Results 1 -
9 of
9
Network Coding Meets Multimedia: a Review
, 2012
"... While every network node only relays messages in a traditional communication system, the recent network coding (NC) paradigm proposes to implement simple in-network processing with packet combinations in the nodes. NC extends the concept of “encoding” a message beyond source coding (for compression) ..."
Abstract
-
Cited by 8 (1 self)
- Add to MetaCart
While every network node only relays messages in a traditional communication system, the recent network coding (NC) paradigm proposes to implement simple in-network processing with packet combinations in the nodes. NC extends the concept of “encoding” a message beyond source coding (for compression) and channel coding (for protection against errors and losses). It has been shown to increase network throughput compared to traditional networks implementation, to reduce delay and to provide robustness to transmission errors and network dynamics. These features are so appealing for multimedia applications that they have spurred a large research effort towards the development of multimedia-specific NC techniques. This paper reviews the recent work in NC for multimedia applications and focuses on the techniques that fill the gap between NC theory and practical applications. It outlines the benefits of NC and presents the open challenges in this area. The paper initially focuses on multimedia-specific aspects of network coding, in particular delay, in-network error control, and media-specific error control. These aspects permit to handle varying network conditions as well as client heterogeneity, which are critical to the design and deployment of multimedia systems. After introducing these general concepts, the paper reviews in detail two applications that lend themselves naturally to NC via the cooperation and broadcast models, namely peer-to-peer multimedia streaming and wireless networking.
Proactive seeding for information cascades in cellular networks
- in 2012 Proc. IEEE INFOCOM
, 2012
"... Abstract—Online social networks (OSNs) play an increasingly important role today in informing users about content. At the same time, mobile devices provide ubiquitous access to this content through the cellular infrastructure. In this paper, we exploit the fact that the interest in content spreads o ..."
Abstract
-
Cited by 7 (0 self)
- Add to MetaCart
(Show Context)
Abstract—Online social networks (OSNs) play an increasingly important role today in informing users about content. At the same time, mobile devices provide ubiquitous access to this content through the cellular infrastructure. In this paper, we exploit the fact that the interest in content spreads over OSNs, which makes it, to a certain extent, predictable. We propose Proactive Seeding– a technique for minimizing the peak load of cellular networks, by proactively pushing (“seeding”) content to selected users before they actually request it. We develop a family of algorithms that take as input information primarily about (i) cascades on the OSN and possibly about (ii) the background traffic load in the cellular network and (iii) the local connectivity among mobiles; the algorithms then select which nodes to seed and when. We prove that Proactive Seeding is optimal when the prediction of information cascades is perfect. In realistic simulations, driven by traces from Twitter and cellular networks, we find that Proactive Seeding reduces the peak cellular load by 20%-50%. Finally, we combine Proactive Seeding with techniques that exploit local mobile-to-mobile connections to further reduce the peak load. I.
Efficient social-aware content placement for opportunistic networks
- in IFIP/IEEE WONS, Kranjska
"... Abstract—As content provisioning becomes the driving application of today’s (opportunistic) networking environments and the User Generated Content explodes, the problem of devising scalable approaches to placing it optimally within a networking structure becomes more important and challenging. Since ..."
Abstract
-
Cited by 7 (4 self)
- Add to MetaCart
(Show Context)
Abstract—As content provisioning becomes the driving application of today’s (opportunistic) networking environments and the User Generated Content explodes, the problem of devising scalable approaches to placing it optimally within a networking structure becomes more important and challenging. Since the wellknown k-median optimization problem that is typically formulated to address it requires global topology and demand information, different approaches are sought for. The latter is the focus of this paper that aims at exploiting social structures, present in emerging networking environments, in order to devise a scalable approach to the optimal or near-optimal content placement. A new metric that captures the node’s social significance or potential for helping establish paths between nodes is introduced and serves as the basis for creating a small scale network sub-graph over which the small-scale content placement problem is solved sequentially until the optimal or near-optimal location is identified. The trade-off between the sub-graph’s size and the degree of convergence to the optimal solution is studied through simulations on E-R and B-A random graphs and the effectiveness of the proposed approach is demonstrated. I.
