  With recent advances in wireless communication, networking, and low power
sensor technology, wireless sensor network (WSN) systems have begun to take
significant roles in various applications ranging from environmental sensing to
mobile healthcare sensing. While some WSN applications only require a lim- ited
amount of bandwidth, new emerging applications operate with a notice- ably
large amount of data transfers. One way to deal with such applications is to
maximize the available capacity by utilizing the use of multiple wireless
channels. This work proposes DynaChannAl, a distributed dynamic wireless
channel algorithm with the goal of effectively distributing nodes on multiple
wireless channels in WSN systems. Specifically, DynaChannAl targets applica-
tions where mobile nodes connect to a pre-existing wireless backbone and takes
the expected end-to-end queuing delay as its core metric. We use the link qual-
ity indicator (LQI) values provided by IEEE 802.15.4 radios white-list
potential links with good link quality and evaluate such links with the
aggregated packet transmission latency at each hop. Our approach is useful for
applications that require minimal end-to-end delay (i.e., healthcare
applications). DynaChannAl is a light weight and highly adoptable scheme that
can be easily incorporated with various pre-developed components and
pre-deployed applications. We eval- uate DynaChannAl in on a 45 node WSN
testbed. As the first study to consider end-to-end latency as the core metric
for channel allocation in WSN systems, the experimental results indicate that
DynaChannAl successfully distributes multi- ple (mobile) source nodes on
different wireless channels and enables the nodes to select wireless channel
and links that can minimize the end-to-end latency.
