As shown in Figure 3, the Admission Control module can handle simple requests by directly modifying
the STRG. Simple requests include ones that merely
consume excess resources and do not involve revocation of resources. More complex admission requests are
forwarded to the Resource Allocation and Adaptation
(RAAM) module (described below). In principle, the
RAAM module can consider a wide variety of rearrangements of resources to satisfy requests – constrained only
by policies, QoS requirements, and user preferences.
Should the RAAM module decide that a request cannot be satisfied, however, the Admission Control module
will forward the rejection back to the original requester,
at which point the user may need to become involved.