Wearable Technology

Abstract

Since the development of the ENIGMA (the first digital computer), computers have inspired

our imagination. In this period came the World War II code breaking machine designed by

Alan Turing, and Von Neuman's ENIAC which can be called dinosaurs compared to present

day PCs. In the earlier days, computers were so huge that it took an entire building, or at least

a floor to occupy one. Computers of that era were very slow by today's standards. In the non-

ending struggle to increase computing speed, it was found out that speed of electricity might

become a limiting factor in the speed of computation, and so it was a need to lessen the

distance that electricity had to travel in order to increase the computing speed. This idea still

holds true in modern computing. 

By the 1970s, computers grew fast enough to process an average user's applications. But,

they continued to occupy considerable amount of space as they were made of solid blocks of

iron. The input was done by means of punch cards, and later came the keyboard, which

revolutionalized the market. In 1971 came the 4004, a computer that was finally small in

size. The programmability of these systems were quite less. Still, computers had to be

plugged directly in to AC outlets, and input and output done by punch cards. These

computers were not built keeping users in mind. In fact, the user had to adjust himself with

the computer.

This was the time when wearable computer was born. In the 1970s, wearable computer

challenged the other PCs with its capability to run on batteries. Wearable computers were a

new vision of how computing should be done. Wearable computing showed that man and

machine were no more separate concepts, but rather a symbiosis. The wearable computers

could become a true extension of one's mind and body. In the beginning of 1980s, personal

computing emerged. IBM's PC and other cheaper clones spread world-wide like fire. Finally

the idea of a small PC on your desktop that cost you quite less became a reality.

In the late 1980s PC's introduced the concept of WIMP (Windows, Icons, Mice & Pointers)

to the world which revolutionalized the interface techniques. At the same time, wearables

went through a transformation of their own. They were now eyeglass based, with external

eyeglass mounts. Though they remained visible to all, wearable computer were developing

1

Wearable Technology

principles of miniaturization, extension of man's mind and body, secrecy and personal

empowerment. Now, the only thing needed was an environment for them to flourish. People

began to realize that wearable computer could be a powerful weapon in the hands of an

individual against the machinery. The 1990s witnessed the launch of laptops. The concept

was a huge success as people could carry their PC wherever they go, and use them any time

they need. A problem remained still. They still had to find a workspace to use their laptops

since keyboards and mice (or touch-pads) remained. 

During all these years of fast transformation, there remained visionaries who struggled to

design computers that were extension of one's personality, computers that would work with

your body, computers that will be with you at all times, always at your disposal. In the last

two decades, wearable computer grew smaller still. Now you have completely covert systems

which would reside inside your average glasses. One of the prevalent ideas in wearable

computing is the concept of mediated reality.

2

Wearable Technology

…………………………………………………………………………………… 1

TABLE OF CONTENTS………………………………………………………… 2LIST OF FIGURES……………………………………………………………… 3ACKNOWLEDGEMENTS……………………………………………………… 4Chapter 1 – Introduction…………………………………………………………. 51.1 Wearable Technology……...…………………………………………………. 51.2 History………………………………………………………………………... 61.3 Evolution Of Smartwatch………………......………………………………... 71.4 Ethernet TCP/IP……………………………………………………………… 81.5 Ethernet Address……………………………………………………………... 81.6 Access method – CSMD/CD………………………………………………… 91.7 Back-off Algorithm………………………………………………………….. 9Chapter 2 – Ethernet Frame Structure And Ethernet Media…………………... 102.1 Ethernet Frame Structure……………………………………………………. 102.2 Ethernet Topologies…………………………………………………………. 11 2.2.1 Bus Topology…………………………………………………………… 12 2.2.2 Star Topology…………………………………………………………… 13 2.2.3 Ring Topology………………………………………………………….. 152.3 Ethernet Media………………………………………………………………. 16 2.3.1 Twisted Pair……………………………………………………………… 17 2.3.2 Coaxial Cable……………………………………………………………. 18 2.3.3 Wireless Transmission…………………………………………………… 19Chapter 3 – Types of Ethernet…………………………………………………… 213.1 Fast Ethernet…………………………………………………………………. 213.2 Gigabit Ethernet…………………………………………………………….... 223.3 10 Gig Ethernet………………………………………………………………. 23Chapter 4 – Challenges and Future……………………………………………... 244.1 Challenges…………………………………………………………………… 244.2 Future………………………………………………………………………… 24References………………………………………………………………………... 25

