Subject: [NEXTEL-1] Homeland Security and Public Safety Networks Countering Terrorisim and Disasters with Technology

From: Marcel <[email-masked]>
Date: Sun, 16 Mar 2003 18:44:12 -0500

Homeland Security and Public Safety Networks Countering Terrorisim and Disasters with
Technology

; Preamble

One of the six focus areas identified by The ATM Forum in their “Broadband Roadmap” is
that of Homeland Security and Public Safety networks. The roadmap approaches these as
market opportunities – with three new networking architectures and three innovative
application areas. This topic is one of the new application areas.

The role of ATM has long been established in many military and public service networks.
However, it became necessary to assess in what way the latest Government sponsored
Homeland Security initiatives and investment in networking infrastructure to support
Public Safety networks would present new requirements on the underlying networking
technologies.

The ATM Forum featured this topic as the basis for its Broadband Exchange in October 2002.
As the latest in a series of events it supports The ATM Forum’s broadband roadmap to bring
together industry groups with common aims to accelerate the deployment of new broadband
solutions.

The ATM Forum has collaborated with ETSI and the TIA to investigate this subject. This
white paper looks at some of the key findings that have evolved from this collaboration;
it also paves the way for defining the next steps for The ATM Forum in developing the
specifications required.

The two topics of Homeland Security and Public Safety networks have both separate needs
and purpose but also have interdependencies and reliance on common technologies. Given the
breadth of these topics emphasis has been placed on these areas of commonality. A major
part of Public Safety networks actually relates to those operated by the emergency
services. In terms of commonality, air transportation is an example of an area that spans
both topics. Perhaps the most visible example of this is the Air Traffic Control network
that is featured as a case study in this white paper. Clearly, the result of terrorist
activity requires co-ordination within the emergency services. It is for this reason that
both topics have been approached as part of a single area of focus for The ATM Forum. In
order to assist the reader in understanding the structure of the white paper, the first
four sections take an introductory view and analysis of the key technology requirements
for each of Homeland Security and Public Safety networks. The next section looks at the
organisations active in these areas and their collaborative projects. The emphasis then
moves to the technology and examines firstly the supporting technologies required for
Homeland Security and Public Safety networks and then the work of The ATM Forum in
connection with some of these technology areas. The white paper concludes with a case
study of an Air Traffic Control (ATC) network and finally with identification of potential
work items for The ATM Forum.

Table of Contents

1. Introduction to Homeland Security

2. Introduction to Public Safety Networks

3. Key Technology Requirements for Homeland Security

4. Key Technology Requirements for Public Safety Networks

5. ETSI Collabroative Projects

5.1 Project MESA

5.2 ETSI EMTEL Project

5.2.1 User Needs

5.2.2 Standardization

6. Key Technology Areas

6.1 Digital Radio

6.1.1 TETRA

6.1.2 Project 25

6.2 Security

6.3 ATM as a Supporting Technolgy

7. ATM Supporting Features and ATM Forum Specifications

7.1 Security

7.1.1 User Plane Security Services

7.1.2 Authentication

7.1.3 Confidentiality

7.1.4 Integrity

7.1.5 Access Control

7.2 Bandwidth Efficient Voice (AAL2)

7.3 Session Control and Routing

7.3.1 Mobile PNNI

7.3.2 Soft PVC

7.4 Q0S

8. Case Study - Air Traffic ControI

9. Future Work Plans

10. Conclusions

Appendix

1. Introduction Homeland Security

Homeland Security has now become a familiar term in the US, especially since the events of
September 11th brought to light the vulnerability of any nation’s infrastructure to a
terrorist attack. However, it would be overly simplistic to assume that this is an
initiative sparked by recent events or one that relates only to the US. The underlying
concept and requirements have been around for decades. Homeland Security is very much a
global concern. Even the terminology is becoming more commonplace in these days of a
global market. Even where the term has not yet become a part of everyday language,
governments have established counter terrorism units within their own national defence
organisations.

Homeland Security includes the protection of operations and infrastructures critical to
public health and safety and the national economy. This entails protecting government
operations, transportation, telecommunications, financial regulation, information systems,
law enforcement organizations, emergency operations and utilities such as gas and oil,
electrical energy and water supply systems.

So while the requirement for these matters to be taken seriously may have existed for some
years, it is perhaps the evolution of technology that required more sophisticated
technology counter measures. Also, as was demonstrated on September 11th, the scale of
potential disaster is now much greater. It also represents an area of battle fought, not
just with conventional weapons, but also with information and communications. Networking
technology will therefore be used both as a weapon and as a counter measure. It is for
that reason that networking is gaining more prominence as a key part of the overall
Homeland Security picture.

It is fair to say that various initiatives have gathered pace since September 11th with
the US having established the Office of Homeland Security on October 8th, 2001, to develop
and coordinate the implementation of a comprehensive, national strategy for homeland
defense and to protect the United States from terrorist threats or attacks. There have
been calls around the world for national governments to establish comparable bureaus.

Homeland Security establishes a set of standards for dealing with disasters or threats to
national security – that will allow officials to “detect, prepare for, prevent, protect
against, respond to and recover from terrorist threats or attacks.”

It is generally agreed that information technology, and specifically that of networking
and communications, will play a significant role in these counter-terrorism efforts

2. Introduction to Public Safety Networks

The area of Public Safety networks actually extends to cover the entire area of Emergency
Services. Public safety "users" includes all criminal justice services, emergency
management, emergency medical services (EMS), fire, land, natural resource management,
military, transportation, wildlife management, and other similar governmental and quasi
governmental functions that have a need for aeronautical and terrestrial, high-speed,
broadband, digital, mobile wireless communications and telemetry-related services and
applications.

Understandably, various Public Safety and Emergency Services may have very different
communications needs, which may differ between individual agencies and countries. Having a
common, standardized broadband communications system will help to ensure interoperability
of Public Safety and Emergency Services applications, within and between agencies and/or
countries. Also, to facilitate effective communication and interoperability in emergency
situations, it is crucial that both users and various types of user devices can
communicate with each other, allowing for information exchange via multiple and divergent
facilities, platforms and devices.

