Cooperative Internet Access in Resource Constrained Environments

Access to the Internet has become available at virtually any place in developed and developing countries, either by fixed-line or wireless access. The Internet users are used to check emails, read web pages, or see a video at any time via the Internet and are annoyed if the access does not work or does work but too slowly for the used application. The access to the Internet is stable and fast enough in metro areas, but even in these area the access network is just too slow under certain circumstances. In many other situations, such as in rural areas or while being on the move, the network capacity is usually not sufficient to keep up with the capacity demand of the applications used by the users. The easiest conclusion in cases where the network access is too slow for a specific application is simply: give up. Another approach is to call for an upgrade of the network to offer more capacity, but this is not as easy, as this involves the network operator to do the upgrade. We call such a situation where the Internet access is too slow a resource constrained environment. This thesis presents throughput measurements of such an environment for 2 UMTS-based mobile wireless networks to show the limits of a real deployments. However, typically there is not a single user in an area with such a limited Internet access, but multiple users with their Internet terminal. We use the possibility of having multiple users in the same area to let them cooperatively retrieve data from the Internet. The scheme we introduce allows a group of users in physical proximity to jointly access a resource or resources, by efficiently using the Internet access ressources each user contributes to the group, with the goal to overcome a resource constrained environment of each single host. The basic idea is: use several (fixed-line or wireless) Internet access links at the same time and distribute the data retrieval load among them ( application layer channel bonding ). This assumes the presence of a 2nd high-bandwidth local network (e. g., WLAN in ad-hoc mode) which allows content redistribution between these users free of charge. The framework we are proposing is called Cooperative Internet Access and is defined on the conceptual level in this thesis and elaborated with 2 applications using the frame work. We show how the cooperative Internet access enables near live peer-to-peer video streaming in a resource constrained environment where it would be otherwise impossible to watch video. We present the system design for peer-to-peer video streaming in such an environment and evaluate it with a simulative study which uses the results of the above mentioned 3G measurements for the network environment.As 2nd application we use web browsing which is also an application type which suffers from a resource constrained environment, as the web content is delivered too slowly to the users, making most of today s web pages hard to use. The system design for our cooperative web access approach re-uses the foundation framework, as also used by the peer-to-peer use case, to improve the access to web pages.