EPCglobal Architecture design considerations

 Seminar #63, October 6th, 2011

Mazen Khair, Presents:

Authors: Mazen G. Khair, Hussein. T. Mouftah

Presentation Outline RFID (Radio Frequencies Identification) EPC (Electronic Product Code) GS1 “EAN International”

GS1 Identification Keys (ID Keys) Relationship Between EPCs and GS1 Keys EPC Schemes &Corresponding GS1 Keys

Uniform Resource Identifier (URI) EPC URI

A typical ONS query ONS Formal Specification

1. DNS Query Format 2. DNS Records for ONS 3. Processing ONS Query Responses

Multi polarity ONS Discovery Services

Radio Frequency Identification (RFID)

What is RFID? RFID is the reading of physical tags on single products, cases, pallets, or re-

usable containers which emit radio signals to be picked up by reader devices. One of its central applications is efficient identification of physical objects. Three types: Passive, Semi-Passive, and Active

RFID Tags contain a unique identification number called an Electronic Product Code (EPC), and potentially additional information of interest to manufacturers, healthcare

organisations, military organisations, logistics providers and retailers that need to track the physical location of goods or equipment.

All information on RFID tags can be scanned wirelessly by a reader at high speed and from a distance of several metres. ”Several hundreds of RFID per sec”

The Electronic Product Code (EPC): A Universal Identifier for Physical Objects

The Electronic Product Code is designed to facilitate business processes and applications that need to manipulate visibility data data about observations of physical objects.

The EPC is a universal identifier that provides a unique identity for any physical object.

The EPC is designed to be unique across all physical objects in the world, over all time, and across all categories of physical objects.

It is expressly intended for use by business applications that need to track all categories of physical objects, whatever they may be.

GS1 “EAN International”

GS1 is an international not-for-profit association dedicated to the development and implementation of global standards and

solutions to improve the efficiency and visibility of 

supply and demand chains globally and across multiple sectors. GS1, formerly called 'EAN International',

adopted the name 'GS1' in 2005. GS1 has its head office in Brussels.

There are GS1 member organizations in 108 countries. Seven GS1 identification keys defined in the GS1

General Specifications that can identify categories of objects

GS1 Identification Keys (ID Keys)

GTIN: identify categories of objects (SSCC, GLN, GIAI, GSRN): unique objects (GRAI, GDTI): a hybrid that may identify either

categories or unique objects depending on the absence or presence of a serial number.

(Two other keys, GINC and GSIN): identify logical groupings, not physical objects.

GS1 Identification Keys (ID Keys), http://www.gs1.org/barcodes/technical/id_keys

Relationship Between EPCs and GS1 Keys There is a well-defined relationship between EPCs and

GS1 keys. A Global Trade Identification Number (GTIN) by itself does not

correspond to an EPC, because a GTIN identifies a class of trade items, not an individual trade item.

The combination of a GTIN and a unique serial number, however, does correspond to an EPC

This combination is called a Serialized Global Trade Identification Number, or SGTIN

The GS1 General Specifications do not define the SGTIN as a GS1 key.

EPC Schemes &Corresponding GS1 Keys

Uniform Resource Identifier (URI) 

One can classify URIs: as locators (URLs), or as names (URNs), or as both.

A Uniform Resource Name (URN) functions like a person's name, while A Uniform Resource Locator (URL) resembles that person's street

address. In other words: the URN defines an item's identity, while the URL provides a

method for finding it.

In computing, URI is a string of characters used to identify a name and/or a resource on the Internet.

EPC URI

The primary representation of an Electronic Product Code is as an Internet Uniform Resource Identifier (URI) called the Pure Identity EPC URI.

The EPC memory bank of a Gen 2 RFID Tag contains the EPC plus additional “control information” that is used to guide the process of data capture from RFID tags.

The EPC URI is the preferred way within an information system to denote a specific physical object.

The EPC URI is a string having the following form: urn:epc:id:scheme:component1.component2.… where scheme names an EPC scheme, and component1,

component2, and following parts are the remainder of the EPC whose precise form depends on which EPC scheme is used.

