Distinguishing between connectivity, intermittent connectivity, and intermittent disconnectivity

ABSTRACT

Research in Challenged Networks is evolving nicely. Starting with early research in Interplanetary Networks and disconnected ad hoc networks, more recent research efforts have focused on the challenges of novel network architectures like delay tolerant mobile networks, vehicular, and underwater networks. One particular aspect of interest is the seemingly insignificant, yet important distinction between the philosophies of connectivity, intermittent connectivity, and intermittent disconnectivity. Assuming a different connectivity model has profound and often unexpected effects on a wide variety of system characteristics. The lesson going forward, therefore, is the suggestion that the research community should continue to disregard long-held assumptions while also finding ways to evolve network architectures in a way that expand opportunities for novel modes of communication. The goal of this talk is to offer opinions, insight, and direction for three areas of perceived need. These are:

1. 1. The need to focus research attention beyond network layer issues, i.e., the need to focus on aspects of data transport and applications.
2. 2. The need to work on network architectures that are realistic within the particular environments of their deployment, e.g., sparse networks with intermittent disconnectivity and multiple egress points.
3. 3. The need to work in areas that leverage efforts to (radically) re-think the fundamental design of the Internet, e.g., cross-layer protocol and clean-slate architectures.

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Within these themes, this talk will briefly review some exemplary systems and applications, and then identify the aspects that are most relevant to Challenged Networks.

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.1 Network Architecture and Design
          Subjects: Wireless communication

Additional Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.1 Network Architecture and Design
          Subjects: Distributed networks; Network communications; Store and forward networks
      C.2.2 Network Protocols
          Subjects: Protocol architecture (OSI model); Applications (SMTP, FTP, etc.)

General Terms:
Design, Economics, Experimentation, Performance, Reliability

Keywords:
delay tolerant networks