1. A seamless handover between cdma2000 and WLAN for 3G-WLAN interworking service continuity 指導教授：黃培壝 學生：陳鵬宇

2. Outline  Introduction  Overview of Interworking Architecture among Heterogeneous Networks  Development of Mobile Controlled handover algorithm  Results of Simulation  Conclusion

3. Introduction  WLAN and cdma2000 that based on packet switch are one of the technologies being used most frequently.  Interworking of two technologies will bring the user a drastic increase of wireless service performance.  To perform effective services under interworking environments protocol authentification technology intelligent resource management algorithm varied handover technologies

4. Introduction  In this paper, we focus on soft handover algorithm that initiated by the terminal between WLAN and cdma2000, seamless data transmission, and also on maintaining service continuity.

5. Overview of Interworking Architecture among Heterogeneous Networks  In Figure 1 a), a varied networks already existed exchange packet data using interworking service server (ISS).

6. Overview of Interworking Architecture among Heterogeneous Networks  In Figure 1 b), a varied networks already existed exchange packet data through IP network.

7. Overview of Interworking Architecture among Heterogeneous Networks - Configuration of cdma2000 and WLAN  We constitute heterogeneous networks using cdma2000, WLAN and LAN. In case terminal moves between WLAN and cdma2000, we think about soft handover method that controlled by terminal by seamless connection control (SCC) scheme.

8. Overview of Interworking Architecture among Heterogeneous Networks – TCP/IP  TCP consists of 4 layers as shown in Figure 3.

9. Overview of Interworking Architecture among Heterogeneous Networks – TCP/IP  The cdma2000 can set up channel using two paths. One is connected remotely by using modem and dialup line. Point to Point Protocol (PPP) InterWorking Function (IWF)  IWF provides such functions as protocol change and data transformation in order to use data network access by using telephone line like Remote Access Server (RAS).  Another one is the case that uses Packet Data Serving Node (PDSN).

10. Overview of Interworking Architecture among Heterogeneous Networks - WLAN  IEEE 802.11x technical standard is a modulation method in terms of Wireless LAN Direct Sequence (DS) Frequency Hopping (FH)  In order to access to IP network using WLAN, hot spot method, specifically, a system configuration like public wireless LAN method is used.

11. Overview of Interworking Architecture among Heterogeneous Networks – CDMA2000  CDMA200 is the third generation technology of IS-95.  And to provide mobility service at IP level, it uses Mobile IP(MIP) and Authentication, Authorization, Account (AAA).  Packet Data Service Node (PDSN) is a device that enables user to provide packet data service at Base Station Controller (BSC).

12. Overview of Interworking Architecture among Heterogeneous Networks – CDMA2000  Mobile terminal and PDSN are connected by using Point-to-Point Protocol (PPP) and after connected, it is transformed into IP.  If handover occurs between BS and BS, there will be established location updating of HA by MIP.  Quality of Service (QoS) uses a mode of managing priority of packet employing Differentiated Service (Diffserv).

13. Overview of Interworking Architecture among Heterogeneous Networks – CDMA2000

14.  Mobile terminal can set up channel up to the server placed in the particular location by using largely 3 types of path. PDSN IWF RAS  In all three cases, it is connected to terminal by using PPP, and then after, it will be changed into IP.

15. Overview of Interworking Architecture among Heterogeneous Networks – CDMA2000  PDSN can be provided the best possible transmission performance.  IWF provides protocol and data transformation in order to perform interworking between networks of different kinds.

16. Development of Mobile Controlled handover algorithm  Two types of handover have been displayed. Network Controlled (NC) Handover Mobile Controlled (MC) Handover  In MC Handover, however, terminal recognizes changes of wireless service network range by using signal strength of access node of network and also terminal move.  In previous chapter, we have mentioned that we will consider Seamless Connection Control (SCC) only between WLAN and cdma2000.

17. Development of Mobile Controlled handover algorithm  The soft handover developed this time maintains channel at border area between WLAN and cdma2000.  Home site of terminal updates information of terminal, and this method is called "Active Update."  Taking other case like Passive Update, there occurs information updating only when network system requests terminal for information updating.

18. Development of Mobile Controlled handover algorithm

19. Results of Simulation

20.  We used PDA as for terminal. PDA was equipped with CDMA and WLAN modem.  To test data transmission, server listens to mp3 music file that stored in PDA. At this time, user produces handover by moving PDA.  We used hard handover (H.HO) and soft handover (S.HO) based on MC Handover.

21. Results of Simulation

23.  Figure 7 displays measurement of HA updating signals according to handover.

24. Results of Simulation S.O.

25. Conclusion  MC Handover sets up channel actively at terminal, and transmits handover signals to destination server.  Soft handover maintained data transmission regardless handover by using each channel between WLAN and cdma2000.  MC soft handover can be used as a seamless connection control method that enables us to provide critical status for data transmission.