.2	Mobility Management	11
2.3	Vertical Handover Strategies	14
2.3.1	Network layer solution : Mobile IP	14
2.3.2	Transport layer solution : mSCTP	16
2.3.3	Application layer solution : SIP	18
2.3.4	Other Proposals for Vertical Handover	19
2.4	IEEE 802.21 MIH	21
2.4.1	Media Independent Event Service (MIES)	22
2.4.2	Media Independent Command Service (MICS)	24
2.4.3	Media Independent Information Service (MIIS)	26
2.4.4	MIH Reference models	27
3	Using MIH for Vertical Handover between Wi-Fi and WiMAX	31
3.1	Scenario 1: the AP has a unique interface – Wi-Fi	32
3.2	Scenario 2: the AP supports dual module – Wi-Fi/WiMAX	35
4	Procedure of the MIH-based Vertical Handover	38
4.1	Handover Procedure of Scenario 1	40
4.1.1	Vertical Handover from WMAN to WLAN in Scenario 1	40
4.1.2	Vertical Handover from WLAN to WMAN in Scenario 1	47
4.2	Handover Procedure of Scenario 2	50
4.2.1	Vertical Handover from WMAN to WLAN in Scenario 2	50
4.2.2	Vertical Handover from WLAN to WMAN in Scenario 2	53
5	Performance Evaluation	57
5.1	Statistical Analysis	58
5.2	Simulation Setup and Results	60
5.2.1	Handover operation time	61
5.2.2	Throughput	63
5.2.3	Power saving	64
6	Conclusion and Future Work	66
6.1	Conclusion	66
6.2	Future Work	67
Bibliography	68
Appendix A. Publication List	73
Appendix B. “Cooperative System for Micromobility Management in Wireless Communication Networks,” International Journal of Electrical Engineering (IJEE)	75
Appendix C. “Adaptive MAP Selection with Load Balancing Mechanism for the Hierarchical Mobile IPv6,” Tamkang Journal of Science and Engineering (TKJSE)	86
Appendix D. “The MIH-based Vertical Handover Method for Wi-Fi and WiMAX Integrated Network,” International Journal of Autonomous and Adaptive Communications Systems (IJAACS)	93


List of Figures
Figure 1-1	Future wireless networks	2
Figure 1-2	Handover cases for different layers	3
Figure 2-1	Wireless technology evolution	7
Figure 2-2	IEEE standards for wireless networks	8
Figure 2-3	General architecture of IEEE 802.11 [Cole2007]	9
Figure 2-4	General architecture of IEEE 802.16 [Murias2006]	10
Figure 2-5	Micro mobility and macro Mobility	12
Figure 2-6	Horizontal handover and vertical handover	13
Figure 2-7	Mobile IP oeration	15
Figure 2-8	A mSCTP example	18
Figure 2-9	Example of SIP session setup	19
Figure 2-10	MIH function location and Key Services	22
Figure 2-11	Link events and MIH events	23
Figure 2-12	Remote MIH events	24
Figure 2-13	Link commands and MIH commands	25
Figure 2-14	Remote MIH commands	26
Figure 2-15	General MIHF reference model and SAPs [Gupta2006]	27
Figure 2-16	MIH reference model for IEEE 802.11 [Gupta2006]	29
Figure 2-17	MIH reference model for IEEE 802.16 [Gupta2006]	30
Figure 3-1	Hard handover vs. soft handover	32
Figure 3-2	Before handover in scenario 1 and scenario 2	33
Figure 3-3	After handover in scenario 1	34
Figure 3-4	After handover in scenario 2	36
Figure 4-1	The three phases of the proposed handover method	39
Figure 4-2	MSC of handover from WMAN to WLAN in scenario 1	41
Figure 4-3	Local event service (Link Detected)	42
Figure 4-4	Local event service (Link Up)	43
Figure 4-5	Remote command service (MN Handover Commit) – MN request	44
Figure 4-6	Remote command service (MN Handover Commit) – BS response	45
Figure 4-7	Local command service (Link Action) – Request frame	46
Figure 4-8	Local command service (Link Action) – Response frame	47
Figure 4-9	MSC of handover from WLAN to WMAN in scenario 1	48
Figure 4-10	MSC of handover from WMAN to WLAN in scenario 2	51
Figure 4-11	MSC of handover from WLAN to WMAN in scenario 2	54
Figure 4-12	Remote command service (MN Handover Complete) – MN request	56
Figure 4-13	Remote command service (MN Handover Complete) – BS response	56
Figure 5-1	The simulation results of handover operation time (WiMAX to Wi-Fi)	62
Figure 5-2	The simulation results of handover operation time (Wi-Fi to WiMAX)	63
Figure 5-3	The simulation results of throughput variation	64
Figure 5-4	The simulation results of energy disruption	65

[Ahmavaara2003]	K. Ahmavaara, H. Haverinen, and R. Pichna, “Integration of wireless LAN and 3G wireless - Interworking architecture between 3GPP and WLAN systems”, IEEE Communications Magazine, Vol. 41, Issue 11, pp.74-81, Nov. 2003.
