Passive Optical Network (PON) has utilizes for transporting higher bandwidths with secured triple play services (Voice, Video and Data -VVD) in the fiber based broadband access network applications. Time division multiplexing PON (TDM PON) architecture can be made to support the transmission of higher data rates similar to WDM/DWDM PON. As per the literature analysis, TDM network limitation is to be upgraded still for time slot allocation and synchronization in higher bit rate transmission for more number of end users if required. In this paper we have analyzed the link power estimation for 10 Gbit/s TDM PON downstream transmission based on above issue. Also a complete investigation has done using optical signal delay, Fiber dispersion, splitting loss as major performance parameters. We have taken various measurements such as received signal and noise power, signal delay, extinction ratio, electrical and Optical signal-to-noise ratio (ESNR and OSNR) with respect to Q-Factor and BER with case studies to improve the Quality of service(QoS) for 10G bit/s dynamic bandwidth allocation (DBA) scheme. The entire architecture performance has been found out through simulations with different approaches using normal and sweep iterative mode analysis (NIA and SIA).