Swimming seamless and efficient wi fi based internet access from moving vehicles
- 1. SWIMMING: Seamless and Efficient WiFi-Based Internet Access from Moving Vehicles Abstract: Demand for Internet access from moving vehicles has been rapidly growing. Meanwhile, the overloading issue of cellular networks is escalating due to mobile data explosion. Thus, WiFi networks are considered as a promising technology to offload cellular networks. However, there pose many challenging problems in highly dynamic vehicular environments for WiFi networks. For example, connections are easily disrupted by frequent handoffs between access points (APs). A scheme, called SWIMMING, is proposed to support seamless and efficient WiFi-based Internet access for moving vehicles. In uplink, SWIMMING operates in a “group unicast” manner. All APs are configured with the same MAC and IP addresses, so that packets sent from a client can be received by multiple APs within its transmission range. Unlike broadcast or monitor mode, group unicast exploits the diversity of multiple APs, while keeping all the advantages of unicast. To avoid possible collisions of ACKs from different APs, the conventional ACK decoding mechanism is enhanced with an ACK detection function. In downlink, a packet destined for a client is first pushed to a group of APs through multicast. This AP group is maintained dynamically to follow the moving client. The packet is
- 2. then fetched by the client. With the above innovative design, SWIMMING achieves seamless roaming with reliable link, high throughput, and low packet loss. Testbed implementation and experiments are conducted to validate the effectiveness of the ACK detection function. Extensive simulations are carried out to evaluate the performance of SWIMMING. Experimental results show that SWIMMING outperforms existing schemes remarkably. Existing System: First, channel condition in a vehicular environment is usually harsh owing to severe multi-path fading, interference and noise, which results in high packet loss rate. Second, since clients move at a vehicular speed, it is extremely difficult for a client to always be associate with the most appropriate AP. Third, due to the limited coverage of each single AP, the clients suffers from frequent connection disruptions caused by handoffs and reassociations. Proposed System: We propose a solution, referred to as SWIMMING, to support seamless and efficient WiFibased Internet access from moving vehicles. In SWIMMING, a group of APs are employed to communicate with a client (called “AP diversity”), and the transmission succeeds if any AP in the group accomplishes the delivery with the client (called “opportunistic transmission”). Such AP diversity and opportunistic transmission are exploited to overcome the high packet loss rate, which is achieved by configuring. Hardware Requirements:
- 3. • System : Pentium IV 2.4 GHz. • Hard Disk : 40 GB. • Floppy Drive : 1.44 Mb. • Monitor : 15 VGA Colour. • Mouse : Logitech. • RAM : 256 Mb. Software Requirements: • Operating system : - Windows XP. • Front End : - JSP • Back End : - SQL Server Software Requirements: • Operating system : - Windows XP. • Front End : - .Net • Back End : - SQL Server