[Akyildiz1999]	I. F. Akyildiz et al., “Mobility Management in Next-Generation Wireless Systems”, Proceedings of the IEEE, Vol. 87, No. 8, pp.1347-1384, August 1999
[Brandt2007]	“IEEE Standard for Local and metropolitan area networks - Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems - Amendment 3: Management Plane Procedures and Services”, IEEE Std 802.16g-2007, December 2007.
[Chen2005]	J. C. Chen, H. W. Lin, “A gateway approach to mobility integration of GPRS and wireless LANs”, IEEE Wireless  Communications, Vol. 12, Issue 2, pp.86-95, April 2005.
[Cole2007]	“IEEE Standard for Information technology - Telecommunications and information exchange between systems - Local and metropolitan area networks - Specific requirements, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications,” IEEE Std 802.11-2007, June 2007.
[Eastwood2008]	L. Eastwood, S. Migaldi, Q. Xie, V. Gupta, “Mobility using IEEE 802.21 in a heterogeneous IEEE 802.16/802.11-based, IMT-advanced (4G) network”, IEEE Wireless Communications, Vol. 15, Issue 2, pp.26-34, April 2008.
[EMNTG2007]	EMNTG Seamless and Secure Mobility. Obtained through the Internet: http://www.antd.nist.gov/seamlessandsecure/pubtool.shtml#tools
[Gundavelli2008]	S. Gundavelli et al., “Proxy Mobile IP”, IETF RFC 5213, August 2008.
[Gupta2006]	“Draft IEEE Standard for Local and Metropolitan Area Networks: Media Independent Handover Services”, IEEE P802.21/D00.05, January 2006.
[Gustafsson2003]	E. Gustafsson; A. Jonsson, “Always best connected”, Wireless Communications, IEEE, Vol. 10, Issue 1, pp. 49-55, 2003.
[Handley2002]	M. Handley, H. Schulzrinne, E. Schooler, and J. Rosenberg, “SIP: Session Initiation Protocol”, IETF RFC 3261, Jun 2002.
[Hart2008]	“Draft Standard for Local and Metropolitan Area Networks - Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems - Multihop Relay Specification”, IEEE P802.16j/D3, February 2008.
[Johnson2004]	D. Johnson, C. Perkins, J. Arkko, “Mobility support in IPv6”, IETF RFC 3775, June 2004.
[Jung2003]	J. W. Jung, R. Mudumbai, D. Montgomery, H. K. Kahng, “Performance evaluation of two layered mobility management using mobile IP and session initiation protocol”, IEEE Global Telecommunications Conference, Vol. 3, pp.1190-1194, Dec. 2003.
[Kong2008]	K. S. Kong et al., “Mobility management for all-IP mobile networks: mobile IPv6 vs. proxy mobile IPv6”, IEEE Wireless Communications, Vol. 15, Issue 2, pp.36-45, April 2008.
[Lampropoulos2008]	G. Lampropoulos, A. K. Salkintzis, N. Passas, “Media-independent handover for seamless service provision in heterogeneous networks”, IEEE Communications Magazine, Vol. 46, Issue 1, pp.64-71, Jan. 2008.
[Lee2005]	C. W. Lee, L. M. Chen, M. C. Chen, and Y. S. Sun, “A framework of handoffs in wireless overlay networks based on mobile IPv6”, IEEE Journal on Selected Areas in Communication, Vol. 23, No. 11, pp.2118-2128, November 2005.
[Ma2004]	L. Ma, F. Yu, C. M. Leung, Tejinder Randhawa, “A new method to support UMTS/WLAN vertical handover using SCTP”, IEEE Wireless Communications, Vol. 11, Issue 4, pp.44-51, Aug. 2004.
