General IP Based Mobility Mechanisms

1. General IP Based Mobility Mechanisms Belghoul Farouk Christain Bonnet Yan Moret

2. Introduction • Today Many Heterogeneous Radio Access Technologies coexist • Typically They are not compatible with each others • Internet Protocol as Common network layer • 4th Generation, ALL-IP wireless and Wireline network

3. IP Mobility Management, definition • Goal: Continuous TCP or UDP connection even MN moves causes IP address changes • MN move to change its point of attachment and reminds in the network • MN can change its point of attachment and the network in the same time • Mobile IP process • Location management..?? • IP address is key that defines the Node and its location • Handover management ( next slide)

4. Mobile IPv4, a first proposal Home Agent Home network Correspondentnode Internet 1. Connection and foreign agent discovery 2. FA attributes CoA to MN 3. MN registers its COA with HA. 3 Foreign Agent Foreign network Access Router 1 2 MN • Triangular routing • Control traffic load in network • No specify handover management mechanisms

5. IP Handover • Important issue in mobility management • Efficient way to Manage MN roaming from its Old Access point to the new one. • Handoff management, caused by • signal strength deterioration • user mobility

6. Mobile IPv4, handover Steps • Dmip = + MIP4+ MIP4 • Tmip = TCN,HA+THA,AR+Tradio

7. Mobile IPv6 Correspondent node Home Agent Home network 2 Internet 3 2 1. MN Connection , CoA auto-configuration 2. MN registers its COA with both HA and its CNs. Access Router 1 MN • CN Binding update avoids triangular routing. • No tunneling on MIPv6. • Address stateless auto configuration : suppression of FAs • Ipv6 : enough IP addresses available. • Long handoff delay,

8. Mobile IPv6

9. Fast Handover • Reduces the handoff delay. • Predicts L2 handover to anticipate L3 handover

10. Fast handover Fast handover, bicasting 5a. Packets forwarding OAR NAR Agent solicitation/advertisement 2. MN initiates Fast handovers RtSolPr 3. OAR send PrRtAdv: NAR Subnet @ the MN 7. Packets sent to mobile 6. Informs its arrival and start registration process 4. FBU 1.MN receives L2 triggers to initiate handover 5b. MN changes AR • Reduces the handoff latency • New L3 Care-of address establishment before the L2 movement • It is based on L2 triggers ( L2 triggers: information on MN L2 connection)

11. Fast handover , data transmission

12. Fast handover, • Disadvantages: • Fast Handoff aims to reduce the handoff latency by using interaction between the radio and IP layers to detect the mobile movements. This can work only if the radio technology allows such interaction between layers.( its not solution for heterogenous wireless network) • The packet loss during the handover is  * Thp. • The handoff process performances, depend of wireless network Radio technologies, it can make problems when mobile node perform roaming between heterogeneous network

13. Mobile-IPv6 Soft handover, • In order to manage Efficiency mobility across heterogeneous radio access technologies • The development of Mobile devices with multiple physical or software-defined interfaces is expected to allow users to switch between different radio accesses technologies • In the border of coverage Area, Soft handover allows to improve the low signal level in wireless part of the network by the duplication and the merging of data in IP layer through more than one AR asynchronously, in uplink and downlink. • IPv6 Soft handover Solution coexist with MIPv6 and can allows high level of QoS for real- time application.

14. SHO main process • Registration process • Duplication Process • Merging Process • Handover process

15. Mobile registration process • Each mobile is defined by one or more Care of Address CoA. • PCoA private CoA is used within MIPv6. • LCoA are local addresses, used to define Mobile multiples connections. • D&M agent associate PCoA with LCoAs in order to duplicate MN designated packets. • The Mobile also duplicate packets to send them throw its multiples ARs to its CN.

16. Duplication Process • Duplication & Merging agent intercepts all IP packets sent to the MN • Extracts destination PCoA, and uses registered corresponding MN LCoAs to duplicate MN designated packets via different Access Routers. • Duplicated packets have LCoAs as new destination address . • Insertion of merging and control information in all duplicated packets with a sequence number in each packet. • Each duplicated packets had the same sequence number and same sender IP address . • The MN does the same thing with uplink streams.

