1、Network Reliability Council Focus Group IVEssential Communications During EmergenciesTeam ReportFindings and RecommendationsPertaining toEmergency Service Network ReliabilityJanuary 12, 1996Focus Group Leader: M. Michael FosterGTE Telephone OperationsFocus Group Mentor: Arthur PrestCellular Telecomm
2、unications Industry AssociationiiReport to the Network Reliability Councilby theEssential Communications During Emergencies TeamTable of ContentsPage No.1. Executive Summary 12. Background 42.1 Organization of the Technical Paper . 43. Essential Communications During Emergencies Focus Team Membershi
3、p . 54. Data Collection and Analysis Methodology . 64.1 Introduction . 64.2 9-1-1 Outage Data Collection and Analysis Process . 74.3 Best Practices Questionnaire . 84.3.1 Best Practices Questionnaire Description 84.3.2 Best Practices Data Collection and Analysis Process . 84.4 PSAP Questionnaire 84.
4、4.1 PSAP Questionnaire Description . 84 .4.2 PSAP Data Collection and Analysis Process . 94.5 Alternate Technology Provider (ATP) Questionnaire . 114.5.1 ATP Questionnaire Description . 114.5.2 ATP Data Collection and Analysis Process 125. Study Analysis and Findings . 125.1 Introduction . 125.2 9-1
5、-1 Service Outage Analysis and Findings . 125.3 Best Practice Implementation Analysis and Findings . 135.4 PSAP Analysis and Findings . 185.4.1 PSAP Perceived Network Link Reliability . 185.4.2 PSAP Automatic Location Identificatio n (ALI) System Reliability . 205.4.3 PSAP Alternate Route/Location f
6、or Outage or All Trunk BusyConditions 215.4.4 PSAP Comments Related to Private Switch ALI (PSALI) Arrangements 225.4.5 Other PSAP Special Arrangements . 235.4.6 PSAP Spending Priority . 235.5 Alternative Technology Provider Analysis and Findings 24iii5.5.1 Commercial Mobile Radio Services (CMRS) . 2
7、45.5.1.1 CMRS - Facility Diversity 275.5.1.2 CMRS - Cell Site Power . 275.5.1.3 CMRS - Switching Equipment . 2 75.5.1.4 CMRS - People Plan 285.5.1.5 CMRS - Emergency Calling . 285.5.2 Cable Television Services . 285.5.3 Two-way Radio Networks . 305.5.4 Microwave Systems 305.6 Disaster/Contingency Pl
8、anning Analysis and Findings 305.7 GETS (Government Emergency Telecommunications Service) Analysisand Findings . 325.8 Telecommunications Service Priority (TSP) System Analysis and Findings 325.9 Cellular Priority Access Service (CPAS) Analysis and Findings . 336. Essential Services Best Pr actice R
9、ecommendations . 346.1 Defensive Measures for Interoffice Facilities 366.1.1 Best Practice ES01 Diverse Interoffice Transport Facilities . 366.1.2 Best Practice ES02 Diverse Interoffice Transport Facilities withStandby Protection . 376.1.3 Best Practice ES03 Diverse Interoffice Transport FacilitiesU
10、sing DCS . 376.1.4 Best Practice ES04 Fiber Ring Topologies for 9-1-1 Circuits . 376.1.5 Best Practice ES05 Red-Tagged Diverse Equipment . 386.2 Alternate Path when the P rimary 9-1-1 Interoffice Facility Fails . 386.2.1 Best Practice ES06 Alternate PSAPs from the 9-1-1 Tandem Switch 386.2.2 Best Pr
11、actice ES07 Alternate PSAPs from the Serving End Office 396.2.3 Best Practice ES08 PSTN as a Backup for 9-1-1 Dedicated Trunks 406.2.4 Best Practice ES09 Wireless Network as 9-1-1 Backup for9-1-1 Dedicated Trunks 406.2.5 Best Practice ES10 Intraoffice 9-1-1 Termination to a Mobile PSAP 416.2.6 Best
12、Practice ES11 Backup PSAP in the LECs Serving Office 426.3 Defensive Measures for 9-1-1 Tandem Switches . 426.3.1 Best Practice ES12 Dual Active 9-1-1 Tandem Switches 426.3.2 Best Practice ES13 Re-home to Backup 9-1-1 Tandem Switch 436.3.3 Best Practice ES14 Redundant Paired 9-1-1 Tandem Switches 43
13、6.3.4 Best Practice ES15 Multiple Diverse 9-1-1 Tandem Switches withPaired Diverse DCSs 446.3.5 Best Practice ES16 TOPS as a 9-1-1 Tandem Backup . 446.4 Best Practice ES17 Reverse Trends Toward Centralization . 456.5 Best P ractice ES18 Local Loop Diversity . 456.6 Best Practice ES19 Network Managem
14、ent Center and Repair Priority 456.7 Best Practice ES20 Diverse ALI Data Base Systems 456.8 Mass Call Management . 46iv6.8.1 Best Practice ES21 Move Mass Calling Stimulator away from9-1-1 Tandem Switch . 466.8.2 Best Practice ES22 Pre-Planning for Mass Calling Events 476.9 Contingency Planning . 476
15、.9.1 Best Practice ES23 Contingency Plan Development . 486.9.2 Best Practice ES24 Contingency Plan Training . 496.9.3 Best Practice ES25 Public Education on Proper Use of EssentialCommunications 506.10 Best Practice ES26 Improve Communications among Network Providersand PSAPs . 526.11 Best Practice
16、ES27 Common Channel Signaling (CCS) . 536.12 Best Practice ES28 Critical Response Link Redundancy/Diversity . 536.13 Best Practice ES29 Media and Repair Link Redundancy/Diversity 546.14 Best Practice ES30 Private Switch/Alternative LEC ALI 546.15 Best Practice ES31 CM RS - Emergency Calling . 546.16
17、 Best Practice ES32 Cable Television Services . 546.17 Best Practice ES33 Outage Reporting . 557. Metrics . 558. Path Forward . 558.1 Introduction . 558.2 Lessons Learned on Questionnaire Preparation and Distribution 578.2.1 Time Required for Questionnaire Development 578.2.2 Neutral Responses to Qu
