1 PERFORMANCE COMPARISON OF VERTICAL HANDOVER STRATEGIES FOR PSDR HETEROGENEOUS NETWORK 學生 : 鄭宗建 學號 :

2 Outline Abstract Introduction Overview of high-level strategies for VHO Performance Evaluation Conclusion

3 Abstract In this article we suggest a vertical handover (VHO) solution able to optimize mobility management over heterogeneous networks in terms of handoff delay and signaling load. The article presents the operational scenarios where integration between TETRA and WiFi/WiMAX is needed and the main resulting benefits. Performances of the suggested VHO management scheme are described and evaluated against other protocol solutions.

4 Introduction TETRA( Terrestrial Trunked Radio)  TETRA provides radio capabilities encompassing network controlled services and direct mobile-to-mobile communications, with a range of functionalities such as group calls, instantaneous connections of calls, encryp- tion, real-time localization, and high-priority connections.  However, the access capability offered by TETRA is not enough to satisfy the requirements needed to support the new generation of mobile applications. An integrated network architecture is to be realized in order to guarantee PSDR users technology-independent access to a common IP-based core network.

5 Introduction  Some critical issues are solved concerning radio resources, network, quality of service (QoS), and mobility and security management Mobile IP (MIP) and Session Initiation Protocol (SIP) are the two major protocols for IP-based mobility management. A joint integrated approach is suggested in [7]that exploits the complementary capabilities of MIP and SIP  SBC ( Session border controller)  SIP location management and handover procedures  Security weaknesses, reliability issues, and the lack of QoS support in MIP, as well as the increase of signaling load and handoff delay in centralized SIP SBC system are only a few problems which are to be solved. A integrated MIP-SIP with SBC architecture

6 Introduction The performance of the PTS strategy is evaluated compared to typical approaches. A TETRA user can gain access to services exploiting the coverage offered by other communi- cation networks, provided that interworking procedures are implemented.  Non-overlapping  Overlapping Always best connected (ABC) paradigm

7 Introduction Multimode handheld terminals are to be realized, able to access TETRA as well as other available networks, discriminating the most suitable technology based on an opportune policy. The core network of the integrated system  TETRA Switching and management infrastructure (SwMI)  Switching networking gateway  database management  Interfacing capabilities for the system

8 Overview of high-level strategies for VHO Single-Layer Approach  MIP In MIP two mobility agents, home and foreign agents (HA/FA), are introduced to handle location updates and route traffic.  In basic MIP, the corresponding host (CH) sends IP packets to the mobile host (MH) using the MH’s IP home address (HoA).  The HA encapsulates the packets using the MH’s care-of address (CoA) and forwards them to the MH’s foreign network.  Then the FA decapsulates the packets and sends them to the MH  Route optimization  It allows a CH to cache a dynamic binding of the MH HoA and CoA.

9 Overview of high-level strategies for VHO  SIP As for SIP, it was initially designed as an application-layer multimedia signaling protocol However, it has potential capabilities for personal, session, and service mobility. Mobility management  The SBC hosts a mobility management server (MMS) that, in conjunction with the mobility management client (MMC) in the MH, allows the user agent (UA) to be reached in case of incoming calls and to keep ongoing sessions active despite changes in the access networks.  The MMS in the SBC updates its media proxy, and starts transmitting and receiving over the target network

10 Overview of high-level strategies for VHO  Actually, a single registration mechanism between the MH and the SBC is needed as a replacement for procedures of CH reinviting and registration of a new IP address at the SIP registrar server  A multilayer protocol strategy combining MIP and SIP Both MIP and SIP signaling and data flows are handled through home/foreign mobility servers (HMS/FMS)  Integrating the traditional MIP HA/FA and SIP home/foreign servers (HS/FS)  manage various addresses The HMS and FMS are optimized to minimize any functionality redundancy or signaling duplication between MIP and SIP

11 Overview of high-level strategies for VHO  Scheduling Although MIP alone can handle mobility for both real-time (RT) and non-real-time (NRT) traffic, we let it handle only NRT traffic, while SIP is charged with mobility management in case of RT traffic.

12 Performance Evaluation

13 Performance Evaluation

14 Performance Evaluation

15 Conclusion The article presents an innovative vertical handover solution for mobility management over hetero- geneous networks. We report the signaling messages flows and the timelines for various analyzed mobility protocols.

16 End