  Streaming codes are a class of packet-level erasure codes that ensure packet
recovery over a sliding window channel which allows either a burst erasure of
size $b$ or $a$ random erasures within any window of size $(\tau+1)$ time
units, under a strict decoding-delay constraint $\tau$. The field size over
which streaming codes are constructed is an important factor determining the
complexity of implementation. The best known explicit rate-optimal streaming
code requires a field size of $q^2$ where $q \ge \tau+b-a$ is a prime power. In
this work, we present an explicit rate-optimal streaming code, for all possible
$\{a,b,\tau\}$ parameters, over a field of size $q^2$ for prime power $q \ge
\tau$. This is the smallest-known field size of a general explicit rate-optimal
construction that covers all $\{a,b,\tau\}$ parameter sets. We achieve this by
modifying the non-explicit code construction due to Krishnan et al. to make it
explicit, without change in field size.
