Non-IMS Rich communication suite

1. A non-IMS RCS telecommunications system comprising four logical entities, the first logical entity is a protocol conversion gateway (PCG), the second logical entity is a session controller (SC), the third logical entity is a control node (CN), and the fourth logical entity is a subscriber and routing database (DB or SRDB), wherein said logical entities function in operative association with a telecommunication network having a plurality of user agents, a home location register (HLR) and one or more legacy controllers selected from a short messaging service center (SMSC) and a multimedia messaging service center (MMSC) to transmit a message from a first subscriber to a second subscriber over the telecommunication network, wherein the protocol conversion gateway (PCG) handles the conversion from rich communication services/message session relay protocol (RCS/MSRP) traffic to legacy short message peer to peer (SMPP) or multimedia messaging service standard 4/multimedia messaging service standard 7 (MM4/MM7) for delivery to SMSCs and/or MMSCs, wherein the PCG acts as an RCS client to the Session Controller and as an external short message entity (ESME) to the legacy SMSC/MMSC infrastructure, wherein the session controller(s) is responsible for the set up and control of MSRP sessions in the RCS ecosystem, wherein the control node handles the signaling interfaces, including both SIP and SS7, necessary to handle the registration, session set up, and subscriber authentication, wherein the control node acts in the IMS infrastructure as both the proxy call session control function (P-CSCF) and the serving call session control function (S-CSCF), wherein the control node acts as the application controller for RCS, and wherein the SRDB acts as the home subscriber server (HSS) in the IMS infrastructure and holds the individual handset capability information garnered in the registration process, as well as any operator- or handset-specific routing information.