Internet of Everything

 Module -1 - Introduction


History of IoT:


IoT was originally introduced by the Auto-ID research centre at

the MIT (Massachusetts Institute) where an important effort

was made to uniquely identify products. The result was termed EPC

(electronic product code), which was then commercialized by

EPCglobal. EPCglobal was created to follow the AutoID objectives in

the industry, with the EAN.UCC (European Article Numbering –

Uniform Code Council), now called GS1, as a partner to

commercialize Auto-ID research, mainly the EPC. 



Objects in IoT:


A “thing” or “object” is any possible item in the real world that might join the communication chain. As presented by [HOD 01], the initial main objective of the IoT was to combine the communication capabilities characterized by data transmission. This was viewed as the Internet, also known as the network of bits representing the “digital world”. The process of automation was viewed as connecting the real or physical world, named the “network of atoms” characterized by the smallest component, which is the atom, to the digital world, named the “network of bits”, characterized by the smallest component, which is the bit. 


Object Classification

RFID tags and sensors are connecting inanimate objects and are building the actual things enabling the first IoT services.


 

The identifier in the IoT:

The term “identifier” is similar to the term “name”. A name does not change with location.

Anything can be assigned an identifier – a physical object, person, place or logical object.

IP addresses identify nodes on the Internet and serve as locators for routing. IPv6 allows a larger address space than IPv4.

In the IoT, where objects are addressed via identifiers stored into tags and interrogated by networked readers

RFID technology is naturally used for identification, the standardization of the identifier stored in the RFID is the current IoT concern.

Areas in which identifier-triggered information access could be valuable are in:

– medicine/pharmaceuticals;

– agriculture;

– libraries;

– the retail trade;

– the tourist industry;

– logistics; and

– supply chain management


EPCglobal first standardized the EPC identifier, followed by the International Standardization Organization (ISO). In addition to ISO and EPCglobal, the Ubiquitous ID Center (uIDcenter) has defined a generic identifier called “ucode”, which is not only intended to identify physical objects but also extended to places and digital information. ISO has addressed the issue of standardized identifiers by considering proprietary proposals, such as EPCglobal and uIDcenter, but it also offers the chance to define other identifiers that conform to ISO recommendations. 


The Object Name Service (ONS) is an automated networking service similar to the Domain Name Service (DNS) that points[vague] computers to sites on the World Wide Web.[citation needed] When an interrogator reads an RFID tag, the Electronic Product Code is passed to middleware, which, in turn, goes to an ONS on a local network or the Internet to find where information on the product is stored. ONS points the middleware to a server where a file about that product is stored. The middleware retrieves the file (after proper authentication), and the information about the product in the file can be forwarded to a company's inventory or supply chain applications.


Technologies in IoT:


The full-scale commercialization of many of the technologies related to IoT may

require some time yet to come to fruition. Early developments have

already led to a lot of innovative applications that are likely to become

ubiquitous in everyday life: in the home, at work, on the farm, in the

hospital, at the shop, on the road, and even inside the body. 


An increasing number of technologies will be connected to the

existing and future network in order to interact with the real world to allow different applications around the user of IoT services. Other applications will involve more object-to-object

communication for different types of IoT services more closely related to the real-world environment. 


The main IoT enabling technologies will first be the electronic

identification technology such as RFID and sensing and actuating

technology such as sensors/actuators. Communication technologies

from object-to-object and from the network of objects to the existing

networks, such as wired and wireless communication networks and

other technologies such as nanotechnology, smart technologies,

robotics, location, etc. will also enable different IoT services. 


1. Identification technology


Identification technology was initially achieved with simple

barcodes that uniquely identify items for tracking. Barcodes evolved

to 2D barcodes in order to contain more information or more

identifiers in the same 2D space. Finally, electronic bar-coding with

the introduction of RFID will allow us to store the identifier in the

memory of the RFID tag. In the IoT, RFID technology is considered

as one of the enabling technologies for building new services over the

network.

 RFID technology will identify, track the location and provide a specific IoT application to

the object. It mainly answers the question “What, which, where?”,

while the sensor answers the question “How?” . RFID

systems consist of four main components:

– a transponder or a tag to carry data:

- tags can be passive, semi-passive or active, based on their

power source and the way they are used, as shown in Table 1.1;

– microwave antenna or coil and a microchip data located on the

object to be identified; 

– an interrogator or reader. Compared with tags, readers are larger,

more expensive and power-hungry:

- that can be read-only, read/write or read/write/re-write,

depending on how their data is encoded;

– middleware, which forwards the data to another system, such as a

database, a personal computer or robot control system, depending on

the application. 


