PSAP Operations Guide for Wireless July 2005

Transcription

1 PSAP Operations Guide for Wireless July 2005

2 Notice 2005 Intrado Inc., Longmont, Colorado, USA - All rights reserved. Intrado, triangle beacon design, Informed Response, and the logo forms of the foregoing, are trademarks and/or service marks of Intrado Inc. in the United States, other countries, or both and may be registered therein. This documentation may not be altered, copied, distributed, published, displayed, or reproduced in whole or in part without Intrado's prior written consent except as otherwise provided in writing. Any authorized use, in whole or in part, must contain the following statement: 2005 Intrado Inc. All rights reserved. Trademark Information All trademarks are properties of their respective owners. It is the policy of Intrado to improve products and services as new technology, software, hardware, and firmware become available. Intrado, therefore, reserves the right to change specifications without prior notice. PSAP Operations Guide for Wireless ii

3 Table of Contents INTRODUCTION... 1 A BRIEF HISTORY OF WIRELESS E GETTING READY FOR PHASE I... 5 GETTING READY FOR PHASE II... 7 PHASE I OVERVIEW... 8 PHASE I TECHNOLOGY OVERVIEW... 9 PHASE I WHAT THE DISPATCHER SEES PHASE II TECHNOLOGY OVERVIEW GLOBAL SYSTEM FOR MOBILE COMMUNICATIONS OTHER SOLUTIONS ACCURACY TESTING AND VERIFICATION PHASE II WHAT THE DISPATCHER SEES LOCATION RE-QUERIES AND MID-CALL UPDATES FREQUENTLY ASKED QUESTIONS GLOSSARY PSAP Operations Guide for Wireless iii

4 INTRODUCTION Authorities involved in find themselves facing ever changing and new technologies giving people the ability to access emergency services by multiple means. This document provides information about wireless Enhanced (E9-1-1) history, technology, mandates, and implementation activities. Intrado Inc. has been involved in developing processes, identifying technical methodologies, and deploying wireless E since This document represents the collective knowledge of individuals who have faced similar challenges. Intrado provides this information to help you deploy, train, and understand wireless E PSAP Operations Guide for Wireless

5 A BRIEF HISTORY OF WIRELESS E9-1-1 Earlier solutions for wireless E9-1-1 implementation were developed based on the call flow model that E9-1-1 systems have been operating under since the 1970s. Alternative solutions have been developed that minimize the economic impact of adding wireless to the existing E9-1-1 infrastructure. There are a few core methods used by Intrado and others for connecting wireless calls through the Mobile Switching Center (MSC) to the Public Safety Answering Point (PSAP) and moving the call-back number and cell site information either directly to the PSAP or to the Automatic Location Identification (ALI) database for subsequent display at the PSAP. Those methods are discussed later in this document. Wireline E9-1-1 infrastructure has been implemented in the United States since the 1970s, using primarily analog technology. The wireline version of E9-1-1 uses a single telephone number Automatic Number Identification (ANI) to route the call and retrieve the data that provides PSAPs with information about who is calling and where the caller is located. With the advent of wireless telecommunications and its inherent mobility the "who" and "where" were no longer associated with the caller s telephone number. The challenge in integrating wireless and wireline technologies is to provide the PSAPs with essentially the same information to which they are accustomed to receiving from the wireline system. After several years of handling wireless calls without any associated data, the public safety community embodied by several national professional organizations (NENA, APCO, and NASNA 1 ) joined together in 1994 to officially lobby the Federal Communications Commission (FCC) for service parity between existing wireline E9-1-1 systems and wireless services. The Commission requested that wireless subscribers be provided the same level of service available to wireline subscribers. The result of the Commission s efforts was the opening of a Notice of Proposed Rule Making (NPRM) in FCC Docket # The magnitude of the technical challenge became evident to the communications industry and professionals as soon as the NPRM was released for comment. The result of these comments led the FCC to release a Report and Order (R&O) that identified two phases of implementation, occurring over a specified time period, to allow for appropriate technological adjustments to bring wireless service up to par with wireline service. Phase I requires that the calling party s mobile telephone number and location of the cell site and sector from which the call originated be delivered to the PSAP. The logic was that the caller s number would be used to call back in the event the connection was lost; and the location of the originating cell site and sector would provide a level of location information that would allow delivery of the call to the appropriate PSAP. 1 NENA: National Emergency Number Association; APCO: Associated Public Safety Communications Officers; and NASNA: National Association of State Nine-One-One Administrators. PSAP Operations Guide for Wireless

