###### Abstract  
With the growing demand, Wireless Multimedia Sensor Networks (WMSNs) play an increasingly important role, which enhances the capacity of typical Wireless Sensor Networks (WSNs). Additionally, integrating satellite systems into WMSNs brings about the beneficial synergy, especially in rural and sparsely populated areas. However, the available spectrum resource is scarce, which contradicts the high-speed content required for multimedia. Cognitive radio is a promising solution to address the conflict. In this context, we propose a novel spectrum-sharing method for the integrated wireless multimedia sensor and cognitive satellite network based on the dynamic frequency allocation. Specifically, the Low Earth Orbit (LEO) satellite system plays the role of the auxiliary to connect sensor nodes and the remote control host, and it shares the same frequency with the Geostationary Earth Orbit (GEO) system in the downlink. Because the altitudes of GEO and LEO satellites differ greatly, the beam size of GEO is much larger than that of LEO, which provides the opportunity for LEO beam to reuse the frequency that was allocated to the GEO beam. A keep-out region is defined to guarantee the spectral coexistence based on the interference analysis in the worst case. In addition, a dynamic frequency allocation algorithm is presented to deal with the dynamic configuration caused by the satellite motion. Numerical results demonstrate that the dynamic spectrum-sharing method can improve the throughput. cognitive radio; wireless multimedia sensor networks; spectrum-sharing; multibeam; dynamic frequency allocation +
Footnote †: journal: Journal of the Acoustical Society  
16 October 201810 November 201812 November 201812 November 201816 October 201810 November 201812 November 201 to WMSNs brings about a beneficial synergy in support of many scenarios, especially in rural and sparsely populated areas because of the inherent wide coverage and unrestricted geography [5]. Moreover, Low Earth Orbit (LEO) satellite constellation systems are attracting more attention because of almost the same delay as terrestrial communication systems and the revolutionary mass production of satellites [6]. The satellite-based sensor networks have been investigated for various application scenarios [7; 8; 9; 10]. Specifically, the architectures and applications of satellite-based WSNs and the roles of the satellite systems were studied in [4]. The work in [11] addressed four architectures of satellite-based WSNs and analyzed the performance of average end-to-end packet delay, packet loss rate and overall energy consumption. In addition, Reference [12] presented the model to evaluate the capacity of the remote sensor and satellite network and attempted to optimize the integrated wireless sensor and satellite network schedules. However, with increasingly many satellites launched into space, the available radio spectrum resource becomes scarce, which contradicts the high bandwidth required for satellite-based WMSNs. Currently, the spectrum resource is mainly allocated and coordinated by International Telecommunication Union (ITU) according to the service regions and categories, and the frequency for satellite is depleting [13]. Nevertheless, the spectrum-sharing method emerges as one of the most promising options for future networks, where different communication systems share the same spectrum. [PERSON] first proposed the concept of cognitive radio in 1999 [14]. With the usage of cognitive radio, the spectrum can be shared between heterogeneous systems, which brings an effective method for addressing the spectrum scarcity issue. It plays an important role in many fields of research, e.g., Internet of Things [15], cellular mobile communication [16], WiMAX [17], wireless sensor network [18], aeronautical communication [19], ad hoc network [20] and satellite communication [21].