# High Throughput and Acceptance Ratio Multipath Routing Algorithm in Cognitive Wireless Mesh Network
## 1 Introduction
A cognitive cross-layer multipath probabilistic routing was therefore proposed by [PERSON] [16]. A spectrum aware on-demand routing protocol, which focused on reliable routing and considered opportunistic spectrum, link disruption, as well as node failure, was proposed by [PERSON] [17]. A route selection metric for multipath routing in cognitive networks was also proposed by [PERSON] [18]. Route closeness, the proposed metric, favors routes that are not close to each other, therefore, selecting non-close routes makes them less vulnerable to the activities of the PUs as it would be less possible for an active mobile PU to interrupt all of the routes at the same time. When the PU node needs to access the channel, the SU node must quit the occupied authorized channel, which will cause link failure and the throughput to decrease. Multipath routing can effectively solve the link failure in CVMNs and improve network throughput. In contrast, this paper differs from the existing research as it not only uses multipath to improve network throughput, but it also saves the network resources that are based on channel interference and a reusability strategy in the construction of multipath, which can further improve network throughput. In this paper, the motivations based on the channel interference and reusability strategy is as follows:  
1. The primary and backup paths that are configured for the wireless request are not transmitted at the same time, therefore, a link with the higher primary path interference degree is included when constructing a backup path. The higher the degree of interference, then the higher the priority to be selected as the backup path. 2. The probability that the primary path of two wireless requests with the same backup path (or backup link) emerges as a link failure at the same time is relatively low. Therefore, a wireless link with the interference of multiple wireless requests is included for constructing the backup path. The link with the highest reuse degree, which is selected as the backup path, has a higher priority. This paper offers the following innovations when compared to the existing research. (1) The problem of multi-path routing and spectrum allocation based on channel interference and reusability with the Quality of Service (QoS) constraints is investigated, with the goal of improving the network throughput and the acceptance ratio of wireless requests. For each new arriving wireless request, a primary path and a backup path are constructed simultaneously. The differences between the available channels are considered, which means that different channels have different bandwidths; (2) Based on the characteristics of the primary and the backup path that are not transmitted simultaneously, when the backup path is constructed, the link with a higher interference to the primary path and with a higher reuse degree has a higher priority selected for constructing the backup path. This can save the use of network resources, and improve the acceptance ratio of wireless requests and network throughput; (3) A multi-path routing and spectrum allocation algorithm (MRIR) with QoS constraints is proposed based on channel interference and reusability, which contains the primary path construction and spectrum allocation algorithm, as well as the backup path configuration and spectrum allocation algorithm. The remainder of the paper is organized as follows. We discuss the network model and problem description in Section 2. The proposed multipath routing and spectrum allocation algorithm MRIR is presented in Section 3. Sections 4 and 5 present the primary path construction and spectrum allocation algorithm and the backup path configuration and spectrum allocation algorithm, respectively. Simulations comparing the performance of the proposed algorithms are presented in Section 6. Section 7 concludes the paper and outlines our future work.