[Marques2005]	V. Marques et al., “Evaluation of a mobile IPv6-based architecture supporting user mobility QoS and AAAC in heterogeneous networks”, IEEE Journal on Selected Areas in Communication, Vol. 23, No. 11, pp.2138-2151, November 2005.
[Marquez2005]	F. G. Marquez, “Interworking of IP multimedia core networks between 3GPP and WLAN”, IEEE Wireless Communications, Vol. 12, Issue 3, pp.58-65, June 2005.
[Montavont2002]	N. Montavont, T. Noel, “Handover management for mobile nodes in IPv6 networks”, IEEE Communication Magazine, Vol. 40, Issue 8, pp.38-43, Aug. 2002
[Murias2006]	“IEEE Standard for Local and metropolitan area networks - Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems - Amendment 2: Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands”, IEEE Std 802.16e-2005, December 2005.
[Pahlavan2000]	K. Pahlavan et al., “Handover in Hybrid Mobile Data Networks”, IEEE Personal Communications, April 2000.
[Perkins1998]	C.E. Perkins, “Mobile networking through Mobile IP”, IEEE Internet Computing, Vol. 2, Issue 1, pp.58-69, Jan.-Feb. 1998
[Perkins2002]	C. Perkins, “IP mobility support for IPv4”, IETF RFC 3344, Aug 2002.
[Pontes2008]	A. B. Pontes et al., “Handover management in integrated WLAN and mobile WiMAX networks”, IEEE Wireless Communications, Vol. 15, Issue 5, pp.86-95, Oct. 2008.
[Riegel2002]	M. Riegel, M. Tuexen, “Mobile SCTP”, draft-riegel-tuexen-mobile-sctp-00.txt, August 2002.
[Rosenberg2002]	J. Rosenberg et al., “SIP: Session Initiation Protocol”, IETF RFC 3261, June 2002.
[Salkintzis2002]	A. K. Salkintzis, C. Fors, R. Pazhyannur, “WLAN-GPRS integration for next-generation mobile data networks”, IEEE Wireless Communications, Vol. 9, Issue 5, pp.112-124, Oct. 2002.
[Salkintzis2004]	A. K. Salkintzis, “WLAN/3G interworking architectures for next generation hybrid data networks”, IEEE Communications Society, Vol. 7, pp.3984-3988, June 2004.
[Schulzrinne2000]	H. Schulzrinne, E. Wedlund, “Application-layer mobility using SIP”, ACM Mobile Computing and Communications Review, Vol. 1, No. 2, July 2000.
[Soliman2008]	H. Soliman, C. Castelluccia, K. ElMalki, L. Bellier, “Hierarchical Mobile IPv6 (HMIPv6) Mobility Management”, IETF RFC 5380, October 2008.
[Stewart2000]	R. Stewart et al., “Stream Control Transmission Protocol”, IETF RFC 2960, October 2000.
[Stewart2001]	R. Stewart, C. Metz, “SCTP: new transport protocol for TCP/IP”, IEEE Internet Computing, Vol. 5, Issue 6, pp.64-69, Nov.-Dev. 2001.
[VINT1995]	The Network Simulator - ns-2. Obtained through the Internet: http://www.isi.edu/nsnam/ns/
[Wang2004]	Q. Wang, Abu-Rgheff, A. Akram, “Design and evaluation of an integrated mobile IP and SIP framework for advanced handoff management”, IEEE Internal Conference on Communications, Vol. 7, pp.3921-3925, June 2004.
[Wang2006]	Q. Wang, M. Ali, Abu-Rgheff, “Mobility management architectures based on joint mobile IP and SIP protocols”, IEEE Wireless Communications, Vol. 13, Issue 6, pp.68-76, Dec. 2006.
[Wu2005]	W. Wu, N. Banerjee, K. Basu, S. K. Das, “SIP-based Vertical Handoff between WWANs and WLANs”, IEEE Wireless Communications, Vol. 12, Issue 3, pp.66-72, June 2005.
[Xing2002]	W. Xing, H. Karl, and A. Wolisz, “M-SCTP: Design and Prototypical Implementation of an End-to-End Mobility Concept”, Proceeding 5th Int’l. Workshop The Internet Challenge: Technology and Applications, Oct. 2002.