RFID in Europe Magazine Febuary 2016
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European RFID survey
RFID in Europe AISBL is a not-for-profit organization established in 2012. RFID in Europe's principle goal is to promote the adoption of Radio Frequency Identification and related technology solutions enabling small and medium sized organizations throughout Europe to gain competitive advantage through their best use. RFID in Europe connects with European end-users, operators, solution providers, universities, research establishments, non-government and government organizations and all other European stakeholders through own initiatives and promotion of national projects via our international network. RFID in Europe is an extension of a European Commission FP7 Thematic Network called RACE networkRFID initiated in 2009.
What Do You Need To Know
As a first level of choice we need to have an awareness of the systems we have in our silicon-based RFID portfolio, their attributes and the benefits they can provide when effectively applied. Since it’s all about carrying and moving data in a wireless fashion here are some of the first things to know:
- Data capacity – This specifies how much data the tag can carry. It is often expressed in bits. For example, a 64-bit carrier is effectively capable of carrying eight digits and eight characters or a combination of characters and digits. A 2kbit tag would be capable of carrying 256 characters.
- Read-write capabilities – This specifies what is possible in terms or read-only and read-write capability. It is worth remembering that many read-only tags are factory programmed and carry an identification number (tag ID). Other tags, including read/write devices can also carry a tag identifier which is used to unambiguously identify a tag. This identifier is distinct from user introduced identifiers for supporting other application needs.
- Read-only devices are generally less costly and may be factory programmable read-only or one time programmable (OTP). One-time programmability provides the opportunity to write once then read many times thus supporting ‘passport’ type applications where data can be added at key points during the lifetime or usage of an item and thus providing an incorruptible history or audit trail for the item data.
- Read/write data carriers offer the facility for changing the content of the carrier as and when appropriate within a given application. Some devices will have both a read-only and read-write component that can support both identification and other data carrier needs. The read-write capability can clearly support applications in which an item, such as a container or assembly support, is re-usable and requires some means of carrying data about its contents or on what is being physically carried. It is also significant for life-time applications such as maintenance histories, where a need is seen to add or modify data concerning an item over a period of time. The read/write capability may also be exploited within flexible manufacturing to carry and adjust manufacturing information and item-attendant details, such as component tolerances. A further important use of read/write is for local caching of data as a portable data file, using it as and when required, and selectively modifying it as appropriate to meet process needs.
- Data transfer – Specifying how fast the data can be transferred from tag to host management system. It is generally quoted in bits per second.
- Data security and error control support features – This deals with what is required to support the realisation of security-centric applications where stored or encrypted data is used as part of a security application. In the case of error control, exploiting algorithms for error detection and correction, the facility should provide greater confidence in the accuracy and integrity of the data transferred from a tag to a host or vice versa.
- Time to read – This is the time it takes to read a tag, which of course is related to data transfer rate. For example, a system operating at 1 kbit per second transfer rate will take approximately 0.1 of a second to read a 96 bit tag (96/100 with a bit of time for communication management). Various factors can influence read time including competing readers and tags (reader access and batch readability).
- Batch Readability – Where readers are competing for attention this can have an influence upon the time to read depending upon the access management methods that are used to control them. Where a number of tags are competing for attention this can also have an influence upon the time to read and requires anticontention facilities to handle the reading process. The time to read them all is clearly multiplied by the number of tags. This may be fine if the tags are stationary. However, if the tags are on items moving through the read zone the time they are available for read becomes important and may indicate the need for a faster transfer rate. For higher capacity tags the time to read is correspondingly higher if all the data is to be transferred. Where parts of the tag-held data can be selectively read the time to read will depend upon the amount of data to be transferred in the selective read. For read / write systems the time to write can also be significant.
- Range – the distance over which the data can be transferred from tag to host, primarily related to available power and carrier frequency, which it should be remembered is governed by national and, in some cases, international regulations. Generally speaking active tag systems exhibit longer ranges than passive, but this is not always the case. For read/write systems the write range is usually shorter than the read range due to the higher energy generally required for writing data to a tag. It should also be appreciated that there are numerous factors that can influence the range that can be achieved, other than power and carrier frequency. These factors include tag-to-reader orientation and obstacles within the reading zone that can reflect, diffract, absorb or otherwise distort the fields that couple the tag and interrogator/reader devices. Close proximity of tags may also impede or even prevent communications if sufficiently close.
- Interference – Systems need to be immune from interference by signals or fields from other sources and commissioned to ensure that they comply with regulatory requirements and do not cause interference with other systems.
- Form and robustness – This relates to the various forms that the data carriers may take in respect of the physical form, size and weight and robustness of the tags and facilities for attachment to items.
- Standards – Knowing what technical and application standards are applicable to the applications envisaged.
- Regulatory requirements – Knowing what regulations govern the usage of RFID systems, including spectrum usage, safety regulations and guidelines.
- Costs – You need to determine how much the basic parts of a system are likely to cost. This should include support costs that can have an important bearing upon determining and justifying an application for RFID .
- Application features – This can have a significant bearing upon the type of RFID system to be used and provide insight into where best the technology can be applied.
Of all these features the costs and areas of application should provide the greatest comfort feeling in appreciating what can be achieved and the opportunities for the technology to meet your own needs.
The other features are important to consider once you have achieved a level of appreciation of the system capabilities and how they relate to your own sphere of business activity. Information concerning the majority of these features is generally to be found in product data sheets. The attributes identified for RFID, in part or in total, can often provide advantage over and above other AIDC data carrier technologies that are limited by read/write capability, range, data carrying capability and robustness in respect of environmental conditions. RFID should, in general, be considered complementary to such technologies, opening up opportunities for new applications.
Although a consideration of the general attributes can provide a useful insight into the relevance of the technology for data handling processes, more specific, and often technical, considerations are important in moving to a solution. It is also important to consider the limitations on usage. In the very prescriptive sense of the word, these limitations relate essentially to the performance of systems with respect to the defining attributes; the limitations on range, data capacity, and data transfer.
One should bear in mind that the performance ratings are generally influenced by the system design and the practicalities of the applications, including the environment in which they operate. Some attributes such as range will be influenced by a number of factors including, for example, power, frequency, antenna characteristics and environmental “clutter” (the features present in the application environment that can reflect, refract or absorb the radio signals used to communicate with the RFID data carriers). The guiding principle is to ask appropriate questions and obtain reliable information concerning product capabilities and performance ratings.
In addition to the categorisation based upon carrier frequency other categories of system should be considered for particular areas of application. These include:
- Active RFID devices and systems
- Smart labels and Smart active labels
- Electronic Article Surveillance (EAS) and EAS/RFID
- High temperature tags
- Sensory tags
- Cryptographic tags
- Chipless RFID