APRServe then removes all dupes and sends it out to all logged on users. Thus everyone sees everyone and everything. The bandwidth of the internet is easily able to keep up with this throughput. It is important to note that this process is completely transparent to the callsigns of the IGates, and thus the mobile user does not need any a priori knowledge. The Naval Academy provides a display of the last 8 passes of Mir downlink packets .
Optional accessories are a GPS for moving position reports, and a laptop for entering messages.
Most modern TNCs will accept the GPS data directly and will transmit the data in a timed packet burst. There is even a tiny handheld TNC called the APRS MicEncoder that includes front panel switches for selecting 1 of 7 pre-canned status messages without needing a laptop to change the status report. 2-input NAND gate connected as an XOR gate or using a single XOR gate out of a 7486 chip. Just connect to the two points shown. The problem with any amateur satellite is the very low bandwidth available compared to the very large worldwide amateur population.