Desirable Attributes of Public 

Safety Networks

Vint Cerf

VCAT Chair

18-19 Oct 2011
Members of Public Safety Net 

Sub-Committee

• 1. Vint Cerf – Chair

• 2. Shaygan Kheradpir

• 3. Pradeep Khosla

• 4. Michael McRobbie

• 5. Roberto Padovani

• 6. Darlene Solomon
Charge to VCAT

• Key architectural recommendations for 

wired and wireless networks that take 

into account public safety sector needs

• Comments and recommendations for 

establishing and structuring a NIST 

program in this area
Objectives

• Characterize desirable attributes and 

features of a Public Safety Network 

architecture

• Analyze potential implications

• Augment commercial designs and/or 

services with new capabilities

• Set stage for exploratory design, 

prototyping and testing
Tactical Plan

• VCAT Working Group meets and hears 

presentations from a variety of sources

• Draft questions circulated; comments from a 

range of experts

• Synthesis by the WG via email 

• Final report to the full VCAT and report 

submitted to Undersecretary of NIST and WH 

(CTO)
Context

• 500 MHz bandwidth new assignment

• Funding driven by 700 MHz auction

• State/Local: 758-763 (D),763-768, 788-793 

(D), 793-798 [no guard bands]

– Note: lower band: Base Station Tx

– Note: upper band: Mobile Tx

• PSN Narrowband 

– 769-775, 799-805 MHz in 12.5 KHz channels
Context

• NATIONWIDE BROADBAND 

NETWORK CONCEPTUAL DESIGNS

– MARCH 1, 2011

– SAN ANTONIO, TX.

– NATIONAL PUBLIC SAFETY 

TELECOMMUNICATIONS COUNCIL

• Against “network of networks”

• Promotes “One Nationwide Network”
Context

• Wireless Technology, Prospects and Policy Options, 

NRC, 2011

• FCC NPRM Nationwide, Broadband Interoperable 

Public Safety Network, Jan 2011

• WINNFORUM, Software Defined Radio, Dec 2007, 

Dec 2008

• PSCR (“P25”) Compliance Assessment Program

• DARPA: Maingate (inter-radio-net gateway)

• Wireless Innovation Forum Public Safety Special 

Interest Group analyses (London bombing, chemical 

plant explosion)
Public Meetings

• June 7-8, 2011 VCAT Meeting

• August 10, 2011 APCO (Philadelphia)

• Sept. 7, 2011 SAFECOM (Chicago)

• Sept 13, 2011 PCAST Planning Meeting 

• October 18-19, 2011 VCAT Meeting
Conceptual Features

• Resilient

• Self-organizing

• Strongly access 

controlled

• Meshed

• Compatible with 

commercial 

infrastructure

• Adaptable (e.g multifrequency? SDR?)

• Multi-modal (voice, 

video, data, sensor)

• Open Standards 

(explain)

• Scalable

• Power-aware (battery 

limits); signal power

• Affordable (!)

• Business/opex models
Observations

• Scope of Public Safety “community”

– Distinct from National Security

• Modern Communications

– Voice, video, data

– Packet switched
Observations - 2

• Resilience, Robustness, Recovery

– Redundant provisioning

– Rapid deployment of temp or perm infra

– Critical role of standards (national or local 

caches of equipment)

– Ruggedization (not everything has to be)

– Regional Resilience Networks (?)
Observations - 3

• Security, Authentication, Access Control

– User Name/Password - weak

– Pre-authorization

– Role authorization

– Two-factor authentication

– Distributed authentication
Observations - 3

• Cost

– Serious barrier: affordability

– Standards, competition

– Bulk purchase, warehousing

– Commercial compatibility

– Non-ruggedized for less hostile 

environments
Observations - 4

• Interoperation w/Commercial Systems

– LTE

– Prioritization question

– Extensions beyond LTE (multiradio?)

