RFID, radio-frequency identification, is an automated data collection technology, which uses radio frequency waves to transmits data between a movable object and a reading device for identifying, tracking and categorizing said object. In comparison with the conventional bar codes, there is no direct contact or line of sight between the tags and the reading device needed.

(Jemuel)

A RFID system consists of the following components:

• RFID-Tag or transponder: microchip & copper- or aluminium-antenna
• Radio interface (magnetic field (inductive coupling) or electromagnetic waves (backscatter coupling))
• Recording device (reader or reading-/ writing device) with antenna
• Local interface to the IT-System and to the data bases
• Software for data processing

Basis components of a RFID system (IHK Reutlingen, p. 2)

The recording device, which consists of a reading / writing device and one or more antennas, serves retrieving data sent from the transponder or new labeling the transponder. By emitting electromagnetic waves, the device generates an electromagnetic field. Energy transmission and communication between the reader and the transponder occurs through radio waves. For various applications of the RFID system, only specific frequency domains are admitted. By means of an additional local interface, the retrieved data can be forwarded to IT systems. There are local fixed installed devices, so-called 'gates', or mobile devices.

(IHK Reutlingen, p. 2 ff.)

The transponder or RFID tag is the core of the RFID system. It consists of a microchip with simple processor, a permanent memory and an antenna. The RFID tag can be attached to an object (e.g. to a product) or rather build into an object (e.g. a chip).

RFID tag (IHK Reutlingen, p. 3)

Passive RFID technology (Bai, Yuntian Brian, et al., p. 2)

The RFID system consists of three components: the stationary or mobile reading device, the information carrier, referred to as transponder or tag and an internal antenna, which receives and transmits signals. Passive RFID tags consist of an antenna and an integrated circuit (IC) or a microchip (Smiley, Suzanne). A passive RFID transponder doesn’t need any batteries. Therefore, its durability is almost indefinite. There is no visual contact necessary between the transponder and the reading device. Signals can be received through all non-metal materials independent from the reading angle, the lighting conditions or other environmental influences (EURO I.D.). To read the tag, the reader sends energy to an antenna that converts it into radio waves. After the tag is read in the established read zone, the internal antenna collects energy from the radio waves. The collected energy charges the microchip which generates a signal back to the system. By means of the antenna, the reader can identify this change in the electromagnetic field or backscatter (Smiley, Suzanne). Those pieces of information send by the transponder are read, decoded, displayed and / or provided for further data processing at an interface (EURO I.D.). The energy diffused by the reading device’s electromagnetic field is absorbed by the passive RFID transponder / tag to provide the needed power to operate (Jemuel).

Smart labels are passive RFID tags, which are enclosed in an adhesive paper label. The benefit of this specific type of tag is that it cannot only be used by RFID or barcode readers, but also by human readable characters. There are various scenarios a smart label proves itself as necessary. For example they can be used in a division where the type of reader is unknown. This division may have either a RFID reader or a barcode reader, but not both types of readers. In this case a smart label comes in handy, as it is a combined RFID and barcode tag.

(Poole, Ian)

Active RFID technology (Bai, Yuntian Brian, et al., p. 2)

In comparison to the passive RFID technology, there is an internal energy source. This battery enables a long range for data exchange up to 100 m, a memory up to 32 kByte and an integration of further functions like signal-LEDs. The service life of the battery can last approximately 7 years. To gather information for the first time, the reading device querys all of the transponders in area, which answer with their address code. Consequently, the transponders can be queried individually (EURO I.D.). Like in passive RFID systems, the reader sends a signal first. The active tag will reply with a signal containing the specific information. Active RFID tags have a rather bulky exterior and are normally larger than passive RFID tags. Some active tags also have integrated sensors which track environmental key figures, such as temperture, moisture levels and so on (Smiley, Suzanne).

• Increase of order and shipment accuracy, productivity, business intelligence and efficiency (Lowry, p. 2)
• Costs and amount of inventory management are reduced (Lowry, p. 2, Donaldson, Tara, p. 4 ff.)
• Less time spent looking for a specific product (Danby)
• Improved contentment of employees (Danby)
• Rewritability of tags (IHK Reutlingen, p. 4)
• Storing valuable statistical data sets directly on the object (Mannel, Michael, p. 2)
• Improvement of loss prevention (Donaldson, Tara, p. 6)
• Almost unlimited life span of passive tags (no batteries needed) (IHK Reutlingen, p. 4, Donaubauer, Tobias)
• Non-contact Identification and tracking of several objects (Mannel, Michael, p. 2, IHK Reutlingen, p. 14)
• Readability through various materials (Mannel, Michael, p. 2)
• High storage capacity of active tags (IHK Reutlingen, p. 4)
• Real time capability possible (Mannel, Michael, p. 7, IHK Reutlingen, p. 15)
• Easy integration into products, packaging and transport units (IHK Reutlingen, p. 15)
• Relatively insensitive to contamination and to interference (Donaubauer, Tobias, IHK Reutlingen, p. 15)
• Sometimes large reading range possible: (Active tags can send a signal over a comparatively high distance in the microwave range) (IHK Reutlingen, p. 4)
• Combinability with sensors and protection mechanisms against unauthorized reading (IHK Reutlingen, p. 14 ff.)
• Small size, Low weight and Lower price of passive tags (IHK Reutlingen, p. 4)