3. Key Technology Requirements for Homeland Security

One of the greatest challenges of creating a single infrastructure is that it calls for
various levels of government (from federal through to local) and the private sector to
coordinate efforts that facilitate the exchange of intelligence information. The
sometimes-frantic response to the September 11th attacks demonstrated the need for the
immediate availability of information on potential individual terrorists or terrorist
organizations. It became evident that it was not the fact that the information didn’t
exist but it was housed, at varying levels of detail, in a variety of sources owned by
different agencies. The challenge is to allow information access and flow to appropriate
agencies that require the same level of information. This methodology would be impossible
for agencies to follow without a constant exchange of information and best practices.

Another aspect is that of timeliness. Organizations involved in Homeland Security need to
access accurate information in a timely manner. In times of crisis, it is especially
important to be able to get the right information in the hands of the appropriate people.
Given that the majority of infrastructures are both privately and government-owned, it is
essential for the public and private sectors to share knowledge and experience. In order
to meet this challenge, agencies involved in Homeland Security are increasingly looking to
sophisticated networked infrastructures.

But this can itself present a significant challenge, particularly for agencies that store
vast amounts of sensitive data. How then to keep this information secure? Most security
regimes exist specifically to prevent the free flowing of sensitive information. So, even
with the help of new technology, collaborating and sharing data is not simple, given the
typically differing security requirements of each agency involved.

The requirements then can be grouped into the following areas. Any technology
infrastructure must support each of these areas.

1. Data: The gathering and centralizing of data from multiple sources into a common data
repository requires consolidation of data from many disparate sources into a single entity
thereby making the task of analysis simpler.

2. Security: Sharing information among agencies requires a comprehensive and pervasive
security architecture that ensures individual privacy and protection of critical
intelligence. Sharing and security are often seen at odds. Powerful transaction-level
analysis is required with authentication capabilities built in to its architecture to
allow agencies to limit access to data as necessary.

3. Analysis: There is a need to conduct various analyses to track performance, identify
risk factors, and predict activity. These capabilities should include statistical
functionality as well as simple report viewing and data manipulation. Various supporting
systems should supply query, reporting and analysis capabilities that apply to users at
all levels within an organization.

4. Information Access and Delivery: This is an area where the role of the network becomes
critical. Accessing reports via Web, wireless and voice and personalized alerting.
Organizations involved in Homeland Security should be able to distribute information to
thousands of users in a format with which they are familiar, or deliver critical alerts
simultaneously to thousands of users instantaneously. Speed of delivery is key as is the
certainty that critical information has been received and understood. Users should be able
to access information quickly and easily via their conventional network access devices.
They should also have the ability to automatically receive reports and information via
email and wireless devices, like mobile phones and personal digital assistants (PDAs).

5. Action: The availability of accurate data and analysis capabilities drives appropriate
actions. Homeland Security officials should be able to further interact with data to
replicate solutions and best practices across multiple departments or agencies.

4. Key Technology Requirements for Public Safety Networks

A prime example of the requirements for PSN can be seen with the Statement of Requirements
developed by Project MESA. The work of Project MESA is covered in the next section. The
SoR describes and defines future MESA specifications involving technical specifications,
air interfaces, proposed applications and data rates (2 Mb/s or greater). The SoR also
includes descriptions of multiple levels of security and encryption to allow public
safety/public protection professionals to communicate over a wide area, using a myriad of
input/output technological platforms and applications that would include, but not be
limited to, secure information, voice, video and infrared video, high-speed data, still
photos, enhanced patient and firefighter bio-telemetry information.

It can be found at www.projectmesa.org/SOR.htm. The users of professional wireless
telecommunications equipment within the Sector of Public Safety, Protection and Disaster
Relief (PPDR) have developed the MESA Statement of Requirements document, as they are
uniquely aware of, and therefore most qualified to define, qualify and quantify the
current and future requirements of Public Safety and other Emergency Services users. It
describes the services and applications that a future advanced wireless telecommunications
system must be able to support in order to realize the most effective operational
environment. Emphasis has been placed on those applications that current applied
technology cannot carry out to the fullest extent, but have been identified by the users
and their agencies to be key requirements.

It would be beyond the scope of this white paper to examine all the requirements
identified by Project MESA but the following list highlights some of the more important
aspects.

Real-time, high-speed wireless access and transmission of remote computer applications and
files.
Rapid messaging, including e-mail, free-form text, and file transfers.
Constantly updated personnel and equipment location and status data.
Aerial video for major events, or disaster response coordination.
Transmission and reception of high-resolution digital images, including maps, floor plans
and complex diagrams.
Satellite connectivity of disaster “hot-spots.”
Bandwidth on demand.
Prioritization of services.
Highly secure (encrypted) as may be required.
Finally, it represents the establishment of a clear understanding that the advanced needs
of the PPDR Sector should be based on a high mobility broadband wireless network that
allows the provision of dynamic bandwidth, offering self-healing characteristics and
secure network access. The Project MESA SoR also reflects the vision of a mobile
broadband-shared network that can be simultaneously accessed by multiple users, with
multiple applications in a specified geographical area that may be fully independent from
availability of public networks and supply of electrical power.

5. ETSI Collaborative Projects

Although not the only organisation with an interest in the topic, ETSI has been highly
active in supporting these areas through the formation of projects. These projects not
only bring together key representatives from within the associated industries but also
provides a mechanism for collaboration with other industry bodies that share common goals.

5. Project Mesa

  Project MESA is the first international communications research and development
standardization partnership project whose aim is to develop joint specifications for
advanced and future public safety/emergency response communications. Its scope covers
mobile broadband communications technology involving Law Enforcement, Fire Fighting,
Homeland Security, National/International Crime and Terror investigations, Emergency and
Medical Services and Disaster Response (including mass destruction and bio-terrorism)
professionals. The International Telecommunication Union (ITU) refers to such applications
as Public Protection and Disaster Relief (PPDR). The project was given the name “Project
MESA” in recognition of the city, where the partnership agreement was finalized. The
current Partnership Agreement for Project MESA was ratified January 2001 in the City of
Mesa, Arizona between the Telecommunications Industry Association (TIA) of the U.S.A. and
the European Telecommunications Standards Institute (ETSI) of Europe.

