ATIS 0500034-2017 Comparison of Enhanced 9-1-1 (E9-1-1) and Next Generation 9-1-1 (NG9-1-1) Focused on Reportable Outage Data Points.pdf

1、 TECHNICAL REPORT ATIS-0500034 Comparison of Enhanced 9-1-1 (E9-1-1) and Next Generation 9-1-1 (NG9-1-1) Focused on Reportable Outage Data Points As a leading technology and solutions development organization, the Alliance for Telecommunications Industry Solutions (ATIS) brings together the top glob

2、al ICT companies to advance the industrys most pressing business priorities. ATIS nearly 200 member companies are currently working to address the All-IP transition, 5G, network functions virtualization, big data analytics, cloud services, device solutions, emergency services, M2M, cyber security, n

3、etwork evolution, quality of service, billing support, operations, and much more. These priorities follow a fast-track development lifecycle from design and innovation through standards, specifications, requirements, business use cases, software toolkits, open source solutions, and interoperability

4、testing. ATIS is accredited by the American National Standards Institute (ANSI). The organization is the North American Organizational Partner for the 3rd Generation Partnership Project (3GPP), a founding Partner of the oneM2M global initiative, a member of and major U.S. contributor to the Internat

5、ional Telecommunication Union (ITU), as well as a member of the Inter-American Telecommunication Commission (CITEL). For more information, visit www.atis.org. Notice of Disclaimer alternate routing may also be invoked under certain circumstances A callback number is delivered to the PSAP with the ca

6、ll (although there are some exceptions for certain wireless implementations and non-initialized handsets) The PSAP uses information received in call setup signaling to query the ALI database to obtain location information for the caller The PSAP call-taker may transfer the call to another agency for

7、 further handling (e.g., for dispatch). As described above, a unique feature of E9-1-1 is selective routing. Selective Routing allows 9-1-1 calls to be routed to the appropriate PSAP based on the calling number/ANI, or other location information that may be provided with the call. To support selecti

8、ve routing, an SR will interact with a Selective Routing Database (SRDB). The SR provides the calling number/ANI or location key to the SRDB, and the SRDB returns an Emergency Service Number (ESN). An ESN is a three- to five-digit number representing a unique combination of emergency service agencie

9、s (law enforcement, fire, and EMS) designated to serve a specific range of addresses within a particular geographical area referred to as an Emergency Service Zone (ESZ). The SR uses the ESN to select the path to the destination PSAP for the emergency call. The ESN may also play a role in selecting

10、the transfer-to PSAP if the primary PSAP requests selective transfer of the emergency call, and identifying English Language Translations (ELTs) that specify the corresponding police, fire, and EMS. The introduction of the ANI feature was critical to supporting E9-1-1 because it allowed delivery of

11、the 9-1-1 callers telephone number1to the PSAP with the call. Using this information, the PSAP could identify the caller and, if necessary, call back the caller. A CAMA-like MF signaling scheme was initially used to support ANI delivery to the PSAP. This signaling scheme, referred to as Traditional

12、MF, is still in use in certain areas today, and supports the delivery of a 7-digit number, along with a single Numbering Plan Digit (NPD) that can be used to derive the NPA and to indicate whether the ANI information should be displayed using a steady or flashing display. A flashing display is inten

13、ded to alert the Telecommunicator of special conditions related to call treatment. A Feature Group D-like signaling scheme, referred to as Enhanced MF (E-MF), is more commonly used between SRs and PSAPs, and supports the delivery of either one or two 10-digit numbers to the PSAP with the call, along

14、 with an ANI II value that tells the PSAP Customer Premise Equipment (CPE) whether to display the information using a steady or flashing display. 4.1 Legacy Wireline E9-1-1 Service Architecture The delivery of the wireline 9-1-1 callers telephone number allows PSAPs to access the location informatio

15、n associated with the telephone number by querying the ALI database. In the case of wireline emergency callers, the ALI database contains static telephone number-to-street address mappings. The carrier that serves the PSAP typically operates the ALI databases. Figure 4.1 shows a representative archi

16、tecture for wireline E9-1-1. 1Technically, the ANI is the billing number associated with the calling party; however, in most cases, the ANI is the same as the calling directory number. ATIS-0500034 8 Figure 4.1 E9-1-1 Architecture for Wireline Emergency Calls 4.2 Legacy Wireless E9-1-1 Service Enhan