6 Phase II requires that the mobile telephone number and location of the caller, within a specified accuracy margin, be delivered to the call taker in the form of earth coordinates (latitude and longitude). This phase requires the incorporation of new components into the wireless infrastructure to determine and provide the specific location information. When the FCC s R&O was released, there were a limited number of location technologies being used and tested in connection with the Department of Defense and other research activities. Since that time, wireless use across the country has exploded. In some markets, customers have actually chosen to discard their wired telephone service in exchange for the much more portable and sometimes more cost-effective wireless service. The growth can be seen in these numbers: Year Number of Subscribers million million million million million The first proposed wireless solution used Call-path Associated Signaling (CAS). CAS allowed for the caller s wireless telephone number to be routed along with the voice call to the PSAP. Both the Telecommunications Industry Association (TIA) and NENA supported this solution. This method followed the existing wireline model: the caller s number (ANI) would arrive with the voice and be displayed for the call taker. In a wireline E9-1-1 system, the ANI not only identifies the caller s telephone number but is used to retrieve the ALI from the database. Given that wireless callers are often on the move and there is no static relationship between their location and their callback number, a modification was needed to route the call within the existing wireline infrastructure. The response to this need in a CAS solution was the creation of a pseudo-ani (pani) for each sector of each Phase I cell site. The pani, like a telephone number (ANI), is a ten-digit number that cannot be assigned to a wireless subscriber s telephone and is only used to provide routing and location information to the wireless E9-1-1 system. Because the cell site, unlike the wireless telephone, is at a fixed location, the pani assigned to a sector of a cell site can be used to route the call to the correct PSAP and retrieve the ALI from the database. A second issue related to ANI delivery was that some wireline systems used a type of shorthand or numbering plan digit (NPD) for identifying the area code of the calling party. The trunk group delivering each ANI to the selective router represented a specific area code, or numbering plan area (NPA). In addition, there was a limitation of four NPAs that any specific selective router could manage. In the wireless environment, a cell PSAP Operations Guide for Wireless

7 phone user whose telephone has a New York area code can make a wireless call in California as easily as local users who may need to make calls. This means that any number of NPAs had to be supported by a selective router. In order for the CAS solution to work, network-signaling capabilities had to be enhanced to allow both the caller s callback number and a pani in the delivery of a wireless call to a PSAP. In effect, the proposed solution more than doubled the number of digits from eight to twenty that would be forwarded to the PSAP. This change created other issues within the existing systems, such as network capabilities, call set-up time, and limitations of PSAP customer premise equipment (CPE). As a result, additional solutions emerged for deployment of Wireless E9-1-1, including Non-Call-path Associated Signaling (NCAS), Hybrid CAS, and NCAS with WID solutions. PSAP Operations Guide for Wireless

8 GETTING READY FOR WIRELESS This section highlights the steps necessary to become ready at the PSAP level to accept wireless enhanced calls and to have all the necessary data elements available to the public safety professionals who are responsible for answering the caller s request for service. GETTING READY FOR PHASE I The PSAP must address administrative, operational, and technical considerations to prepare for wireless E For public safety related to Phase I, the FCC requires that the PSAP: Is capable of receiving and using Phase I data Has a mechanism in place to pay their costs associated with the service Requests the service in writing from the wireless carrier. When all of these requirements are met, the wireless carrier has six months or 180 days to either provide the service or have the consensus of the authority for a later deadline. Deployment of Phase I service also requires that the PSAP coordinate with the Local Exchange Carrier (LEC) and/or service provider to do the following: Assure and/or modify the ALI format to allow the wireless caller s information to be displayed correctly on the PSAP s ALI screen Request an Emergency Services Number (ESN) for wireless E9-1-1 calls Request (from ALI provider) that appropriate MSAGs be built for wireless records Determine the PSAP s SR to PSAP trunking configuration for wireless calls. Some considerations for this decision are as follows: - Does the PSAP want both wireless and wireline calls to be transported across the same trunks? If the answer is yes, are there currently enough trunks? OR - Does the PSAP want dedicated wireline and wireless trunks? If the answer is yes, does the PSAP s CPE need to be upgraded to accommodate this configuration? The following table shows the deployment process and roles and responsibilities during the Phase I deployment process. PSAP Operations Guide for Wireless