• Role of 911 and other online systems

– GPS, other location methods

– Sensor networks, civilian inputs
Observations - 5

• Frequency Allocations

– 763-768 MHz (base stn)

– 758-763 MHz (D block)

– 793-798 MHz (mobile)

– 788-793 MHz (D block)

– 769-775 MHz (12.5 KHz channels)

– 799-805 MHz (12.5 KHz channels)

– 4940-4990 MHz 

– 2.4 GHz, 5 GHz license-free

– Television White Spaces

– 60-100 GHz Public Safety Allocations
Observations - 6

• Wired Communications

– Backhaul for wireless (underprovisioned?)

– National and global grid (e.g. Internet)

– Essential for flexible incorporation of all 

potential public safety incident actors
Desirable Features - 1

• Flexible System Architecture

– Internet Protocols

– Small Cells

– Packet multicast and broadcast

– Multi-modal (voice, video, data)

– Maingate concept (US Army, DARPA)

– Delay and Disruption Tolerance

– Peer-to-Peer (“talk around”)
Desirable Features - 2

• Backward Compatibility

– P25 (versions?)

– LTE (and 2G, 3G, 4G?)

– Auto-configuration (gateways)

– Voice broadcast fallback?

• Mesh (MANET) Networking

– Aerostats, Packet Relays

– PSSIG London Bombing Analysis
Desirable Features - 3

• Robustness and Recovery

– Reconstitution

– Rapid deployment

– Redundant provisioning
Desirable Features - 4

• Security and Authentication

– Strong Authentication

– Device, Person, Role Authentication

– Two factor, biometric (?)

– Distributed Authentication Databases
Desirable Features - 5

• Standards

– Use and Development

– SGIP analogy: PSIP

– Facilitate Standards development and 

adoption

– Facilitation of Public Safety “App” Dev’t
Desirable Features - 6 

• Ruggedization

– Interworking of “commercial” and 

“ruggedized” devices (standards again)

– Impact on affordability

– Use while wearing haz-mat protective 

clothing
Desirable Features - 7

• Sensor and Location Systems

– Location of responders

– GPS, Radio Triangulation, WiFi locations

• High Density Radio Operation

– What to say about congestion with high 

density usage?
Prototyping, Collaboration, 

Testing

• NIST Boulder Facilities

• Ft. Bliss? Ft. Huachuca?

• Municipal Facilities (Seattle?)

• Interoperability confirmation

• Realistic Testbeds and Testing

• In regular use to support evolution (not just 

development)
Multiple Stakeholders

• Conventional First Responders

• Volunteers

• Military, National Guard

• Civilian agencies and Private Sector

• Implication: broad ability of PSN to 

support wide range of stakeholder 

interaction.

• Note funding variability
Programmatic Considerations

• Public Safety Interoperability Panel

• Coordinated Research, Development and 

Testing

– NIST, DARPA, NSF, OSTP, NSTC, DHS, NIJ, 

State and Local agencies, private sector public 

safety organizations

– $300M, 5 year program

• Private or Quasi-Public Entity for 

Development (and operation??) of National 

Public Safety System
Research and Development

• Dynamic Spectrum Management

• Power Management

• Mobile, Adhoc Networks and Protocols

• Packet Broadcast and Multicast

• Peer-to-Peer LTE

• Strong Authentication Technology

• Platforms for public safety applications
Research and Development

• Certification regimes and practices

– Note scope (horizontal, vertical!)

• Multi-media applications and integration

• Tools for collaboration (e.g. 

collaborative display)
National Incident Management 

System

• Role for NIMS in the design of the public 

safety network

• See also Emergency Support Function (ESF)

• Policies and procedures for information 

sharing, collaboration, planning

• (should this be placed earlier in the 

document?) - see relevance to scenarios 

section of report.
Notes from Oct 18-19
Notions

• Commonality of functions across system

• Prioritization at need

• QOS (when required)

• Coherent release cycles (implications for 

funding model?)

