A Novel Domain Re-organizing Algorithm for Network-Layer Mobility Management in 4G Networks Jianwen Huang, Ruijun Feng, Lei Liu, Mei Song, Junde Song Communications, Circuits and Systems, ICCCAS 2004 Date:2006/03/22 Reporter : Bor-Shyang Liang

Outline Introduction –Hierarchical Mobile IPv6 Management Motivation Domain Re-organizing Algorithm Simulation scenario and result analysis Conclusion

Introduction Network-Layer Mobility Management (NMM) combines the mobile communication technology and IP technology to form an enhanced mobility management for next generation All-IP wireless/mobile Internet. By extending Mobile IP protocol, the functions of hierarchical NMM is implemented.

Hierarchical Mobile IPv6 Management (HMIPv6) When high handoff frequently happens between two neighboring ARs, which are in the different domains respectively, it will cause a lot of inter-domain handoff signaling cost and delay.

Motivation How to adjust the network topology to against the fact that user mobility characteristics are always in changing?

Domain Re-organizing Algorithm Using real-time measurement to make different cells with highest handoff frequency into the same domain. –inter-domain handoff -> intra-domain handoff

Domain Re-organizing Scheme Whole Network –AN={a, b, c, d, e, f, g, …} Pre-planned MAP domain set –MN={(a, b, g, f), (d, e, h, i), (c, e, j, k),…} ={M 1, M 2, M 3, …} The set of neighbor cells of special cell –N(a)={b, c, d, e, f, g} Handoff times between cell i and cell j between t

Domain Re-organizing Scheme (Cont.) Tight neighbor cells –Assume |N(i)|=n i, cell j is not under the same MAP domain as cell i, HFi,j(t) > λ/ni (λ: weight factor) => j is one of the set N t (i) –N t (a)={e, d} Benefit gained form the algorithm –λ 1 : intra-handoff cost factor λ 2 : inter-handoff cost factor (λ 2 >= λ 1 ) cell j is not under the same domain as cell i

Domain Re-organizing Algorithm (Cont.) Assume N t (a) = {d,e} (HF a,d (t) > λ/6, HF a,e (t) > λ/6)

Domain Re-organizing Scheme (Cont.)

Simulation scenario Simulation –Tool : NS2 –Area : 400m x 400m –802.11b wireless AP : 7 –Radio transmission range : 100m –Cell overlap distance : 20m –Data Rate : 11Mb/s –Mobile Node :28 (MAP 1 MAP 2 :20) MAP –MAP1={1, 3}, MAP2={2, 5}, MAP3={4, 6, 7} –Connected with ARs Bandwidth = 10Mb/s, delay = 2ms HA connected with network –Bandwidth =100Mb/s, delay = 16ms

Signaling Cost v.s. Speed of MNs

Comparison of handoff delay before and after reorganizing scheme

Conclusion A good algorithm can make inter-handoff change to inter-handoff so that the signaling cost and handoff delay can be reduced. May frequent attachment process bring extra overhead to the network?