9 Item PSAP LEC WSP 3 rd Party Send request for wireless E9-1-1 service (RFS) to the wireless service provider (WSP). Notify Intrado (3 rd -party provider) to proceed with deployment. Gather specific PSAP information. Verify PSAP boundary. Provide MSC and cell site data to 3 rd -party vendor. Plot wireless carrier cell sites on the verified PSAP boundary map. Perform network analysis/recommend an appropriate number of MSC to SR trunks. Order and install required MSC to SR trunks. Connect MSC to MPC/GMLC (initial market deployment) Request/provide routing numbers. Discuss PSAP ALI screen display format. Determine default and alternate routing requirements at the MSC. Determine sector routing and PSAP cell sector location description. Determine whether new ESNs will be used for wireless calls. Ensure MSAGs are built to support wireless deployment. Provision ALI database records. Provision E9-1-1 selective router. Configure and provision MPC/GMLC. Incorporate E9-1-1 translations into wireless carrier s MSC. Verify network, selective router, ALI database and MPC/GMLC readiness. Determine testing schedule. Provide all routing and test documentation. Conduct pre-deployment testing of all network components. Conduct pre-production and live call testing at all cell sectors. Declare cutover a success! PSAP Operations Guide for Wireless

10 GETTING READY FOR PHASE II The considerations that have to be made for Phase II wireless E9-1-1 service are similar to the considerations for Phase I. For public safety related to Phase II, the FCC requires the following from the PSAP: Is capable of receiving, displaying, and using the horizontal latitude/longitude coordinates Has a mechanism in place to pay their costs associated with the service Requests the service in writing from the wireless carrier When all of these requirements are met, the wireless carrier has six months or 180 days to either provide the service or have the consensus of the authority for a later deadline. Note: Many of the carriers have been granted waivers in reference to the six-month deadline. Please check the FCC website at to verify the new date requirements. As in Phase II, the PSAP must coordinate with the LEC and/or service providers to ensure the following: The LEC and/or database provider has the proper interface in place to the database. The current interfaces are E2, E2 Plus, or enhanced PAM. The ALI format is modified to allow the display of the latitude/longitude coordinates. The CPE can manually re-query the ALI database to request updates for the location of the Phase II caller. If the PSAP has chosen to interface with a mapping system and/or computer-aided dispatch (CAD) system, the PSAP must make sure the interface and data format from the CPE to these systems meets all of the requirements to display and use the Phase II data properly. If Intrado has not verified your PSAP boundaries within the previous six months, Intrado will contact you to verify the wireless jurisdictional boundary. PSAP Operations Guide for Wireless

11 PHASE I OVERVIEW This section starts with a high-level understanding of wireless Phase 0 and provides a discussion of the technical solutions employed in wireless E A number of Phase 1 and Phase 2 solutions are discussed and illustrated with appropriate diagrams to provide you with an overview of wireless To develop an understanding of wireless 9-1-1, it is extremely helpful to understand the wireline environment from which it evolved. The Wireline E9-1-1 Call Environment E9-1-1 networks components operate together in order to deliver a call including caller data to a PSAP. In the wireline E9-1-1 environment, a call is placed from a wireline telephone and sent to the local central office that serves that specific telephone. The central office recognizes the call as and forwards the call to a specialized switch, referred to as a selective router. The selective router routes both the voice and the caller s telephone number (ANI) to the appropriate PSAP. The PSAP s Customer Premise Equipment (CPE) uses the ANI to retrieve the caller s Automatic Location Information (ALI) by querying the ALI database. Landline Phone Central Office 911 Selective Router ANI Controller PSAP ANI (TN) ANI (TN) Workstation ALI Controller Telephone ANI (TN) Location Information = Voice Path = Data Path PSAP's ALI What is Phase 0? Wireless Phase 0 is the delivery of the wireless call to a PSAP without the display of any caller information. In most cases, Phase 0 calls are delivered through the public telephone switch network to the PSAP. However, in some limited situations, Phase 0 calls may be delivered through the trunks to the PSAP. If the call is delivered on an administrative line and the PSAP subscribes to caller ID services through its LEC, the telephone number of the wireless device may be delivered to the call taker. PSAP Operations Guide for Wireless

