國立臺灣大學資訊工程學系Lin, Ching-JuChing-JuLinChou, Cheng-FuCheng-FuChou2006-09-272018-07-052006-09-272018-07-052004http://ntur.lib.ntu.edu.tw//handle/246246/20060927122912101416In traditional infrastructure-based IEEE 802.11 wireless LAN network, all the mobile nodes associated themselves with an access point (AP) share the same wireless channel with other mobile devices. In such wireless network environ-ment, there are two major inefficiencies: (a) load imbalance among different APs: when the distribution of the location of mobile nodes is non-uniform, this might result in a situ-ation where a lot of mobile nodes access a single AP and the rest of APs are idle, and (b) poor resource utilization: most of the mobile nodes contend for the wireless channels of APs while there are some unused and available wireless channels, which can be used to set up ad hoc groups. In this paper, we propose the hybrid WLAN (H-WLAN) framework to address these two problems. First, our H-WLAN frame-work provides the adaptive service selection module for the mobile node to figure out a better wireless channel and the server to get its service. Second, the popularity-aware chan-nel management module is able to efficiently integrate the ad hoc mode with the infrastructure mode by allowing mo-bile nodes to set up a new ad hoc group and then share their resources with other nodes within that group. The simula-tion results show that our H-WLAN framework can substan-tially (a) achieve high utilization and load balance among wireless channels with lower control overhead, and (b) pro-vide better quality of service for the mobile nodes. of the operation mode in WLAN is the infrastructure mode, where each mobile node associates itself with an ac-cess point (AP) within its direct transmission range. The AP is connected to a wired network and provides a conduit to the external network for the mobile nodes.application/pdf156504 bytesapplication/pdfzh-TWotherhttp://ntur.lib.ntu.edu.tw/bitstream/246246/20060927122912101416/1/04_mascots.pdf