Project 25 Console Subsystem Interface Overview
|Publication Date:||1 February 2008|
The scope of this document is restricted initially to information relevant to the development of standards supporting voice services, and certain supplemental services involving the CSSI:
• Services specified in [TSB102A]
• Services specified or implied in recent TIA documents that are not currently included in [TSB102A]
• Services specified in the recent SOR documents that are not currently included in [TSB102A]
The CSSI is split into Trunking CSSI and Conventional CSSI, with a document suite for each type of interface.
The Conventional CSSI is made up of three "Complexities": Complexity 1, 2 and 3. Complexity 1 is based upon the Fixed Station Interface control and voice conveyance protocols and the ISSI Transmission Control protocol. CSSI Complexity 1 is defined in the suite of Conventional ISSI documents. CSSI Complexity 1 is IP based utilizing UDP and the Real-time Transport Protocol (RTP). Conventional Complexity 2 uses the Trunking CSSI, described below, and utilizes pre-configured mappings between conventional working IDs and fully qualified IDs and mappings between the fully qualified IDs fixed stations. The Trunking CSSI is also used for Conventional Complexity 3 which supports full dynamic mobility of conventional SUs. Complexity 3 also needs changes to the CAI to support conventional mobility. Conventional Complexities 2 and 3 are IP based utilizing UDP, RTP and the Session Initiation Protocol (SIP).
The Trunking CSSI utilizes the P25 ISSI architecture with slight modifications to some messages for specific console features. The Trunking CSSI is a standard protocol that enables a console subsystem to communicate with Trunking RFSSs and be part of a trunking communications system. The Trunking CSSI is IP based utilizing UDP, RTP and SIP. The Trunking CSSI is also used for Conventional Complexity 2 and Conventional Complexity 3 as described above.
The Messages and Procedures Definition documents for the Trunked CSSI and Conventional CSSI, which provides detailed specification of the CSSI protocol suite and functional services, establish the fundamental technical basis underlying development of the other indicated documents.
The scope of this document is expected to be extended in the future to include identification of CSSI requirements and standards considerations involving the following:
• CSSI support for data services through transport of packet data;
• CSSI support for emerging multimedia services;
• CSSI-related traffic engineering, traffic control, resource reservation, and service level agreements (e.g., based on operational experience);
• Interconnection of CSSI lower layers in an interoperable manner (e.g., based on operational experience).
• Network Management Support
Future revisions of this document are intended to identify new and revised documents that compose the evolving CSSI standards documentation suite.