A dynamic bandwidth assignment algorithm for B-PON

To meet the explosive increase in TCP/IP data traffic that has occurred due to the rapid growth of the Internet, the broadband passive optical network (B-PON) with dynamic bandwidth assignment (DBA) is considered to be one of the most cost-effective solutions. The DBA function enables B-PON users to share their upstream bandwidth with each other dynamically. This paper proposes a new DBA algorithm that completely satisfies the requirements specified in ITU-T G983.4. The proposed algorithm consists of three processes. The first process predicts the requested bandwidth and ensures quick response to ONT input data. The second process determines the number of cell slots (CS) of each bandwidth type in each bandwidth assignment period (BAP) and ensures complete assignment of guaranteed bandwidth, and fair assignment for non-assured bandwidth among transmission containers (T-CONT). The third process determines the CS locations of each bandwidth type in each BAP according to the number of CS obtained from the second process so as to minimize the cell delay variation (CDV). This paper also evaluates the proposed algorithm using a prototype system.