3

TABLE OF CONTENTS

Wearable Technology

Figure 1.1Ethernet and TCP/IP……………………………………………………… 8

Figure 1.2 Access method: CSMA/CD………………………………………….. 9Figure 2.1 Ethernet Frame Structure…………………………………………….. 10Figure 2.1.1 Ethernet Address……………………………………………………... 11Figure 2.2 Ethernet Topologies………………………………………………….. 11Figure 2.2.1 Bus Topology……………………………………………………… 13Figure 2.2.2 Star Topology……………………………………………………… 14Figure 2.2.3 Ring Topology…………………………………………………….. 16

Figure 2.3 Ethernet Media………………………………………………………. 16Figure 2.3.1 Twisted Pair ……………………………………………………….. 17Figure 2.3.2 Coaxial Cable………………………………………………………. 18Figure 2.3.3 Wireless Transmission …………………………………………….. 19Figure 3.1 Fast Ethernet …………………………………………………………. 21Figure 3.2 Gigabit Ethernet………………………………………………………. 22

4

LIST OF FIGURES

Wearable Technology

Acknowledgment

It is needed a great pleasure to express my thanks and gratitude to all those who helped me.

No serious and lasting achievement or success one can ever achieve without the help of

friendly guidance and cooperation of so many people involved in the report.

I am very thankful to my guide Prof. Hemang Kothari, the person who makes me to follow

the right steps during a seminar work. I express my deep sense of gratitude to for his

guidance, suggestions and expertise at every stage. Apart from that his valuable and expertise

suggestion during documentation of my report indeed help me a lot.

Thanks to my friend and colleague who have been a source of inspiration and motivation that

helped to me during my seminar work. I would heartily thankful to head of our computer

department Prof. Jay Teraiya to give me an opportunity to work over this topic and for their

endless and great support. And to all other people who directly or indirectly supported and

help me to fulfill my task.

And at last but not least, I would be grateful towards my parents and friends who had

supported a lot and provided inspiration and motivation to go in this area.

Paras Shah

110970107063

5

Wearable Technology

CHAPTER 1: INTRODUCTION

1.1 Wearable Technology:

Wearable technology (also called wearable gadgets) is a category of technology

devices that can be worn by a consumer and often include tracking information

related to health and fitness. Other wearable tech gadgets include devices that have

small motion sensors to take photos and sync with your mobile devices.

Examples of wearable tech include:

Smartwatch: a wearable Bluetooth personal communicator for iPhone and

Android.

Google glass: a downloadable image recognition application created by

Google, used for searches based on images taken by handheld devices.

Wearable computers are basically small and compact electronic devices designed to

be worn by a user. They are also referred to as body-borne computers, considered as a

type of wearable technology that has in its core an electronic device that performs

calculations and processes information. With this definition, watches from the 1990s

that doubled as calculators can be considered as wearable computers. However,

today’s concept of a wearable computer has advanced into something that is more

than just simple calculations and information processing. This is similar to how

devices are being classified as smartphones. Before, many advanced phones were

already referred to as smartphones but were eventually relegated to being simply

called “feature phones” as more powerful smartphones emerged. Today’s wearable

computers are characteristically more powerful, more efficient, and more compact.

They also possess a greater range of features and are more convenient to wear.

Additionally, they feature better technologies in terms of displays, processors,

batteries, and input and output systems. There’s still so much room for improvement

but we may have to revisit the predecessors and forefathers of these modern wearable

tech to better appreciate all the features we already have.

6

Wearable Technology

1.2 History:

333 BC -Armour -This mosaic from Pompeii shows Alexander the Great at the Battle of

Issus. He is wearing laminated linen body armor called linothorax, which has been shown to

be effective in protecting the wearer from injury by arrows, swords, axes and spears.

1286 - Spectacles - The first eyeglasses, thin lenses that rested directly on the eyeball, were

made in Italy around 1286. The portrait detail (left) shows the spectacle-wearing Dominican

Cardinal and biblical scholar Hugh of Saint-Cher, painted by Tomaso da Modena in 1352.

1571 - Elizabeth I's wristwatch -Elizabeth I (1533-1603) was reportedly given a jeweled

armlet-mounted watch by her favorite, Robert Dudley, 1st Earl of Leicester in 1571. The

earliest wristwatches were worn by women, men generally preferring pocket watches until

the late 19th century, when wrist-borne watches became useful to the military.