17. Merging Process • Need to filter duplicated packets at MN and D&M • DIO information of received packet are saved in MCT table ( merging control table) • MCT table located in MN and D&M, it defines for each correspondent, its LCoA and serial numbers of expected IP packets. • At the reception of packet, If the DIO is included and source address has an entry in MCT, and its serial number is not expected in MCT table The packet is discard. • First received packet among duplicated packets, is routed to upper layer.

18. TLC System closes First MN connection Merging process deactivated Soft Handover Process PCoA LCoA1 LCoA2 (MN, PCoA) HA D&M Tunel 2 AR2 IP AR1 IP radio LCoA1 radio LCoA2 PCoA MN

19. Handover Process interface priority choice is dynamic • the primary interface is always the interface with the best connection quality • The secondary interface is used to perform the handover and avoid signal strength degradation if possible • Two signal strength thresholds are defined. Handover threshold (H_SH), is the threshold used in mobile IPv6 to initiate the handover. Primary threshold (P_SH) is higher threshold, it is used in soft handover to initiate the secondary interface connection process.

20. Advantages of the approach (uplink - downlink) • Uplink • Not covered by FHO bi-casting • Downlink • If more than one link interface • D&M covers the low signal level period plus the handover period. • We have 2 chances to receive a packet • Reduces jitter as 1st packet arrives faster and 2nd packet is destroyed • Divides by 2 the probability to loose a packet

21. Where do we place D&M Agent? • In any conventional router located within the data path in the IPv6 network • Preferably located at a median position along the data communication path, between AR1 and AR2 and CN. • Could be located in Access Routers. • Possibility to distribute the load between several D&M Agents organized in a multilevel hierarchical architecture (see next slide) • APs broadcast the address of their D&M agent using RADV.

22. Hierarchical topology of D&M Agents

23. Simulation model CN Application UDP :emission debit 1 mb/s 2001::fa::2 • We Implement MobileIPv6 with Soft and fast handover in Gemini2, a home made simulator • Radio technology: IEEE802.11b , at 11mb/s 2001::fa::1 R1 Virtual network 2001::E1 Virtual network 2001::E2 D&M agent 2001::E0 HA R2 802.11 11Mb/s Rb Rc R8 R9 Ra Rd Re Rf 100 m Application UDP :reception

24. Simulations Results, delays and jitters

25. Simulations Results, throughput

26. Prototype Implementation • In Linux Kernel 2.4.19 Based on MIPL 0.9.3. • Mobile with two WLAN IEEE802.11 interfaces. • Support of Basic Mipv6 handover and Soft Handover • A modified RADVD to dynamically broadcast the presence and the address of D&M agent in the visited network. • A support of Multiple DM agent without Hierarchical architecture.

27. Testbed

28. Testbed2

29. Conclusion and future work • Solution to manage pure IP mobility in heterogonous network • no handoff effects on real time application • Improves wireless connexion in overlapping region • Improves MIPv6 micro mobility (Transparency of the MN’s mobility to CNs and HA). • Reduces the « ping-pong effect » • Cohabite this solution with QoS mechanisms..? • Introduce Checksum to reconstruct two erroneous duplicated packets….?

30. Related Publication • “Eurecom IPv6 soft handover “, ICWN 2003, International Conference on Wireless Networks- June 23rd - 26th, 2003 - Las Vegas, USA. • “IP-based handover management over heterogeneous wireless networks “, LCN 2003, 28th Annual IEEE Conference on Local Computer Networks, October 20-24, 2003, Bonn, Germany. • Journal paper : “Mécanismes de handover pour les réseaux IP sans-fil’ to appear in Technique et Sciences Informatiques, Revue des sciences et technologies de l'information.( TSI journal) . To appear in January 2005. • “A Multilevel Hierarchical topology of DM agents for MIPv6 Soft handover »,   World Wireless Congress  SANFRANCISCO, USA 2004 •  « Performance comparison and analysis on MIPv6, fast MIPv6 bi-casting and Eurecom IPv6 soft handover over IEEE802.11b »     IEEE VTC, MILAN 2004 . • “Performance analysis on IP- based soft handover across ALL-IP wireless networks »   IWUC, PORTO, Portugal 2004