18、estions . 578.2.3 Prototyping the Questionnaire . 578.2.4 Questionnaire Respondents 588.2.5 Increasing Questionnaire Responses . 588.2.6 Technical Informatio n about Essential Communications NetworkConfigurations . 588.3 Emerging Technologies 589. Acknowledgments 5910. References . 6011. Glossary of
19、 Terms and Abbreviations . 62List of ExhibitsvE-1 Companies Responding to the ECOMM Team Surveys . 66E-2 E9-1-1 Portion of the NRC Best Practices Questionnaire for ServiceProviders. 68E-3 Questionnaire for Public Safety Answering Point (PSAP) Information . 72E-4 National Reliability Council PSAP Loc
20、ations . 75E-5 Number of Responden ts to the PSAP Questionnaire by State 76E-6 Questionnaire for Wireless/Satellite/CATV/CAP Information . 78E-7 PSAP Spending Priorities . 80E-8 Other PSAP Suggested Practices to Evaluate 83List of Tables4-1 Number of Companies Surveyed, by Industry Segment . 74-2 AT
21、P Survey Responses Requested and Received, by Industry Segment 126-1 NRC Essential Services Best Practices . 34List of Figures4-1 PSAP Respondent Distribution 105-1 9-1-1 Special Facilities Outages, by Failure Category . 135-2 P SAP Perceived Number of Redundant and Diverse Links . 185-3 Metro Users
22、 - PSAP Perceived Link Reliability 195-4 Non-Metro Users - PSAP Perceived Link Reliability 205-5 PSAP Perceived Database System Reliability 215-6 Percent Alternate Routing, by Type 225-7 PSAP Special Arrangements for Wireline Backup 235-8 PSAP Spending Priorities . 245-9 Contingency Plan for LEC Net
23、work Failure . 315-10 Contingency Plan for PSAP Unavailability . 316-1 Interoffice Facility Architecture with Diversity 366-2 Int eroffice Facility Architecture with DCS Diversity 376-3 Interoffice Facility Architecture with Ring Diversity 386-4 Alternate PSAP for Backup/Overflow . 396-5 Alternate P
24、SAP for Backup/Overflow . 396-6 Diversity Through the Public Switched Telephone Network 406-7 Diversity Through the Wireless Telephone Network 416-8 Diversity Through Intra-Office Call Termination 416-9 Interoffice Facility Architecture with Tandem Diversity 426-10 Interoffice Facility Architecture/
25、Multiple Tandem Diversity . 436-11 TOPS for Backup/Overflow . 446-12 ALI Retrieval Architecture with ALI Diversity 466-13 Media-Stimulated Calling Architecture 471Report to the Network Reliability Councilby theEssential Communications During Emergencies Team1. Executive SummaryAccess to essential em
26、ergency communications must continue, even in the event of a networkoutage. Essential communications during emergencies in this report are focused on two areas: 9-1-1 service that enables the public to request emergency assistance. Government communications that enables government officials to coord
27、inate efforts inresponse to an emergency or disaster.It is important to understand how current and future networks that rely upon new technologies,e.g., commercial mobile radio services (CMRS) or cable television, can back-up existing essentialcommunications networks such as 9-1-1. Focus Group IV of
28、 the Network Reliability Council(NRC) was asked to focus on how effectively these new services can augment and/or replaceessential emergency communications networks that may be unavailable in case of a networkoutage. Further, the Focus Group was asked to assess the effectiveness and implementation s
29、tatusof the E-9-1-1 Best Practice recommendations contained in the 1993 Network Reliability: AReport to the Nation .The term “Recommendation” or “Best Practice” as used in this report is as follows:“Recommendations are those countermeasures (but not the only countermeasures)which go the furthest in
30、eliminating the root cause(s) o f outages. None of the recommendations are construed to be mandatory.Service providers and suppliers are strongly encouraged to study and assess the applicability of all countermeasures for implementation in their company products.It is understood that all countermeas
31、ures may not be applied universally.”The Focus Group, for the purposes of this report, is referred to as the “Essential CommunicationsDuring Emergencies (ECOMM) Team”. The ECOMM Team designed questionnaires to solicitdata from a wide range of traditional and new telecommunications industry companies
32、 and thepublic safety sector including: Local Exchange Carriers (LECs). Public Safety Answering Points (PSAPs). Alternate Technology Providers (ATPs).2The data requests were analyzed and followed up with several interviews. In addition, the teamanalyzed performance data on 9-1-1 outages as reported
33、to the Federal CommunicationsCommission (FCC).The ECOMM Team found the following: Generally, the LECs have implemented (at the 80 to 100 % level) the originalrecommended Best Practices which improve communications with the PSAPs, providediverse routing of transport facilities, improve contingency pl
