CCS/SS7 Generic Requirements in Support of E9-1-1 Service
Document Number GR-2956
Issue Number 05
Issue Date Dec 2002
ABSTRACT: .Issue 5 of GR-2956, CCS/SS7 Generic Requirements in Support of E9-1-1 Service, completely replaces Issue 4.
This document provides generic requirements for Signaling System 7 (SS7) signaling to support E9-1-1 service. These SS7 requirements
are intended to propose a solution to address E9-1-1 related issues associated with current wireline and wireless telecommunications
The generic requirements in this document cover SS7 signaling for end office to E9-1-1 tandem interfaces, Mobile Switching Center
(MSC) to E9-1-1 tandem interfaces, as well as SS7 signaling for E9-1-1 tandem to E9-1-1 tandem interfaces. These requirements include
signaling of information needed to support wireline calls and signaling of information associated with supporting Phase 1 and Phase 2
wireless calls using Call Associated Signaling (CAS) and Non-Call Associated Signaling (NCAS) arrangements. Additional generic
requirements included in this document define the mappings necessary for an E9-1-1 tandem to perform for E9-1-1 calls incoming on
SS7-supported trunks that are to be terminated to Public Safety Answering Points (PSAPs) using various signaling and architectural
The generic requirements in this document are aimed at supporting arrangements where E9-1-1 calls are routed over SS7-supported
trunks that are either dedicated to E9-1-1 traffic or shared with other types of calls (e.g., nonemergency calls.). These requirements
also include discussion of the use of MF trunks in a backup arrangement for the SS7-supported trunks via the use of trunk hunting
sequences and Simulated Facility Groups (SFGs).
The generic requirements provided in this document describe generic E9-1-1 service functionality and are not intended to describe
supplier-specific implementations of E9-1-1 service capabilities. Implementation of these generic requirements may provide additional
capabilities that are beyond the scope of this document. These additional capabilities, some of which may be at an E9-1-1 tandem or
PSAP, are not discussed in this document.
The requirements in this document for supporting E9-1-1 service using SS7 signaling will decrease the current call setup delay
associated with MF trunking as well as provide a means for carrying the necessary information to support Phase 1 and Phase 2 wireless
requirements (i.e., transporting cell site and sector information, as well as latitude and longitude). In addition, these requirements
allow for variations in the processing of wireless Emergency Calls based on the functionality supported by the wireless network. For
example, these requirements address scenarios where selective routing is performed on a wireless Emergency Call prior to it being
received by an E9-1-1 tandem, as well as where a wireless Emergency Call is routed to an E9-1-1 tandem prior to any selective routing
being performed. Note that the SS7 protocol is flexible and expandable and therefore could provide a means for signaling additional
information associated with E9-1-1 service as additional needs are identified in the future. These future needs are beyond the scope of
Issue 5 of GR-2956-CORE reflects the evolution of industry standards related to the signaling of information to support both CAS and
NCAS approaches to wireless Emergency Call setup.
When using GR-2956, you may need to refer to GR-268, GR-317, GR-350, GR-394, TR-NWT-000444, GR-474,
GR-477, GR-478, TR-NWT-001268, GR-1298, GR-2953, GR-2967, GR-2968, ANSI T1.628, and/or TIA/EIA J-STD-036-A.
You may also want to refer to GR-1176, GR-3023, SR-4163, and/or NENA Recommendation 03-002.
This GR also includes one or more Issue List Reports (ILRs) that details open or closed technical issues in the main document. The
ILR(s) are automatically sent free of charge to the GR document purchaser.
Components of this product are:
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