Due to commonalities TIA and ETSI agreed to collaborate and combine work efforts to
provide a forum in which the key players and users cancontribute actively to the
elaboration of MESA specifications. Please refer to the www.projectmesa.org website for
further information.
Other organizations/agencies that actively support Project MESA include the Association of
Public Safety Communications Officials (APCO), the Project 25 Steering Committee, the
Federal Bureau of Investigation (FBI), and the National Institute of Justice (NIJ), the
United Nations (UN), the National Telecommunications and Information Administration
(NTIA), the Federal Law Enforcement Wireless Users Group (FLEWUG), British Chapter of APCO
(BAPCO), United Kingdom Home Office, United Kingdom Emergency Medical, Copenhagen Fire
Brigade, Norway Emergency Health Services, the Royal Canadian Mounted Police, the American
Red Cross and many other Public Protection agencies.

At its last meeting in Copenhagen, the Project MESA Steering Committee approved three
documents: Project MESA Definitions, Symbols and Abbreviations; the Project MESA Statement
of Requirement (SoR) Matrix; and the revised and updated SoR. Additionally, as a result of
the SoR, industry experts are becoming increasingly involved in the comprehensive
elaboration of user needs into technical specifications. As such, technical groups within
MESA are now active and addressing this phase of the project.

The end result of this Public Safety/Emergency Services user-oriented activity will be a
suite of coordinated specifications and future standards designed for advanced, broadband,
interoperable, terrestrial mobility operations, including connectivity to broadband
satellite communications services, driven by common scenarios (including ATM as well as
other transport technology standards and specifications). These requirements can be
tailored for specific local and regional implementation scenarios and situations. Such
standards and specifications will be designed to benefit the Public Safety/Emergency
Services community and each nation’s citizens. The realisation of these standards and
specifications will be split between system users and system providers.

..
Source : Project MESA

5.2 ETSI EMTEL Project

In addition to their involvement in the Project MESA initiative, ETSI also has a working
group focused on the concept of Emergency Telecommunications (EMTEL) that addresses a
broad spectrum of aspects related to the provisioning of telecommunications services in
emergency situations.

Emergency situations may range from a narrow perspective of an individual being in a state
of personal emergency to a very broad perspective of serious disruptions to the
functioning of society (such as earthquakes, flood, landslides, cyclones, volcanic
eruptions, etc.).

The concept also covers the telecommunications needs of the society's dedicated resources
for ensuring public safety, including police forces, fire fighting units, ambulance
services and other health and medical services, as well as civil defense services.
Telecommunications needs for such services have until now been satisfied by dedicated
telecommunication networks and equipment, often different for the different services, but
it is with modern technology possible to increasingly integrate such services with the
public telecommunications services.

Terrestrial and satellite radio/TV broadcasting and Internet services provide means for
dissemination of information to the general public, in particular in hazardous and
disaster situations.

The provisioning of emergency telecommunications services is particularly important, but
also very difficult to establish and maintain, in disaster situations leading to major
destruction of the telecommunication network. Networks and services may have to be
restored or reinforced with temporary equipment with various degrees of mobility (e.g.
network base stations brought in by helicopters, land or air based communications units,
etc.).

Events that seriously degrade public telecommunications services may also cause situations
that, together with other events or processes, potentially create threats to human safety.

5.2.1 User Needs

The handling of equipment and the use of the facilities are typically non-frequent and
must therefore be simple and intuitive. The user won't have time, or would be simply too
stressed, to be able to learn how to use such equipment and services.

The increasing mobility of people, inside and outside their home territories and language
areas, puts additional requirements on the chain of communication - from human to human,
including the telecommunications part - and provides a challenge to the providers of
service and the manufacturers of equipment.

5.2.2 Standardization

Standardized interoperable telecommunications functions and services are essential. In
this quest for reliable and effective emergency telecommunications services, the standards
developing organizations have an important role to play, in close collaboration with the
public authorities, public service organizations and the citizens. Recent resolutions in
bodies such as the ITU Telecommunication Standards Advisory Group (TSAG), the Global
Telecommunications Standards Collaboration (GTSC), the Asia-Pacific Standardization
Program (ASTAP) and various ETSI Technical Bodies (in relation to work on 2nd and 3rd
generation Mobile Communication systems and Next Generation Networks).

In order that public safety resources of different countries can be cooperatively utilized
in an effective manner, not only at cross-border operations but also at joint operations
in disaster situations, telecommunications networks and equipment must be able to
cooperate.

This calls for coordinated standardization activities, not only between those technical
committees within an SDO that address the various telecommunications function and service
solutions that support emergency telecommunications, but also collaboration between the
various Standards Developing Organizations (SDOs).

As a first effort towards reaching the above goals, ETSI organized in February 2002 a
first workshop on Emergency Telecommunications. The proceedings of this workshop are
provided on the ETSI EMTEL website. For more information please visit www.emtel.etsi.org.

A function of both the Project MESA and EMTEL Project is to ensure specifications and
standards will ensure future wireless, high-speed data applications, including voice,
video, infrared, data, robotics control and many other applications, can be transmitted on
a wide-area basis when and if the need exists. The specifications and future standards
will be capable of extremely high levels of security, yet will contain standardized
interfaces to public and private networks. It is anticipated that these interfaces will
include, but not be limited to, the Public Switched Telephone Network (PSTN), private
networks, public and private microwave systems, high speed leased lines (E3/T3), and
Integrated Services Digital Networks (ISDN) circuits. The following section introduces
some of these technologies.

6. Key Technology Areas

Although it has already been identified that political and organisational issues can play
a part in Homeland Security and Public Safety networks, technology continues to play a
major role in delivering practical solutions.

