Implementation and evaluation of autonomous collaborative discovery of neighboring networks

Emerging mobile devices often want to discover neighboring networks in real time. For example, a mobile may want to know the capabilities of the surrounding WiFi networks so that it can inteliigently determine which one to use next and avoid wasting scarce battery power io attempt to connect the wrong networks. Knowing the address of the authentication server in a neighboring network may allow a mobile device to authenticate with the neighboring network while the device is still using the current network to transport its user traffic, even before the device detects the radio signal from the neighboring network. The Internet Engineering Task Force (IETF) is developing a Candidate Access Router Discovery (CARD) protocol for a mobile device to discover the address and capabilities of access routers in a neighboring aehnork. However, it requires all neighboring access routers to implement CARD and to dynamically exchange network information with each other and with the mobiles, which is diffkult to implement especially when neighboring networks belong to different network providers. Furthermore, CARD can only aUow a mobile to obtain the information a local network provider configures its CARD protocol to provide, making it difficult to provide consistent information from network to network and to support mobile devices that may need different information depending on their different networking Capabilities and user npplications. This paper proposes and evaluates a new approach for real time discovery of neighboring network information: Autonomous Collaborative Discovery (ACD). It is nutonornous because regdar mobile users and their devices act autonomously to collect information and make the information available to other mobile users and devices. It is collaborative as the autonomous actions of the mobile users and devices help each other to discover the information they want.