Unmanned Aerial Vehicles (UAVs) are rapidly becoming an important tool for applications like surveillance, target
tracking and facility monitoring. In many of these contexts, one
or more UAVs need to reach an area of interest (AOI) while
streaming live video to a ground station (GS) where one or more
operators inspect the AOI and carry out fine control of UAVs
position. In remote areas, intermediate UAVs can act as relays
and form a line network to extend range. Interactive control
requires a live video stream where both throughput and delay
are important. In this paper, we show that routing packets over
CSMA/CA (native medium access protocol of WiFi, the most
common wireless technology among UAVs) behaves poorly in this
context due to link asymmetries. We propose a novel distributed,
adaptive and self-synchronized TDMA protocol (DVSP) that
both enhances delay and packet delivery while operating on
commodity hardware and leveraging a standard UDP/IP protocol
stack. We prove that DVSP converges to a global solution that
minimizes delay using local information, only, thus in a fully
distributed manner. Real world experiments with multiple UAVs
show gains in delay up to 75%, and packet delivery up to 50%,
without sacrificing goodput