It is worth therefore examining some of the technology areas most critical to the
implementation of Homeland Security and Public Safety networks and how they can be
interworked with the existing networking infrastructure. The technologies examined are
categorised under the broader areas of digital radio communications and network security.
It then opens the way to a closer examination of the use as ATM as a supporting
technology.

6.1 Digital Radio

6.1.1 TETRA

TErrestrial Trunked RAdio (TETRA) is the modern digital Private Mobile Radio (PMR) and
Public Access Mobile Radio (PAMR) technology for police, ambulance and fire services,
security services, utilities, military, public access, vehicle fleet management, transport
services, closed user groups, factory site services, mining and others.

With support of the European Commission and the ETSI members, the TETRA standard has been
developed over a number of years by the co-operation of manufacturers, users, operators
and other experts, with emphasis on ensuring the standard will support the needs of
emergency services throughout Europe and beyond. The standard builds upon the lessons and
techniques of previous analogue trunked radio systems and the successful development of
GSM during the 1980s. The work started in 1990 and the first standards were ready in 1995.

TETRA offers fast call set-up time, addressing the critical needs of many user segments,
excellent group communication support, Direct mode operation between radios, packet data
and circuit data transfer services, frequency economy and excellent security features.
TETRA uses Time Division Multiple Access (TDMA) technology with 4 user channels on one
radio carrier and 25 kHz spacing between carriers. This makes it inherently efficient in
the way that it uses the frequency spectrum. For emergency systems in Europe the frequency
bands 380-383 MHz and 390-393 MHz have been allocated for use by a single harmonized
digital land mobile systems. Additionally, whole or appropriate parts of the bands 383-395
MHz and 393-395 MHz can be utilized should the bandwidth be required.

For civil systems in Europe the frequency bands 410-430 MHz, 870-876 MHz / 915-921 MHz,
450-470 MHz, 385-390 MHz / 395-399,9 MHz, have been allocated for TETRA.

TETRA trunking facility provides a pooling of all radio channels that are then allocated
on demand to individual users, in both voice and data modes. By the provision of national
and multi-national networks, national and international roaming can be supported, the user
being in constant seamless communications with his colleagues. TETRA supports
point-to-point, and point-to-multipoint communications both by the use of the TETRA
infrastructure and by the use of direct mode without infrastructure.

TETRA standardization has reached a mature state. The major current activities are the
continuation, by standardizing the next generation in TETRA Release 2 and by the
maintenance of existing TETRA standards.

The objective of TETRA Release 2 is that EP TETRA produces an additional set of ETSI
deliverables (and maintenance thereafter) in order to enhance TETRA in accordance with the
following requirements:

a) Evolution of TETRA to provide packet data at much higher speeds than are available in
the current standard. This is to support multimedia and other high-speed data applications
required by existing and future TETRA users.

b) Selection and standardisation of additional speech codec(s) for TETRA, to enable
intercommunication between TETRA and other 3G networks without transcoding, and to provide
enhanced voice quality for TETRA by using the latest low bit rate voice codec technology.

c) Further enhancements of the TETRA air interface standard in order to provide increased
benefits and optimisation in terms of spectrum efficiency, network capacity, system
performance, quality of service, size and cost of terminals, battery life, and other
relevant parameters.

d) Production and/or adoption of standards to provide improved interworking and roaming
between TETRA and public mobile networks such as GSM, GPRS and UMTS.

e) Extension of the operating range of TETRA, to provide increased coverage and low cost
deployments for applications such as airborne public safety, maritime, rural telephony and
’linear utilities’ (e.g. pipelines).

f) Ensure full backward compatibility and integration of the new services with existing
TETRA standards, in order to future proof existing and future investments by TETRA users.

6.1.2 Project 25

APCO Project 25 is a user-driven effort to develop a digital standard for wireless
communications users. These standards enable critical communications for the safety and
security of communities across North America and the world. In emergency situations,
Project 25 users can communicate with other agencies and mutual aid response teams.
Project 25 wireless mission critical communications user needs include these key digital
standard attributes:

Backward compatibility and graceful migration. Project 25 enables system migration that is
backward compatible with existing systems, and allows forward compatibility with
next-generation radios.
Scalable trunked and conventional capabilities. Project 25 enables systems to be scalable
from single channel conventional to regional trunking. They can be configured in voting,
multicast, and/or simulcast designs, and still includes the talkaround capability required
by public-safety agencies.
Interoperability. Project 25 enables communication between neighboring systems. This is
important for mutual aid where resources are gathered from many different locations.
Spectral efficiency. Project 25 enables 12.5 kHz systems migration to 6.25 kHz or
equivalent spectral efficiency performance.
6.2 Security

It has been stated that “Anything worth hacking will get hacked”. Maybe this takes a
slightly cynical view, (some may say an entirely realistic one), of the subject of
security. Unfortunately, the most secure system is one that would be entirely unusable.
Security is not a tangible thing you can buy. Rather, it is a process; a way of organizing
and maintaining your resources to prevent unauthorized access.

To accomplish this, network security should be designed to be multi-layered, with each
layer performing a specific function to make it more difficult for an attacker to gain
access to corporate systems while making it easier to detect a security breach if it does
happen. The network must have its components installed correctly so that no security holes
are left open to attack. In addition, a process must be created and put in place to
monitor the network for illicit activity. Finally, in the event of an attack, procedures
must be in place to respond to the attack. Part of that action may indeed be to correct
the flaws in what was, until then, considered to be an effective security plan.

A good security strategy starts with the network design itself. A solid initial plan is
vital for ensuring network security, and without such, upgrade and repair costs can be
steep, not to mention the tangible and intangible costs associated with a security breech.

Once the security needs are mapped out, the second step is to examine the segments to
determine the vulnerabilities of each portion of the network and further refine the
security requirements. Once all the needs and vulnerabilities are assessed, equipment can
be identified to meet the criteria that have been established.

In every design, there will be some weaknesses – it takes only time and imagination to
find them. Therefore, it is very important to watch the network for behavior that is
suspicious or contrary to the security policies created during the design of the security
system. Regular monitoring of network logs and reports can identify potential security
breaches.

