1. A Handoff Architecture with Relay Agent in Nested Mobile Networks 1 Jae Kul Lee, 2 Choong Seon Hong 1,2 School of Electronics and Information, Kyung Hee University Korea 449-701 jaekul75@networking.kyunghee.ac.krjaekul75@networking.kyunghee.ac.kr, cshong@khu.ac.kr

2. Introduction The evolution of information technology has enabled a mobile object such as person, car, bus, train, airplane, or ship to carry a plethora of information device Although Mobile IPv6 can be considered as a solution for the problem, it does not support in the situation Routing is inefficient in nested mobile networks with several subnets This paper proposes an architecture and element to support packet routing for mobile networks

3. Packet Format of the Binding Update 081623 Option TypeOption Length A|H|R|D|P|Rervd Prefix LengthSequence Number Lifetime Sub-Options Table 1. Binding update option format 081623 Sub-Option TypeSub-Option LenPrefix Length MONET Prefix Table 2. MONET prefix sub-option

4. Operation of main components Correspondent node operation Checks validity of binding update Creates a new entry in binding cache Looks for entry corresponding to the destination address Home agent operation Checks validity of binding update Tunnels the packet to the CoA coincide with a prefix Mobile router operation Sends the prefix scope binding update to its HA Decapsulates packet and send packet to the original destination Sends prefix scope binding update to the original sender

5. Scenario of mobile network : : CN Stationary Network HAMR1 FR HAMR2 MR2 FR Mobile Network (e.g., Train) LFN1LFN2 MR1 Mobile Network (e.g., Person) Routing Table : Prefix2 -> MR2 Prefix3 -> MR2 Binding Cache : MR2 -> CoA MR2 Prefix2 -> CoA MR2 Prefix3 -> CoA MR2 : : Routing Table : Prefix1 -> MR1 Binding Cache : MR1 -> CoA MR1 Prefix1 -> CoA MR1 (1) (2) (4 ) (3 ) (5 ) Figure 1. Traditional nested mobile network

6. Handoff within the nested mobile network Figure 2. Handoff within the nested mobile network CN Stationary Network HA MR1 FR LFN1LFN2 MR1 FR MR2 FR HA MR2 Mobile Network (e.g., Train) : Routing Table : Prefix2 -> MR2 Prefix3 -> MR2 Binding Cache : MR2 -> CoA MR2 Prefix2 -> CoA MR2 Prefix3 -> CoA MR2 : Prefix 3 Prefix 2 Routing Table : Prefix1 -> MR1 Binding Cache : MR1 -> CoA MR1 Prefix1 -> CoA MR1 Prefix 1 FR

7. Proposed Architecture MRA(Mobile Relay Agent) Role Upon receiving a packet, the MRA set its address in this packet and relays it to next MRA or destination Manage cache to support for mobile node or networks Assignment MRA is dynamically assigned mobile router on the path when mobile node or router sends Binding Update massage to Home Agent

8. Operation scenario in proposed Architecture CN Stationary Network HAMR1 FR LFN1LFN2 MTA1 FR MTA2 FR HAMR2 Mobile Network (e.g., Train) Mobile Network (e.g., Person) : Routing Table : Prefix2 -> MR2 Prefix3 -> MR2 : (3) (4) (5 ) (6 ) Prefix 1 Prefix 3 Prefix 2 Binding Cache : MR1 -> CoA MTA1 Prefix1 -> CoA MTA1 (1 ) Routing Table : Prefix1 -> MR1 Binding Cache : MR1 -> CoA MTA2 Prefix1 -> CoA MTA2 (2) Binding Cache : MR2 -> CoA MTA2 Prefix2 -> CoA MTA2 Prefix3 -> CoA MTA2 Figure 3. Scenario in nested mobile network with MRA

9. Handoff in proposed Architecture Figure 4. Handoff within the nested mobile network

10. Simulation(1) Figure 5. Response time of HTTPFigure 6. Average of response time in the FTP download

11. Simulation(2) Figure 8. End-to-end of Video conference Figure 7. Response time of DB Query

12. Conclusion This paper proposes MRA that supports route optimization in the nested mobile network Mobile IPv6 with MRA allows top-level Router on a mobile network to directly communicate with CN The simulation corresponding to response time of HTTP, FTP, DB and end-to-end delay of video conference shows that the proposed method is much better than the existing one