a-presentation-on-wireless-communication

What Is Wireless Communication ?
 Wireless communication is the
transfer of information over a
distance without the use of electrical
conductors or "wires".
 The distances involved may be
short (a few meters as in television
remote control) or long (thousands or
millions of kilometers for radio
communications).
 When the context is clear, the term
is often shortened to "wireless".
Wireless communication is generally
considered to be a branch of
telecommunications.

 It encompasses various types of fixed, mobile, and portable
two way radios, cellular telephones, personal digital assistants
(PDAs), and wireless networking.
 Other examples of wireless technology include GPS units,
garage door openers and or garage doors, wireless computer
mice, keyboards and headsets, satellite television and cordless
telephones.

History
 The term "Wireless" came into public use to
refer to a radio receiver or transceiver
(a dual purpose receiver and transmitter
device).
 Establishing its usage in the field of wireless
telegraphy early on; now the term is used to
describe modern wireless connections such as
in cellular networks and wireless broadband
Internet.
 It is also used in a general sense to refer to
any type of operation that is implemented
without the use of wires, such as "wireless
remote control" or "wireless energy transfer",
regardless of the specific technology that is
used to accomplish the operation
 Examples - radio, infrared, ultrasonic.

WHATIS WAP ?
The wireless industry came up with the idea of
WAP. The point of this standard was to show
internet contents on wireless clients, like
mobile phones.
 WAP stands for Wireless Application Protocol.
 WAP is an application communication protocol.
 WAP is used to access services and information.
 WAP is inherited from Internet standards.
 WAP is for handheld devices such as mobile phones.
 WAP is a protocol designed for micro browsers.
 WAP enables the creating of web applications for mobile devices.
 WAP uses the mark-up language WML (not HTML).
 WML is defined as an XML 1.0 application.

TheWirelessApplicationProtocol
 WAP is published by the WAP Forum, founded in 1997
by Ericsson, Motorola, Nokia, and Unwired Planet.
 Forum members now represent over 90% of the global
handset market, as well as leading infrastructure
providers, software developers and other organizations.
 The WAP protocol is the leading standard for
information services on wireless terminals like digital
mobile phones.
 The WAP standard is based on Internet standards
(HTML, XML and TCP/IP).
 It consists of a WML language specification, a
WMLScript specification, and a Wireless Telephony
Application Interface (WTAI) specification.

what happens when you access a Website using a WAP-enabled device :-
 You turn on the device and open the minibrowser.
 The device sends out a radio signal, searching for service.
 A connection is made with your service provider.
 You select a Web site that you wish to view.
 A request is sent to a gateway server using WAP.
 The gateway server retrieves the information via HTTP from the Web
site.
 The gateway server encodes the HTTP data as WML.
 The WML-encoded data is sent to your device.
 You see the wireless Internet version of the Web page you selected.

What happens between the gateway and the client relies on features of
different parts of the WAP protocol stack :-
 WAE - The Wireless Application Environment
holds the tools that wireless Internet content
developers use. These include WML and WMLScript,
which is a scripting language used in conjunction
with WML. It functions much like JavaScript.
 WSP - The Wireless Session Protocol determines
whether a session between the device and the
network will be connection-oriented or
connectionless.
 WTP - The Wireless Transaction Protocol acts
like a traffic cop, keeping the data flowing in a
logical and smooth manner. It also determines how
to classify each transaction request:
 Reliable two-way
 Reliable one-way
 Unreliable one-way

What happens between the gateway and the client relies on features of
different parts of the WAP protocol stack :-
 WTLS - Wireless Transport Layer Security
provides many of the same security features found
in the Transport Layer Security (TLS) part of
TCP/IP. It checks data integrity, provides
encryption and performs client and server
authentication.
 WDP - The Wireless Datagram Protocol works in
conjunction with the network carrier layer . WDP
makes it easy to adapt WAP to a variety of bearers
because all that needs to change is the information
maintained at this level.
 Network carriers - Also called bearers, these
can be any of the existing technologies that
wireless providers use, as long as information is
provided at the WDP level to interface WAP with
the bearer.

Examples of WAP use
 Checking train table information.
 Ticket purchase.
 Flight check in.
 Viewing traffic information.
 Checking weather conditions.
 Looking up stock values.
 Looking up phone numbers.
 Looking up addresses.
 Looking up sport results.

What is WML?
 WML stands for Wireless Markup Language. It is a mark-up language
inherited from HTML, but WML is based on XML, so it is much stricter
than HTML.
 WML is used to create pages that can be displayed in a WAP browser.
Pages in WML are called DECKS. Decks are constructed as a set of
CARDS.

What is WMLScript ?
 WML uses WMLScript to run
simple code on the client.
 WMLScript is a light JavaScript
language.
 WML scripts are not embedded in
the WML pages.
 WML pages only contains
references to script URLs.
 WML scripts need to be compiled
into byte code on a server before
they can run in a WAP browser.