Establishing a response plan also informs employees about how to respond to an attack on
the network in an efficient and effective manner, preventing or reducing damage. Network
security is an ongoing, ever changing process. New technologies and changing business
needs make it difficult to plug all the security holes that evolve with the network.

There are many standards for the various layers of network and systems security and indeed
it would be beyond the scope of this white paper to document all these. Many are concerned
with the securing of the payload carried by a network and therefore apply to individual
end systems. This is broadly covered by the area of cryptography.. Much of this work is
associated with the Data Encryption Standard (DES), more formally known as the ANSI X3.92
Data Encryption Algorithm. DES was the workhorse for over two decades and has been in
existence since 1975, reinforcing the fact that many of the supporting elements are not
new. Today, it has been superceded by triple-iterated DES (3-DES) or Advanced Encryption
Standard (AES).

Whilst securing the data being transferred is a critical part of security, there are also
a number of ways in which the network itself can secure the transmission of the data.
Works exists within a number of bodies and for a number of purposes. The IP world
regularly relies on IPSec for secure communications (for example VPN) over public
infrastructure.

6.3 ATM as a Supporting Technology

The next step is to examine the potential role(s) for ATM to play in supporting these
technology requirements. Some will be already clearly defined and have been the subject of
existing specification work. Others will need to be investigated further, by the various
various working groups of The ATM Forum, to establish the true extent of ATM’s role as a
supporting technology. In some technology areas there will be no specific role for ATM or
for The ATM Forum to do further work. The following section highlights which areas have
been already supported by ATM and the ATM Forum. In Section 9 there are some indications
of the potential areas of future work, although these will be subject to further
discussion and investigation.

7. ATM Supporting Features and ATM Forum Specifications

This section introduces four technology areas where ATM already plays a key supporting
role. They mostly correspond to the areas where the ATM Forum Technical Committee Working
Groups have been active in defining the appropriate specifications. In the case of Quality
of Service it reflects a fundamental feature of ATM rather than a specification.

These four areas are:

Security
Bandwidth Efficient Voice
Session Control and Routing
Quality of Service (QoS)
7.1 Security

7.1.1 User Plane Security Services

The user plane security services apply on a per-VC (virtual circuit) basis, where a VC
could be either a VCC (virtual channel connection) or a VPC (virtual path connection).
Security services for physical links (which may carry many VCs) are not provided for. The
following security services for the user plane are defined: authentication, data
confidentiality, data integrity, and access control. These services are supported in
point-to-point and point-to-multipoint connections for both SVCs and PVCs.

7.1.2 Authentication

User plane authentication (also described as “entity authentication”) determines at the
beginning of the connection that the identities of the calling and/or called parties are
genuine. Since this service provides protection against impersonation or “spoofing”
threats, it is essential for establishing secure connections and the operation of other
security services, including key exchange (described below), and the secure exchange of
security negotiation parameters. Authentication can be either mutual or unilateral. If
authentication is mutual, then both parties are authenticated to each other, whereas with
unilateral authentication, only one party is authenticated to the other. Authentication is
specified in the ATM Forum’s ATM Security Specification to use cryptographic algorithms,
including asymmetric (public key) algorithms (e.g. RSA) and symmetric (secret key)
algorithms (e.g. DES-MAC).

7.1.3 Confidentiality

User plane confidentiality provides cryptographic mechanisms that protect “user” data on a
VC from unauthorized disclosure. (The term “user” refers to the protocol entity that
directly uses ATM services.) This specification defines ATM confidentiality at the cell
level, rather than the AAL level, because the fixed-length of the ATM cell allows for
efficient encryption. Furthermore, only the payload of the cell is encrypted–the header is
sent in the clear. This allows the encrypted cell to be switched by the network without
decryption at each hop. The confidentiality service is specified in theis ATM Security
Specificationdocument to use symmetric (secret key) algorithms. Symmetric algorithms are
suitable for ATM cell encryption due to their speed, block sizes, and security properties.

7.1.4 Integrity

The data integrity service (also described as “data origin authentication”) provides a
mechanism that allows for detection of modification to data values or sequences of data
values, even in the presence of malicious modification threats. This service is provided
between endpoints at the AAL Service Data Unit (SDU) level for AAL 3/4 and AAL 5. In
addition, two options are provided for this service:

1) data integrity without replay/reordering protection, and

2) data integrity with replay/reordering protection.

When data integrity is provided without replay/reordering protection, the source appends a
message authentication code (MAC) to the tail of each AAL SDU before transmission. This
MAC is calculated over the entire AAL SDU. This option is useful to higher layer protocols
that provide their own sequence numbers (e.g., TCP), without the added overhead required
to duplicate this function at the AAL. When the data integrity service is provided with
the replay/reordering protection option, the data integrity service provides protection
against replay and reordering attacks, so that “old” or “reordered” AAL-SDUs are detected
and may be discarded. At the source, this is achieved by first appending a sequence number
to the tail of each AAL-SDU and then computing a MAC on the totality of the AAL-SDU
including the sequence number. This MAC, which protects both the AAL-SDU and the sequence
number, is then appended to the total AAL-SDU (which includes the sequence number). This
method provides protection for ATM applications that do not implement their own sequence
numbers. As with the confidentiality service, the integrity service is specified in the
ATM Security specification is document to use symmetric (secret key) algorithms.

7.1.5 Access Control

Access Control is the application of a set of rules to a request for a service. These
rules may depend upon attributes of the invoking entity, such as identity, attributes of
referenced parameters, such as a target address, system attributes, such as time, and the
history of prior requests by this and/or other client entities. Access control rules can
be thought of as a predicate over the state space formed by all such attributes. If the
predicate is satisfied, the requested service is performed, if the predicate is not
satisfied, the requested service is not performed. User plane access control requires
mechanisms to transport access control information used during connection establishment,
as well as mechanisms within ATM components to use that information to determine whether
access to the connection should be granted. User plane access control can be based on
security labels (e.g., Standard Security Label) source or destination user identities,
time of day, type of service, upper-layer protocol (e.g., AAL type) fields, or other
parameters that can be determined during connection establishment.

