Architecture
Speago Push-to-talk solution is a PTT system built upon the IP Multimedia Subsystem (IMS). IMS is a vendor-independent architecture specified by 3rd Generation Partnership Project (3GPP) for delivering IP-based multimedia services to the users of telecommunications networks. IMS is not an end-user service as such, but an infrastructure on which services can be built. IMS-based services are independent of the access network, so they can be used, for example, over 2G, 3G, 4G, WLAN, and Broadband connections.
The IMS architecture is based on Internet protocols, especially the Session Initiation Protocol (SIP), and defines how these protocols are used to create a scalable and efficient service architecture.
An IMS Core consists of SIP proxies and a user database:
- Proxy Call Session Control Functions (P-CSCF)
- Interrogating Call Session Control Function (I-CSCF)
- Serving Call Session Control Function (S-CSCF)
- Home Subscriber Server (HSS)
The functionality of the IMS core is extended using application servers. The Speago PTT solution adds PoC, Presence, RLS, XDM servers to the IMS core functionality enabling Push-to-talk and presence services.
The Speago solution comes with all necessary components to start providing Push-to-talk services in a timely fashion.
The Speago PTT solution includes the following components:
- An IMS Solution including HSS database and CSCF SIP servers
- PoC Server
- Presence Server
- RLS Server
- XDM Server
- Aggregation Proxy
- Client software for supported platforms
- Development tools for Value Added Services
- Development tools for Special Clients
Figure below shows the architectural view of the system.
