TIA TSB-102.BACC-A

The scope of this document is restricted initially to the provision of information relevant to the development of standards supporting wide area voice services involving the ISSI via interconnection of multi-vendor P25 Phase 1 and Phase 2 RFSSs over IP-based networks. The scope of this document in specifying the ISSI for support of wide area voice services includes the following:

• ISSI interoperability complementing the air interface interoperability standards for voice calls involving the U_m and E_f interfaces;

• End-to-end encrypted voice services supporting Subscriber Units (SUs) spanning multiple RFSSs;

• Mandatory and standard option services as specified in [TSB102A], although there may be P25 Phase 1 signaling related service limitations between conventional P25 systems, and between conventional and trunked, which are not detailed in [TSB102A]. For example, with conventional P25 systems using abbreviated addressing format [AABC] [BAAA] for SU-to-SU voice calls, subscriber unit A on a conventional P25 system cannot establish a voice call directly (over the ISSI) with subscriber unit B on a trunked P25 system or on another conventional P25 system; operator intervention would be required to establish the call.

Within this scope (i.e., focus on ISSI support of wide area voice service), the planned suite of ISSI-related documents consists of (in addition to this document):

• ISSI Messages Definition for Voice Services;

• ISSI Measurement Methods for Voice Services;

• ISSI Performance Recommendations for Voice Services;

• ISSI Conformance Tests for Voice Services;

• ISSI Interoperability Test Methods for Voice Services.

The ISSI Messages Definition for Voice Services document, which will provide detailed specification of the ISSI protocol suite and functional services, establishes 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 ISSI requirements and standards considerations involving the following, listed in the order of priority (with 1 being the highest priority):

1. Console interactions across the ISSI (e.g., via the E_c interface);

2. ISSI support for supplementary data services (e.g., call alert, via the U_m and E_f interfaces);

3. ISSI support for data services (e.g., via the E_d interface);

4. ISSI support for network management of subscriber units and network elements, which is not considered part of the ISSI (e.g., via the E_n interface);

5. ISSI support of Telephone Interconnect (including emergency services) by roamers (e.g., via the E_t interface), back over their ISSI interconnected home P25 system, with signaling in conformance with [BADA];

6. ISSI support for emerging multimedia services;

7. ISSI-related traffic engineering, traffic control, resource reservation, and service level agreements (e.g., based on operational experience);

8. Interconnection of ISSI lower layers in an interoperable manner (e.g., based on operational experience).

Future revisions of this document will also identify new and revised documents that compose the evolving ISSI standards documentation suite.