TYPES OF WIRELESS COMMUNICATION
 Wi-Fi wireless
 Bluetooth wireless
 IrDA (Infrared Data Association)
 PC card (also known as PCMCIA)
 USB cable
 Radio

 Meaning of PC card or PCMCIA
 Card types
Type I
Type II
Type III
Type IV
 Card Information Structure
 Card Bus
 Card Bay
 Descendants and variants
 Technological obsolescence
A PC Card network adapter
Contents
 PC card(also known as PCMCIA)

PC card
(also known as PCMCIA)
 PCMCIA stands for Personal Computer Memory Card
International Association, the group of industry-leading
companies that defines and develops the standard.
 While this acronym did clearly describe the original intentions
of the organization's standard, it was difficult to say and
remember, and was sometimes jokingly referred to as "People
Can't Memorize Computer Industry Acronyms".
 To aid in the widespread marketing and branding of the
standard, and to account for the standard's widening scope
(beyond just memory cards), the association acquired the rights
to the simpler term "PC Card" from IBM, and began using it,
rather than "PCMCIA", from version 2 of the specification
onwards.
Meaning of PC card or PCMCIA :-

Card types
 All PC Card devices use an identical 68 pin dual row connecting
interface.
 All are 85.6 mm long and 54.0 mm wide.
 This is the same size as a credit card. The form factor is also used by
the Common Interface form of Conditional Access Modules for DVB
broadcasts.
Two PC Card devices: Xircom Real Port
(top) type III and 3Com (bottom) type II.
Type I
 Cards designed to the original specification
(version 1.x) are type I and feature a 16-bit
interface.
 They are 3.3 mm thick.
 Type-I PC Card devices are typically used
for memory devices such as RAM, flash
memory, OTP, and SRAM cards.

Type II
 Type-II PC Card devices feature a 16- or 32-bit interface.
 They are 5.0/5.5 mm thick.
 Type-II cards introduced I/O support, allowing devices to attach an
array of peripherals or to provide connectors/slots to interfaces for
which the host computer had no built-in support.
 For example, many modem, network and TV cards use this form
factor.
 Due to their thinness, most Type II interface cards feature miniature
interface connectors on the card which are used together with a
dongle: a short cable that adapts from the card's miniature connector
to an external full-size connector.
 Some cards instead have a lump on the end with the connectors.
This is more robust and convenient than a separate adaptor but can
block the other slot where slots are present in a pair.

Type III
 Type-III PC Card devices are 16-bit or 32-bit.
 These cards are 10.5 mm thick, allowing them to accommodate
devices with components that would not fit type I or type II height.
 Examples are hard disk drive cards, and interface cards with full-
size connectors that do not require dongles (as is commonly
required with type II interface cards).
Type IV
 Type-IV cards, introduced by Toshiba, have not been officially
standardized or sanctioned by the PCMCIA.
 These cards are 16 mm thick.

Card Information Structure
 The Card Information Structure (CIS) is information stored on a PC
card that contains information about the formatting and organization
of the data on the card.
 The CIS also contains information about:
 The type of card
 Supported power supply options
 Supported power saving features
 The manufacturer
 Model number
 and so on.
 When a card is unrecognized it is frequently because the CIS
information is either lost or damaged.
Card Information Structure (CIS)

Card Bus
Two Xircom Real Port Ethernet/56k
modem cards. Top one is Card Bus,
and the bottom is the 5 volt PCMCIA
version. Note the slightly different
notch.
 Card Bus are PCMCIA 5.0 or later (JEIDA 4.2 or
later) 32-bit PCMCIA devices, introduced in 1995
and present in laptops from late 1997 onward.
 Card Bus is effectively a 32-bit, 33 MHz PCI
bus in the PC Card form factor.
 Card Bus includes bus mastering, which allows
a controller on the bus to talk to other devices or
memory without going through the CPU.
 Many chipsets are available for both PCI and
Card Bus, such as those that support Wi-Fi.
 The speed of Card Bus interfaces in 32 bit
burst mode depends on the transfer type; in
byte mode it is 33 MB/s, in Word mode it is 66
MB/s, and in DWord mode it is 132 MB/s.

Two Xircom Real Port Ethernet/56k
modem cards. Top one is Card Bus,
and the bottom is the 5 volt PCMCIA
version. Note the slightly different
notch.
 The notch on the left hand front of the device
is slightly shallower on a Card Bus device, so a
32-bit device cannot be plugged into a slot that
can only accept 16-bit devices.
 Most new slots are compatible with both Card
Bus and the original 16-bit PC Card devices.
 Card bus cards have a gold band with eight
small studs on the top of the card next to the pin
sockets, which is not present in earlier models.
Card Bus

Card Bay
 Card Bay is a variant added to the
PCMCIA specification in 2001.
 This was intended to add some
forward compatibility with USB and IEEE
1394, but was not universally adopted
and only some notebooks have PC Card
controllers with Card Bay features.
The PC Card bay when in use

Descendants
Descendants and variants
 The interface has spawned a generation
of flash memory cards that set out to
improve on the size and features of Type I
cards:
 Compact Flash
 Mini Card
 Smart Media
 For example - The PC Card electrical
specification is also used for Compact Flash,
so a PC Card Compact Flash adapter need
only be a socket adapter.
Compact Flash Mini Card Smart Media
socket adapter

 Express Card is a later specification from the
PCMCIA, intended as a replacement for PC Card,
built around the PCI Express and USB 2.0
standards.
 The PC Card standard is closed to further
development and PCMCIA strongly encourages
future product designs to utilize the Express Card
interface.
 As of 2007, the majority of laptops now ship with
only Express Card slots or neither slot type (leaving
expansion to USB and Fire wire only), though the
Lenovo ThinkPad T60 and Z60m, among other
models, currently ships with both Card Bus and
Express Card slots.
variants
Fire wire Fire wire Variants
Express Card
USB

 Express Card and Card Bus sockets are
physically and electrically incompatible.
 A simple mechanical adapter between the
two formats is infeasible.
 Several companies now produce Express
Card-to-Card Bus and Card bus-to-Express
Card adapters that use a secondary slot to
allow older cards to work with newer PCs and
vice versa.
Express Card and Card Bus

Technological obsolescence
 Fire wire and USB devices are available for almost all
functions that the PC Card interface was used for in the
past, although it retains the advantage of containing
devices entirely or almost entirely inside the case of the
portable device.
 This can be an important consideration for portable
systems, where additional external peripherals and their
associated cables, space, and sometimes additional
power supplies can reduce portability and convenience.
 Even in this case Express Card devices have the same
advantages as PC Card devices, with additional
bandwidth & functionality.
 On the other hand many devices do not need the
speed of PCI Express, and often PC Card devices with
adequate performance can be found cheaply, as
discounted new parts or on the used components
market, and will suffice for many users' purposes.