1650 - Qing Dynasty Abacus Ring-This pure-silver abacus is inlaid into a ring and measures

just 1cm by 0.5cm, with beads of less than 1mm in diameter. The tiny beads are too small for

finger operation, and would need to be moved using a fine implement like a woman’s

hairpin.

1886 - C. P. Stirn's Concealed Vest Camera- This ‘spy’ camera came in two sizes, using

round film plates with a diameter of 14cm or 17cm. It had an exposure dial and a funnel-

shaped lens barrel, and could be fitted in a vest pocket with the lens poking through the

pocket’s buttonhole. The Concealed Vest Camera proved popular, with sales of 13,000

between 1886 and 1888.

1949 – The Radio Hat - The invention of Victor T. Hoeflich’s American Merri-Lei

Corporation, the 1949 ‘Man From Mars Radio Hat’ combined a pith helmet and a battery-

powered two-tube AM radio, which had a range of 20 miles. The aerial, vacuum tubes and

tuning dial were all prominent external features of the Radio Hat, giving it the ‘Man From

Mars’ look.

7

Wearable Technology

4 Oct 1960 - Telesphere Mask - Morton L. Heilig, who has been described as 'the father of

virtual reality', was granted a US patent for his 'Stereoscopic Television Apparatus for

Individual Use', later dubbed the Telesphere Mask, in 1960. It incorporated 3D TV, a wide

field of view and stereo sound, and was the forerunner of a long line of virtual reality

headsets.

1980 - EyeTrap - Wearable technology pioneer Steve Mann created the first EyeTap device

as a backpack-hosted computer connected to a helmet-borne camera and viewfinder.

Subsequent models shrank to more manageable form factors. EyeTap uses a beam splitter to

send a scene both to the user’s eye and to a computer-connected camera, allowing the overlay

of augmented-reality information.

1982 - Seiko TV Watch - ‘TV-Watch’ is something of a misnomer, because the watch part

only contained the monochrome 1.2-inch LCD. The TV receiver was in a Walkman-sized

190g 2xAAA-powered box that connected to display via a cable, which also served as an

antenna. You were expected to carry the receiver in a pocket and thread the display cable

through your jacket sleeve. Another wire connected the headphones to the receiver. The

Seiko TV Watch appeared in the 1983 James Bond film Octopussy.

2002 - MicroOptical MV-1 - MicroOptical, founded in 1995, was an early developer of

optical head-mounted displays. The MV-1 pictured here provided 600-by-340-pixel

resolution, while later products such as the Crystal 701 (released in 2008 after the company

changed its name to MyVu) supported VGA (640 by 480 pixels). MicroOptical founder Mark

Spitzer was later hired by Google as a director of operations at Google X, which

developed Google Glass, among other emerging-technology products.

2003 - Garmin Forerunner - Garmin's extensive Forerunner series of GPS sport watches

launched in 2003. Pictured here is the Forerunner 205, which was released in 2006, while the

video describes 2008's more compact Forerunner 405. Depending on the model, you can

measure and display metrics like distance, speed, cadence (stride pattern), heart rate and

estimated oxygen consumption.

8

Wearable Technology

Aug 2009 – Jetlev - The first 'hydro' jet pack was invented by Chinese-born

Canadian Raymond Li. A prototype was shown on YouTube in 2009, while a commercial

model, the R200, launched in early 2012. A powerful marine engine pumps water up a hose

to the backpack, where it is ejected at high pressure through two user-controllable nozzles.

Sep 2009 - Fitbit Tracker - The Fitbit Tracker was unveiled at TechCrunch 50 in 2008, and

shipped a year later priced at $99. A clip-shaped device that fastened onto your clothing, the

original Fitbit logged steps taken, distance travelled and calories burned, and also monitored

sleep patterns when slipped into a wristband. It came with a USB-connected base station that

charged the device when docked, and gathered data wirelessly (via ANT) when the Fitbit

came within its 15-foot (4.6m) range.

Feb 2012 - Nike+ Fuelband - Nike's activity-tracking wristband combined standard

pedometer functionality with gamification features based around the Nike Fuel metric. Its

display comprised white LEDs for readouts and a line of color LEDs that changed from red

to green as goals were approached. Connection to the companion iOS app was via USB or

Bluetooth.