17、ced wireless emergency services (i.e., wireless E9-1-1), requiring wireless carriers to provide the location of the wireless 9-1-1 callers to PSAPs, is mandated by the U.S. Federal Communications Commission (FCC). For the initial stage, Phase I, the FCC required Wireless Service Providers (WSPs) to

18、upgrade their networks to support delivery of a callback number, and an identifier of the cell site or base station location where the 9-1-1 call originated, to the PSAP. Phase I of the FCCs mandate was required to be implemented by April 1998. Phase II requires delivery of E9-1-1 service that inclu

19、des the latitude and longitude of the 9-1-1 call within specific accuracy and reliability parameters, depending on the location technology that the carriers have chosen. For network-based technologies, location must be accurate to within 100 meters for 67 percent of calls, and 300 meters for 90 perc

20、ent of calls. For handset-based technologies, location must be accurate to within 50 meters for 67 percent of calls, and 150 meters for 90 percent of calls. While the original order called for handset-based geographic location to be provided to the PSAPs by October 1, 2001, the FCC has since introdu

21、ced a phased-in implementation schedule for handset and network-based location that extends until January 2019. The industry standard for E9-1-1 Phase I, J-STD-034, uses the term Emergency Services Routing Digits (ESRD) for the cell site identifier that is associated with an emergency call. With E9-

22、1-1 Phase I, the SR uses the ESRD to selectively route the wireless 9-1-1 call to the appropriate PSAP. Specifically, the SR queries the SRDB using the ESRD. As in the wireline architecture described above, the SR receives an ESN in the response from the SRDB and associates the ESN with the destinat

23、ion PSAP. The PSAP uses this ESRD to query for callback number and cell site location information. To satisfy the FCC Phase I mandate, the MSC may provide emergency call-related information to the SR using SS7 or Feature Group D (FGD) signaling. The interface between the SR and the PSAP may support

24、(depending on PSAP capabilities) the delivery of the two 10-digit numbers (i.e., callback number and ESRD) provided by the MSC to the PSAP using the E-MF signaling interface defined by NENA. However, there are still PSAPs that support Traditional MF interfaces and a small percentage of PSAPs that su

25、pport a custom Integrated Services Digital Network (ISDN) interface that is also capable of delivering 20 digits from the wireless carriers. To fulfill Phase II requirements for the delivery of latitude and longitude associated with the 9-1-1 call, wireless carriers have had to deploy location deter

26、mination technology in their networks. The location technology may be handset-based (e.g., Assisted Global Positioning System AGPS) or network-based (e.g., Time Difference of Arrival TDOA, Angle of Arrival AOA, etc.). Technically, if SS7 ISDN User Part (ISUP) signaling is supported between the MSC a

27、nd the SR, Phase II location information could be delivered in the ISUP Initial Address Message (IAM), provided the wireless network is able to determine the location coordinates prior to call setup. However, due to limitations in todays location determination technology that result in delays in obt

28、aining Phase II location, existing Phase II implementations only support the delivery of Phase I information or a location key in the call setup signaling. Phase II location information is delivered over a separate data link between the wireless network and the emergency services network. The E2 pro

29、tocol defined in J-STD-036-C and NENA-05-001 is typically used over the data link ATIS-0500034 9 between the wireless network and emergency services network to request/deliver transport initial caller location information to the PSAP via the ALI system, and to provide updated location information wh

30、en requested. There are also some implementations that use the Mobile Location Protocol (MLP) between the ALI system and the Mobile Positioning Center/MPC/Gateway Mobile Location Center (GMLC) in the wireless network to obtain the location associated with an emergency call. The method in which Phase

31、 II location is delivered by the wireless network to the emergency services network via a separate data link is referred to as the Non-Call Associated Signaling (NCAS) approach in J-STD-036-C. There are two variants of this approach: one which is just referred to as NCAS, and the other which is refe

32、rred to as Wireline Compatibility Mode (WCM). Of the two variants, the WCM approach is more widely deployed. 4.2.1 Wireline Compatibility Mode Approach With the WCM approach, all the FCC-mandated Phase I and Phase II location information and the callback number are sent over a separate data link to

33、the ALI database from the wireless network. The MSC may support either an MF or an SS7 interface over which a single 10-digit number is delivered to the SR, and the SR supports an interface where only a single 7/10-digit number is delivered to the PSAP. The one piece of information sent by the MSC t

34、o the SR is referred to as the Emergency Services Routing Key (ESRK). The ESRK may represent the PSAP or an ESZ in the jurisdiction of a PSAP, and also uniquely identifies the 9-1-1 call. The ESRK also uniquely identifies an MPC/GMLC in the wireless network that the ALI must query. The MPC/GMLC stor

