SIP EXTENSION FOR DMR NETWORKS MATCHING PMR FEATURES

A system comprising: a SIP Proxy Server, and one or more DMR Gateways to interface the SIP Proxy Server with one or more DMR Networks matching Private/professional Mobile Radio (PMR) features; wherein each DMR Gateway is univocally assigned with a SIP ID and is designed to: interpret messages from the SIP Proxy Server to manage DMR signalling/data/voice features toward DMR Terminals, and initiate DMR features on account of DMR Terminals operating under it and make requests for DMR signalling/data/voice features toward destinations belonging to another Network; wherein each DMR Gateway is further designed to: transcode an over-the-air, manufacturer-specific DMR Terminal registration into a SIP REGISTER message to result in the SIP Proxy server perceiving and managing the DMR Terminal as a SIP User Agent; and wherein the SIP Proxy Server is designed to: manage DMR signalling features, including voice call set-up, and DMR data features using the SIP MESSAGE method, and/or manage DMR signalling/data/voice group features.