These physics refer to the characteristics of the PON splitter, specifically a parameter called directivity. When light is injected into one of the output ports of the splitter, some of the light propagates back through the other output ports. Directivity is defined as the fraction of power transferred from one output port to another output port, and in PON splitters it is typically higher than 50 dB. The difference between the maximum transmit power of the optical transmitter and the minimum sensitivity level of the optical receiver is less than 40 dB, so directivity of 50 dB means there is no way for one customer to receive the transmissions of another customer. This applies to any wavelength. Regarding the question of a person who could 'shine' light and disrupt that PON segment, if the light is at the 1310 nm wavelength it would definitely disrupt the PON, so yes - it’s a potential issue. It is similar to a rogue ONU, and you can learn more about it in our video “Detecting and Identifying a Rogue ONU/ONT on GPON”, kzbin.info/www/bejne/b6uzlJWrosh-sKM.

@@tracespancommunications6556 Thank you for your prompt and concise reply ! I thought afterwards about prisms and light isolation. Another thing that intrigues me is bandwidth on a PON segment and splitter ratios. If the PON speed is at say 1G each split would halve the throughput but not the speed of each packet ?. So each customer would get 1G but in 'small' bursts to the split ratio ? - I think of cars on a single track road being 'split' off each car to side roads, say each 32nd car in a 1:32 splitter ratio down a specific road - I hope that makes sense !

@@SolarPV. In general, the total available bandwidth of the PON is divided among the different customers, but there are some other points to consider: 1. A customer doesn’t use all his available bandwidth all the time, and as a matter of fact, most of the time he/she will use only a portion of it. Based on this, service providers can offer service packages based on oversubscription. As an example, they offer a “1 Gig” service, even though if 3 customers make an attempt to consume 1 Gb/s simultaneously, they will exceed the total available throughput of GPON. 2. For some types services the same downstream traffic is broadcast simultaneously to multiple customers. The classical example is IPTV, in which each TV channel is transmitted only once on a multicast port, and multiple customers connected to different ONUs on the PON can watch it simultaneously.

@@tracespancommunications6556 Thanks again !, Most users as you say only use bursts of data. But overall I feel it has the possibility of being a big bottleneck - I'm a frequent bittorrent user for example ... :-)

GPON is a PON network with capability of transmitting data at Gigabit speed. The same with XGPON a PON network with 10G data transmitting capabilities.

PON Means Passive Optical Network. It Means the cabling between the Provider (OLT) and Customer (ONU) is a Fiber Optic Network that does not have Electronic Power equipment but Just passive Splitters like your TV splitters only that this one splits the incoming fiber into several fibers 32/64/128

What for ???