35、es a pool of ESRKs in its database that represent a PSAP or ESZ and assigns them to wireless 9-1-1 calls. Upon completion of the 9-1-1 calls, the ESRKs are released, after the expiration of a guard timer, to be assigned to other 9-1-1 calls. The PSAP receives only the ESRK from the SR and uses it to

36、 query the ALI database to receive the callback number, cell site identifier (ESRD), and the latitude and longitude information for the mobile caller. Figure 4.2 illustrates wireless emergency call handling using the WCM approach. Figure 4.2 Wireless E9-1-1 Wireline Compatibility Mode 4.2.2 Wireless

37、 NCAS Approach With the wireless NCAS approach, the MSC sends a callback number and the cell site identifier (ESRD) to the SR using either MF or SS7 signaling. Call setup using the wireless NCAS approach is identical to the call setup in the E9-1-1 Phase I scenario documented in J-STD-034. The SR us

38、es the ESRD to interact with the SRDB, and the SRDB returns an ESN that causes the SR to route the 9-1-1 call to the appropriate PSAP. The interface between the SR and the PSAP will typically be an E-MF interface that supports the delivery of both the callback number and the ESRD to the PSAP, althou

39、gh hybrid arrangements (involving the real-time update of the ALI data via the SR) ATIS-0500034 10 may be used if the PSAP supports either a Traditional MF interface or the delivery of a single 10-digit number via an E-MF interface. Figure 4.3 illustrates wireless emergency call handling using the N

40、CAS approach. Figure 4.3 Wireless E9-1-1 NCAS Approach 4.2.3 Handling of Interim VoIP Originations Using E9-1-1 Infrastructure Existing interim VoIP implementations use the wireless E9-1-1 WCM techniques described above as a basis for delivering emergency originations from VoIP callers to legacy PSA

41、Ps that are served by SRs, as shown in Figure 4.4 . To support emergency calling, VoIP customers location is managed by the VoIP provider. This location information is provisioned to a system referred to as a VoIP Positioning Center (VPC). When a 9-1-1 call is initiated, the VPC allocates an Emergen

42、cy Services Query Key (ESQK) to the call (in a manner similar to the way that an MPC/GMLC allocates an ESRK to a wireless emergency call). The ESQK identifies a call instance at a VPC, and is associated with a particular SR/ESN combination. The ESQK is delivered to the SR (without a callback number)

43、 via an Emergency Services Gateway (ESGW) over an MF or SS7 interface. The SR then queries the SRDB using the ESQK to determine the route (i.e., trunk group) to the target PSAP. The SR delivers the ESQK to the PSAP via MF signaling. The PSAP uses the ESQK to query the ALI system, and the ALI system

44、steers the query back to the VPC (in the same manner as it would steer a query to an MPC/GMLC for a wireless emergency call). The VPC responds with the provisioned location information and a callback number. The ALI system then passes the location and callback information to the PSAP. ATIS-0500034 1

45、1 Figure 4.4 VoIP Originations to E9-1-1 5 NG9-1-1 Architecture Overview The goal of Next Generation 9-1-1 (NG9-1-1) is to provide at least E9-1-1-equivalent functionality in support of emergency call originations from fixed, nomadic, and mobile IP users, and to build on those capabilities to improv

46、e performance and extend feature functionality (e.g., to support delivery of text-based emergency services requests to PSAPs). There are a number of alternative NG9-1-1 Service architectures under discussion in various industry groups. NENA has defined a long term solution for emergency calling, ref

47、erred to as the i3 Solution, whose end state assumes end-to-end IP signaling from an IP-enabled endpoint to an IP-enabled PSAP, with callback and caller location information provided to the PSAP with the call. Similarly, a joint work group in ATIS is defining the architecture, protocol, and procedur

48、es to support the processing of emergency calls by an IP Multimedia Subsystem (IMS)-based NG Emergency Services Network. Regardless of the Functional Elements and interfaces that make up these architectures, NG9-1-1 Service architectures must, at a minimum, support the E9-1-1 capabilities identified

49、 in Clause 4. A fundamental capability required of any NG Emergency Services network is the ability to selectively route an emergency call to the appropriate PSAP based on the location from which the call was originated. This implies that information identifying the location of the caller must be available at any routing element in the call path. Emergency call setup in an NG9-1-1 environment is expected to be Session Initiation Protocol (SIP)-based. The SIP signaling associated with an emergency session request is expected to include location information, eit