General IP Based Mobility Mechanisms Belghoul Farouk Christain

General IP Based Mobility Mechanisms Belghoul Farouk Christain Bonnet Yan Moret

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

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) 3

Mobile IPv 4, a first proposal Home Agent Correspondent node Home network Internet 1. Connection and foreign agent discovery 2. FA attributes Co. A 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 4

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 5

Mobile IPv 4, handover Steps Dmip = + MIP 4+ MIP 4 Tmip = TCN, HA+THA, AR+Tradio 6

Mobile IPv 6 Correspondent node Home Agent 2 3 Home network Internet 2 1. MN Connection , Co. A auto-configuration Access Router 2. MN registers its COA with both HA and its CNs. 1 MN CN Binding update avoids triangular routing. No tunneling on MIPv 6. Address stateless auto configuration : suppression of FAs Ipv 6 : enough IP addresses available. Long handoff delay, 7

Mobile IPv 6 8

Fast Handover Reduces the handoff delay. Predicts L 2 handover to anticipate L 3 handover 9

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

Fast handover , data transmission 11

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 12

Mobile-IPv 6 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. IPv 6 Soft handover Solution coexist with MIPv 6 and can allows high level of Qo. S for realtime application. 13

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

Mobile registration process Each mobile is defined by one or more Care of Address Co. A. PCo. A private Co. A is used within MIPv 6. LCo. A are local addresses, used to define Mobile multiples connections. D&M agent associate PCo. A with LCo. As in order to duplicate MN designated packets. The Mobile also duplicate packets to send them throw its multiples ARs to its CN. 15

Duplication Process Duplication & Merging agent intercepts all IP packets sent to the MN Extracts destination PCo. A, and uses registered corresponding MN LCo. As to duplicate MN designated packets via different Access Routers. Duplicated packets have LCo. As 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. 16

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 LCo. A 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. 17

Soft Handover Process TLC PCo. A LCo. A 1 LCo. A 2 System closes First MN connection (MN, PCo. A) HA D&M Tunel 2 LCo. A 1 IP radio AR 1 AR 2 IP radio LCo. A 2 Merging process deactivated PCo. A MN 18

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 IPv 6 to initiate the handover. Primary threshold (P_SH) is higher threshold, it is used in soft handover to initiate the secondary interface connection process. 19

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 1 st packet arrives faster and 2 nd packet is destroyed – Divides by 2 the probability to loose a packet 20

Where do we place D&M Agent? In any conventional router located within the data path in the IPv 6 network Preferably located at a median position along the data communication path, between AR 1 and AR 2 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. 21

Hierarchical topology of D&M Agents 22

Simulation model CN Application UDP : emission debit 1 mb/s 2001: : fa: : 1 Virtual network D&M agent 2001: : fa: : 2 R 1 Virtual network 2001: : E 1 2001: : E 0 2001: : E 2 HA R 2 R 8 802. 11 11 Mb/s R 9 Ra Rb Rc Rd Re Rf 100 m Application UDP : reception We Implement Mobile. IPv 6 with Soft and fast handover in Gemini 2, a home made simulator Radio technology: IEEE 802. 11 b , at 11 mb/s 23

Simulations Results, delays and jitters 24

Simulations Results, throughput 25

Prototype Implementation In Linux Kernel 2. 4. 19 Based on MIPL 0. 9. 3. Mobile with two WLAN IEEE 802. 11 interfaces. Support of Basic Mipv 6 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. 26

Testbed 27

Testbed 2 28

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 MIPv 6 micro mobility (Transparency of the MN’s mobility to CNs and HA). Reduces the « ping-pong effect » Cohabite this solution with Qo. S mechanisms. . ? Introduce Checksum to reconstruct two erroneous duplicated packets…. ? 29

Related Publication “Eurecom IPv 6 soft handover “, ICWN 2003, International Conference on Wireless Networks- June 23 rd - 26 th, 2003 - Las Vegas, USA. “IP-based handover management over heterogeneous wireless networks “, LCN 2003, 28 th 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 MIPv 6 Soft handover » , World Wireless Congress SANFRANCISCO, USA 2004 « Performance comparison and analysis on MIPv 6, fast MIPv 6 bi-casting and Eurecom IPv 6 soft handover IEEE 802. 11 b » IEEE VTC, MILAN 2004. “Performance analysis on IP- based soft handover across ALL-IP wireless networks » IWUC, PORTO, Portugal 2004 30