An example of a specific EPC URI

Serialized Global Trade Item Number (SGTIN) General syntax: urn:epc:id:scheme:CompanyPrefix.ItemReference.SerialNumber

urn:epc:id:sgtin:0614141.112345.400 where the scheme is sgtin 0614141 is Company Prefix, assigned by GS1 to a managing entity 112345 is the Item Reference, assigned by the managing entity to a

particular object class. 400 is the Serial Number, assigned by the managing entity to an

individual object.

SGTIN-96 example Header: followed by a series of fields whose overall length,

structure, and function are determined by the header value.

Filter: allow an RFID reader to select or deselect the tags corresponding to certain physical objects, for example in a pallet.

Partition: contains a code that indicates the number of bits in the GS1 Company Prefix field and the Indicator/Item Reference field.

SGTIN-96 example “continue”

A typical ONS query

A typical ONS query

1. A sequence of bits denoting an EPC is read from a 64-bit RFID tag. Example: (1000000000000000000000000000000000110000000000000000000110010000)

2. The tag Reader sends that sequence of bits to a client Application. Example:

(100000000000000000000000000000000011000 000000000000000110010000)

3. The client application converts the bit sequence into the pure identity Uniform Resource Identifier (URI) Form and presented to the local ONS “step 3”.

Example: urn:epc:id:sgtin:0614141.000024.400

4. The local ONS converts the URI form into a domain-name and issues a DNS query for Name Authority Pointer (NAPTR) records for that domain. Example: 000024.0614141.sgtin.id.onsepc.com

A typical ONS query

5. The DNS infrastructure returns a series of answers that contain URLs that point to one or more services (for example, an EPCIS Server).

6. The local ONS extracts the URL from the DNS record and presents it back to the client application.

Example: http://epc-is.example.com/epc-wsdl.xml

7. The client application contacts the correct EPC-IS server found in the URL for the EPC in question

ONS Formal Specification

An ONS Server is an implementation of a DNS Server; . there is no separate specification for an ONS Server. Any DNS server compliant with [RFC 3403] may be used as an

ONS Server.

The ONS specification consists of three ingredients:1. DNS Query Format 2. DNS Records for ONS 3. Processing ONS Query Responses

DNS Query Format

A procedure that an ONS Client SHALL follow in order to present a query to ONS. This procedure specifies how an EPC is converted to a DNS

NAPTR query.

Begin with an EPC represented in the pure identity URI form URIs in this form are ASCII strings beginning with urn:epc:id:,

for example, urn:epc:id:sgtin:0614141.000024.400. Remove the urn:epc: prefix, in the example

id:sgtin:0614141.000024.400.

DNS Query Format “Continue”

Remove the serial number field. In all tag formats currently defined in [EPC] (SGTIN, SSCC, SGLN, GRAI, GIAI,

and GID), the serial number field is the rightmost period (.) character and all characters to the right of it.

(In the example remove “.400”, this leaves id:sgtin:0614141.000024) Replace each colon (:) character with a period (.) character

(in the example, leaving id.sgtin.0614141.000024) Invert the order of the remaining period-delimited fields

(in the example, leaving 000024.0614141.sgtin.id) Append .onsepc.com.

In the example, the result is “000024.0614141.sgtin.id.onsepc.com”.

DNS Records for ONS

ONS Publishers SHALL obey the following rules:

The Order field SHALL be zero. The Pref field SHALL be a non-negative integer.

The value of the Pref field is an ordinal that specifies that the service in one record is preferred to the service in another record having the same Service field.

The Flags field SHALL be set to 'u', indicating that the Regexp field contains a URI.

DNS Records for ONS

The Service field contains an indicator of the type of service that can be found at the URI in question. WS: a generic Web Service by investigating the WSDL file found at the URI in

the Regexp Html: returns a URI that will resolve to an HTML page on some server Epcis: The EPC Information Service Specification

The Replacement field is not used by the EPC Network but since it is a special DNS field its value is set to a single period ('.') instead of simply a blank.

