Software for Real-Time Transfer of GPS Data Over the Open Internet

Real-Time Net Transfer (RTNT) software allows for efficient and reliable transport of raw, GPS (Global Positioning System) observables over the open Internet. Efficiency is achieved by editing and compressing the GPS observables at the remote site, and by using User Datagram Protocol (UDP) rather than the higher overhead required of Transmission Control Protocol (TCP). However, TCP reliability is still achieved by the central server (the central collection computer) by monitoring sequence numbers of the remote client's packets. If there is a skip in sequence numbers, the central server may request retransmission of missed data packets from the remote clients. In this way over 98 percent of the data is returned to the central server. Once the central server receives the data, it may additionally retransmit the packets to other servers on the open Internet. This provides the capability of merging regional servers into a global server. There is a particular secondary server also running receiving data packets from the primary global server. If the secondary server no longer sees incoming packets, it will reroute the entire global network to itself. This provides a backup system should the primary server fail.