In order to coordinate their activities, embedded systems must
implement means to share data with one another.  While robust network
connectivity among them is necessary to achieve this goal, in practice
it is by no means sufficient.  By analogy, advanced Internet
applications are not implemented from IP datagrams alone, but rather
employ a variety of richer services (e.g., DNS, databases, ...) built
over this basic primitive.  We believe that implementing richer
services in networks of embedded systems is a research area that
demands significantly more attention in order to enable the
development of embedded systems for a variety of mission-critical
applications.

In fixed-infrastructure and well-provisioned networks like the
Internet, richer services are typically supported with trusted servers
or server clusters.  However, embedded networks might preclude such an
implementation for at least three reasons.  First, there may not be a
component in the network with the resources to serve access requests
for many clients.  Second, the network latency and congestion that
results from all clients accessing a single location may be
prohibitive.  Third, due to the challenging environments in which
embedded networks may operate, there may not be a node that is
sufficiently trustworthy to be relied upon for authoritatively
providing services to other nodes in the network.  While analogs of
these problems exist in fixed-infrastructure networks, embedded
systems exacerbate several difficult issues, including the need to
continually re-evaluate service-provisioning decisions if nodes move,
and to adapt as nodes depart the system due to failure or
disconnection.

In this talk I will summarize techniques we have developed for
implementing robust distributed services in environments
characteristic of embedded networks.  Our techniques offer ways to
disperse service load across many network elements while mitigating
the extra latency and/or network congestion that this can induce, and
without placing trust in individual nodes to authoritatively serve
others.  We will additionally discuss new research challenges in this
space.