 IrDA(Infrared Data Association)
Infrared Data Association Logo
Contents
 Meaning of Infrared Data
Association
 Specifications
1.IrPHY
2.IrLAP
3.IrLMP
4.Tiny TP
5.IrCOMM
6.IrOBEX
7.IrLAN
8.IrSimple
9.IrSimpleShot
 Popularity

IrDA(Infrared Data Association)
Infrared Data Association logo
 The Infrared Data Association (IrDA) defines physical specifications
communications protocol standards for the short-range exchange of data
over infrared light, for uses such as personal area networks (PANs).
 IrDA is a very short-range example of free space optical communication.
 IrDA interfaces are used in medical instrumentation, test and
measurement equipment, palmtop computers, mobile phones, and laptop
computers (most laptops and phones also offer Bluetooth but it is now
becoming more common for Bluetooth to simply replace IrDA in new
versions of products).
 IrDA specifications include IrPHY, IrLAP, IrLMP, IrCOMM, Tiny TP, IrOBEX,
IrLAN and IrSimple. IrDA has now produced another standard, IrFM, for
Infrared financial messaging (i.e., for making payments) also known as
"Point & Pay".
 For the devices to communicate via IrDA they must have a direct line of
sight similar to a TV remote control.
Meaning of Infrared Data Association :-

1.IrPHY(InfraredPhysicalLayerSpecification)
Specifications
The mandatory IrPHY (Infrared Physical Layer Specification) is the lowest
layer of the IrDA specifications. The most important specifications are:-
 Range : standard 1 m
 Low power to low power : 0.2 m
 Standard to low power : 0.3 m
 Angle : minimum cone ±15°
 Speed : 2.4 Kbit/s to 16 Mbit/s
 Modulation : baseband

 IrDA transceivers communicate with infrared pulses
in a cone that extends minimum 15 degrees half angle
off center.
 The IrDA physical specifications require that a
minimum irradiance be maintained so that a signal is
visible up to a meter away.
 The specifications require that a maximum irradiance
not be exceeded so that a receiver is not overwhelmed
with brightness when a device comes close.
 In practice, there are some devices on the market
that do not reach one meter, while other devices may
reach up to several meters.
 There are also devices that do not tolerate extreme
closeness.
 The typical sweet spot for IrDA communications is
from 5 to 60 cm (2.0 to 24 in) away from a
transceiver, in the center of the cone.

2. IrLAP(Infrared Link Access Protocol)
The mandatory IrLAP (Infrared Link Access Protocol) is the second layer
of the IrDA specifications. It lies on top of the IrPHY layer and below
the IrLMP layer. It represents the Data Link Layer of the OSI model.
The most important specifications are:
 Access control
 Discovery of potential communication partners
 Establishing of a reliable bidirectional connection
 Distribution of the Primary/Secondary device roles
 Negotiation of QoS Parameters
 On the IrLAP layer the communicating devices are divided into a
Primary Device and one or more Secondary Devices.
 The Primary Device controls the Secondary Devices. Only if the
Primary Device requests a Secondary Device to send is it allowed to do
so.

3.IrLMP(Infrared Link Management Protocol)
 The mandatory IrLMP (Infrared Link Management
Protocol) is the third layer of the IrDA
specifications.
 It can be broken down into two parts. First, the
LM-MUX (Link Management Multiplexer) which lies
on top of the IrLAP layer. Its most important
achievements are:
 Provides multiple logical channels
 Allows change of Primary/Secondary devices
 Second, the LM-IAS (Link Management
Information Access Service), which provides a list,
where service providers can register their services
so other devices can access these services via
querying the LM-IAS.

4.Tiny TP(Tiny Transport Protocol)
The optional Tiny TP (Tiny Transport
Protocol) lies on top of the IrLMP layer. It
provides:
 Transportation of large messages by
SAR (Segmentation and Reassembly)
 Flow control by giving credits to every
logical channel

 The optional IrCOMM
(Infrared Communications Protocol) lets the
infrared device act like either a serial or
parallel port.
 It lies on top of the IrLMP layer.
5. IrCOMM(Infrared Communications
Protocol)
Using IrCOMM to Replace a NULL Serial
Cable

 The optional IrOBEX (Infrared Object
Exchange) provides the exchange of arbitrary
data objects
 For Example - vCard, vCalendar or even
applications between infrared devices.
 It lies on top of the Tiny TP protocol, so Tiny
TP is mandatory for IrOBEX to work.
6. IrOBEX (Infrared ObjectExchange)

 The optional IrLAN (Infrared Local Area
Network) provides the possibility to
connect an infrared device to a local area
network. There are three possible
methods:
 Access Point
 Peer to Peer
 Hosted
 As IrLAN lies on top of the Tiny TP
protocol, the Tiny TP protocol must be
implemented for IrLAN to work.
7. IrLAN(Infrared Local AreaNetwork)
CVIS uses a range of communication
technologies including mobile cellular and
wireless local area networks, short-range
microwave and infrared to ensure that
drivers avoid congestion

 IrSimple achieves at least 4 to 10
times faster data transmission speeds
by improving the efficiency of the
infrared IrDA protocol.
A normal picture from a cell phone
can be transferred within 1 second.
8. IrSimple

 One of the primary targets of
IrSimpleShot(IrSS) is to allow the millions
of IrDA-enabled camera phones to
wirelessly transfer pictures to printers,
printer kiosks, flat panel TV's.
9. IrSimpleShot (IrSS)
FIR Transceivers help Implement
IrSimpleShot(TM) protocol

Popularity
 IrDA was popular on laptops and some desktops during the
late 90s through the early 2000s.
 It has been displaced by other wireless technologies such as
Wi-Fi and Bluetooth, favored because they don't need a direct
line of sight, and can therefore support hardware such as mice
and keyboards.
 It is still used in some environments where interference makes
radio-based wireless technologies unusable.
 IrDA popularity is making a comeback with its highly efficient
IrSimple protocols by providing sub 1 second transfers of
pictures between cell phones, printers, and display devices.
 IrDA hardware is still less expensive and doesn't share the
same security problems encountered with wireless technologies
such as Bluetooth.