2. Sensing and actuating technology

As mentioned earlier, an RFID mainly answers the question “what,

which, where?” while the sensor answers “how?”

A sensor is an electronic device that detects senses or measures

physical stimuli from the real-world environment and converts signals 

18 The Internet of Things

from stimuli into analog or digital form. Some sensors also provide

actuation functionality; these are named sensors/actuators.

Sensors can be classified according to the parameters they measure:

– mechanical (e.g. position, force, pressure, etc.);

– thermal (e.g. temperature, heat flow);

– electrostatic or magnetic fields;

– radiation intensity (e.g. electromagnetic, nuclear);

– chemical (e.g. humidity, ion, gas concentration);

– biological (e.g. toxicity, presence of biological organisms), etc.;

– military – enemy tracking or battlefield surveillance.

Many scientific and research groups are working to develop more

efficient and feasible sensor networks. The main technical constraints

are:

– power, size, memory and storage capacity;

– the trade-off between power and size;

– interference, communication model;

– the environment where the sensors are deployed (underwater,

land field, etc.). 


3. Other Technologies:

Emerging technologies will bring more possibilities to develop

new IoT applications involving the user less and becoming more 

object-centric or autonomous. Here are a few of them that we can

mention:

– smart technologies: thinking and deciding technologies based

on sensing and received information building the autonomous

communication;

– process automation and robotics: executing the actuation and

building autonomous communication;

– nanotechnology: the atom is the object, the smallest object in

IoT.

More possible IoT services will be based on new types of material,

feeling cloths, adapting wall painting, etc. pushing ubiquitous

networking many daily life objects.



Module -2:  RFID Technology:


Introduction:


Identity plays a crucial role in writing a success story of the

Internet of Things (IoT). Some of the traditional approaches to collect

the identity are machine-readable characters, MICR (magnetic ink

character recognition), bar-codes, smart cards, magnetic strips, face

and retina scans (especially for human beings), etc. Some of these are

contact type, where the object storing the identity information has to

make physical contact with the reader, and others are of proximity

type. Most of the proximity-based techniques require a clear line-of-sight path for successful identification. This could be a major issue in several applications. 


Principle of RFID:


principle of rfid

*  Consider a coil made of copper wire through which alternating current is flowing. The coil offers impedance to the source and a voltage develops across its terminals. It is possible to increase the voltage by connecting a capacitor in parallel with the coil. Let us call this the “primary” coil. Now we bring in another coil, called the “secondary” coil, close to the first. Due to electromagnetic induction, a voltage appears across the terminals of the secondary coil. The amplitude of the voltage depends on the size, shape, location and orientation of the secondary coil. If we connect a resistor (also known as a load) across the terminals of the secondary coil, current flows through it. The strength of the current flowing through the secondary coil depends on the load. The interesting phenomenon is that the current flowing in the secondary coil induces a voltage back into the primary coil, which is proportional to its strength. The induced voltage, also known as back emf (electromotive force), can easily be sensed by using suitable electronics. Therefore, by observing the voltage on the primary, it is possible to estimate what is connected to the secondary coil.

*  The system is excited by a sinusoidal source. Capacitors are connected across both primary and secondary coils, forming a parallel resonant circuit. A load resistance is also connected in parallel with the secondary coil. 

As the frequency of the source increases, the voltage also increases, reaches a maximum, and then decreases. The frequency corresponding to the maximum voltage is known as the resonant frequency. Now, if the load resistance is changed, the voltage at the primary corresponding to the resonant frequency drops sharply.

*  It is possible to change (or modulate) the voltage at the primary by changing the load connected to the secondary. This is known as “load modulation”.

*  The primary coil can be thought of as the reader of the RFID system, and the secondary coil as the transponder or tag. The tag can convey any message back to the reader using RF signals, by simply changing the load connected to its terminals. This could be achieved by switching in a load to represent a logical state 1 and taking off the load to represent a logical state 0. Using load modulation, a tag is able to communicate with the reader and transfer its identity without actually using a transmitter. The identity information is stored in a memory chip located on the tag. A processor (also known as the state machine) reads this information and modulates the load by operating a switch. Two more ingredients are required to operate the entire system: power and clock

*  Load modulation is the principle used to establish communication between the reader and the tag operating in the LF and HF bands. 

*  When the electromagnetic energy falls on the antenna attached to the tag, it backscatters a portion of the energy. The amount of backscattered energy depends on the load connected to the tag antenna. Therefore, by modulating the load according to the data, it is possible to change the strength of the backscattered signal from the antenna. The backscattered signal is sensed by the reader and is able to extract the information carried by it. 



