Now showing items 21-33 of 33

    • Message Ferries as Generalized Dominating Sets in Intermittently Connected Mobile Networks 

      Ammar, Mostafa H.; Polat, Bahadir K.; Sachdeva, Pushkar; Zegura, Ellen W. (Georgia Institute of Technology, 2009)
      Message ferrying is a technique for routing data in wireless and mobile networks in which one or more mobile nodes are tasked with storing and carrying data between sources and destinations. To achieve connectivity between ...
    • Multicasting in Delay Tolerant Networks: Semantic Models and Routing Algorithms 

      Zhao, Wenrui; Ammar, Mostafa H. (Mostafa Hamed); Zegura, Ellen W. (Georgia Institute of Technology, 2006)
      Delay tolerant networks (DTNs) are a class of emerging networks that experience frequent and long-duration partitions. These networks have a variety of applications in situations such as crisis environments and deep-space ...
    • Multiple-Channel Multicast Scheduling for Scalable Bulk-data Transport 

      Donahoo, Michael J.; Ammar, Mostafa H. (Mostafa Hamed); Zegura, Ellen W. (Georgia Institute of Technology, 1998)
      A key technique for allowing a server to handle a large volume of requests for file transfers is to multicast the data to the set of requesting clients. Typically, the paths from the server to the clients will be ...
    • Network Support for Multicast Video Distribution 

      Bhattacharjee, Samrat; Calvert, Kenneth L.; Zegura, Ellen W. (Georgia Institute of Technology, 1998)
      Multicast video distribution in a best-effort environment presents challenges to system designers, including heterogeneity in the bandwidth availability on the paths from the sender to the receivers and dynamic behavior ...
    • A Novel Server Selection Technique for Improving the Response Time of a Replicated Service 

      Fei, Zongming; Bhattacharjee, Samrat; Zegura, Ellen W.; Ammar, Mostafa H. (Mostafa Hamed) (Georgia Institute of Technology, 1997)
      Server replication is an approach often used to improve the ability of a service to handle a large number of clients. One of the important factors in the efficient utilization of replicated servers is the ability to ...
    • On Scalable QoS Routing: Performance Evaluation of Topology Aggregation 

      Hao, Fang; Zegura, Ellen W. (Georgia Institute of Technology, 1999)
      A number of important questions remain concerning the scalability of networks with quality of service guarantees. We consider one of these questions: can QoS routing scale to large networks? To address this question, ...
    • Optimal Allocation of Clients to Replicated Multicast Servers 

      Fei, Zongming; Ammar, Mostafa H. (Mostafa Hamed); Zegura, Ellen W. (Georgia Institute of Technology, 1999)
      Server replication is an approach that is often used to improve the scalability of a service. One of the important factors in the efficient utilization of replicated servers is the ability to direct client requests to ...
    • Routing in Space and Time in Networks with Predictable Mobility 

      Merugu, Shashidhar; Ammar, Mostafa H. (Mostafa Hamed); Zegura, Ellen W. (Georgia Institute of Technology, 2004)
      We consider the problem of routing in emerging wireless networks where nodes move around explicitly carrying messages to facilitate communication in an otherwise partitioned network. The absence of a path at any instant ...
    • Scalability Techniques in QoS Routing 

      Hao, Fang; Zegura, Ellen W. (Georgia Institute of Technology, 1999)
      One barrier to deployment of large-scale QoS networks is scalability of QoS routing. Two major sources of overhead incurred by QoS routing are frequent network state updates and QoS-based path computation. Researchers have ...
    • Scheduling Uplink Bandwidth in Application-layer Multicast Trees 

      Srinivasan, Sridhar; Zegura, Ellen W. (Georgia Institute of Technology, 2004)
      Many applications can benefit from the use of multicast to distribute content efficiently. Due to the limited deployment of network-layer multicast, several application-layer multicast schemes have been proposed. In these ...
    • Selecting Among Replicated Adaptive Multicast Servers 

      Fei, Zongming; Ammar, Mostafa H. (Mostafa Hamed); Zegura, Ellen W. (Georgia Institute of Technology, 2000)
      Server replication and multicasting are well-established techniques for increasing capacity of a networked service and improving client performance. In this paper, we consider the combination of these two techniques. ...
    • Serendipity: A Distributed Computing Platform for Disruption Tolerant Networks 

      Shi, Cong; Lakafosis, Vasileios; Ammar, Mostafa H.; Zegura, Ellen W. (Georgia Institute of Technology, 2011-01)
      The opportunistic or disruption tolerant networking (DTN) paradigm shows up in a variety of settings, from military to disasters to the developing world to deep space; anywhere that fixed infrastructure is either ...
    • Trading Latency for Energy in Wireless Ad Hoc Networks using Message Ferrying 

      Jun, Hyewon; Zhao, Wenrui; Ammar, Mostafa H. (Mostafa Hamed); Zegura, Ellen W.; Lee, Chungki (Georgia Institute of Technology, 2004)
      Power management is a critical issue in wireless ad hoc networks where the energy supply is limited. In this paper, we investigate a routing paradigm, Message Ferrying (MF), to save energy while trading off data delivery ...