2012 - Oculus Rift- -Oculus VR launched a successful Kickstarter campaign in August 2012

to raise funds for a developer kit of its Oculus Rift virtual reality headset. The $350 dev kit is

now on itssecond generation, delivering a resolution of 960 by 1,080 pixels per eye with a

100-degree field of view. A consumer version is under development and is expected to ship

in 2015.

Jan 2013 – Pebble - Pebble was an early success story for the crowd-funding platform

Kickstarter, raising $10.27 million by 19 May 2012 and entering production in January 2013.

It had a 1.26-inch white e-paper display and ran a proprietary, lightweight, Pebble OS on an

ARM processor with just 128KB of RAM. The Pebble’s 4MB of storage could hold up to

eight apps, installed via a Bluetooth connection to an iOS or Android smartphone. There’s no

9

Wearable Technology

camera, microphone or speaker, but the Pebble does include a 3-axis accelerometer (with

gesture detection), a magnetometer and an ambient light sensor. Battery life is rated for 7

days, although this will vary depending on usage pattern.

Feb 2013 - Google Glass-The poster-child for the current wave of wearable devices, Google

Glass is an Android-powered augmented-reality headset with an optical head-mounted

display that delivers the equivalent of a 25-inch screen viewed from distance of 8 feet (2.4m).

It’s controlled via voice commands (prefaced by the infamous "OK Glass") and by a

touchpad on one side of the frame, and can connect to both Android and iOS devices via

Bluetooth or Wi-Fi. It has a 5-megapixel camera that can shoot 720p video (in 10-second

bursts by default) and has a 2.1Wh battery that’s rated to last for a day. As well as running

many existing Google apps, a Glass Development Kit allows the creation of third-party Glass

apps. Initially available to US-based beta testers as a $1,500 Explorer Edition, Google Glass

is expected to become generally available later this year.

18 Mar 2014 - Android Wear - Android Wear, a version of Google's Android OS designed

for smartwatches and other wearable devices such as Google Glass, is currently available as a

developer preview. Partners include Asus, Broadcom, Fossil, HTC, Intel, LG, Mediatek,

MIPS, Motorola, Qualcomm and Samsung. Android Wear smartwatches have been

announced by LG (G Watch) and Motorola (Moto 360) and are due to ship in summer 2014.

9 Sep 2014 – Apple watch - Apple's much-rumored Watch (not iWatch, as it turned out) was

unveiled as 'one more thing' at the iPhone 6/6 Plus launch event. The rectangular device will

come in two case sizes (38mm and 42mm), cost 'from $349' and ship early in 2015. There are

three 'editions', offering different combinations of build materials: Apple Watch (stainless

steel, sapphire crystal glass, 'stylish' straps); Apple Watch Sport (anodizedaluminum, Ion-X

glass, 'colorful, durable' straps); and Apple Watch Edition (18-carat yellow or rose gold,

sapphire crystal glass, 'exquisitely crafted straps and closures'). Apple Watch will work with

iPhones 5, 5c, 5s, 6 and 6 Plus running iOS 8.

10

Wearable Technology

1.3 Evolution Of Smartwatch:

1 Pulsar Time Computer Calculator

Widely regarded (though with some debate) as the first calculator watch, at the time of its

release, the $2100, 18-karat gold Pulsar Time Computer Calculator was luxury incarnate, the

kind of thing you’d see on the classy wrist of, say, an Oleg Cassini or Vidal Sassoon. When

the Time Computer shipped in 1975, the digital watch was still a new concept. Time was a

pretty hot commodity in the 70s; busy folks didn’t have a moment to spare, and had to resort

to handy abbreviations like BTO, ELP, and CREEP, just to get by. By 70s standards, the

Time Computer practically transformed its owners into futuristic supermen, free from the

cruel drudgery of having to reach into one’s pocket or desk to retrieve a calculator, and able

to compute restaurant gratuities at lightning speed.

11

Wearable Technology

12

Wearable Technology

2 Casio C-80In 1980, the $49 Casio C-80 Calculator Chronograph forever changed the face of the

smartwatch. The iconic Japanese wearable boasted a stopwatch, a calendar, and the first

calculator with raised keys, spaced, as an advertisement proudly proclaimed, “far enough

apart that even the broadest fingers can work them.” And though one might think that a

calculator watch would be more useful to those who spent the 1980s hocking leveraged

buyouts, the C-80 was primarily a youth trend, a perfect nerd accessory for an age that

celebrated the geeky savants of movies like Weird Science, War Games, and Real Genius.

