Bay Area Research Wireless Access Network (BARWAN)
Applications Support Services Layer
This layer provides resource management and distributed processing
services that allow applications to migrate computation between the
mobile's environment and the backend processing environment. The
quality of network connectivity, in terms of bandwidth and latency,
as well as the mobile host's processing capabilities and available
battery life, will determine how aggressively to partition the
application. The management of backend processing, choice of data
representation, and level of compression will be determined by
agents running on behalf of the mobile host in the backend environment.
Certain application-specific mechanisms can also yield improved efficiency.
One idea is to combine multiple TCP connections into a single connection to
reduce round trip latency. For example, all image link references within an
HTML document could be packaged into a single TCP connection, thereby
incurring a single round-trip network delay for a document spanning multiple
images. This is particularly effective when the network exhibits highly
asymmetric communications paths or particularly long latencies, which is
often the case for satellite communications channels. As we develop pilot
applications, we expect to discover a range of mechanisms like this that
can be incorporated into the applications building block libraries.
Randy H. Katz, ed., randy@cs.Berkeley.edu; Last edited: 21 APR 95