{'fraction_non_alphanumeric': 0.01990521327014218, 'fraction_numerical': 0.0, 'mean_word_length': 5.478527607361963, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Study on the performance of spectrum mobility in cognitive wireless network

Current frequency allocation scheme results in poor spectrum utility. In some frequency bands, the spectrum may not be fully utilized either on geographical or at temporal level. In addition, on some hot spot business frequency bands, spectrum resources become in short supply. Many papers discuss the new spectrum management policies, and the focus is dynamic spectrum access (DSA) technology based on cognitive radio. However, spectrum mobility and spectrum handoff are new challenges for cognitive wireless networks. Little research addresses these fields now. In this paper, we discuss concepts of spectrum mobility/handoff and research probability models of spectrum holes and cognitive user¿s behavior. A time relationship model of spectrum handoff is proposed. We also research the impact of spectrum mobility and service duration of cognitive user on spectrum handoff probability. Finally, theoretical and simulation results of spectrum handoff probability are obtained.