A Three Stage Communication Network Model with Homogeneous Bulk Arrivals and Dynamic Bandwidth Allocation

Recently the growth of packet switched networks lead to new traffic problems. To solve these problems, the differentiated service models have been considered as a scalable traffic management mechanism to ensure guaranteed quality of service. In this paper, a three stage/node communication network model with homogeneous bulk arrivals and dynamic bandwidth is developed and analyzed. The data packets after getting transmitted from the first node are forwarded to the second buffer connected to the second node and the packets leaving the second node are forwarded to the third node. Dynamic Bandwidth Allocation (DBA) is the strategy that the transmission rate at each node is adjusted depending upon the content of the buffer at every packet transmission. It is assumed that the arrival of packets follow compound Poisson processes and the transmission completions at each node follow Poisson processes. This model is more accurately fit into the realistic situation of the communication network having a predecessor and successor nodes for the middle node. Using the difference – differential equations, the joint probability generating function of the number of packets in each buffer is derived. The performance measures like, the probability of emptiness of the three buffers, the mean content in each buffer, mean delays in buffers, throughput etc. are derived explicitly under transient conditions. This network model is much useful in communication systems like, Telecommunications, Wireless communications, the Internet, ATM networks etc.