34、anning, establish diverse ALIdatabase systems, improve Network Management Center procedures, and alleviate theeffects of mass stimulated calling events on 9-1-1 service. Of the seventy-four 9-1-1 reportable outages during the period analyzed, 53 were causedby facility outages. Of the 53 facility out
35、ages, 30 (57%) were in the PSAP network and 23(43%) were in the LEC network. Cable cuts are the major causes of these outages. In the PSAP networks, only 30% of the PSAPs have a dedicated link to the media andonly 22% have a dedicated link to the LEC repair center. During periods of networkcongestio
36、n or network outage conditions, the PSAP should have the means tocommunicate with the public to reduce call attempts and an available link to theappropriate LEC for assistance and response. While 78% of the PSAPs have established some form of alternate route capability, only28% have automatic altern
37、ate routing. Any delay caused by lack of alternate routing couldresult in the loss of 9-1-1 calls. The cellular industry handles over 18,000 calls daily to 9-1-1. Routing and identification ofwireless callers are considered significant problems for emergency service providers. PSAP administrators in
38、dicate that if additional funding were available to them, 54% wouldinvest in improving display capability and 39% would invest in improving the reliability ofthe network or Automatic Location Identification (ALI) units.The ECOMM Team makes the following recommendations to improve essential communica
39、tionsduring emergencies: LECs should continue to implement those Best Practices identified as defensive measuresfor interoffice facilities to eliminate single link failure points. Configuration arrangementsto be considered include:- Providing for facility route redundancy and diversity.- Arranging f
40、or inter-jurisdictional call taking and/or PSAP backup location.- Providing for automatic alternate facility route selection via redundant tandemswitch arrangements.3 PSAPs should improve their networks to eliminate single link points between end officesand the PSAP. PSAPs should implement those Bes
41、t Practices that will provide appropriate call routingarchitectures to reach the media or LEC repair forces during network congestion orfailure. LECs and PSAPs should continually work to improve information and communicationsflow between themselves to avoid procedural errors due to switch, facility,
42、 and softwareconversions. PSAPs should focus on improving their network and ALI reliability when funds areavailable. CMRS and cable television operators should develop, in partnership with the PSAPs,work plans to support essential communications during emergencies. CMRS providers should work to impl
43、ement practices and standards in support of wirelesscaller identification (including location) for E-9-1-1. The former Best Practice recommendation to avoid use of CCS networks (e.g., SignalingSystem 7) for emergency communications was determined to be obsolete. The CCStechnology and network have ma
44、tured, and are now considered safe to use for emergencycommunications applications.Detailed descriptions of each of the Best Practices recommended by the ECOMM Team may befound in Section 6 of this report.The rapid introduction of new technology, continual organizational churn within the providerind
45、ustry, and cost pressures within the PSAP community lead to the major conclusions of theECOMM team: There is a critical need for the provider industry and PSAP community to work moreclosely together to improve communications and information flow, not only duringemergencies, but also in day-to-day op
46、erations. Proper implementation of a number of selected Best Practices will enhance the servicereliability of both the LEC and PSAP networks. The use of alternate technologies as backup for these networks will be beneficial to servicereliability.2. Background4The FCC referred, in Docket 91-273 Secon
47、d Report and Order, several issues to the newlychartered NRC. Three were assigned to the ECOMM Team for study. Specifically, the ECOMMTeam was to: Analyze the current effectiveness of essential communications and make improvementrecommendations. Explore how/where alternate technologies can augment e
48、ssential communications duringmajor outages or emergencies. Identify methods to educate the public on when and how to contact emergency responseagencies during emergency/disaster situations.2.1 Organization of the Technical PaperSection 1: Executive SummarySection 2: BackgroundSection 3: ECOMM Team
49、MembershipSection 4: Data Collection and Analysis MethodologySection 5: Study Analysis and FindingsSection 6: Essential Services Best Practice RecommendationsSection 7: MetricsSection 8: Path ForwardSection 9: AcknowledgmentsSection 10: ReferencesSection 11: Glossary of Terms and AbbreviationsExhibits53. Essential Communications During Emergencies Focus Team MembershipNRC Focus Group IV-Team LeaderCompany AffiliationMike Foster GTE Telephone OperationsNo Rest IITeam ChampionArth