• Short range of passive tags (Lowry, p. 3, IHK Reutlingen, p. 14)
• Different factors influencing the error rates in readability and the reading range (e.g. metal, liquids, glass, frozen goods, as well as humidity or temperature fluctuations), intensitivity being dependent on the frequency range (Lowry, p. 4, IHK Reutlingen, p. 14)
• Costs of infrastructure investments (Donaubauer, Tobias, IHK Reutlingen, p. 14)
• Dependence of the reading range on the orientation of the antenna (IHK Reutlingen, p. 14)
• Dependence on national and international radio regulations ( no standards available) (IHK Reutlingen, p. 14)
• Health hazard caused by electromagnetic radiation are not sufficiently clarified (IHK Reutlingen, p. 15)
• Short life span, size, price of active tags (IHK Reutlingen, p. 4)
• Low storage capacity of passive tags (IHK Reutlingen, p. 4)

RFID factory (Danby)

Through the use of RFID technology it can be determined at which point in the production chain the product is located. The localization occurs in this case through distribution of readers across the building. The accuracy depends on the frequency range used in the system. RFID tags can be used for transmitting target coordinates, which are stored on an employee’s card to a building control system, e.g. touchscreen or terminal solution. The best route starting from the present location is displayed on the chosen building control system.

(infsoft)

Where the position should be determined, RFID tags need readers in these areas. A typical use case is tracking of goods in a big warehouse. At specific locations a product will pass a reader and will be identified. Consequently, this product transmits the information „product xy has passed control point 3” to a server or a database.

(Gaudlitz, Eva)

The fashion retailer Superdry will be performing a rollout of RFID technology this financial year after its pilot in five other stores in the UK is a success. The retailer implemented RFID to support managing the instore inventory. Additionally, this technology provides considerable operational benefits, digital marketing opportunities, labour reduction for store staff and brand protection.

(Baldwin, Caroline)

In 2003 Superdry was founded in the UK and now has stores all over Europe and the U.S. The company has an innovative culture supporting its growth and the increasing e-commerce sales. After implementing UHF RFID technology, sales improved, the inventory increased in accuracy and out-of-stocks got reduced. The long-term goal is the integration of RFID into every Superdry store. The fashion retailer wants to enable additional technology-based implementation. During the first phase of the rollout, 27 additional U.K stores and all U.S. stores will be taken live. This rollout shall be completed at the end of this year. The following rollout phase includes all the U.K. stores and the stores across Europe. The pilot of implementing RFID technology in five stores and its distribution center, has been executed in between December 2017 and February 2018. The stores which participated in the pilot project, are situated in the United Kingdom and picked out after business size, merchandising selections to represent the variety of the company. The deployment took place at its flagship store in Regent Street, at its Redding Store of the Future and other smaller stores. For the implementation of RFID technology, the company used UHF RFID tags. The unique identification number encoded on each tag has been linked to a particular item’s stock keeping unit in the software of the RFID system (TrueVUE). Employees at the distribution center fulfilled orders from the five picked stores. After the ordered products arrived at a store, the sales personnel used handheld readers (Zebra) and iPods(Apple). The used readers recorded the tag’s identification number of every item, transmitting the data to the iPods and then to the software by means of the Wi-Fi network. After placing the products in the store front, the status of every item has to be updated, so the tags were read again. The data collected of product sales can request replenishment orders to the distribution center.

• Decrease of labour time needed to receive products at the store
• Faster and more frequent conduction of audit counts
• Conduction of unceasing inventory checks by automation (the installed software seeks a specific type of product, counts the present items in the back and front of the store) Within the next year, the stores will be receiving items which are already tagged since the products will be processed at the manufacture. It is planned to deploy RFID readers at all distribution centers with the potential of a follow up plan to install tunnel readers. This system will make it possible to capture outbound tags when the goods are shipped to stores and with this benefit also saves labour time at the distribution centers.
• Evaluation of the period of time items remain on display in particular stores
• What products are performing well and what products are performing badly?
• Creation of individual planograms for each store and customers
• Providing information on the location, sales and the need for replenishment of products There are also benefits in customer service. For Example customers, looking for products which were placed incorrectly, can address this issue with the staff. Thanks to the RFID technology, the personnel could locate the misplaced item.