RFID Issues:


  • When the tag is attached to an object whose electrical properties are different from that of free space. This generally degrades the performance of the tag.
  • There could be several tags trying to communicate with the reader and several readers trying to read several tags at the same time. This results in a collision of data being transferred between the readers and tags. 
  • The schemes used in a standard communication system for multi-access cannot be used here. Anti-collision schemes, very specific to the RFID system, have been proposed and are very effective in enabling several tags to communicate with the reader.
  • The amount of energy reaching the tag antenna depends on the interaction of the waves and the environment in which the reader and the tag are placed. 
  • The behaviour of a tag stuck on a dielectric sheet, such as a wooden board or a glass sheet, depends on the permittivity of the material, the thickness of the material and the location of the tag itself. 
  • Privacy of data stored in the tag becomes an issue when these are associated with people.
  • Security of information stored on the tag also plays a crucial role in several applications. Issues such as tampering with the data stored in the tag, altering the association between the tag and the product, collecting security-related data stored on the tags, etc. have prompted designers to implement encryption techniques to secure the information on the tag itself. 
  • This help the data to transfer even faster  because redundant data is cancelled from it and add a shortcut to it access the data after transferring for proper 
  • This contributes the data loss cau



Components of RFID System:


Reader and tag constitute

two important components of an RFID system. The reader gets the

identity information stored in the tag. An RFID system, in general, can

have several readers and tags. A reader will be able to “see” several

tags, and systematically read the identity of each of the tags. The

reader is capable of storing information into a tag as well as altering

the state of the tag. The information collected by the reader is not

really useful unless it is available to a network server. Therefore, two

more components also enter into the system: a server and a network. 



RFID Reader:


RFID Reader


The RF carrier is modulated according to the information to be

transmitted to the tag. The modulated carrier is amplified and radiated

out of the antenna. The reader also receives the electromagnetic waves

backscattered by the tag, amplifies the received signals, and

demodulates to extract the information. 


An important component of the reader is the antenna. Antennas are

generally the largest and the most visible component of an RFID

system. The size of the antenna depends on the operating frequency.

The size of the reader antennas is usually of the order of wavelength.

For example, the size of the reader antenna in a UHF system

(operating frequency of 865 MHz) is about 200 to 300 mm (see Figure

2.6). The reader antenna of an HF system can be as large as a meter in size. 

It is also possible to design a reader with a single antenna. Such a

the system is known as “monostatic”.


RFID Tag:


An RFID tag in its basic form could be made of a simple inductor

in parallel with a capacitor. This could be easily designed to operate in

the HF band. The inductance and the capacitance are chosen such that

they form a resonance circuit that resonates at 13.56 MHz. When this

tag is brought close to the reader antenna, the tag induces back emf

into the reader antenna, which can be sensed by the reader. This way,

the reader knows the presence or absence of the tag. This is called a

“1-bit” tag, and is used in electronic article surveillance to protect

goods in shops. One of the major problems with this system is false

triggering. Any article that has similar resonance characteristics as that of a tag, e.g. a bundle of electrical cable, can potentially trigger the

system and generate a false alarm. However, simplicity and cost have

made this system very popular. 


RFID Middleware:


A typical RFID system can have several readers and tags

and several applications accessing these tags via the readers. It is

important to provide seamless connectivity between the RFID

hardware and the application by insulating the applications from the

RFID hardware. In systems with large amounts of raw RFID data

being generated at the reader end, it is necessary to perform some kind

of pre-processing of data before the information is passed on to the

application. Such tasks are performed by a software subsystem known as middleware. 


General middleware architecture is comprised of three components:

– device interface;

– core processing interface;

– application interface.


rfid middleware

Device interface

The device interface provides the necessary functionality to

establish a connection between the core processing interface and the

RFID hardware. This forms one of the peripheral components of the

middleware and is also known as edgeware. This interface enables

RFID systems to discover, manage and control readers and tags. 


Core processing interface

The decision-making component of the middleware is the core

processing interface. The core processing interface gets the raw RFID

data from the RFID hardware. The core processing interface manages

and manipulates a large amount of raw RFID data before passing

them on to the application interface. The processing is also sometimes referred to as filtering. 


Application interface

The last component of the middleware is the application interface.

The application interface forms a boundary between the core

processing interface and enterprise applications (such as warehouse

management, enterprise resource planning and supply chain management, etc.). It is also a form of edgeware that is responsible for delivering RFID data to and from enterprise applications. 











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