  The proliferation of wireless-enabled applications with divergent quality of
service (QoS) requirements necessitates tailored QoS provisioning. With the
growing complexity of wireless infrastructures, application-specific QoS
perceived by a user equipment (UE) is jointly determined by its association
with the supporting base station in heterogeneous networks (HetNets) and the
amount of resource allocated to it. However, conventional application-agnostic
objective-based user association and resource allocation often ignore the
differences among applications' specific requirements for resources, inevitably
preventing tailored QoS provisioning. Hence, in this paper, the problem of
joint user association and resource allocation with application-specific
objectives is investigated for achieving tailored QoS provisioning in 6G
HetNets. This problem is intrinsically difficult to solve directly due to the
extremely large solution space and the combination of discrete and continuous
variables. Therefore, we decompose the original problem into two subproblems,
i.e. user association and resource allocation, and propose an interactive
optimization algorithm (IOA) to solve them iteratively in an interactive way
until convergence is achieved. Specifically, matching theory is utilized to
solve resource allocation and user association is solved heuristically.
Extensive experimental results confirm that IOA algorithm outperforms several
baseline algorithms in terms of both average utility and UE satisfaction ratio.
