Performance evaluation of IEEE 802.11 fast BSS transition algorithms

Multimedia services are becoming increasingly available over the wireless devices. Handover performance has a direct impact on user satisfaction from such services. The high transition delay can be unaccepted for the multimedia application or can be a source of disruption on the session. On the other side, IEEE 802.11 standard is being extended with new functionalities. Security and QoS features, included in recent IEEE 802.11-2007 standard, add management frames that are exchanged during the transition process. In consequence the handover delay is increased. IEEE 802.11r-2008 amendment introduces Fast BSS transition (FT) that simplifies the handover process. The authors propose the new handover algorithms based on FT protocol and compare them with existing algorithm. Additionally, simulation experiments are conducted to answer the question if multimedia services can be properly supported in IEEE 802.11r networks. The authors prove that handover delay can be reduced to 22 ms in the average case.