Content-Oriented Approaches for Efficient Data Transmission in Future Internet

This dissertation presents several content-oriented approaches for efficient data transmission in the future Internet. These approaches leverage known properties of contents in various aspects to facilitate content delivery. Our proposed approaches are grounded in two main techniques: 1) Content-Centric Networking (CCN) architecture and 2) QoSaware routing with network coding. They are used to address problems in particular parts of the Internet, which can be categorized by location into the core and edge areas. An increasing amount of content retrieval traffic raises concern about network congestion in the core area of the modern Internet. An effective solution to network congestion is network caching, whose basic principle is to store some contents in the storage close to content requesters so that some requests can be solved locally. Available implementation of network caching is often unnecessarily complicated. It requires complex middleware for content-to-location translation since contents are not natively identifiable to the data plane of routers. Content-Centric Networking (CCN), which is also called Named Data Networking (NDN), is a new architecture for the future Internet that solves this issue by substituting host addresses in packets with content names and using caches of routers as in-network caches. One of major challenges in CCN is how to efficiently utilize the in-network caches which have limited storage. We address this challenge with two approaches: an Optimal Cooperative Routing Protocol (OCRP) and a probabilistic caching scheme. The OCRP is an intra-domain routing protocol that utilizes the content retrieval statistics offered by CCN routers to adjust transmission routes. The OCRP consists of three main processes: (1) Prefix Popularity Observation; (2) Prefix Group (Un)Subscription; and (3) Forwarding Information Base (FIB) Reconstruction. In Prefix Popularity Observation, each CCN router observes popularly cited prefixes to activate Prefix Group (Un)Subscription. Prefix Group (Un)Subscription notifies a central routing controller that which CCN router wants to join or leave which prefix group. A prefix group is the group of the CCN routers that frequently forward requests for the same contents. Based on prefix groups, a central routing controller computes an optimal cooperative path by solving an integer linear programming. Finally, FIB Reconstruction adjusts the routes by updating the routing tables of the CCN routers involved in a newly computed optimal cooperative path. Simulation results show that the OCRP offers better reduction of server load and round-trip hop distance than the shortest path routing. In addition to the routing scheme, we investigate cache management for CCN because it is another important factor that affects the utilization of in-network caches. The cache management schemes of interest to us are combinations of a probabilistic caching scheme and different cache replacement policies. The cache replacement policies include Least Frequently Used (LFU), Least Recently Used (LRU), Random Replacement (RR), and First In First Out (FIFO) policies. Computer simulations are organized to evaluate the performance of the cache management schemes by using several network topologies. Simulation results show that the performance of in-network caches can be improved by using a probabilistic caching scheme along with LRU. Furthermore, we develop a new analytical model to gain deeper understanding of a probabilistic caching scheme. By using this model, several important properties of the probabilistic caching scheme are established as a function of cache replacement policies and network topologies. We have found that a combination of a probabilistic caching scheme and LRU offers the best performance among considering cache management schemes. However, if a CCN router cannot afford LRU due to a complexity constraint, RR is preferred to FIFO since the former yields better performance than the latter. We proceed to address data transmission problems in the edge area of the Internet. Specifically, we facilitate reliable data transmission in multi-hop wireless networks, which are increasingly often the front-end accesses to the Internet.