 Bluetooth wireless
Bluetooth Logo
Contents
 Meaning of Bluetooth
 Origin of the Bluetooth logo
 Implementation
 Uses

 The word Bluetooth is an anglicized
version of Old Norse Blátönn or Danish
Blåtand, the name of the tenth-century
king Harald I of Denmark and Norway, who
united dissonant Scandinavian tribes into a
single kingdom.
 The implication is that Bluetooth does the
same with communications protocols,
uniting them into one universal standard
Meaning of Bluetooth :-
Bluetooth wireless
A typical Bluetooth mobile phone headset.
Bluetooth Logo

Bluetooth Logo
Originof theBluetoothlogo
 The Bluetooth logo design merges the
Germanic runes analogous to the modern
Latin letters H and B : (for Harald
Bluetooth ) (Hagall) and (Berkanan)
merged together, forming a bind rune.
A Bluetooth USB dongle with a 100m range.

Bluetooth Logo
Implementation
 Bluetooth uses a radio technology called frequency-hopping spread
spectrum, which chops up the data being sent and transmits chunks
of it on up to 79 frequencies.
 In its basic mode, the modulation is Gaussian frequency-shift
keying (GFSK). It can achieve a gross data rate of 1 Mb/s.
 Bluetooth provides a way to connect and exchange information
between devices such as mobile phones, telephones, laptops,
personal computers, printers, Global Positioning System (GPS)
receivers, digital cameras, and video game consoles through a
secure, globally unlicensed Industrial, Scientific and Medical (ISM) 2.4
GHz short-range radio frequency bandwidth.
 The Bluetooth specifications are developed and licensed by the
Bluetooth Special Interest Group (SIG). The Bluetooth SIG consists of
companies in the areas of telecommunication, computing, networking,
and consumer electronics.

Bluetooth Logo
Uses
 Bluetooth is a standard and communications protocol primarily
designed for low power consumption, with a short range (power-class-
dependent: 1 meter, 10 meters, 100 meters) based on low-cost
transceiver microchips in each device.
 Bluetooth makes it possible for these devices to communicate with
each other when they are in range. Because the devices use a radio
(broadcast) communications system, they do not have to be in line of
sight of each other.
Class Maximum Permitted Power Range(approximate)
mW (dBm)
Class 1 100 mW (20 dBm) ~100 meters
Class 2 2.5 mW (4 dBm) ~10 meters
Class 3 1 mW (0 dBm) ~1 meter

Bluetooth Logo
In most cases the effective range of class 2 devices is
extended if they connect to a class 1 transceiver,
compared to a pure class 2 network.
This is accomplished by the higher sensitivity and
transmission power of Class 1 devices.
Version Data Rate
Version 1.2 1 Mbit/s
Version 2.0 + EDR 3 Mbit/s
WiMedia Alliance
(proposed) 53 - 480 Mbit/s
A typical Bluetooth USB dongle
An internal notebook Bluetooth card (14×36×4 mm)Nokia BH-208 headset internals

 Wi-Fi wireless
Wi-Fi logo
Contents
 Meaning of Wi-Fi wireless
 History
 Uses

Wi-Fi logo
 Wi-Fi is a trademark of the Wi-Fi Alliance for
certified products based on the IEEE 802.11
standards (also called Wireless LAN (WLAN) and Wi-
Fi).
 This certification warrants interoperability between
different wireless devices.
 The term Wi-Fi often is used by the public as a
synonym for wireless Internet (WLAN); but not every
wireless Internet product has a Wi-Fi certification,
which may be because of certification costs that must
be paid for each certified device type.
 Wi-Fi is supported by most personal computer
operating systems, many game consoles, laptops,
smartphones, printers, and other peripherals
Meaning of Wi-Fi wireless :-
Wi-Fi wireless

Wi-Fi logo
History
Half-size ISA 2.4 GHz WaveLAN card
by AT&T
 Wi-Fi uses both single carrier direct-
sequence spread spectrum radio technology
(part of the larger family of spread spectrum
systems) and multi-carrier OFDM (Orthogonal
Frequency Division Multiplexing) radio
technology.
 The regulations for unlicensed spread
spectrum enabled the development of Wi-Fi,
its onetime competitor HomeRF, Bluetooth,
and many other products such as some types
of cordless telephones.
 Unlicensed spread spectrum was first made available in the US by
the Federal Communications Commission in 1985 and these FCC
regulations were later copied with some changes in many other
countries enabling use of this technology in all major countries.
 The FCC action was proposed by Michael Marcus of the FCC staff
in 1980 and the subsequent regulatory action took 5 more years.

