Measurement of management and data frames in IEEE802.11x to model new (QoS) trigger for vertical handover initialization

Rapid growth in mobile broadband wireless networks invoked the next generation networks (NGN) to integrate heterogeneous networks (WLAN/ WiMAX/ WiPAN/ UMTS) i.e. having individual coverage and capacity covering hotspots with high data rates and mobile cellular systems with full coverage. To attain seamless transfer of an ongoing session in NGN, we need an optimized vertical handover (VHO) i.e. handover between two different air-interface standards. We have some VHO decision algorithm which helps in network selection during VHO like SAW, MEW, GRA, TOPSIS and etc. These decision algorithms are based on certain quality of service (QoS) metrics include bandwidth, jitter, BER, delay. It is very important to know how these metrics have been measured. Based on this parameter-measurement, a decision has to be made to execute VHO. This paper investigates performance characteristic measurements of PHY and MAC layer in IEEE802.11x i.e. baseband measurements in terms NAV and EVM for data and management frames. Finally, EVM is introduced as a new trigger to initiate VHO. This paper is supported by simulated experimental results to propose a new QoS trigger. This trigger initiates a new session to execute a VHO. Suggestions are accompanied with this paper for improvement in modulation schemes for network selection criteria for emerging WLAN technology.