• Common interfaces (protocols, API, 

application platforms, radio capabilities...) -

allows competitive provisioning

• Uniform, universal access to system
Historical Material
Additional considerations

• Next generation 911 

(role for Internet-like 

facilities) -

leveraging locationbased services in 

private sector

• Operational Cost 

Model(s)

• Business Model(s)
Resilience

• Overcomes local failures (alternate 

routing, alternative transmission 

options, rapid back up deployment)

• Self-relaying mesh capability 

• Redundancy vs armor/gold plate

• Simplex modes of operation? (also 

broadcast?)

• Peer-peer voice (and data)
Self-Organizing

• Neighbor discovery

• Strong Authentication to join network

• Pairwise/Groupwise interoperation 

(direct exchange of “data” by mutually 

authenticated devices)

• Make use of broadcast for efficiency

• Note: LTE may evolve to peer-peer and 

neighbor discovery capability
Strong Authentication

• Nodes mutually authenticate with crypto 

certs

• Cryptographic passwords to join 

network

• Two-factor authentication by users
Meshed

• Nodes are store/forward devices

• Form network using variety of 

underlying transmission alternatives

• Can work with encrypted payloads

• [Is DTN a useful adjunct?]
Commercial Compatibility

• Use organic and commercially available 

transport (LTE, 4G, 3G, 802.11, 802.15.4, 

White Spaces? ...)

• Roberto’s List!!!!

• NOTE: LTE DOES NOT YET SUPPORT 

VOICE! However, it IS digital (and 

packetized?).

• Distinguish services from equipment -

interested in both cases of compatibility.
Adaptability

• Multiple radios and/or software defined 

radio(s) for flexibility

• Using packet methods, support all forms of 

communication

• Allows for mesh networking, error recovery, 

forward error correction...

• Can use alternative routes and transport

• What are the operational modes that need to 

be supported?

• Higher protocol layer awareness of network 

conditions!?
Multi-modal

• Should be able to carry voice, data, 

video, sensor information in digital form

• System should be insensitive to 

application (except perhaps for 

latency?) - prioritization?
Open Standards

• Should use or develop open standards

• Maximize potential for competitive 

procurement

• Maximize interoperability among multiple 

suppliers

• Create Public Safety Interoperability Panel 

(PSIP) to facilitate and identify standards 

requirements and conformance to the 

standards?
Power-Aware

• Protocols sensitive to available battery 

power

• Transmitter power adaptation to 

minimize near-far and hidden 

transmitter problems

• Standards are available to deal with 

these issues.
Affordable!

• Take advantage of commercially available designs

• Operational expense model(s)?

• Business model(s)?

• First responder markets - 4-5 M?

• Are the features of the PS devices also of interest to 

commercial market? Private sector security fire 

services? Federal services? Military services? 

• Note implications of volunteer fire dept operations

• Apparent scale of PS market will not produce 

economy of scale on its own. 

• Is there a commercial “play” to increase $ support for 

the PS “network” (but can be pre-empted)
Questions

1. Can MANET work in same bands as 

LTE? Tentative answer: NO

2. Can we use multiple radios and/or 

software-defined radios to operate in 

multiple bands? YES

3. How can we make “joining” the (a?) 

logical network easy but strongly 

access controlled? TBD
Questions

4. How can we make “roaming” work in MANET 

design? TBD (R&D?)

5. What frequency bands are available? 

802.11? 802.15.4? White Spaces? PSN BB 

and D-Block? 60-100 GHz?

6. Does satellite have a role? Yes, at least for 

backhaul. 

7. What about blimp/balloon or aerostats for 

connectivity? 
Questions

8. How can co-habitation work? CDMA? 

OFDM? Roberto: nope.