Wi-Fi logo
It was part of a broader proposal to allow civil
use of spread spectrum technology and was
opposed at the time by main stream equipment
manufacturers and many radio system
operators.
The precursor to Wi-Fi was invented in 1991
by NCR Corporation/AT&T (later Lucent &
Agere Systems) in Nieuwegein, the
Netherlands.
It was initially intended for cashier systems;
the first wireless products were brought on
the market under the name WaveLAN with
speeds of 1 Mbit/s to 2 Mbit/s. Vic Hayes, who
held the chair of IEEE 802.11 for 10 years and
has been named the 'father of Wi-Fi,' was
involved in designing standards such as IEEE
802.11b, and 802.11a.
A keychain size Wi-Fi detector

Wi-Fi logo
Uses
A Wi-Fi antenna
 A Wi-Fi enabled device such as a PC, game
console, mobile phone, MP3 player or PDA can
connect to the Internet when within range of a
wireless network connected to the Internet.
 The coverage of one or more interconnected
access points — called a hotspot — can
comprise an area as small as a single room
with wireless-opaque walls or as large as many
square miles covered by overlapping access
points.
 Wi-Fi technology has served to set up mesh
networks, for example, in London.
 Both architectures can operate in community
networks.
A roof mounted Wi-Fi antenna

Wireless USB Logo
 USBcable
(Universal Serial Bus)
Original USB Logo
Contents
 Meaning of USB
 History
 Device classes
1. USB mass-storage
2. Human-interface devices (HIDs)
 Types of USB connector
1. USB-A.
2. USB-B.
3. Mini and micro.
4. USB OTG Sockets: Mini-AB, Micro-AB.
5. Proprietary connectors and formats.
 Uses

Original USB Logo
USBcable
(Universal Serial Bus)
Meaning of USB :-
 In information technology, Universal Serial Bus
(USB) is a serial bus standard to connect devices to a
host computer.
 USB was designed to allow many peripherals to be
connected using a single standardized interface
socket and to improve plug and play capabilities by
allowing hot swapping; that is, by allowing devices to
be connected and disconnected without rebooting the
computer or turning off the device.
 Other convenient features include providing power
to low-consumption devices, eliminating the need for
an external power supply; and allowing many devices
to be used without requiring manufacturer-specific
device drivers to be installed.
The USB trident logo
A USB Series “A” plug, the most
common USB plug

Original USB Logo
History
 The USB 1.0 specification was introduced in 1994.
 USB was created by the core group of companies that consisted of
Intel, Compaq, Microsoft, Digital, IBM, and Northern Telecom.
 Intel produced the UHCI host controller and open software stack;
Microsoft produced a USB software stack for Windows and co-authored
the OHCI host controller specification with National Semiconductor and
Compaq; Philips produced early USB-Audio; and TI produced the most
widely used hub chips.
 USB was intended to replace the multitude of connectors at the back of
PCs, as well as to simplify software configuration of communication
devices.
 The USB 2.0 specification was released in April 2000 and was
standardized by the USB-IF at the end of 2001.
 Hewlett-Packard, Intel, Lucent (now LSI Corporation since its merger
with Lucent spinoff Agere Systems), Microsoft, NEC, and Philips jointly
led the initiative to develop a higher data transfer rate, 480 Mbit/s, than
the 1.0 specification of 12 Mbit/s.

Original USB Logo
 The USB 3.0 specification was
released on November 17, 2008 by
the USB 3.0 Promoter Group.
It has a transfer rate of up to 10
times faster than the USB 2.0 version
and has been dubbed the Super
Speed USB.
 Equipment conforming with any
version of the standard will also work
with devices designed to any previous
specification (a property known as
backward compatibility).
A conventional USB hub.
Vodafone 3G USB modem

Original USB Logo
Deviceclasses
USB defines class codes used to identify a device’s functionality and to
load a device driver based on that functionality. This enables a device
driver writer to support devices from different manufacturers that
comply with a given class code.
Device classes include:
Class Usage Description Examples
00h Device Unspecified (Device class is unspecified.
Interface descriptors are used
for determining the required
drivers.)
01h Interface Audio Speaker, microphone, sound
card

Class Usage Description Examples
02h Both Communications
and CDC Control
Ethernet adapter, modem,
serial port adapter
03h Interface Human Interface
Device (HID)
Keyboard, mouse, joystick
05h Interface Physical Interface
Device (PID)
Force feedback joystick
06h Interface Image Webcams
07h Interface Printer Laser printer, Inkjet printer
08h Interface Mass Storage USB flash drive, memory card
reader, digital audio player,
digital camera, external drives
09h Device USB hub Full speed hub, hi-speed hub
0Ah Interface CDC-Data (This class is used together
with class 02h -
Communications and CDC
Control.)

Original USB Logo
1. USBmass-storage
 USB implements connections to storage devices using a set of
standards called the USB mass storage device class (referred to
as MSC or UMS).
 This was initially intended for traditional magnetic and optical
drives, but has been extended to support a wide variety of
devices, particularly flash drives.
 This generality is because many systems can be controlled
with the familiar idiom of file manipulation within directories
(The process of making a novel device look like a familiar device
is also known as extension).
 Though most newer computers are capable of booting off USB Mass
Storage devices, USB is not intended to be a primary bus for a
computer's internal storage: buses such as ATA (IDE), Serial ATA
(SATA), and SCSI fulfill that role.
 However, USB has one important advantage in that it is possible to
install and remove devices without opening the computer case.

Original USB Logo
 Originally conceived and still used today for optical
storage devices (CD-RW drives, DVD drives, etc.), a
number of manufacturers offer external portable USB
hard drives, or empty enclosures for drives, that offer
performance comparable to internal drives[citation
needed].
 These external drives usually contain a translating
device that interfaces a drive of conventional
technology (IDE, ATA, SATA, ATAPI, or even SCSI) to
a USB port.
 Functionally, the drive appears to the user just like
an internal drive.
 Other competing standards that allow for external
connectivity are eSATA and FireWire.
 Another use for USB Mass Storage devices is the
portable execution of software applications without the
need of installation on the host computer,e.g. Web
Browser, VoIP, etc.
A flash drive, a typical USB
mass-storage device.

