A case study: IEEE 802.21 enabled mobile terminals for optimized WLAN/3G handovers

Wireless LAN hotspots are becoming widely spread. This, combined with the availability of new multi-mode terminals integrating heterogeneous technologies, opens new business opportunities for Mobile Operators. Scenarios in which 3G coverage is complemented by Wireless LAN deployments are becoming available. Therefore all IP based networks are ready to offer a new variety of services across heterogeneous access. However, to achieve this, some aspects still need to be analyzed. In particular, how and when to execute handovers in order to minimize service interruptions and maximize the use of the most appropriate technologies according to user’s preferences (for example, a user may prefer to use a lower cost technology if available). This paper presents a simulation study of handover performance between 3G and Wireless LAN access networks. The mobile devices are based on the IEEE 802.21 cross layer architecture and use Wireless LAN signal level thresholds as handover criteria.