13

Wearable Technology

14

Wearable Technology

3 Timex DatalinkReleased in 1994 in collaboration with Microsoft, the Timex Datalink was an attempt to put a

PDA on your wrist. It was capable of syncing phone numbers, reminders, and calendar items

from your computer wirelessly, but to do so, the watch had to be physically held up to the

monitor while the Datalink read coded flashes of light from the screen.Though Timex came

out with several evolving versions over the next 10 years and the Datalink was actually

certified by NASA for use during space travel, the smartwatch failed once again to become a

popular accouterment for the general public.

15

Wearable Technology

16

Wearable Technology

4 Pebble Smart watch

The Pebble is perhaps the most significant smartwatch released to date. In 2012, the team

building it raised $10.2 million on Kickstarter, making it, at that time, the most successful

crowdfunding project ever. The idea was to build a smartwatch with a low-energy "e-paper"

display that could last an entire week on a single charge. Over 66,000 individuals had

ordered this thing without ever seeing it in person—we were ready.Now, even though a

substantial amount of Pebbles have shipped, you rarely see them out in the wild, and reviews

have been mixed. Nonetheless, this was the gadget that inspired the current wearable device

gold rush, and probably finally convinced giants like Apple to jump into the smartwatch fray.

17

Wearable Technology

18

Wearable Technology

1.4 Ethernet and TCP/IP:

Figure 1.1 Ethernet and TCP/IP1.5 Ethernet Address:

Also known as “MAC address”.

Globally unique ID for each device.

Burnt into ROM, cannot be modified.

6 Bytes in which manufacture, device model and serial number are coded.

Readable with many auxiliary tools for that e.g. WINIPCFG.

1.6 Access method: CSMA/CD

19

Wearable Technology

Figure 1.2 Access Method CSMD/CD

1.7 Back-Off Algorithm: If a collision has occurred, the stations try to send again after a certain period of time.

After the first collision there a two different Back-Off times available, from which one is chosen at random. Transmission probability is 50%.

After the second consecutive collision there are four different Back-Off times available, from which one is chosen at random.

The transmission probability now is 75%.

20

Wearable Technology

CHAPTER 2: Ethernet Frame Structure & Media

2.1 Ethernet frame structure:

Figure 2.1 Frame structure

Preamble: 7 byte with pattern 10101010 followed by 1 byte wit pattern 10101011 used to synchronies receiver, sender clock rates

Address: 6 bytes, frame is received by all adaptor on an LAN and dropped if

address does not match.

Length: Bytes, length of data field.

CRC: 4 bytes generated using CR-32,checked at receiver, if error is detected,

the frame is simply dropped.

Data payload: maximum 1500 bytes,minimum 46 bytes is data is less than 46 bytes pad with zeros to 46 bytes.

Ethernet Address:

21

Wearable Technology

Figure 2.1.1 Ethernet Address

2.2 Ethernet topologies:

Bus topology Star topology

Ring topology

Figure 2.2 Ethernet Topologies

22

Wearable Technology

2.2.1 Bus topology:

This is the simplest topology

In this one-cable LAN, all workstations are connected in succession on a single cable.

All transmission go to all the connected workstations.

Use a bus topology for a large network with many users and longer segments.

Traditional Ethernet employs a bus topology, meaning that all devices or host on the network use the same shared communication line.

Advantages:

Easy to connect a computer or peripheral to a linear bus.

Requires less cable length than a star topology.

It works well for small networks.

Disadvantages:

Entire network shuts down if there is a break in the main cable.

Terminators are required at both ends of the backbone cable.

Difficult to identify the problem if the entire network shuts down.

Not meant to be used as a stand-alone solution in a large building.

It is slow when more devices are added into the network.

If a main cable is damaged then network will fail or be split into two networks.

23

Wearable Technology

Figure 2.2.1 Bus Topology

2.2.2 Star Topology:

Each of several devices has its own cable that connects to a central hub, or sometime a switch, multipoint repeater, or even multi station unit(MSU).

The star topology reduces the chance of network failure by connecting all of the system to central node.

The star topology reduces the damage caused by line failure by connecting all of the systems to a central node. When applied to a bus-based network, this central hub rebroadcasts all transmissions received from any peripheral node to all peripheral nodes on the network, sometimes including the originating node.

