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Next Generation Corporate Networks (NGCN) - Emergency calls

2nd edition, December 2010

This Ecma Technical Report is one of a series of publications that provides an overview of IP-based enterprise communication involving Corporate telecommunication Networks (CNs) (also known as enterprise networks) and in particular Next Generation Corporate Networks (NGCN).

The series particularly focuses on session level communication based on the Session Initiation Protocol (SIP), with an emphasis on inter-domain communication. This includes communication between parts of the same enterprise (on dedicated infrastructures and/or hosted), between enterprises and between enterprises and public networks. Particular consideration is given to Next Generation Networks (NGN) as public networks and as providers of hosted enterprise capabilities. Key technical issues are investigated, current standardisation work and gaps in this area are identified, and a number of requirements are stated. Among other uses, this series of publications can act as a reference for other standardisation bodies working in this field.

This particular Ecma Technical Report discusses issues related to emergency calls from an enterprise user to a safety answering point (SAP), using SIP within the NGCN. A SAP can be either a public safety answering point (PSAP) or a private emergency answering point (PEAP). This Technical Report uses terminology and concepts developed in ECMA TR/95. It identifies a number of requirements impacting NGN standardisation and concerning deployment of enterprise networks.

The scope of this Technical Report is limited to calls from a user of an enterprise network to an authority, where the authority is represented by a SAP (PSAP or PEAP). This includes the special case where a PEAP acts as an enterprise user in making an emergency call to a PSAP. Authority to authority calls, authority to enterprise user calls and enterprise user to enterprise user calls within the context of an emergency are out of scope, with the exception of return calls and verification calls as follow-up to an emergency call from the user to an authority.

This Technical Report focuses on emergency calls within a SIP-based NGCN using geographic location information to indicate the whereabouts of the caller. Emergency calls can originate from devices connected to the NGCN via various access technologies, e.g., SIP over fixed or wireless LAN (Local Area Network), TDM (Time Division Multiplex) networks, DECT (Digital Enhanced Cordless Telephone) networks, PMR (Private Mobile Radio) networks, PLMN (Public Land Mobile Network) etc.. SAPs are assumed to be reachable either directly using SIP or via a gateway to some legacy technology (e.g., TDM). Furthermore, SAPs are assumed to be reachable either directly from the NGCN or via a public network accessed from the NGCN using SIP. In the latter case, the NGCN might identify the SAP and instruct the public network to route to the SAP, or alternatively the NGCN might leave the public network to identify the SAP, based on the location of the caller. In all cases the NGCN is assumed to deliver the location of the caller to the SAP, gateway or public network in order to provide appropriate information to the call taker at the SAP.

The handling of incoming emergency calls at a SAP, even when the SAP is provided within an NGCN, is outside the scope of this Technical Report. This includes the case where a PSAP is provided within an NGCN and hence the NGCN can receive emergency calls from public networks. This also includes the case where a PEAP is provided within an NGCN and can receive emergency calls from other enterprise networks or other parts of the same NGCN.

Different territories have different regulations impacting emergency calls, together with national or regional standards in support of these regulations. This Technical Report takes a general approach, which should be largely applicable to any territory. However, detailed differences might apply in some territories, e.g., country- or region-specific dial strings used to identify emergency calls.

The scope of this Technical Report is limited to emergency communications with a real-time element, including but not limited to voice, video, real-time text and instant messaging. The focus, however, is on voice, which in the majority of situations is likely to be the most effective medium for emergency calls. However, it is recognised that some users with special needs will require other modes of communication (e.g., real-time text, fax), as discussed in Annex B of ETSI TR 102 180, and also different modes can be used for the emergency call and the verification call. The focus is also on calls in which the caller is a human user. There may also be applications where automatic sensors can make similar emergency calls (subject to regulation), but the special needs of such applications are not considered.

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Technical CommitteeTC32

ISO/IEC numberTR 16167


  • ECMA TR/101, 1st edition, December 2009Download