(Swedberg, Claire b, 2018)

Sponda Plc., the owner of the Citycenter shopping mall in Helsinki, has been trialing a RFID technology solution to provide promotional and location specific content. This system works without the involvement of smart phones or a customer’s personal information. Since 2014 customers of the mall have been using RFID tags (Citycenter VIP keys) to receive marketing messages and store specific offers in connection to their purchasing behavior. The developed system for identifying customer movements, for analyzing their behavior patterns and for presenting individual content on digital screens is known as "the Physical Cookie“. 15 retailers and 14, 000 customers participated in the pilot. Sponda is a property investment company and Citycenter is one of its retail locations. The mall includes about 60 stores across five levels. With RFID one can collect information on customers’ behaviours without knowing their identities and one also can provide personalized promotions without customers looking at their phones. The so-called VIP Keys are made of plastic, measure about 10 cm in length, about 2 cm in width and are meant to be attached to customers’ key chains. Embedded in the key is a passive UHF RFID tag. Customers, that use those keys don’t need to provide any personal information for the RFID solution only tracks the unique ID transmitted by the tags. About 24 UHF RFID readers were installed in Citycenter, including entrances to the stores and the mall. While a shopper walks through the mall, the readers capture the ID of the tag and transmit the data to the Physical Cookie software on a cloud based server. The collected data is then stored and analysed. If a customer often stops at a particular store or spends a longer period of time in this store, the software detects that this person might be interested in promotional content, coupons or rewards connected to the store or the products this store sells. When a shopper passes a digital sign a reader near the sign discovers the presence of the person and shows specific content due to the person’s behaviour. The collected data is also meant to support the participating companies to understand the movement of traffic throughout the entire shopping center. During the pilot, the implementation of the RFID system has increased the movement of customers into the stores by 14.5 % and the amount of time shoppers spend at Citycenter has also increased by 21.7 percent.

(Swedberg, Claire a, 2015)

The department of industrial and systems engineering of the Hong Kong Polytechnic University deals with this paper, which examines the feasibility of the use of passive RFID tags for indoor positioning and object location determination for extraction of real time data on motion tracking. Results of this study show that the system’s readability is satisfactory and it is more cost-effective compared to other technologies. There is no direct contact or rather visual contact needed. While choosing tags, you have to keep in mind that different RFID tags can work on various frequencies. Factors, like for example damping elements and crossings of radio waves as well as impairments from other RFID tags, RFID reading devices can interfere with the communication between the mentioned devices. Various objects, that are equipped with RFID tags, can also disturb the performance. The accuracy of the RFID positioning system amounts to 93% which is a very high success rate. Since the passive RFID tags are quite cheap, there is a mass deployment of the positioning system possible. The durability is unlimited because the passive RFID tags don’t need any batteries. The RFID indoor positioning system has already been used in some application areas of the supply chain. You can see a trend that fuels the development of positioning systems that employ RFID.

(Ting, S. L., et al., p. 9 ff.)

Criterion	Description
Range	Various ranges 1. Low Frequency LF (30 – 500 kHz) Up to 1m 2. High Frequency HF (10-15MHz) Up to 2 m 3. Ultra High Frequency UHF (850MHz – 5,8GHz) Passive: up to 5m Active: up to 100m (Lipps, Jakob)
Accuracy	Punctual measurement It can be measured up to 10 cm accurately (Donaubauer, Tobias)
Power consumption	Passive RFID tags don't have an integrated power source. Therefore, their needed energy for sending data is extracted from the received radio waves of the reader. The antenna of the transponder functions as a coil and thus can charge a capacitor. Active RFID tags have an integrated battery. (XTremeGN , Lipps, Jakob)
Life span	Passive RFID tags: nearly unlimited Active RFID tags: 5 – 10 years (Koprek, Matthias)
Bit rate	1. Low-End Systems 1-Bit Systems that only signal whther a tag is present or not. For applicating Low-End Systems in the area of localization, a 32-bit-read-only-code is used. 2. Medium Systems The performance spectrum is formed by RFID systems from a few byte up to over 100 Kbyte. 3. High-End Systems The data transfer rate can be up to 848 kBit/s. (Bundesamt für Sicherheit in der Informationstechnik)
Disturbing factor	Depends on the type of frequency Humidity: 1. LF: no impact 2. HF: no impact 3. UHF/microwave: negative impact Metal: 1. LF: negative impact 2. HF: negative impact 3. UHF/microwave: no impact (Baulig, Christian, p. 24 ff., Mähnz, Andreas, p. 6 ff.)
Embedding (no additional Hardware required)	No additional hardware needed. (Noll, Josef)