**2.2 Enhanced Differentiated Bandwidth Allocation Mechanism (eDBAM)**

In case of DBAM, the order of bandwidth allocation follows the below sequence:

High-priority RTPS > Regular priority RTPS > Low-priority RTPS > High-priority nRTPS > Regular priority nRTPS > Low-priority nRTPS > High-priority BE > Regular priority BE > Low-priority BE

Basically DBAM ensured that the order of service class is maintained and within the service class we can have graded users. However there is scope for further optimization. We can have seven different ways in which the bandwidth can be allotted. Table 5 and Table 6 list the seven different ways in which bandwidth can be allotted. Each column in the table represents a unique way of bandwidth allotment. The order of allotment is from top to bottom (Kumar et. al, 2011b).


Table 5. Method 1 to Method 3 of eDBAM.


Table 6. Method 4 to Method 7 of eDBAM.

In eDBAM (for example Method 2), low priority service class of high priority user (ex: Low-Priority BE) can be allocated bandwidth ahead of high-priority service class of regular/low-priority user (Regular/Low priority nRTPS). This out of turn allocation of bandwidth improves the throughput for even low priority service class (BE) for highpriority users.

### **2.2.1 Implementation**

Implementation of eDBAM is similar to DBAM. The AAA server shall maintain a mapping of MAC address to the priority value associated with the MAC address. When a MS sends RNG-REQ to BS, BS shall obtain the priority value associated with the MS and allocated bandwidth based on one of the seven methods proposed for eDBAM. BS does not switch between the seven different methods of eDBAM. Each BS shall implement one of the seven methods and stick to that method throughout its operation.
