Efficient content-distribution in a hybrid opportunistic network

Information or content centric networking is believed by many to have great potential to be the appropriate networking paradigm for the future Internet. In information centric networking, focus is shifted from the end-points in the network to the information objects themselves, with less care being placed on from where the information is fetched. In addition to the benefits this networking paradigm has in fixed networks, it also simplifies operation in mobile networks and has the potential to improve performance. In this paper, we describe one way in which the NetInf network architecture can be used in a hybrid mobile network in an urban setting, and run simulations to evaluate the benefits that this approach can yield, both to the end users (in terms of improved performance such as reduced latency with over 50%), as well as to the operators in terms of a reduction of traffic load in the cellular access networks with up to 97%

V2X Content Distribution Based on Batched Network Coding with Distributed Scheduling

Content distribution is an application in intelligent transportation system to assist vehicles in acquiring information such as digital maps and entertainment materials. In this paper, we consider content distribution from a single roadside infrastructure unit to a group of vehicles passing by it. To combat the short connection time and the lossy channel quality, the downloaded contents need to be further shared among vehicles after the initial broadcasting phase. To this end, we propose a joint infrastructure-to-vehicle (I2V) and vehicle-to-vehicle (V2V) communication scheme based on batched sparse (BATS) coding to minimize the traffic overhead and reduce the total transmission delay. In the I2V phase, the roadside unit (RSU) encodes the original large-size file into a number of batches in a rateless manner, each containing a fixed number of coded packets, and sequentially broadcasts them during the I2V connection time. In the V2V phase, vehicles perform the network coded cooperative sharing by re-encoding the received packets. We propose a utility-based distributed algorithm to efficiently schedule the V2V cooperative transmissions, hence reducing the transmission delay. A closed-form expression for the expected rank distribution of the proposed content distribution scheme is derived, which is used to design the optimal BATS code. The performance of the proposed content distribution scheme is evaluated by extensive simulations that consider multi-lane road and realistic vehicular traffic settings, and shown to significantly outperform the existing content distribution protocols.Comment: 12 pages and 9 figure

The julia content distribution network

Abstract — Peer-to-peer content distribution networks are currently being used widely, drawing upon a large fraction of the Internet bandwidth. Unfortunately, these applications are not designed to be network-friendly. They optimize download time by using all available bandwidth. As a result, long haul bottleneck links are becoming congested and the load on the network is not well balanced. In this paper, we introduce the Julia content distribution network. The innovation of Julia is in its reduction of the overall communication cost, which in turn improves network load balance and reduces the usage of long haul links. Compared with the state-of-the-art BitTorrent content distribution network, we find that while Julia achieves slightly slower average finishing times relative to BitTorrent, Julia nevertheless reduces the total communication cost in the network by approximately 33%. Furthermore, the Julia protocol achieves a better load balancing of the network resources, especially over trans-Atlantic links. We evaluated the Julia protocol using real WAN deployment and by extensive simulation. The WAN experimentation was carried over the PlanetLab wide area testbed using over 250 machines. Simulations were performed using the the GT-ITM topology generator with 1200 nodes. A surprisingly good match was exhibited between the two evaluation methods (itself an interesting result), an encouraging indication of the ability of our simulation to predict scaling behavior. I