Original USB Logo
2. Human-interface devices(HIDs)
 Mice and keyboards are frequently fitted
with USB connectors, but because most PC
motherboards still retain PS/2 connectors
for the keyboard and mouse as of 2007,
they are often supplied with a small USB-
to-PS/2 adaptor, allowing usage with
either USB or PS/2 interface.
 There is no logic inside these adaptors:
they make use of the fact that such HID
interfaces are equipped with controllers
that are capable of serving both the USB
and the PS/2 protocol, and automatically
detect which type of port they are plugged
into.
 Joysticks, keypads, tablets and other
human-interface devices are also
progressively migrating from MIDI, PC
game port, and PS/2 connectors to USB.
INTERFACE
CABLES

Original USB Logo
Types of USB connector : -
1. USB-A
 The Standard-A type of USB connector takes on
the appearance of a flattened rectangle that plugs
into downstream-port sockets on the USB host or a
hub and receives power.
 This kind of connector is most frequently seen on
cables that are permanently attached to a device,
such as one on a cable that connects a keyboard or
mouse to the computer.
Different types of USB
connectors from left to right
• 8-pin AGOX connector
• Mini-B plug
• Type B plug
• Type A receptacle
• Type A plug

Original USB Logo
2. USB-B
 Standard-B connectors—which
have a square shape with beveled
exterior corners—typically plug into
upstream sockets on devices that use
a removable cable, e.g. between a
hub and a printer.
 Type B plugs deliver power and are
therefore analogous to a power
socket.
 This two-connector scheme
prevents a user from accidentally
creating a loop.
Pin configuration of the USB
connectors Standard A/B, viewed from
face of plug

Original USB Logo
3. Mini and micro
 Various connectors have been used
for smaller devices such as PDAs,
mobile phones or digital cameras.
 These include the now-
deprecated(but standardized) Mini-A
and the current standard Mini-B,
Micro-A, and Micro-B connectors.
 The Mini-A and Mini-B plugs are
approximately 3 by 7 mm.
 While the Micro plugs have a
similar width but approximately half
the thickness, enabling their
integration into thinner portable
devices.
Schematic diagram of Standard,
Mini, and Micro USB receptacles.

Original USB Logo
4. USB OTGSockets: Mini-AB,Micro-AB
 Except for special standard-to-Mini-A and
standard-to-Micro-A adapters, USB cables always
have an A-connector and a B-connector, on opposite
ends.
 A-connectors can always connect to A-sockets; B-
connectors can always connect B-sockets.
 These sockets all come in standard, mini, and
micro versions.
 For USB On-The-Go (or 'OTG') support for another socket type is
defined: the AB, in both mini and micro versions.
 It can accept both A and B connector, through careful mechanical
design.
OTG software detects the difference by use of the ID pin, which is
grounded in A-connectors and is otherwise floating.

Original USB Logo
 When a B-connector is used, the socket
consumes VBUS power and starts in the peripheral
or device role.
 OTG allows those two roles to be switched by
software, as needed for the task at hand.
 When an A-connector is connected to an AB
socket, the socket supplies VBUS power to the
cable and starts in the host role.
Type A and Type B
USB Plugs and Sockets

Original USB Logo
5. Proprietary connectors andformats
 Microsoft's original Xbox game console uses
standard USB 1.1 signaling in its controllers and
memory cards, but features proprietary connectors
and ports.
 IBM UltraPort uses standard USB signaling, but via
a proprietary connection format.
 American Power Conversion uses USB signaling
and HID device class on its uninterruptible power
supplies using 10P10C connectors.
 HTC manufactures Windows Mobile-based
Communicators and the T-Mobile G1 which have a
proprietary connector called HTC ExtUSB.
 The ExtUSB combines mini-USB (with which it is
backwards-compatible) with audio/video input and
output in an 11-pin connector.
ExtUSB

Original USB Logo
 Nokia includes a USB connection as
part of the Pop-Port connector on
some older mobile phone models.
 The second- and third-generation
iPod Shuffle use a TRS connector to
carry USB, audio, or power signals.
 Iriver added a fifth power pin
within USB-A plugs for higher power
and faster charging, used for the
iriver U10 series.
 A mini-USB version contains a
matching extra power pin for the
cradle.
Proprietary connectors and formats

Original USB Logo
Uses
 Wireless USB is used in game
controllers, printers, scanners, digital
cameras, MP3 players, hard disks and
flash drives.
 It is also suitable for transferring
parallel video streams.
 Kensington released a Wireless
USB universal docking station in
August, 2008.

 Radio
Classic radio receiver dial
The Radio Portal
Contents
 Meaning of Radio
 Processes
 History
1 Invention
2 Development
 Uses of radio
1 Audio
2 Telephony
3 Video
4 Navigation
5 Radar
6 Data (digital radio)
7 Heating
8 Amateur radio service
9 Unlicensed radio services
10 Radio control (RC)
 The electromagnetic spectrum

The Radio Portal Radio
Meaningof Radio :-
 Radio is the transmission of signals by modulation of
electromagnetic waves with frequencies below those of visible light.
 Electromagnetic radiation travels by means of oscillating
electromagnetic fields that pass through the air and the vacuum of
space.
 Information is carried by systematically changing (modulating)
some property of the radiated waves, such as amplitude, frequency,
or phase.
 When radio waves pass an electrical conductor, the oscillating
fields induce an alternating current in the conductor.
 This can be detected and transformed into sound or other signals
that carry information.

The Radio PortalProcesses
 Radio systems used for communications will have
the following elements.
 With more than 100 years of development, each
process is implemented by a wide range of methods,
specialized for different communications purposes.
 Each system contains a transmitter.
 This consists of a source of electrical energy,
producing alternating current of a desired frequency of
oscillation.
 The transmitter contains a system to modulate
(change) some property of the energy produced to
impress a signal on it.

