# High Throughput and Acceptance Ratio Multipath Routing Algorithm in Cognitive Wireless Mesh Network
## 1 Introduction  
A Cognitive Wireless Mesh Network (CWMN) is a kind of Wireless Mesh Network (WMN) that uses Cognitive Radio (CR) [1]. CWMN uses CR technology to sense the spectrum and to share spectrum resources [2]. A CR-Mesh node (such as a CR-Mesh gateway, a CR-Mesh router, or a CR-Mesh client) integrates CR technology, can sense the spectrum that Primary Users (PUs) are not using and access the vacancy spectrum resources, and improve the spectrum utilization and end-to-end network performance, and are called Secondary Users (SUs). The PU has a higher usage priority for the authorized (licensed) spectrum (channel). Once the PU needs to re-occupy the authorized channel, then the SU must unconditionally quit the occupied channel, which causes the link to be interrupted. Multipath routing is an effective technique used to solve the link failure problem. The research results on the routing problem in the WMNs cannot be directly applied to CWMNs [3, 4]. Some research results on the routing problem in the CWMNs were obtained from References [5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18]. A problem-solving framework based on economics with the goal of network profit maximization was proposed by [PERSON] et al. [6]. Aiming to minimize the end-to-end delay for the joint optimization of routing and resource allocation problem, the problem was formulated as a nonlinear integer programming problem. The Lagrange dual method was proposed based on a distributed solution in CWMN by [PERSON] et al. [7], and a novel opportunistic spectrum aware routing in the CWMNs was proposed by [PERSON] [8], which allowed for the CR users to effectively occupy the spectrumband depending on the spectrum availability, and to also perform dynamic channel switching for performance optimization. The throughput maximization problem in the CVMNs in combination with power control, channel allocation, and routing under the Signal to Interference plus Noise Ratio (SINR) model was studied by [PERSON] [9]. Furthermore, a decision theory framework was used to model the problem of routing under the uncertainties involved in a cognitive radio network by [PERSON] [10]. A utility function was designed to capture the effect of spectrum measurement, fluctuation of bandwidth availability, and path quality, and the authors investigated how to jointly optimize the route setup and channel assignment. An integrated data transmission cost to quantitatively measure the communication quality of links was proposed by [PERSON] [11]. Spectrum-mobility-incurred route-switching problems in both the spatial and frequency domains for CRNs was investigated by [PERSON] [12], where spatial switching determined which relays and links should be reselected, and the frequency switching decided which channels ought to be reassigned to the spatial routes. A geographic routing protocol for cognitive radio mobile ad hoc networks (TIGHT) was proposed by [PERSON] [13]. TIGHT offered three routing modes and allowed for secondary users to fully explore the transmission opportunities over a primary channel without affecting the primary users (PUs). A spectrum aggregation-based cooperative routing protocol, termed as SACRP, was proposed by [PERSON] [14] to provide higher energy efficiency, improve throughput, and reduce network delay. A routing metric, including link security, link conflict, link reliability, and link available bandwidth was proposed by [PERSON] [15]. The SIEB (link Security, link conflct, link rEliability, and link available Bandwidth) included the two aspects of link security and link performance. To resist various hole attacks, the link trust value based on two hop neighbor feedback was computed in the link security weight computing of SIEB. The problem of routing in Cognitive Radio Ad Hoc Networks (CRAHNs) is that it targets the creation and maintenance of the wireless multi-hop paths among the cognitive nodes by deciding both the spectrum to be used and the relay nodes of the path.