For more information on the ATM Forum’s ATM Security Specification review
af-sec-0100.002.pdf.

7.2 Bandwidth Efficient Voice (AAL2)

With the existing dependency on voice communications, there is a clear need for Homeland
Security and Public Safety networks to support a converged voice and data model. In most
converged networks, the voice calls are treated in one of two ways. Voice could be treated
as just another form of “data” but, equally so, gets the same quality of service as would
be acceptable for an average data application. Alternatively, to provide guaranteed
service levels, bandwidth is pre-allocated and reserved for voice calls. Both approaches
have their flaws. The former clearly does not work for mission critical voice calls while
the latter is wasteful of resources. What is needed is a compromise solution that
maintains the QoS while finding a more efficient model for allocating bandwidth. The
solution from the ATM Forum and the ITU-T has been to define variable bit rate voice using
the ATM AAL2 adaptation later. The use of AAL2 can provide more than a 15x bandwidth gain
over the existing AAL1 voice transmissions or the standard TDM PCM voice multiplexing
techniques currently in use. Additionally it brings advanced bandwidth-efficiency
features, like compressed, voice, silence detection and suppression, comfort noise
generation, FAX demodulation. Some implementations will also support secure telephone
calls with efficient bandwidth.

In addition, AAL2 partial cell fill and cell delay control options allow multiple calls
per ATM cell to be carried, improving bandwidth efficiency.

Voice compression rates are implementation dependent but typically include G.729a/b
CS-ACELP 8 kbps, and G.726 ADPCM 16, 24, 32kbps. FAX transmission can be supported at
native data rates of 9.6kbps & 14.4kbps.

Bandwidth efficiency is a critical requirement for converged voice and data networks. ATM
is more bandwidth efficient than standards-based IP over PPP for mixed voice/video/data
environments – something of a surprise perhaps for those that cite the “cell tax” as a
reason for not using ATM. There are therefore few, and arguably none at all, proprietary
VoIP products that are as efficient for transporting voice as ATM using AAL-2. Even then
the VoIP market is constantly churning, with several competing (non-interoperable)
standards and many proprietary products.

7.3 Session Control and Routing

A critical part of any network is in the setting up and routing of sessions between
network users. Technologies tend to fall into the categories of connection-based or
connectionless. IP networks are connectionless; ATM is connection-based. Often these two
alternatives become combined (as with IP over ATM) and indeed MPLS provides a
connection-based solution for routing IP traffic.

Just as IP networks have provided mechanisms for routing information to be exchanged
automatically to maintain a consistent picture of the network, so ATM has used its own
routing methodology (PNNI).

7.3.1 Mobile PNNI

In recent years, two networking technologies, ATM and wireless, have developed rapidly due
to the growing consumer demand for broadband and mobile services. Because of the superior
cost performance and QoS support provided by ATM switching technology, it is widely used
as the backbone network for future-proof integrated telecommunication infrastructures.
Therefore, services accessed through wireless technologies may need to interwork with ATM
networks in order to have a wide area inter-networking capability. The 'Mobile ATM'
concept is such an idea that allows an ATM backbone network to support mobile services
independent of the wireless access technologies. A mobile ATM network is a regular ATM
network with wireless access points (base stations) plus mobility support extensions in
ATM protocols. Two basic mobility functions are supported:

Location management - locating users during connection establishment
Handoff control - dynamic rerouting of mobile connections as users move.
A mobile ATM network can be used to provide infrastructure for one or more existing
wireless access method, such as GSM, PHS, TDMA or CDMA. The same mobile ATM network can
evolve towards a wireless ATM network that supports end-to-end broadband ATM services. The
motivation for the mobile ATM concept is to provide a common infrastructure to serve a
diverse set of mobile services in the near term, while migrating to broadband end-to-end
wireless ATM services in the long-term. The mobile PNNI specification is actually a much
under-utilised specification and has been under implemented in the industry. The reader is
encouraged to seek further information on this subject by reviewing ATM Specification
af-ra-0123.000.

7.3.2 Soft PVC

Most ATM networks have been built on permanent virtual circuits (PVC) differing from
switched virtual circuits (SVC) in the usual meaning of a VC that is not signalled by the
end points. Both of the endpoint VC values are manually provisioned. The link-by-link
route through the network is also manually provisioned. If any equipment fails along the
path, the PVC fails unless the underlying physical network (e.g. SONET/SDH) can re-route
below the ATM layer. So the PVC is statically mapped at every point in the ATM network.

This can be too restrictive in order to cope with network or link failures. Soft PVC also
has manually provisioned endpoints, but the route through the network can be automatically
revised if there is a failure. The PNNI specification defines a standard way of doing this
that does not require a vendor proprietary solution. So a Soft PVC is a VC that is
programmed to be present at all times (like a PVC), but does not use static routes to
determine its path through the ATM network. Failure of a link causes a Soft PVC to route
around the outage and remain available.

This is a feature of ATM networks often much overlooked especially as those more familiar
with the IP world are used to the concept of automatic best path/least cost routing.

7.4 Q0S

The primary advantage of ATM technology is its ability to dynamically utilize available
bandwidth while prioritizing traffic during traffic peaks. For example, by utilizing the
appropriate Quality of Service (QoS) Classes, such as real-time Variable Bit Rate (VBR-rt)
for voice circuits and Unspecified Bit Rate (UBR) or non real-time VBR (VBR-nrt) for
Internet Protocol (IP) traffic, the maximum available bandwidth can be used on any pipe.

ATM gives higher priority to the VBR-rt traffic, so it allocates the available bandwidth
to voice calls when they are initiated. Any remaining bandwidth is used by the UBR or
VBR-nrt traffic. During times of congestion, IP traffic (UBR) is buffered and, if
necessary, dropped. Once the voice calls are released, the UBR traffic will burst to use
any available bandwidth. At times where there are no voice calls, the UBR traffic will use
the entire pipe.