The Radio Portal
This modulation might be as simple as turning the
energy on and off, or altering more subtle properties
such as amplitude, frequency, phase, or combinations
of these properties.
 The transmitter sends the modulated electrical
energy to an antenna; this structure converts the
rapidly-changing alternating current into an
electromagnetic wave that can move through free
space.
 Early radio systems relied entirely on the
energy collected by an antenna to produce
signals for the operator.
 Radio became more useful after the
invention of electronic devices such as the
vacuum tube and later the transistor, which
made it possible to amplify weak signals.
 Today radio systems are used for
applications from walkie-talkie children's toys
to the control of space vehicles, as well as for
broadcasting, and many other applications.

The Radio PortalHistory
1. Invention :-
 Development from a laboratory
demonstration to commercial utility
spanned several decades and required
the efforts of many practitioners.
 Thomas Edison applied in 1885 to the
U.S. Patent Office for a patent on a
wireless telegraphy system which
anticipated later developments in the
field.
 The patent was granted as Patent #
465971 on December 29, 1891, and
Guglielmo Marconi felt it necessary to
purchase rights to the Edison wireless
telegraphy patent as a foundation stone
of his own subsequent work in wireless
telegraphy.
Tesla demonstrating wireless transmissions
during his high frequency and potential lecture of
1891. After continued research, Tesla presented
the fundamentals of radio in 1893.

The Radio Portal
Telephone Herald in Budapest, Hungary (1901).
 In 1893, in St. Louis, Missouri, Nikola
Tesla made devices for his experiments
with electricity.
 Addressing the Franklin Institute in
Philadelphia and the National Electric
Light Association, he described and
demonstrated in detail the principles of
his wireless work.
 The descriptions contained all the
elements that were later incorporated
into radio systems before the
development of the vacuum tube.
 He initially experimented with magnetic receivers, unlike the coherers
(detecting devices consisting of tubes filled with iron filings which had
been invented by Temistocle Calzecchi-Onesti at Fermo in Italy in 1884)
used by Guglielmo Marconi and other early experimenters

The Radio Portal
 The first radio couldn't transmit sound or speech and
was called the "wireless telegraph."
 The first public demonstration of wireless telegraphy
took place in the lecture theater of the Oxford
University Museum of Natural History on August 14,
1894, carried out by Professor Oliver Lodge and
Alexander Muirhead. During the demonstration a radio
signal was sent from the neighboring Clarendon
laboratory building, and received by apparatus in the
lecture theater.
 In 1895 Alexander Stepanovich Popov built his first radio receiver,
which contained a coherer.
 Further refined as a lightning detector, it was presented to the Russian
Physical and Chemical Society on May 7, 1895.
 A depiction of Popov's lightning detector was printed in the Journal of
the Russian Physical and Chemical Society the same year.
 Popov's receiver was created on the improved basis of Lodge's
receiver, and originally intended for reproduction of its experiments.

The Radio Portal
2. Development :-
 In 1896, Marconi was awarded the British patent
12039, Improvements in transmitting electrical
impulses and signals and in apparatus there-for, for
radio.
 In 1897 he established the world's first radio
station on the Isle of Wight, England.
 Marconi opened the world's first "wireless" factory
in Hall Street, Chelmsford, England in 1898,
employing around 50 people.
 One of the first developments in the early 20th century (1900-1959)
was that aircraft used commercial AM radio stations for navigation.
 This continued until the early 1960s when VOR systems finally became
widespread (though AM stations are still marked on U.S. aviation charts).
 In the early 1930s, single sideband and frequency modulation were
invented by amateur radio operators.
This photo shows an early
1930's wooden radio receiver in
the classic "cathedral" shape

The Radio PortalUsesof radio :-
1. Audio
A Fisher 500 AM/FM hi-fi receiver
from 1959.
 AM broadcast radio sends music and voice
in the Medium Frequency (MF, 0.3 MHz to 3
MHz) radio spectrum.
 AM radio uses amplitude modulation, in
which the amplitude of the transmitted signal
is made proportional to the sound amplitude
captured (transduced) by the microphone,
while the transmitted frequency remains
unchanged.
 Transmissions are affected by static and interference because lightning
and other sources of radio emissions on the same frequency add their
amplitudes to the original transmitted amplitude.
 In the early part of the 20th century, American AM radio stations
broadcast with powers as high as 500 kW, and some could be heard
worldwide; these stations' transmitters were commandeered for military
use by the US Government during World War II.

The Radio Portal2. Telephony
Pure One Classic- DAB
Digital Radio from 2008
 Mobile phones transmit to a local cell site
(transmitter/receiver) that ultimately connects to
the public switched telephone network (PSTN)
through an optic fiber or microwave radio and other
network elements.
 When the mobile phone nears the edge of the
cell site's radio coverage area, the central
computer switches the phone to a new cell.
 Cell phones originally used FM, but now most use various digital
modulation schemes.
 Recent developments in Sweden (such as DROPme) allow for the
instant downloading of digital material from a radio broadcast (such as a
song) to a mobile phone.
 Satellite phones use satellites rather than cell towers to communicate.

The Radio Portal
3. Video
 Television sends the picture as AM and the sound
as FM, with the sound carrier a fixed frequency (4.5
MHz in the NTSC system) away from the video
carrier.
 Analog television also uses a vestigial sideband
on the video carrier to reduce the bandwidth
required.
 Digital television uses 8VSB modulation in North America (under the
ATSC digital television standard), and COFDM modulation elsewhere in the
world (using the DVB-T standard).
 A Reed–Solomon error correction code adds redundant correction codes
and allows reliable reception during moderate data loss.
 Although many current and future codecs can be sent in the MPEG-2
transport stream container format, as of 2006 most systems use a
standard-definition format almost identical to DVD: MPEG-2 video in
Anamorphic widescreen and MPEG layer 2 (MP2) audio.

