We present an analytical model that enables a comparison of multiple design options of Opportunistic Spectrum Orthogonal Frequency Division Multiple Access (OS-OFDMA) . The model considers continuous and non-continuous subchannel allocation algorithms, as well as different ways to bond separate non-continuous frequency bands. Different user priorities and channel dwell times, for the Secondary Users and the Primary Users of the radio spectrum, are studied. Further, the model allows the inclusion of different types of Secondary User traffic. Finally, the model enables the study of multiple two-stage spectrum sensing algorithms. Analysis is based on a discrete time Markov chain model which allows for the computation of network characteristics such as the average throughput. From the analysis we conclude that OS-OFDMA with subchannel notching and channel bonding could provide , under certain network configurations, almost seven times higher throughput than the design without those options enabled .
We present an analytical model that enables throughput evaluation of Opportunistic Spectrum Orthogonal Frequency Division Multiple Access (OS-OFDMA) networks. The core feature of the model, based on a discrete time Markov chain, is the consideration of different channel and subchannel allocation strategies under different Primary and Secondary user types, traffic and priority levels. The analytical model also assesses the impact of different spectrum sensing strategies on the throughput of OS-OFDMA network. The analysis applies to the IEEE 802.22 standard, to evaluate the impact of two-stage spectrum sensing strategy and varying temporal activity of wireless microphones on the IEEE 802.22 throughput. Our study suggests that OS-OFDMA with subchannel notching and channel bonding could provide almost ten times higher throughput compared with the design without those options , when the activity and density of wireless microphones is very high. Furthermore, we confirm that OS-OFDMA implementation without subchannel notching, used in the IEEE 802.22, is able to support real-time and non-real-time quality of service classes, provided that wireless microphones temporal activity is moderate (with approximately one wireless microphone per 3,000 inhabitants with light urban population density and short duty cycles). Finally, two-stage spectrum sensing option improves OS-OFDMA throughput, provided that the length of spectrum sensing at every stage is optimized using our model .
R
a comparison of multiple design options of
throughput evaluation of
R
. The model considers continuous and non-continuous subchannel allocation algorithms, as well as different ways to bond separate non-continuous frequency bands. Different user priorities and channel dwell times, for the Secondary Users and the Primary Users of the radio spectrum, are studied. Further, the model allows the inclusion of different types of Secondary User traffic. Finally, the model enables the study of multiple
networks. The core feature of the model, based on a discrete time Markov chain, is the consideration of different channel and subchannel allocation strategies under different Primary and Secondary user types, traffic and priority levels. The analytical model also assesses the impact of different spectrum sensing strategies on the throughput of OS-OFDMA network. The analysis applies to the IEEE 802.22 standard, to evaluate the impact of
R
algorithms. Analysis is based on a discrete time Markov chain model which allows for the computation of network characteristics such as the average throughput. From the analysis we conclude
strategy and varying temporal activity of wireless microphones on the IEEE 802.22 throughput. Our study suggests
R
, under certain network configurations, almost seven
almost ten
R
than
compared with
R
enabled
, when the activity and density of wireless microphones is very high. Furthermore, we confirm that OS-OFDMA implementation without subchannel notching, used in the IEEE 802.22, is able to support real-time and non-real-time quality of service classes, provided that wireless microphones temporal activity is moderate (with approximately one wireless microphone per 3,000 inhabitants with light urban population density and short duty cycles). Finally, two-stage spectrum sensing option improves OS-OFDMA throughput, provided that the length of spectrum sensing at every stage is optimized using our model