9. SDR economics? TBD but probably 

more expensive
Actions
Additional Consultants

• Dave Liddle

• David Reed (ex-MIT)

• Justin Ratner/Craig 

Mundie

• Milo Medin

• Robin Chase 

(MIT/Paris)

• Sascha Meinrath (NEA)

• Stagg Newman (exFCC)

• Donna Dodson (NIST)

• John Gustafson, TX

• Hans-Werner Braun

• Farnam Jahanian 

(NSF/CISE)

• Robert Kahn (CNRI)

• Preston Marshall 

(USC/ISI, ex-DARPA)

• Dereck Orr (NIST)

• Paul Steinberg (cto, 

motorola)

• Henning Schulzrinne 

(FCC)
Summary Public Safety Net

Subcommittee

June 8, 2011
Members of Public Safety Net 

Working Group

• Public Safety Networks

• 1. Vint Cerf – Chair

• 2. Shaygan Kheradpir

• 3. Pradeep Khosla

• 4. Michael McRobbie

• 5. Roberto Padovani

• 6. Darlene Solomon
Charge to VCAT

• Key architectural element 

recommendations for next-gen wireless 

that take into account public safety 

sector needs

• Comments and recommendations for 

establishing and structuring a NIST 

program in this area
Objectives

• Characterize desirable attributes and 

features of a Public Safety Network 

architecture

• Analyze potential implications

• Augment commercial designs and/or 

services with new capabilities

• Set stage for exploratory design, 

prototyping and testing
Tactical Plan

• VCAT Working Group meets and hears presentations 

from a variety of sources

• Draft questions circulated; comments from a range of 

experts

• Synthesis by the WG via email (Google Docs?)

• Final report to the full VCAT and report submitted to 

Undersecretary of NIST and WH (CTO)
Conceptual Features

• Resilient

• Self-organizing

• Strongly access 

controlled

• Meshed

• Compatible with 

commercial 

infrastructure

• Adaptable (e.g multifrequency? SDR?)

• Multi-modal (voice, video, 

data, sensor)

• Open Standards (explain)

• Scalable

• Power-aware (battery 

limits); signal power

• Affordable (!)

• Business/opex models
Notions

• Commonality of functions across system

• Prioritization at need

• QOS (when required)

• Coherent release cycles (implications for funding 

model?)

• Common interfaces (protocols, API, application 

platforms, radio capabilities...) - allows competitive 

provisioning

• Uniform, universal access to system

• Public Safety Interoperability Panel ?
Actions

• Get “Nationwide Broadband Network Conceptual Design” report 

to team (softcopy)

• Develop report outline (Cerf) - July 1

• Final Report Target 9/30 (or earlier if PCAST requires)

• Face/Face or Telephonic meetings during summer? How many? 

3-4 two hour calls. At least one f/f meeting in Boulder - Doodle 

poll for date (CERF) - July??? Aug??? Ask Carla to pursue the 

call schedules.

• Target report for 9/30? Sooner? 9/11 (!)

• Can we also have a non-VCAT working site? Maybe use Google 

Docs? Need to query each participant for gmail address for 

access control. Also set up a mailing list for use in discussions.

• Recommend additional consultants to review and comment on 

draft ideas.
Additional Consultants

• Dave Liddle

• David Reed (ex-MIT)

• Justin Ratner/Craig Mundie

• Milo Medin

• Robin Chase (MIT/Paris)

• Sascha Meinrath (NEA)

• Stagg Newman (ex-FCC)

• Donna Dodson (NIST)

• Hans-Werner Braun

• Farnam Jahanian 

(NSF/CISE)

• Robert Kahn (CNRI)

• Preston Marshall (USC/ISI, 

ex-DARPA)

• Dereck Orr (NIST)

• Paul Steinberg (cto, 

motorola)

• Henning Schulzrinne (FCC)
This is a sample slide that is 

used for video B-roll

• Gotta get back to 

woodhurst for dinner 

and remember to 

open the wine in 

time to breathe!

• Gotta check out the 

chardonnay - is it 

really ok? Meusault 

vs the pulignymontrachet, for 

example.
Dinner menu?

• Jose Andres is going to enjoy product from 

his own team but they don’t know that yet!!

• Lessee, we will start with appetizers and then 

go to salad and main courses. I can’t 

remember whether we are going to have a 

fish course or not. Have to check with Sigrid. 

• Also need to make sure we can keep the 

white wine cool - we have a problem in that 

we only have the one cooling bin for white 

wine. Maybe we can order a couple more of 

them?