12 PHASE I TECHNOLOGY OVERVIEW This section discusses the wireline and wireless E9-1-1 network configurations and common Phase 1 solutions. The Wireless E9-1-1 Call Environment There are several Wireless E9-1-1 solutions currently deployed that provide the required voice and data to a PSAP from the WSP s network. These solutions can be grouped into three basic categories: Call-path Associated Signaling (CAS), which uses an expanded call signaling path through the E9-1-1 network; Non-Call-path Associated Signaling (NCAS), which uses digital out-of-band signaling over a separate data path; and Hybrid- CAS (HCAS), which uses an expanded call signaling path to the Selective Router and out of band signaling from Selective Router to ALI to deliver the unique call data. In all of these solutions the WSP must connect a voice and signaling path from its MSC to the E9-1-1 selective router. This transports the caller s voice to the PSAP. The MSC is a switch that serves as the entry point for wireless calls received by multiple cell site sectors into the public switched telephone network (PSTN) and performs a role that is parallel to that of the end office in the wireline environment. Non Call-Path Associated Signaling (NCAS) Solution The NCAS solution uses a Mobile Positioning Center (MPC) or Gateway Mobile Location Center (GMLC) that provides routing of all necessary data to both the MSC and the ALI database. The call is routed by two (2) separate paths to the PSAP. Voice over the voice path and ALI information over the data links are already in place. The voice call and routing number called an Emergency Service Routing Key (ESRK) are delivered to the PSAP through the serving selective router. The MPC/GMLC dynamically populates the callback number and cell sector location information data for this call into the ALI database record indexed by the ESRK (aka pani) assigned to the call. When the PSAP receives the voice call, the ESRK retrieves a record containing the call-back number and the cell site location data from the ALI database. Cell Site MSC 911 Selective Router ANI Controller PSAP ESRK ESRK Workstation 911 (Send) ORREQ/IAM in Message (MSC, Cell Site and Sector IDs, Callback #) ORREQ Response/ IAM Out (ESRK) ALI Push (ESRK, Loc Info, Callback #) ALI Controller Telephone ESRK Location Info Callback # = Voice Path = Data Path MPC Acknowledgment PSAP's ALI NCAS Network Configuration PSAP Operations Guide for Wireless

13 Call-Path Associated Signaling (CAS) Solution The CAS solution delivers the caller s voice and call-back number to the PSAP through the voice portion of the network. The MSC forwards the call-back number along with the voice using a routing number called an Emergency Services Routing Digit (ESRD) that mimics the ANI for the purposes of call routing. To accommodate the transmission of both the ESRD and callback number, CAS requires that 20 digits of data be transmitted to the PSAP along with the voice. The ESRD is pre-provisioned in the selective router and ALI database, similarly to a wireline telephone record, to appropriately route the call based on the cell sector that received it. When the call is received at the PSAP, the ESRD serves as a lookup key into the database to retrieve static cell sector location information. While the use of the CAS solution is a viable solution for Phase I, this solution does not have a migration path from Phase I to Phase II. CAS does not accommodate the additional data latitude and longitude required to identify actual caller location (nor will it in the foreseeable future). With a CAS solution, the SR, SR to PSAP trunks, and PSAP CPE must be capable of receiving 20 digits (accommodating call-back number and the routing number) through the voice call path. Often, the implementation of CAS requires upgrades to selective routers, trunking between selective routers and PSAPs, and upgrades to PSAP CPE to accommodate the extra ANI digits. Cell Site MSC 911 Selective Router ANI Controller PSAP ESRD (pani) + Callback # ESRD (pani) + Callback # Workstation ALI Controller Telephone 911 (Send) = Voice Path ANI (TN) Location Info = Data Path PSAP's ALI PSAP's ALI Call Path Associated Signaling (CAS) PSAP Operations Guide for Wireless

