An Expedited WiFi Connection Establishment Scheme for Railroad Wireless Communications

Always on Internet service has become norm and people are able to enjoy anytime, anywhere broadband wireless communication services. With the emergence of smart phone and tablet, wireless network traffic has increased exponentially. Wireless network traffic is expected to continuously increase dramatically as more and more communication capable multimedia devices are expected to be connected to wireless network. In order to offload heavy traffic of cellular network, WiFi has chosen since WiFi normally operates in license exempt bands. 3rd Generation Partnership Program (3GPP) has started study item on 3GPPWiFi interworking in order to alleviate heavy traffic problem. Since WiFi is independent and different wireless technology, 3GPP needs to be specially designed to provide seamless and high quality interworking with WiFi. Long Term Evolution (LTE)-WiFi interworking has a technical challenge of WiFi network detection. A good solution should provide not only fast WiFi network detection but also battery power saving of mobile phones. In this paper, we propose LTE and WiFi interworking scheme for railroad wireless communication. Our solution is able to provide both expedited WiFi connection establishment and battery power saving by exploiting unique characteristics of railroad communication.