**5. References**


**1. Introduction**

**0**

**3**

**A Fast Handover Scheme for WiBro and**

The continuous development of wireless communication technologies yields diverse wireless networks that are widely deployed and successfully serviced according to their communication capabilities. Representative examples are cellular networks (e.g., cdma2000 and UMTS) capable of wide-area coverage and WLAN (Wireless LAN) efficiently used in public hot spots. WLAN and cellular network are complementary technologies. WLAN has several advantages over cellular networks, including higher data rate and lower operating and equipment costs. However, their coverage is typically limited to corporate buildings, residence, and certain public hot spots. On the other hand, cellular networks provide wide-area coverage but at lower speeds and much higher cost. It is indispensably required to integrate WLAN and cellular networks to serve users who need both high-speed wireless

Integrating heterogeneous networks reveals a lot of difficulties due to their different system specifications, standardization, and service scopes. For this reason, most of research work (3GPP, 2003; Ahmavaara et al., 2003; Buddhikot et al., 2003; Luo et al., 2003) are focused on interworking mechanism between network elements rather than integrating whole network architectures. Recently, with the intention of overcoming the limitation of existing wireless networks, new wireless communication service, WiBro is being deployed in Korea. WiBro is based on IEEE 802.16e (IEEE, 2001; Koffman & Roman, 2002) and is similar with Mobile WiMAX (Forum, n.d.). It is expected to provide enough mobility (60km/h) and higher data rate (50Mbps). So the study of the integration between WiBro and cdma2000 will give better

In order to provide seamless services across heterogeneous wireless networks, efficient handoff procedure as well as flexible integrated network architecture is essentially required. As for handoff procedure, it is possible to use Mobile IP (Perkins, 2002) which is generally used in for homogeneous network or its extended version, so called low-latency handoff which tends to reduce packet loss and delay during the handoff (Maki, 2004). However, since these handoff procedures exploit L3 (layer 3) signaling messages, they have a problem that packet loss and delay can occur while processing L3 messages. In this paper, we propose an efficient L2 (layer 2) handoff scheme between cdma2000 and WiBro networks. The proposed L2 handoff scheme takes advantages over the existing L3 handoff scheme because it exploits L2 messages instead of L3 messages. We show the efficiency of our proposed L2 handoff

effects than the existing works of the integration between WLAN and cdma2000.

access as well as wide-area connectivity (Salkintzis, 2004).

through extensive computer simulations.

Choongyong Shin, Seokhoon Kim and Jinsung Cho

**cdma2000 Networks**

*Kyung Hee University*

*South Korea*