Flocks: Enabling Dynamic Group Interactions in Mobile Social Networking Applications
- in: Proceedings of the 2011 ACM Symposium on Applied Computing (SAC
"... Mobile social networking applications enable end-users to interact on the move. Current applications model user groups as simple lists which have to be manually enumerated. This representation is both unsuitable and inefficient for group interactions: due to the openness and the mobility to which th ..."
Abstract
-
Cited by 5 (3 self)
- Add to MetaCart
(Show Context)
Mobile social networking applications enable end-users to interact on the move. Current applications model user groups as simple lists which have to be manually enumerated. This representation is both unsuitable and inefficient for group interactions: due to the openness and the mobility to which these applications are exposed, the contents of such lists are likely to change frequently. Updating the lists manually while interacting with users quickly becomes impractical. In this paper, we introduce an alternative representation for user groups named flocks. A flock represents a looselydefined user group in terms of an intensional description. The flock content is implicitly updated when changes occur, e.g. the users’s location. Flocks have group interaction provisions based on asynchronous message passing. Benchmarks indicate that flocks can be implemented efficiently by exploiting structure in their definitions. We present the flock abstraction and its implementation as the basis of a new distributed framework called Urbiflock.
Quantifying content consistency improvements through opportunistic contacts
- In CHANTS ’09
, 2009
"... Contacts between mobile users provide opportunities for data updates that supplement infrastructure-based mechanisms. While the benefits of such opportunistic sharing are intuitive, quantifying the capacity increase they give rise to is challenging because both contact rates and contact graphs depen ..."
Abstract
-
Cited by 4 (0 self)
- Add to MetaCart
Contacts between mobile users provide opportunities for data updates that supplement infrastructure-based mechanisms. While the benefits of such opportunistic sharing are intuitive, quantifying the capacity increase they give rise to is challenging because both contact rates and contact graphs depend on the structure of the social networks users belong to. Furthermore, social connectivity influences not only users ’ interests, i.e., the content they own, but also their willingness to share data with others. All these factors can have a significant effect on the capacity gains achievable through opportunistic contacts. This paper’s main contribution is in developing a tractable model for estimating such gains in a content update system, where content originates from a server along multiple channels, with blocks of information in each channel updated at a certain rate, and users differ in their contact graphs, interests, and willingness to share content, e.g., only to the members of their own social networks. We establish that the added capacity available to improve content consistency through opportunistic sharing can be obtained by solving a convex optimization problem. The resulting optimal policy is evaluated using traces reflecting contact graphs in different social settings and compared to heuristic policies. The evaluation demonstrates the capacity gains achievable through opportunistic sharing, and the impact on those gains of the structure of the underlying social network.
Opportunistic Routing in Intermittently Connected Wireless Mobile Social Networks
"... permission of the author. ii ..."
(Show Context)
NETWORK TOPOLOGIES
"... To offload our manuscript we have placed a portion of our work here. In Section 1 we derive analytical closedform expressions for the (w)CBC metric variation in regular topologies while next, we draw insights regarding the cDSMA performance from the degree distributions of the studied ISP topologies ..."
Abstract
- Add to MetaCart
To offload our manuscript we have placed a portion of our work here. In Section 1 we derive analytical closedform expressions for the (w)CBC metric variation in regular topologies while next, we draw insights regarding the cDSMA performance from the degree distributions of the studied ISP topologies. Section 3 presents the way the cDSMA practical implementation operates under multipath routing(MP).Section4experimentallyinvestigateswhether overloadphenomenacanoccurwiththecDSMAimplementations. Finally, we discuss a wide range of solutions that fall in the relevant data replication and placement category.
autonomous
"... Cooperative mechanisms for information dissemination and retrieval in networks with ..."
Abstract
- Add to MetaCart
(Show Context)
Cooperative mechanisms for information dissemination and retrieval in networks with
