【正文】 s mace application”. The EPON/GEPON main shorting is the efficiency low and supports outside the Ether with difficulty the service. The former is because uses 8B/10B the line code, introduces 20% band width loss, in addition other expenses, available load only about 50%, but APON and GPON all use NRZ to harass the code are the line codes, does not have the band width loss. In addition reasons and so on load bearing plate efficiency, transmission gathering plate efficiency, service adaptive efficiency, cause the EPON/GEPON total transmission efficiency to be very low, probably only is GPON half. 4. GPON In 2021, formulated EPON standard positively while IEEE, the FSAN anization starts to initiate the formulation speed to surpass 1Gb/s PON work standard 1,000,000,000,000,000 Ether passive light work (GPON), afterwards, ITUT also involved this new standard formulation work and 1 Dan (speed enhances in 2021 through two related GPON new standard and to ). According to this newest standard stipulation, GPON may provide and the speed and the all standard upward speed。s band width may be higher, and can provide video frequency professional ability and good QOS The hardware is simple, does not need outdoor electronic installation, and enables the installment deployment work to simplify。 in the 3ah flag has already formed the GEPON standard. In reality, EPON and the GEPON basic difference is the standardization, the former often Refers to the nonsign equipment, the latter refers conforms to IEEE , standard equipment. Moreover, the GEPON transmitting range and the bypass pare have pared to EPON reduce. EPON/GEPON and the traditional pointtopoint Ether main different place lies in the work in the pointmultipoint mailing address. Its downward direction work in the TDM way, the data stream changes the long Ether frame way to broadcast ONU, each ONU basis ether frame MAC address, decision choices. The upward direction work in the TDMA way, Comes from the different time slot ONU data stream to gather the public optical fiber facility and OLT. In addition, the traditional Ether work in the continual optical transmission pattern, is receiving and dispatching two directions both is the continual bit class, therefore receives the end fixed time easily to realize with the decision. But the EPON/GEPOkI ONUpward bit class is the sharpedged data packet which transmits in turn, the OLT receive timing recovery, the decision threshold establishment, the range finder and the time delay pensation quite is plex. Looked from the EPON/GEPON structure that, its essential merit Enormously simplified the traditional multilayered overlapping work Structure, the main characteristic included: Eliminated ATM and the SDH level, thus reduced the initial cost and the movement cost。s band width. According to 32 groups’ putations, each branch available band width only remains , again presses 10 user sharing, then each user only can obtain approximately the 2Mb/s band width. Obviously, such performance price pared to is unable to satisfy the work and the service longterm development needs. 3. EPON/GEPON Along with IP rising with the development, some people proposed the EPON concept, namely in with APON and the BPON similar structure and in the foundation, tries to retain its essence part physics level PON。 But the cost the linearity increases along with the number of users actual growth, does not need to plan, the investment risk is low, thus disperses the local cost in the low density user to be low. The shorting is the both sides equipment and the optical fiber facility specialpurpose, the user cannot share the bureau end equipment and the optical fiber, when the demand fast growth also the user are very crowded, optical fiber and both sides equipment quantity and cost as well as spatial demand also along with it rapid increase, thus not too suits the high crowded user region. The influence choice Ether technology another factor is the traditional video frequency service provides the way, for example American Place Bell Company all pledged