Power Efficient Dynamic Bandwidth Allocation Algorithm in OFDMA-PONs

Abstract

We propose two dynamic bandwidth allocation (DBA) algorithms by considering three dimensions, i.e., time slot, subcarrier, and bit allocation, to minimize the transmitting power of optical network units (ONUs) in orthogonal frequency division multiplexing access passive optical networks (OFDMA-PONs). In the first proposed algorithm, we make use of the three-dimensional DBA algorithm from wireless OFDM, modify it according to the characteristics of the fiber channel, and apply it to upstream access in OFDMA-PONs to reduce the transmitting power of ONUs. In order tofurther minimize the total transmitting power, we propose the second algorithm by allocating the subcarrier and bit in the same procedure. The complexity of the two proposed algorithms was evaluated by polynomial time. From simulation results, the transmitting power of ONUs under a certain bit error rate is reduced by ~30% and ~50% using the first and the second proposed algorithms, respectively, compared with the traditional two-dimensional DBA algorithm in OFDMA-PONs.