## 9 Related Works  
In the early routing mechanisms which take network coding as the core, the implementation of network coding and the route selection were separated from each other. The path-given network coding algorithms were always adopted. In this kind of algorithm, coding opportunities are found by identifying the nodes that different data streams pass through in given routes and coding is implemented at these nodes. With the deep study of network coding, more coding opportunities can be created by dynamically adjusting routes.  
Subsequently, many coding algorithms based on dynamically adjusting routes appear. They are mainly based on COPE scheme [12]. COPE constructs a network coding architecture under a given routing mechanism, whose main idea is to raise the amount of information of a forwarded packet. A router selects those packets that can be encoded together and \"merges\" the packets from different source nodes into a big one and sends it out.  
In the COPE scheme, seeking network coding opportunities is mainly focused on. It requires that a node can perform a coding operation just when the node has an \"X\" or \"Alice-Bob\" structure coding opportunity, otherwise, COPE is as the same as a traditional routing mechanism.  
Based on COPE, many researchers gave more detailed discussions on the coding method of path dynamic adjustment under different environments and backgrounds [8; 22; 23; 24; 25].  
[PERSON], [PERSON] et al. [23] proposed a routing selection method based on COPE, which designed a routing mechanism to promote network coding opportunities by discussing the constraints of different transmission rates and bandwidths in a network.  
[PERSON], [PERSON] et al. [8] built a throughput theory model by considering various transmission rates in a wireless network. By calculating the maximum throughput of unicast transmission, this approach controls routing selection and balances network coding opportunities with the use of high-rate links.  
NCR [14], a routing strategy for wireless network environments, was put forward by [PERSON] in MIT. For random and nonrandom monitoring modes, from a theoretical point of view, [14] analysed how to optimize the traffic in a wireless network using COPE. Different transmission rates are taken into account in particular in this strategy. However, this approach, as the same as the mentions in [8; 23], also requires that in a wireless network, all the links have the same transmission success rate and there is the same transmission success rate in two directions of a link.  
For an actual wireless network where there are various transmission success rates on all the links and different transmission success rates in two directions of a link, this paper proposes a new approach, ANCR, based on NCR, which can get more coding opportunities by dynamically adjusting routes in a real network. Different from NCR and the other previous approaches, by considering the various transmission success rates of different links and the different transmission success rate in two directions of a link, ANCR makes routing decisions to increase coding opportunities and decrease the total number of transmission. Further, because the total number of transmission becomes less, the network delay and energy consumption reduce and the network throughput is improved.