8. Case Study - Air Traffic Control

Finally, few Homeland Security challenges will receive as much public scrutiny as the
transportation industry. While it can be said that many transportation systems could
suffer from security deficiencies, aviation security in particular becomes a major focus.
At the very least, this risk factor has forced every traveller to think very seriously
about their safety in the air – not because of mechanical failure but because of security
failures. In that respect then it also can be categorized as a unique type of public
safety network. This duality makes it an interesting example of how to solves some very
unique challenges. ATC organisations have to ensure that their networks are able to evolve
to meet new needs while ensuring certain critical quality and service levels. As can be
imagined this is not a simple task with there being thousands of airports, a huge volume
of air traffic, and people representing different ethnic, religious, and political
backgrounds traveling by air every day.

The mission of the ATC is quite clear – to provide safe air transport services for
aviation and the flying public. This means the provision of flight planning and weather
advisories for commercial and general aviation and Air Traffic Control services for
commercial aviation that improve the operational efficiency of operating aircraft.

ATC networks currently need to support a mix of voice and data traffic. Indeed most
mission critical communications rely primarily on the voice communications – namely the
contact between air traffic controllers and aircraft. This places certain demands on the
network.

Timeliness. Critical voice communication requires very low latency. There can be no call
set-up delays or call blocking. Commands to a pilot have to be received and acted upon in
real time.

Availability. The telco world is familiar with the five nines metric for availability
(99.999%). ATC availability requirements exceed this specification - a difference that
means a lot more in practice than numbers on paper.

Security. As has been explained, security is an umbrella topic that covers a multitude of
areas. For ATC, one important aspect is that of integrity and authentication ensuring that
there can be no masquerading or spoofing. The concerns towards third party interception
and eavesdropping are actually less critical implying less of a need for encryption but
failsafe measures to ensure that a plane’s identity and location is true and accurate.

Legacy support. Although performance is an issue when it comes to low latency, bandwidth
requirements are not exceptionally high relative to today’s standards. This may change in
the future with future video based applications. However, a more critical requirement is
to support a wide variety of legacy end user devices and terminals. Many of these are
unmanned devices and are old and use low speed serial communications based on proprietary
protocols.

To meet these needs the current network relies on separate voice and data infrastructures
thereby ensuring that data traffic can’t interfere with the priority voice traffic. Voice
is therefore based on conventional TDM techniques using a variety of physical transports.
Data networking has been reliant on facilities offered by X.25 and Frame Relay. The
physical infrastructure is based on privately owned fiber and copper or dedicated leased
transmission facilities from the service providers.

Like many public safety networks, the desire for innovation must be placed against the
need for absolute reliability and availability. This tends to limit the adoption of some
new technologies that would be seen as too risky or whose fundamental qualities don’t meet
the stringent requirements. There is a requirement to enable voice and data traffic to be
combined as long as they can be assigned their own QoS. Higher network capacity would also
enable the provision of applications such as video (for example for monitoring
applications). Of course some solutions would simply not be viable. Voice over IP is not a
potential solution due to the lack of guaranteed latency and long call set-up times. The
longer-term vision for the network is based on a backbone transport network based on ATM
capable of carrying a mix of IP traffic, legacy communication protocols and voice. The use
of ATM ensures the differentiated QoS and low call latency for voice. However, many
converged voice and data networks still allocate reserved bandwidth for the voice calls
thereby removing much of the advantage of a converged network. The use of ATM AAL2 based
voice is one of the solutions under consideration to allow variable bit rate voice to be
used and so not waste bandwidth.

Future Direction

The other consideration around a future network architecture is to what degree a move away
from dedicated and private transmission paths could be achieved. Aside from economic
considerations the issue becomes one of achieving the service level agreement to meet the
uptime requirements and security. Going beyond five nines availability presents a
challenge to both equipment providers whose equipment typically has not been designed to
such levels and to service providers whose service offerings have to be highly available.
The use of any network infrastructure not owned and protected by the ATC agency opens up
further security considerations. Private transmission facilities are the most secure with
the use of the public Internet at the other end of the spectrum. In between there are a
number of possibilities. In fact the use of any communication over the public Internet
(even with VPN) is deemed to fall below the level of security required. The alternative to
private transmission networks is the use of a shared service provider infrastructure using
a connection based overlay using X.25, Frame Relay and ATM. The least secure method under
consideration is an end-to-end connection running IP over Virtual Circuits. Adding VPN
tunnelling increases the level of security or better still the use of native Virtual
Circuits over the connection based infrastructure.

The bottom line is that frame relay is roughly as secure as private-line technologies.
Even though the network is a "shared " network, the connection-oriented architecture makes
it immune to most of the address spoofing and other issues associated with connectionless
IP. The transition and evolution will take several years and clearly has to be carried out
in a non-disruptive manner. The fundamental requirement is that safety can never be
compromised.

Multiple network services and technologies will be supported until all risks associated
with a converged technology can be mitigated. This means that voice and data networks will
still be kept separate in the initial phases of this evolution.

Why ATM? A flexible multi-service architecture is needed and connection oriented
technology offers security and performance benefits over connectionless IP. However, the
flexibility of IP is still needed. Separate network management architectures are used for
layer 2 and layer 3 and together IP and ATM technologies hold the greatest promise for a
future converged (voice, video and data) network architecture.

9. Future Works Plans

.The ATM Forum Broadband Exchange meeting on Homeland Security and Public Safety networks
brought together experts from within the ATM Forum, ETSI and other interested
organisations. Aside from exchanging details of work in progress, a key goal was to define
work items yet to be agreed for various bodies. This would enable them to work towards a
common goal. The work of The ATM Forum is, like many such forums, contribution led. The
Broadband Exchange served to provide a guiding light to the contributions that will be
forthcoming over the coming months. The event itself did lead to a number of possible work
areas. Although it is too early yet to have qualified and prioritised these areas, the
following is an indication of the potential scope of these areas. In the area of security,
additional work could be done on AAL2 security, optical security and ATM multicast
security. Voice interworking remains a key area of interest, with Voice over ATM (VoATM),
Voice over Frame Relay (VoFR) and Voice over MPLS (VoMPLS) being the prime candidates.
Indeed there is scope for more work, much of it educational in nature, on the
characteristics of AAL2 voice (and the tradeoffs between bandwidth, latency and voice
quality) and the deterministic nature of ATM switched Virtual Circuits (SVCs). The highly
mobile nature of the public safety applications could also drive further development of
the mobile PNNI specification.

