earticle

영어

In an orthogonal frequency-division multiple access passive optical network (OFDMA-PON) using an interleaved polling method, delay is increased by long cycle time, where the cycle time is the time duration between the current and next upstream transmissions. The cycle time is affected by the number of upstream subcarriers for an optical network unit (ONU). Available subcarriers are limited due to the system implementation cost, but the small number of upstream subcarriers increases the cycle time in sending the same amount of data. In this paper, we determine the number of upstream subcarriers to guarantee low delay under a gated service discipline.