  Channel coding alone is not sufficient to reliably transmit a message of
finite length $K$ from a source to one or more destinations as in, e.g., file
transfer. To ensure that no data is lost, it must be combined with rateless
erasure correcting schemes on a higher layer, such as a time-division multiple
access (TDMA) system paired with automatic repeat request (ARQ) or random
linear network coding (RLNC). We consider binary channel coding on a binary
symmetric channel (BSC) and q-ary RLNC for erasure correction in a star
network, where Y sources send messages to each other with the help of a central
relay. In this scenario RLNC has been shown to have a throughput advantage over
TDMA schemes as K and q tend to infinity. In this paper we focus on finite
block lengths and compare the expected throughputs of RLNC and TDMA. For a
total message length of K bits, which can be subdivided into blocks of smaller
size prior to channel coding, we obtain the channel coding rate and the number
of blocks that maximize the expected throughput of both RLNC and TDMA, and we
find that TDMA is more throughput-efficient for small message lengths K and
small q.
