Heterogeneous Wireless Networks- Networking Protocol to Security

Heterogeneous wireless networks (HWNs) provide flexible and diversifiedwireless network access (e.g. cellular IEEE 802.11) by integrating cellular networkswireless LANs and ad hoc networks with the Internet. It has beenemerging as a promising solution to offer a variety of exciting applicationsanytime and anywhere. The flexibility and benefits of the HWN for exampleis to extend the service coverage of the existing cellular and WLAN infrastructureto improve the communication throughput and reduce packettransmission latency based on availability of different types of radio networkin the roaming area (cellular WLAN or others). In the study we answer somefundamental questions in the design and deployment of a HWN. The first ishow to effectively operate a mobile terminal in ad hoc mode to access theInternet through a cellular network WLAN or other underlying wireless accessnetworks. The second is how to design ubiquitous seamless mobility supportfor a roaming user allowing ubiquitous and bi-directional Internet accessibilityconnectivity and mobility. Finally it answers the questions that whatis the security threats for a mobile terminal that is operating in the ad hocmode and how to provide information confidentiality for a continuously movingmobile terminal.