Vertical handover between HIPERLAN/2 and UMTS cellular system

HIPERLAN/2 (H/2) is a WLAN technology which could be used to complement 3G (UMTS) in hotspot areas, i.e. places where there will be an extraordinary demand for network capacity and bandwidth. WLAN is a relatively inexpensive and uncomplicated technology; hence it is a good investment. Integrating HIPERLAN/2 infrastructure in the 3G network should be taken by the operator as a good opportunity to provide high data rates to customers. WLAN technology will never be an alternative, but rather a complement, to UMTS. The paper presents the packet loss caused by the handover procedure to and from UMTS and HIPERLAN/2 systems in a tight interworking architecture under different link latencies and application data rates. It is shown that the handover latency from UMTS to H/2 is greater than that of H/2 to UMTS handover, where this has a direct influence on the number of data packets that do not get transmitted to the mobile user´s node.