ASN.1 Applications and Standards

ASN.1 is used in many standards of different types and purposes, published by various standards development organizations. Here we describe a few uses of ASN.1.

A more comprehensive list of standards using ASN.1 can be found on the International Telecommunication Union's website at http://www.itu.int/ITU-T/asn1/uses/index.htm.


 

Cellular technologies from 3GPP

3GPP is a collaboration agreement among several telecommunications standards bodies. In the past decade, 3GPP developed UMTS, currently the most widely deployed third-generation mobile technology, supporting both voice and high-speed data connections. More recently, 3GPP developed LTE, a fourth-generation mobile technology that meets user demands for higher data transmission rates and quality of service while maintaining compatibility with earlier 3GPP technologies such as UMTS, GPRS, EDGE, and GSM. LTE is characterized by a streamlined network architecture and a strong emphasis on IP. The upcoming release of LTE, known as LTE Advanced, will enable even higher data rates to/from each mobile device and will have a more sophisticated network architecture with better support for the transfer of higher data volumes and for the use of smaller network components such as picocells and femtocells.

Many of the protocols that are part of GSM, UMTS, LTE, and LTE Advanced use ASN.1.

Here is a partial list of 3GPP protocols using ASN.1:

Name

Abbreviation

Technology

Radio Resource Control

RRC (UMTS)

UMTS

Radio Access Network Application Part

RANAP

UMTS

Radio Network Subsystem Application Part

RNSAP

UMTS

Node B Application Part

NBAP

UMTS

RANAP User Adaption

RUA

UMTS

Home Node B (HNB) Application Part

HNBAP

UMTS

Mobile Application Part

MAP

UMTS

CAMEL Application Part

CAP

UMTS

Handover interface for Lawful Interception

LI

UMTS

Radio Resource Control

RRC (LTE)

LTE

S1 Application Protocol

S1AP

LTE

X2 Application protocol

X2AP

LTE

M2 Application Protocol

M2AP

LTE Advanced

M3 Application Protocol

M3AP

LTE Advanced

The above list includes protocols used between various types of network components. For example, the RRC protocol supports the exchange of control information between a mobile device and a base station, whereas most of the other protocols listed above are used between components of a mobile operator's radio access network.

Another interesting use of ASN.1 within 3GPP technologies is the specification of the files containing charging data records (CDRs) of mobile subscribers, which are continually produced by the mobile operator's core network and sent to its billing department for further processing. Thus within 3GPP technologies, ASN.1 is present not only in the communication protocols, but also in the billing domain.

There is another standard file format that is worth mentioning in this context, although it was developed by the GSM Association and not by 3GPP--the TAP3 specification. TAP3 files contain call details and other information relative to the use of a mobile operator's cellular network services (calls, text messages, data, etc.) by a subscriber of a different operator. TAP3 files are periodically exchanged among mobile operators, allowing correct and timely determination of roaming fees as well as basic customer support.



Worldwide Interoperability for Microwave Access (WiMAX) 2

WiMAX is a wireless broadband access technology that provides performance similar to Wi-Fi with the coverage and quality of service of cellular networks. WiMAX is actively supported by the WiMAX Forum™, a non-profit organization that was formed to promote the adoption of WiMAX compatible products and services, and whose main role today is to certify the interoperability of WiMAX products. While the original Mobile WiMAX is based on the IEEE 802.16e standard, the new version of WiMAX is based on the IEEE 802.16m standard, which was completed in 2011 and uses ASN.1.

Within the IEEE 802.16m standard, ASN.1 is used in the specification of MAC control messages, a complex protocol that plays a role analogous to that of the RRC protocol in 3GPP UMTS and LTE.



Intelligent Transportation Systems

Several standards organizations have developed or are developing standards in the area of Intelligent Transportation Systems (ITS). Some of those standards use ASN.1.

At the international level, a collaborative effort between ISO TC 204 and ETSI is developing new standards for vehicle-to-vehicle and vehicle-to-infrastructure communications, in the context of the Communications, Air-interface, Long and Medium Range (CALM) initiative.

Here is a partial list of international standards for ITS that use ASN.1:

Name

Abbreviation

Cooperative Awareness Messaging

CAM

Decentralized Environmental Notification for Cooperative Road Hazard Warning

DENM

CALM FAST Networking and Transfer Protocol

FNTP

CALM FAST Service Advertisement Protocol

FSAP

In the United States, the SAE J2735 standard specifies a large set of messages for vehicle-to-vehicle and vehicle-to-infrastructure communications, which are designed to be carried over wireless links provided by Dedicated Short-Range Communications (DSRC). DSRC is a widely used technology based on a suite of IEEE wireless networking standards, and SAE J2735 chose ASN.1 for the specification of its messages. The US Department of Transportation regards DSRC and SAE J2735 as essential technologies supporting vehicular safety applications, and has conducted many research initiatives (including test beds and "safety challenges") in which DSRC devices transmitting SAE J2735 safety messages play a central role.