The Radio Portal
4. Navigation
 All satellite navigation systems use
satellites with precision clocks.
 The satellite transmits its position, and
the time of the transmission.
 The receiver listens to four satellites, and can figure its position as
being on a line that is tangent to a spherical shell around each satellite,
determined by the time-of-flight of the radio signals from the satellite.
 A computer in the receiver does the math.
 Radio direction-finding is the oldest form of radio navigation.
 Before 1960 navigators used movable loop antennas to locate
commercial AM stations near cities.
 In some cases they used marine radiolocation beacons, which share a
range of frequencies just above AM radio with amateur radio operators.

The Radio Portal
5. Radar
 Radar (Radio Detection And Ranging) detects objects at a distance by
bouncing radio waves off them.
 The delay caused by the echo measures the distance. The direction of
the beam determines the direction of the reflection.
 The polarization and frequency of the return can sense the type of
surface.
 Navigational radars scan a wide area two to four times per minute.
 They use very short waves that reflect from earth and stone.
 They are common on commercial ships and long-distance commercial
aircraft.
 General purpose radars generally use
navigational radar frequencies, but modulate
and polarize the pulse so the receiver can
determine the type of surface of the reflector.

The Radio Portal
6. Data(digitalradio)
 Most new radio systems are digital, see also:
Digital TV, Satellite Radio, Digital Audio Broadcasting.
 The oldest form of digital broadcast was spark gap
telegraphy, used by pioneers such as Marconi.
 By pressing the key, the operator could send
messages in Morse code by energizing a rotating
commutating spark gap.
 The rotating commutator produced a tone in the
receiver, where a simple spark gap would produce a
hiss, indistinguishable from static.
 Spark gap transmitters are now illegal, because
their transmissions span several hundred megahertz.
 This is very wasteful of both radio frequencies and
power.
Modern GPS receivers.

The Radio Portal7. Heating
 Radio-frequency energy generated for heating of objects is generally
not intended to radiate outside of the generating equipment, to prevent
interference with other radio signals.
 Microwave ovens use intense radio waves to heat food.
 Diathermy equipment is used in surgery for sealing of blood vessels.
 Induction furnaces are used for melting metal for casting.

The Radio Portal8. Amateur radio service
 Amateur radio, also known as "ham radio", is a
hobby in which enthusiasts are licensed to
communicate on a number of bands in the radio
frequency spectrum non-commercially and for their
own enjoyment.
 They may also provide emergency and public service
assistance.
 This has been very beneficial in emergencies, saving
lives in many instances.
 Radio amateurs use a variety of modes, including
nostalgic ones like morse code and experimental ones
like Low-Frequency Experimental Radio.
 Several forms of radio were pioneered by radio amateurs and later
became commercially important including FM, single-sideband (SSB), AM,
digital packet radio and satellite repeaters.
 Some amateur frequencies may be disrupted by power-line internet
service.
Amateur radio station with
multiple receivers and
transceivers

The Radio Portal
9. Unlicensed radio services
 Unlicensed, government-authorized personal radio
services such as Citizens' band radio in Australia, the USA,
and Europe, and Family Radio Service and Multi-Use Radio
Service in North America exist to provide simple, (usually)
short range communication for individuals and small
groups, without the overhead of licensing.
 Similar services exist in other parts of the world. These
radio services involve the use of handheld units.
 Free radio stations, sometimes called pirate radio or
"clandestine" stations, are unauthorized, unlicensed, illegal
broadcasting stations.
 These are often low power transmitters operated on
sporadic schedules by hobbyists, community activists, or
political and cultural dissidents.
 Some pirate stations operating offshore in parts of Europe and the
United Kingdom more closely resembled legal stations, maintaining regular
schedules, using high power, and selling commercial advertising time.

The Radio Portal
10. Radio control(RC)
 Radio remote controls use radio waves to
transmit control data to a remote object as in
some early forms of guided missile, some early
TV remotes and a range of model boats, cars and
airplanes.
 Large industrial remote-controlled equipment
such as cranes and switching locomotives now
usually use digital radio techniques to ensure
safety and reliability.
 In Madison Square Garden, at the Electrical
Exhibition of 1898, Nikola Tesla successfully
demonstrated a radio-controlled boat.
 He was awarded U.S. patent No. 613,809 for a
"Method of and Apparatus for Controlling
Mechanism of Moving Vessels or Vehicles.
SYMA DragonFly Radio Remote
Control Helicopter!

The Radio Portal
The electromagnetic spectrum
 Radio waves are a form of electromagnetic radiation
that are created when a charged object, such as an
electron, accelerates with a frequency that lies in the
radio frequency (RF) portion of the electromagnetic
spectrum.
 In radio, this acceleration is caused by an alternating
current in an antenna.

The Radio Portal
 Radio frequencies occupy the range from a few tens of hertz to three
hundred gigahertz, although commercially important uses of radio use
only a small part of this spectrum.
 Other types of electromagnetic radiation, with frequencies above the RF
range, are microwave, infrared, visible light, ultraviolet, X-rays and
gamma rays.
 Since the energy of an individual photon of radio frequency is too low
to remove an electron from an atom, radio waves are classified as non-
ionizing radiation.
ELECTROMAGNETIC SPESTRUM OR EM
SPECTRUM

References
 http://www.wikipedia.org
 http://www.acrosswireless.com
 http://wireless.fcc.go
 http://www.wirelessdevnet.com
 http://www.schoolsgalore.com

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