10. Conclusions

One of the key findings of the Broadband Exchange was that of diversity. It is clearly
difficult to even generalise as to the networking needs of the various emergency services
without trying to extend this generalisation to the whole of Homeland Security and Public
Safety Networks. But certain themes and areas of commonality become apparent. . Firstly
communications technology and that of IT infrastructure will be critical for the sharing
of information between various agencies.

The exchange of information necessitates the need for networking and the mobile nature of
these agencies will require the use of wireless technologies. But the need for wireless
communications should not cloud the fact that the backhaul into wired infrastructure
networks is also required. It is here that much of the focus of The ATM Forum will be
placed. Homeland Security and Public Safety networks will require the ability to
differentiate voice and data services within the same physical networks – allowing mission
critical voice calls to be guaranteed. Security at a number of different levels will be
required. All of this takes place against a backdrop of an evolution to broadband speeds
to support the applications envisioned in the future. All of these are areas where the
core qualities of ATM are a strong fit. Not that ATM alone will be the solution with an
increasing dependency on IP for network applications. However, ATM is well positioned to
support these applications while meeting the stringent requirements of the network and
application designer.
World events can bring notoriety. The horror of September 11th 2001 will ensure that the
needs of Homeland Security and Public Safety networks remain high on the political and
technical agendas.

Appendix

I. Acknowledgements

The ATM Forum would like to thank the following organisations and individuals for their
contribution to the Broadband Exchange and their support in providing the materials for
this white paper.

Kjell Strandberg, Head of ETSI Standards Making Support Department
Craig M. Jorgensen, Chairman, Project MESA Service Specification Groupð Sumit Ghosh,
Thomas E. Hattrick Professor, Stevens Institute of Technology
Mark E. Graham, Chief Systems Engineer and Network Architect, Harris Corporation
Currey Freeman, Strategic Business Manager, Motorola Inc. (and representative the TIA)
Richard Graveman, Chair of the Security Working Group, The ATM Forum
Thanks are also extended to the Richard Folio, Chair of the Wireless ATM Working Group,
The ATM Forum and Wolfgang Klasen, Vice-Chair of the ATM Security Working Group, The ATM
Forum who co-chaired the Broadband Exchange meeting and contributed to this white paper.

II. Role of The ATM Forum

The ATM Forum is one of the most established names in the broadband arena. It is partly
for this reason that The ATM Forum felt well positioned to take on the ownership of the
Broadband Roadmap and the Broadband Exchange events.

The ATM Forum is an international non-profit organization formed with the objective of
accelerating the use of ATM (Asynchronous Transfer Mode) products and services through a
rapid convergence of interoperability specifications. In addition, the Forum promotes
industry cooperation and awareness. There is no better example of that co-operation than
the Broadband Exchange events, where each event is done in partnership and collaboration
with another industry body or association.

Since its formation in 1991, The ATM Forum has generated very strong interest within the
communications industry. Currently, The ATM Forum consists of approximately 150 member
companies, and it remains open to any organization that is interested in accelerating the
availability of ATM-based solutions. The drive towards a more broadband related position
shows the recognition that it is not just about the success of a single technology but the
role that any one technology plays as part of the bigger broadband picture.

The ATM Forum consists of a worldwide Technical Committee, market awareness and education
programs such as Broadband Exchange, and the User Committee, through which end users
participate.

The Technical Committee

The ATM Forum Technical Committee works with other worldwide standards bodies selecting
appropriate standards, resolving differences among standards, and recommending new
standards when existing ones are absent or inappropriate. Typically this process is
entirely member contribution driven on the basis that its members are key players in the
industry and therefore best positioned to know where this work must take place.

The Technical Committee was created as one, single worldwide committee in order to promote
a single set of specifications, thereby ensuring interoperability among all vendors as ATM
products and services become available. Additionally, the Technical Committee now looks to
the Broadband Exchange as a potential source of work requirements.

The Technical Committee consists of a variety of multi-vendor working groups, which
develop specifications in different areas of ATM technology. In the case of broadband
content delivery, the work is likely to be of interest to the Voice and Multimedia over
ATM (VMOA) group as well as Control Signaling (CS) and Security (SEC). And as content
delivery is not limited to wired networks, the Wireless ATM (WATM) working group will be
actively involved. Indeed the Broadband Exchange meeting’s co-chair was the chair of the
WATM WG.

Broadband Exchange

The ATM Forum’s Broadband Exchange program enables the industry to more easily collaborate
to develop each of the areas on the Forum’s broadband roadmap. By bringing together the
experts in their respective topics in an informative and interactive debate, the barriers
to deployment can be quickly identified and a work plan to resolve them put in place.

Learn how you can participate in a future event and receive the schedule of events for the
2003 Broadband Exchange.

IV. For further reference

If you are interested in finding out more information on this subject then the following
section provides some links to additional information. The electronic version of this
white paper will be updated with new links and so this section should be viewed as the
“living” section of the white paper. Suggestions for links to relevant topics are also
encouraged from readers of this white paper. Members of The ATM Forum are also encouraged
to provide live links to reflect what their companies are doing in this area.

ATM Forum Home Page

ETSI Project Mesa

Project EMTEL

Broadband Exchange
October 2002. Presentation Materials

To find out how you can become a member or to participate further in the work of The ATM
Forum, contact The ATM Forum at one of the regional offices below.

Headquarters (US)

[email-masked]
 EMEA Office

[email-masked]
 Asia Pacific Office

[email-masked]

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