  The high risk of random access collisions leads to huge challenge for the
deployment massive Machine-Type Communications (mMTC), which cannot be
sufficiently overcome by current solutions in LTE/LTE-A networks such as the
extended access barring (EAB) scheme. The recently studied approaches of
grouped random access have shown a great potential in simultaneously reducing
the collision rate and the power consumption in mMTC applications, and exhibit
a good compatibility with the concept of random access resource separation. In
this work, we propose an optimized resource dedication strategy for grouped
random access approaches, which inherits the advantage of resource separation
to isolate device classes from each other, while providing an optional class
preference with high flexibility and accuracy, which has been usually
implemented with access class barring.
