OSGRS is an open source project to provide an open protocol for Assisted-GNSS (AGNSS) development. The protocol is known as GNSS Reference Interface Protocol (GRIP) and it is based on XML. A set of server and client software that support GRIP has also been developed to encourage GRIP usage. The server is called OSGRS and it currently supports a NovAtel OEM3 or OEM4 reference receiver.
AGNSS server provides "assistance" messages to user receivers able to make use of such messages to rapidly acquire weak GPS/GNSS signals. These receivers typically are found within mobile phones and similar devices.
The official webpage for GRIP and OSGRS is
Source codes and documentation can be downloaded
from the project's SourceForge page: