**5. Conclusion**

10 Mobile Networks

Fig. 13. Average delay according to MS's speed (interactive traffic class)

Fig. 14. Average delay according to MS's speed (background traffic class)

Table 2. Summary of average delay according to MS's speed

Traffic class Handoff 20Km/h 40Km/h 60Km/h Conversational L3 0.495 0.743 1.485

Streaming L3 2.953 3.839 5.316

Interactive L3 5.829 8.743 17.487

Background L3 3.358 4.365 6.549

L2 0.335 0.537 1.117

L2 1.726 2.071 3.020

L2 2.459 3.689 8.608

L2 3.371 4.382 6.574

In this paper, we proposed a low-latency L2 handoff procedure between cdma2000 and WiBro which creates a promising next generation wireless network. Even though several efforts are actively in progress to improve mobility services based on Mobile IP, mobility services between different wireless networks, e.g., WiBro and cdma2000 still need more attention. From this viewpoint, we devise an L2 handoff scheme which can provide better performance compared with the L3 handoff. We also define required functionalities of each network element, ACR of WiBro, PDSN of cdma2000, and mobile station.

The proposed L2 handoff procedure does not require additional signaling messages to reduce packet loss which can occur in signaling L3 messages. However, in order to apply our scheme, the necessary functional change of network elements is inevitable. For completion, the detailed protocols above L3, e.g., session control remains to be further studied.
