Software Components


The specific features and functionalities of the software components of an RFID system vary greatly depending on the application and requirements. These components fall into the following categories:

  • RFID system software

  • RFID middleware

  • Host application

Software programs are executed in the tag, the reader, and the host computer.

Although we will describe each of these components separately, it is reasonable to expect cooperation and overlap of functionality between these three software components. Figure 3.7 illustrates these interdependencies and the functionality overlap between the software components.

Figure 3.7. RFID Software Components and Their Interdependencies


RFID System Software

The RFID system software is the collection of functions necessary to enable the basic interaction between a tag and a reader. In its most basic form, the communication occurs at a radio signal processing level. It requires hardware, very low-level software (firmware), and higher-level system software to manage the data that flows between tag and reader. The following sections describe typical RFID system software functions required at the tag and reader level.

Read/Write

These are the most basic functions of a tag. A reader asks a tag to read or write data. The tag accesses its memory to read the data as instructed by the reader and transmits the data back to the reader. The tag also can be supplied data by the reader (from the host application) to write to its memory, provided the tag has write capability.

Anti-Collision

Anti-collision software is used when, at any given point in time, multiple tags are present in a reader's RF field and must be identified and tracked simultaneously. This is typical in most supply chain management applications. For example, in an inventory management application deployed in a warehouse, hundreds or even thousands of tagged objects may be within a single reader's RF field, which can be up to several feet in radius. A single pallet of RFID tagged apparel can have more than 100 cases, each containing dozens of clothing items. The anti-collision function requires cooperation between the tags and readers to minimize the risk of many tags responding all at one time. In some cases, the algorithm may be as simple as each tag waiting a random amount of time before responding to a reader's request.

Error Detection/Correction

A reader may employ sophisticated software to detect and correct transmission errors from the tag. Such software may also include programming to detect and discard duplicate or incomplete data.

Encryption, Authorization, and Authentication (Security)

Encryption, authorization, and authentication are useful when secure data exchange must occur between a tag and a reader. Both the tag and the reader must cooperate to execute the protocol needed to achieve the desired level of data security. For example, to prevent an unauthorized reader from retrieving data from a tag, the tag and the reader may have to execute an authorization protocol by exchanging a common secret or code. After this shared information has been exchanged and validated, the tag then transmits the data to the reader.

Security functionality on the tag requires sophisticated IC design and capability, which can significantly impact the cost of a typical passive tag. The topic of security is discussed in detail in Chapter 10, "Security and Privacy."

RFID Middleware

RFID middleware[2] consists of a set of software components that acts as a bridge between the RFID system components (that is, tags and readers) and the host application software. It performs two primary functions:

[2] The term middleware here should not be confused with the term middleware used in enterprise IT applications. In enterprise IT applications, middleware software is used to connect disparate pieces of enterprise application software.

  • Monitors device (that is, reader) health and status

  • Manages RFID-specific (that is, tag and reader) infrastructure and data flow

These functions are related and often share or leverage common data. However, they fulfill very distinct application requirements and have unique characteristics. We describe each separately in the following sections. Note that most RFID middleware vendors offer software that aggregates both functions into a single package. However, as with any multifunction software package, each vendor addresses these functions with varying degrees of sophistication. Your choice of a particular vendor solution should be based on your own application requirements. We offer extensive advice in Chapter 8, "Vendor Considerations and Landscape," to help you with this choice.

Monitor

This function consists of centrally monitoring and reporting readers' health and status within an RFID-enabled application. This is an especially important function in environments where multiple readers are distributed across a single or multiple locations, and visual or manual monitoring is not practical. For example, consider a large warehouse location where multiple conveyor belts are outfitted with dozens of strategically located readers that automatically collect data on tagged items. In this case, it is important to be alerted to reader breakdowns or malfunctions as quickly as possible. This helps address the problem in real-time and reverses any error that may have occurred, in a timely fashion.

In an ideal situation, the monitoring software should be able to handle devices other than readers (for example, where barcode readers or RFID smart label printer/ encoders are also used).

Manage

In a nutshell, this function consists of encoding, collection, processing, filtering, and aggregation of data transmitted between tags and readers for integration with the host application. This is an especially significant function in an environment where readers can pick up large bursts or constant streams of tag data (such as in a supply chain application). Tag data needs to be cleansedfor example, to remove duplicates massaged, or filtered, and alerts may need to be raised based on certain predefined rules for data collection.

Another important function performed at this stage is data normalization. In the absence of standards, reader data formats and communication protocols with a host are usually proprietary. To function in a multi-vendor environment, the RFID middleware software is responsible for translating various reader data formats into a single, normalized format for easier integration at the host application level.

Host Application

The host application receives processed and normalized data sent from the tag, via the reader and the RFID middleware software. The host application typically is a previously existing software program in an enterprise, such as an inventory control or warehouse management system. Depending on the sophistication of the RFID middleware and the capabilities of the host application, the host application software may not even need to know the actual source of the data it expects to receive. For example, an inventory management application can successfully track all the products on the shelves in a retail store without "knowing" how the data is entered. Before the RFID system was installed, this data may have been entered manually or through a barcode system. As long as the application has a well-defined interface protocol for data input, the RFID middleware software need only process and format the data originating from the tag and use the protocol defined by the host application to pass on this data.

However, some applications may need to be modified to accept a new set of data from the RFID middleware because they lack a fully defined interface protocol. This scenario is more likely if the application is older or home-grown.

In other situations, a different software program must be written or purchased as the host application because an entirely new solution has been deployed within the enterprise. For example, consider an RFID-based access control system implemented in a business where access control was previously achieved through metallic keys. In this case, entirely new application software is required to manage, authenticate, and provide user access.

It is important to note that a significant challenge exists, regardless of whether an existing application can handle RFID data or a new application or interface has to be developed. In many cases, RFID represents new data for an enterprise. It is unlikely that the enterprise has an existing business model that can fully leverage this data. For example, in a typical RFID-enabled supply chain management solution, items are identified by an Electronic Product Code (EPC). EPC is an extended form of UPC (Universal Product Code) used in barcode systems, and allows for encoding of much more detailed item data than UPC. Existing supply chain business models and applications originally developed to use the UPC data now have access to new, extended EPC data that they can and should leverage. This is what we referred to as the unique identification or serialization challenge in Chapter 1's "Supply Chain Integration" section. Businesses will indeed have to re-architect their business models and applications to be able to fully realize the benefits of this additional data generated through RFID systems.



RFID Field Guide(c) Deploying Radio Frequency Identification Systems
RFID Field Guide: Deploying Radio Frequency Identification Systems
ISBN: 0131853554
EAN: 2147483647
Year: 2006
Pages: 112

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net