WAIN: Wireless Ad Hoc in Infrastructure Network Ms.Yogeswari Muthusamy, Faculty of Information Science and Technology, Multimedia University, M5600076@mmu.edu.my Mr.Jaya Kumar Krishnan (Supervisor), Faculty of Information Science and Technology, Multimedia University, jayakumar@mmu.edu.my Abstract -Wireless Local Area Network (WLAN) has grown into a large and diverse field of research, which span from power control to privacy and security that can be operated in two modes: infrastructure and ad hoc mode. Coverage and capacity limitation in infrastructure network causes performance and throughput to degrade. As a step to overcome this crucial problem, ad hoc mode is integrated into infrastructure network. Such architecture, recognized as WAIN (Wireless Ad Hoc in Infrastructure Network) in this paper. WAIN eliminates one hop capabilities of infrastructure network to multihop. Besides, it allows users to make use of ad hoc connections to forward data to avoid congestion at Access Point (AP) which in return improves overall network capacity. In this paper, we propose duration based routing algorithm to route packets to the intended destination that enhances throughput and upgrades the overall network performance. Index Term - Multihop wireless LAN Infrastructure network,ad hoc. 1. INTRODUCTION An infrastructure mode wireless networking bridges a wireless network to a wired network via an Access Point (AP) that enables the wireless clients to access wired network services such as printer and Internet. Although, it offers a high data rate, the transmission range is anyhow limited to single hop; means the mobile nodes forward data packets to AP which in turn will forward the packet to desired destination without the intervention of intermediate nodes in forwarding packets. AP acts as the mediator between source and destination in forwarding packets. Single hop data transmission limits the network coverage to certain distance hence leads to network performance degradation. In order to overcome this limitation, ad hoc mode has been integrated in Wireless Infrastructure and Ad- Hoc Network Integration WIANI [1] to extend the network capacity to multihop thus improving coverage and reducing need of additional infrastructure. Packet transmission to neighboring nodes takes place when nodes knows its destination node with condition both attached to same AP. The capabilities of nodes to send packets among themselves with minimum aid from AP, significantly eliminates congestion at AP which improves network throughput. Besides, the network nodes that operate with low battery power may choose closer neighbor to forward packet than an AP. Hence, energy requirements for communication are properly managed. Communication between closer nodes also increases the received signal quality that allows the 802.11 protocol to operate at higher data rate [1].Wireless Ad Hoc in Infrastructure network (WAIN) is a model that is extended from WIANI [1] with a duration based routing protocol that improves the performance and quality of service in the network. The rest of the paper is organized as follows. The next section elaborates the overview of WAIN Architecture. In section 3 Duration Based Route Discovery is clearly explained. In section 4, we described on the route recovery process in WAIN. We then give an overview of our simulation environment and evaluate our strategies in Section 5. Related Work is discussed in section 6. Finally, conclusions are drawn and future work is discussed in Section 7. 2. OVERVIEW OF WAIN ARCHITECTURE The network is divided into communities which contain AP that connected to wired network and dynamically moving nodes which are connected in wireless mode as depicted in Figure 1.Therefore, it is mandatory for nodes to know AP that they are attached to and APs to know the nodes that they serve. In order to maintain route info in community which has nodes that dynamically moving, an AP-driven mechanism is deployed to periodically transmit beacons with a joining cost. The joining cost used by nodes that receives the beacon message to decide which community(AP) to be chosen as its community and lays a default route to the AP with 978-1-4244-2204-3/08/$25.00 ©2008 IEEE