Signaling in fixed and mobile telecommunication networks

Signaling System #7 (SS7) is a set of standard signaling protocols which support telephone calls in both public switched telephone networks and mobile networks. Besides their primary function, which is the setup, maintenance, and release of phone calls, SS7 protocols support call management services such as call forwarding, voice mail, call waiting, conference calling, calling name and number display, call screening, and so on. In mobile networks, they also support subscriber location management, roaming, subscriber authentication, subscription information, call routing, short message service, and so on.

The original components of SS7 are a set of international standards published by the ITU-T as parts of the Q.700 series. Here is a partial list of ITU-T standards for SS7 that use ASN.1:

Q.73x

Supplementary Services


Q.76x

ISDN User Part

ISUP

Q.77x

Transaction Capabilities Application Part

TCAP

The ITU-T later designed a network architecture called Intelligent Network, which is intended for both fixed and mobile telecommunication networks and allows operators to differentiate themselves by providing value-added services in addition to the standard telecom services. The following protocols, all of which use ASN.1, were developed by the ITU-T and added to SS7 in support of Intelligent Network:

Q.1218

Intelligent Network Application Part CS1

INAP CS1

Q.1228

Intelligent Network Application Part CS2

INAP CS2

Q.1238

Intelligent Network Application Part CS3

INAP CS3

Q.1248

Intelligent Network Application Part CS4

INAP CS4

The core SS7 standards originally developed by the ITU-T were designed to support fixed telephone networks. The following protocols, which use ASN.1, were developed by the GSM Association and 3GPP in support of mobile networks:

Mobile Application Part

MAP

Customised Applications for Mobile networks Enhanced Logic (CAMEL) Application Part

CAP



Security

ASN.1 plays a significant role in two components of security technology—digital certificates and data protection.

Digital certificates are specified in the ITU-T standard X.509, probably the best known component of the X.500 series (the Directory). X.509 specifies standard formats for public key certificates, certificate revocation lists, attribute certificates, and a certification path validation algorithm. Those formats are specified in ASN.1. Today X.509 certificates are ubiquitous and are at the basis of the security infrastructure of the Internet and many other security applications.

Cryptographic Message Syntax (CMS) is a widely used IETF standard, whose current version is RFC 5652. CMS was originally based on a technical specification by RSA Laboratories known as PKCS #7. CMS describes an encapsulation mechanism and syntax for data protection, which is compatible with X.509 and is specified in ASN.1. CMS is used to digitally sign, digest, authenticate, or encrypt arbitrary message content.



Aviation

The Aeronautical Telecommunication Network (ATN) is an internetworking architecture, endorsed by the International Civil Aviation Organization, that manages digital data transfer between aircraft and civil air traffic control facilities. ATN allows ground/ground, air/ground, and avionic data subnetworks to interoperate. The standard protocols that constitute ATN are specified in ASN.1. An example of such protocols is Controller/Pilot Data Communications (CPDLC), which is meant to replace the present controller/pilot voice interactions with digital messages.



Spaceflight

The Consultative Committee for Space Data Systems (CCSDS) is a multinational forum for the development of communications and data systems standards for spaceflight. The Space Link Extension Services (SLE) are a set of communication services developed by CCSDS. SLE services are used between the tracking stations or ground data handling systems of various organizations and the mission-specific components of a mission ground system. SLE services are applicable to routine, contingency and emergency operations, and their messages are specified in ASN.1.



Manufacturing

Manufacturing Message Specification (MMS) is an international standard (ISO 9506) dealing with messaging system for transferring real time process data and supervisory control information between networked devices and/or computer applications. MMS supports the remote control and monitoring of industrial devices such as programmable logic controllers and robots, and has been used in many different applications such as material handling, energy management, electrical power distribution control, and inventory control. MMS messages are specified in ASN.1. MMS is poised to play a significant role in the context of the Smart Grid. IEC 61850, a widely used standard for electricity generation automation that is among the foundational standards selected by the Smart Grid Interoperability Panel, specifies abstract data models while relying on concrete protocols such as MMS for the exchange of information across the communication network.



Voice over IP and conferencing

H.323 is an international standard published by the ITU-T for IP telephony, IP-based videoconferencing systems, and IP-based long distance and toll bypass. The H.323 standard itself is just a member of a large family of ITU-T standards that together provide a foundation for audio, video, and data communications across IP-based networks, including the Internet. Many of those standards use ASN.1.

Here is a partial list of ITU-T standards of the H.323 family that use ASN.1:

H.225

Call signalling protocols and media stream packetization for packet-based multimedia communication systems

H.235

Framework for security in H-series (H.323 and other H.245-based) multimedia systems

H.245

Control protocol for multimedia communication

H.248

Gateway control protocol

T.123

Network-specific data protocol stacks for multimedia conferencing

T.124

Generic Conference Control

T.125

Multipoint communication service protocol specification

T.126

Multipoint still image and annotation protocol

T.127

Multipoint binary file transfer protocol

T.128

Multipoint application sharing

T.135

User-to-reservation system transactions within T.120 conferences