14 Hybrid CAS Hybrid CAS (HCAS) is a combination of CAS and NCAS call delivery. HCAS delivers the call from the wireless carrier s network to the selective router in CAS (full 20 digits). At the router, the ESRD and callback number is sent to the ALI database where ALI creates a temporary record, assigning a routing key to the record (the digits used for the key vary by HCAS solution). The ESRD is used to look up the static location information in ALI. This static location information is copied into the temporary record along with the callback number. The SR then uses the key to deliver voice, over the voice path, to the PSAP. The PSAP s CPE then uses the key to query ALI and obtain the callback and location information for the call. This delivery solution is dependent upon the Local Exchange Carrier s (LEC) or service provider s ability to implement the HCAS software solution within its network (on both the Selective Router and ALI) and is not available in all areas. Cell Site MSC 911 Selective Router ANI Controller PSAP ESRD (pani) + Callback # Key (Callback # or Call ID) Workstation ALI Controller Telephone 911 (Send) = Voice Path Key Key Location Info (inc,y) & Callback # = Data Path ESRD & Callback # PSAP's ALI PSAP's ALI Phase I HCAS Call Flow PSAP Operations Guide for Wireless

15 NCAS Solution with WID Device The functionality of the selective router can be altered to accept twenty digits along the voice path, but if the PSAP on the other end cannot accept the twenty digits, the router must strip off half of those digits to complete the voice call to the PSAP. In some cases, selective router functionality has been altered through either software or hardware upgrades to perform this function. In other cases, a device generically referred to as a wireless integration device (WID) is added into the network to perform this specialized function. A WID can be used to accept 20 digits conveyed from the MSC; the 20 digits are composed of the routing number and the caller s 10-digit number. The WID converts a 10-digit ESRD to an 8-digit ESRD that is then passed with the voice call to the selective router. The WID device routes both the ESRD and the call-back number to the ALI database where the ALI record is dynamically updated with the call-back number. When the PSAP receives the voice call, the PSAP uses the ESRD to query for the ALI record. In some cases mainly related to the type of mobile switch used by the carrier wireless carriers can use this solution to affect only Phase I wireless deployment. Specific technical details must be identified very early during deployment to ensure that the appropriate equipment is available. WIDs can be deployed either by wireless carriers or by LECs to resolve technical systems interface issues if necessary. Similar to the NCAS solution described above, provisioning the ALI record supporting this solution assumes that the caller s call-back number may be dynamically inserted into the ALI record at the time of the call. Information about the cell sector receiving the call is built into an ALI record with the appropriate ESRD number as its lookup key. Cell Site MSC 911 Selective Router ANI Controller PSAP ESRD (pani) Workstation 911 (Send) ESRD (pani) & Callback # WID ESRD (pani) ALI Controller Telephone ESRD Location Info (inc,y) & Callback # ESRD & Callback # = Voice Path = Data Path PSAP's ALI PSAP's ALI WID Solution NCAS PSAP Operations Guide for Wireless

16 Summary Each of the technology solutions described above represents a viable method to provide the Phase I E9-1-1 data to the PSAP, taking into account the needs and capabilities of the WSP, the LEC network, and the PSAP. The selection of the technological solution used to deliver the required Phase I data to the PSAP is dependent upon existing E9-1-1 infrastructure, the technological capabilities of the WSP and the economic realities that PSAPs face. PHASE I WHAT THE DISPATCHER SEES The information displayed at the PSAP to the dispatcher may vary somewhat from the traditional ALI screens, depending on the solution the WSP uses to deploy wireless E Below are examples of the various call technologies. Please remember that individual PSAP equipment may vary from these examples. NCAS Call Display In the NCAS delivery, the call is delivered over two paths. The voice over trunks and the data are retrieved over the ALI circuit or path, just as wireline calls are sent. The ALI record is updated for every call with dynamic information. The ANI or call-back number is displayed along with the identification or description of the cell site. The routing number or ESRK is displayed in the LOC field. The NENA company ID for the wireless carrier whose network is handling the call will also be displayed. The figure below is an example of an NCAS call display. callback number (Dynamic Data in Red) ESN: 787 WIRELESS CARRIER NAME 123 MAIN ST N SECTOR cell sector location description BOULDER PSAP MOBL/WRLS WIRELESS CARRIER ID LOC= routing digit (ESRK/pANI) BOULDER CO WIRELESS - VERIFY VERIFY VERIFY NCAS Call Display Example PSAP Operations Guide for Wireless