The Regexp field specifies a URL for the service being described. The value of this field SHALL be the string !^.*$! , followed by a URL, followed by an exclamation point (!) character.

Processing ONS Query Responses ONS Clients use the following procedure to interpret the ONS query1. The result from the ONS query is a set of NAPTR records 2. From among the results from Step 1, select those records whose

Service field names the desired service. If there is no such record, stop: a pointer to the desired service is not available.

3. From among the results from Step 2, select those records having the lowest value in the Pref field.

4. From among the results from Step 3, select a record at random. 5. Extract the service URL from the record from Step 4, by extracting the

substring between the initial !^.*$! and the final ! character. 6. Attempt to use the service URL from Step 5. 7. If Step 6 is not successful, go back to Step 4, using a different record

from among the records from Step 3. If all records from Step 3 have been tried, go back to Step 3 using records from Step 2 having the next lowest value in the Pref field. If all records from Step 2 have been tried, stop: no service is available.

Example

In the following examples the EPC in question is urn:epc:id:sgtin:0614141.011015.583865

The ONS Client application converts the EPC into a domain-name: 011015.0614141.sgtin.id.onsepc.com

The application then queries the DNS for NAPTR records and receive:

Finally, depending on the service that the ONS Client desires, it uses one or more of the records returned to locate an appropriate service.

Multi polarity ONS

Unlike in the DNS system, the ONS Root is uni-polar, i.e., it could be controlled or blocked by a single country. It is managed and run by Verisign located in US

This could constitute a major acceptance problem for the use of the EPCglobal Network as a future global business infrastructure.

Solutions:1. A straightforward approach to avoid the unipolarity of the ONS is to

replicate the ONS root between a number of servers operated by independent entities, and to synchronize the instances of the root zone file with a master copy published by EPCglobal.

2. Or Regional ONS root: The high load on the root nameservers will be mainly caused by the size and frequent updates of the root zone file. With RFID becoming ubiquitous, their number is expected to grow rapidly, resulting

in millions of resource records (RRs) Splitting it between a number of regional root nameservers Example: 1734.453.400.sgtin.id.onsepc.com

Multi-polarity ONS

Federated ONS

EPCglobal architecture

Discovery Services (DS): not implemented and

EPCglobal is gathering user requirements as a first step to developing Discovery Services.

This module is expected to discover information for a specific object, which may be distributed across many nodes among a chain of trading partners.

Manufacture x, Transport y, Retailer z

Discovery Service

Thank you!

Questions?

Dr. Mazen Khair Email: mkhair@site.uottawa.ca

Prof. Hussein Mouftah Email: mouftah@site.uottawa.ca

GS1 Identification Keys (ID Keys)

There are nine GS1 Identification Keys that support the identification of items, services, locations, logistic units, returnable containers, etc. The GS1 Company Prefix assigned to a user company allow that user company to create any of the GS1 identification keys.

Key Concepts GTIN - Global Trade Item Number GLN - Global Location Number SSCC – Serial Shipping Container Code GRAI – Global Returnable Asset Identifier GIAI – Global Individual Asset Identifier GSRN – Global Service Relation Number GDTI – Global Document Type Identifier GSIN – Global Shipment Identification Number GINC – Global Identification Number for Consignment

GTIN - Global Trade Item Number

As the name implies, the GTIN helps automate the trading process – basically buying and selling. GTINs are therefore assigned to any item (product or service)

that may be priced, or ordered, or invoiced at any point in any supply chain.

GLN (Global Location Number)

As the name implies, the GLN is the GS1 Identification Key for Locations. The GLN can be used to identify physical

locations and legal entities where is a need to retrieve pre-defined information to improve the efficiency of communication with the supply-chain.

SSCC (Serial Shipping Container Code)

The SSCC is the GS1 Identification Key for an item of any composition established for transport and/or storage which needs to be managed through the supply chain. The SSCC is assigned for the life time of the transport item and is a mandatory element on the GS1 Logistic Label using Application Identifier (00)