<Table> <Tr> <Td> </Td> <Td> This article uses abbreviations that may be confusing or ambiguous . There might be a discussion about this on the talk page . Please improve this article if you can . (May 2011) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article uses abbreviations that may be confusing or ambiguous . There might be a discussion about this on the talk page . Please improve this article if you can . (May 2011) </Td> </Tr> <P> The IP Multimedia Subsystem or IP Multimedia Core Network Subsystem (IMS) is an architectural framework for delivering IP multimedia services . Historically, mobile phones have provided voice call services over a circuit - switched - style network, rather than strictly over an IP packet - switched network . Alternative methods of delivering voice (VoIP) or other multimedia services have become available on smartphones, but they have not become standardized across the industry . IMS is an architectural framework to provide such standardization . </P> <P> IMS was originally designed by the wireless standards body 3rd Generation Partnership Project (3GPP), as a part of the vision for evolving mobile networks beyond GSM . Its original formulation (3GPP Rel - 5) represented an approach for delivering Internet services over GPRS . This vision was later updated by 3GPP, 3GPP2 and ETSI TISPAN by requiring support of networks other than GPRS, such as Wireless LAN, CDMA2000 and fixed lines . </P>

What is ip multimedia subsystem (ims)