17 CAS Call Display In the CAS delivery, the call is delivered over a single path. The ANI or call-back number is displayed along with the identification or description of the cell site. The routing number or ESRD is displayed in the pilot number field. The NENA company ID for the wireless carrier whose network is handling the call will also be displayed. The figure below is an example of a CAS call display. callback number routing digit (ESRD/pANI) ESN: 787 WIRELESS CARRIER NAME 123 MAIN ST cell sector tower address BOULDER PSAP MOBL WIRELESS CARRIER ID LOC = N Sector cell sector location description BOULDER CO WIRELESS - VERIFY VERIFY VERIFY CAS Call Display Example HCAS Call Display The HCAS call is delivered using a combination of NCAS and CAS. From the service provider s selective router, the call is delivered to the PSAP over two paths. The voice on the regular trunks and the data are retrieved over the ALI circuit or path, just as wireline calls are sent. The ALI record is updated for every call with dynamic information. The ANI or call-back number is displayed along with the identification or description of the cell site. The routing number or ESRD is displayed in the pilot number field. The NENA company ID for the wireless carrier, whose network is handling the call, will also be displayed. The figure below is an example of an HCAS call display. callback number routing digit (ESRD/pANI) ESN: 787 WIRELESS CARRIER NAME 123 MAIN ST N SECTOR BOULDER PSAP MOBL/WRLS WIRELESS CARRIER ID BOULDER CO WIRELESS - VERIFY VERIFY VERIFY cell sector location description Phase I HCAS Call Display Example PSAP Operations Guide for Wireless

18 PHASE II TECHNOLOGY OVERVIEW Wireless Phase II requires that the specific location of the caller be delivered to the PSAP in the form of earth coordinates, (latitude/longitude, or x,y). This phase requires the incorporation of a positioning determining entity (PDE) into the wireless infrastructure to determine and provide location information. The FCC defines two types of PDE technology network-based and handset-based. Network-based means that the components needed to determine location are embedded into the wireless E9-1-1 network, such as at the MSC and/or cell sites. Handset-based means that some of the location technology is embedded into the wireless handset, such as a Geographical Positioning System (GPS) chip or software modifications. The FCC adopted accuracy and reliability requirements for ALI as part of its rules for wireless carrier E9-1-1 service in CC Docket No , Revision of the Commission s Rules to Ensure Compatibility with Enhanced 911 Emergency Calling Systems. Those rules were adopted in 1996 and revised in the Third Report and Order in that docket (released October 6, 1999). The revised rules set the following accuracy and reliability requirements for E9-1-1 Phase II operations: For network-based solutions: 100 meters for 67 percent of calls; 300 meters for 95 percent of calls; For handset-based solutions: 50 meters for 67 percent of calls; 150 meters for 95 percent of calls. Phase-in schedules for Phase II are incorporated in Section 20.18(g) of the Commission s Rules (47 C.F.R (g) Cell Site MSC 911 Selective Router (ESNE) ANI Controller PSAP ESRK ESRK Workstation ALI Controller Telephone 911 (Send) = Voice Path = Data Path PDE E12 gposreq (Phase 2 location GPOSREQ (request for location) ORREQ MSC, Cell, Callback # E3 MPC orreq (response)- ESRK POSRTEREQ (,Y) CRDB posrtereq (PSAP) ESPOSREQ (query for locationinitial or update) E2 esposreq (Phase I initial and/or Phase 2 location ESRK PSAP's ALI (ESME) Location Info (inc,y) Callback # ANSI NCAS Phase II Wireless Network Diagram PSAP Operations Guide for Wireless

19 GLOBAL SYSTEM FOR MOBILE COMMUNICATIONS To provide a higher level of functionality for wireless services, there are some WSPs that are moving to the next generation of technology called Global System for Mobile Communications (GSM). The network components, functionality, and terminology related to wireless varies. The network configuration diagram for GSM (below) identifies these differences. In many cases the positioning determining functionality for this technology is embedded in both the wireless handset and the carrier s network. Because of complexities and the recent introduction of GSM in North America, the FCC has provided a phased approach for accuracy and time to deployment. This information is located on the FCC website at BSC SMLC BTS Cell Site MSC Ls ESRK 911 Selective Router (ESNE) ESRK ANI Controller PSAP Workstation ALI Controller Telephone 911 (Send) = Voice Path ISUP Looparound Routing Information Lg Location Information ESPOSREQ (query for locationinitial or update) ESRK Location Info (inc,y) Callback # = Data Path GMLC esposreq (Phase I initial and/or Phase 2 location PSAP's ALI (ESME) GSM MAP NCAS Phase II PSAP Operations Guide for Wireless