It is well understood that in wireless networks, channel failures, which are typically caused by equipment or power failures as well as intrinsic features in radio transmissions, such as fading and shadowing, can easily result in network performance degradation. Therefore, fast recovery from channel failures is an important measure that should be incorporated with those networks. Consequently, in a cognitive radio network (CRN), channel failures can cause significant performance degradation in both primary and secondary networks. Instead, retainability, i.e., the capability of providing continuous connection for users must be guaranteed even if a significant network element is disrupted. In this paper, we develop an analytical model to analyze the system performance of CRNs with a focus on random channel failures. In addition to performance analysis under channel failures, a channel reservation scheme is proposed. The scheme can be adopted in dynamic channel access strategies in order to prioritize ongoing sessions over new user requests. Furthermore, optimal channel reservations subject to different performance requirements are also studied.
['Indika A. M. Balapuwaduge', 'Frank Y. Li', 'Vicent Pla']
Significance of channel failures on network performance in CRNs with reserved spectrum