With the wide deployment of wireless local area networks (WLANs), the problem of configuration and maintenance of access points (APs) arises. The traditional manual configuration method greatly increases the cost of configuration and maintenance of the WLANs system and hinders the scalability of WLANs. The plug-and-play (PnP) of APs, which means that APs auto-configure themselves based on the network environment, is a good solution to this problem. The PnP of APs can reduce both the complexity and cost of configuration and maintenance for WLANs and also improve the system performance. The selection of working mode and channel is one of the major challenges for the PnP of multi-mode APs. In this paper, we propose a mode and channel selection scheme that combines analytic hierarchy process (AHP) with grey relational analysis (GRA). The goal of our proposed scheme is to select the most suitable mode and channel for multi-mode AP to improve the performance of WLANs and offer better service to users. In the proposed scheme, AHP is responsible for deciding the weights of criteria factors according to their contributions to the final goal. GRA combines the weights of criteria factors with the values of criteria factors to rank all alternative modes and channels combination and make a decision. It is seen from the simulation results that our proposed scheme can select the most suitable working mode and channel for AP in different scenarios.

To overcome the disadvantage in traditional manual configuration method for WLANs, such as the high configuration and maintenance cost and low efficiency of system performance, we propose the plug-and-play (PnP) of multi-mode APs that APs auto-configure themselves based on the network environment. In order to implement the PnP, the Multi-mode AP must obtain its neighboring APs' configuration and environment information. Existing neighboring APs discovery method can not provide the precise neighboring APs information to satisfy the requirement of PnP of AP. In this paper, we propose three kinds of neighboring AP discovery and information exchange methods, which are passive discovery method, active discovery method and station assistant discovery method. Using these three neighboring AP discovery methods, AP can discover all neighboring APs and obtain needed information. We further propose two whole process flows, which combine three discovery methods in different manner, to achieve different goal. One process flow is to discover the neighboring AP as fast as possible, called fast discovery process flow. Another one is to discover the neighboring AP with minimal interference to neighboring APs, called the minimal interference process flow. The efficiency of the two process flows is shown in the simulation results.

To provide mobile users with seamless wireless access and guaranteed quality of service (QoS) anywhere and anytime, it is a trend to integrate CDMA cellular networks and wireless local area networks (WLANs) into heterogeneous networks in next generation all-IP wireless networks. Network selection and QoS support for different services are two of the major challenges in integrated CDMA cellular/WLAN networks. In this paper, a net utility-based network selection scheme was proposed, which takes into account the network resource, QoS requirements of applications, user mobility, and vertical handoff. The goal of the proposed scheme is to guide users to select the most suitable access network, where the users' QoS requirements can be satisfied and the cost that user paid for is the lowest. Simulation results demonstrate the effectiveness of the proposed network selection scheme in integrated CDMA cellular/WLAN networks.