All peripheral nodes may thus communicate with all others by transmitting to, and receiving from, the central node only. The failure of a transmission line linking any peripheral node to the central node will result in the isolation of that peripheral node from all others, but the rest of the systems will be unaffected.

Advantages:

Better performance: Star topology prevents the passing of data packets through an excessive number of nodes. At most, 3 devices and 2 links are involved in any communication between any two devices. Although this topology places a huge overhead on the central hub, with adequate capacity, the hub very high utilization by one device without affecting others.

24

Wearable Technology

Isolation of devices: Each device is inherently isolated by the link that connects it to the hub. This makes the isolation of individual devices straightforward and amounts to disconnecting each device from the others. This isolation also prevents any non-centralized failure from affecting the network.

Benefits from centralization: As the central hub is the bottleneck, increasing its capacity, or connecting additional devices to it, increases the size of the network very easily. Centralization also allows the inspection of traffic through the network. This facilitates analysis of the traffic and detection of suspicious behavior.

Easy to detect faults and to remove parts.

No disruptions to the network when connecting or removing devices.

Installation and configuration is easy since every one device only requires a link and one input/output port to connect it to any other device.

Disadvantages:

Reliance on central device: star topology relies on the central device (the switch, hub or computer) and if this device fails the whole network will fail in turn.

Higher costs: the need for a central device increases costs compared to the bus and ring topologies. The star topology also requires more cable when using Ethernet cables than ring and bus topologies.

Limited capacity for nodes: as this type of network needs all connections to go through a central device the amount of nodes in a network is limited by this factor whereas bus and ring topologies are not limited in such a way.

Figure 2.2.2 star topology

25

Wearable Technology

2.2.3 Ring topology:

In ring network, every device has exactly two neighbors for communication purposes.

All messages travel through a ring in the same direction(either “clockwise” or “counterclockwise”).

A failure in any cable or device breaks the loop and can take down the entire network.

To implement a ring network, one typically uses FDDI,SONET, or token ring technology.

Advantages:

Very orderly network where every device has access to the token and the opportunity to transmit.

Performs better than a bus topology under heavy network load.

Does not require a central node to manage the connectivity between the computers.

Due to the point to point line configuration of devices with a device on either side (each device is connected to its immediate neighbor), it is quite easy to install and reconfigure since adding or removing a device requires moving just two connections.

Point to point line configuration makes it easy to identify and isolate faults.

Disadvantages:

One malfunctioning workstation can create problems for the entire network. This can be solved by using a dual ring or a switch that closes off the break.

Moving, adding and changing the devices can affect the network.

Communication delay is directly proportional to number of nodes in the network.

Bandwidth is shared on all links between devices.

More difficult to configure than a Star: node adjunction = Ring shutdown and reconfiguration.

26

Wearable Technology

Figure 2.2.3 Ring Topology

2.3 Ethernet Media:

Twisted pair

Co-axial cable wireless transmission

Figure 2.3 Ethernet Media

27

Wearable Technology

2.3.1 Twisted pair:

Twisted pair cabling is type of wiring in which two conductor of a single circuit are twisted to cancel out EMI (electromagnetic interference) from external sources; for instance electromagnetic radiation from unshielded twisted pair (UTP) cables. And cross talk between neighboring pairs.

Twisted pair cables are often shielded in an attempt to prevent electromagnetic interference. Because the shielding is made of metal, it also serve as a ground. Usually a shielded or a screened twisted pair cable has a special grounding wire added call a drain wire which is electrically connected to shield or screen. The drain wire simplifies connection to ground at the connectors.

Advantages:

It is a thin, flexible cable that is easy to string between walls.

More lines can be run through the same wiring ducts.

Electrical noise going into or coming from the cable can be prevented.

Cross-talk is minimized.

Disadvantages:

Twisted pair's susceptibility to electromagnetic interference greatly depends on the pair twisting schemes (usually patented by the manufacturers) staying intact during the installation. As a result, twisted pair cables usually have stringent requirements for maximum pulling tension as well as minimum bend radius.

In video applications that send information across multiple parallel signal wires, twisted pair cabling can introduce signaling delays known as skew which cause subtle color defects and ghosting due to the image components not aligning correctly when recombined in the display device. The skew occurs because twisted pairs within the same cable often use a different number of twists per meter in order to prevent crosstalk between pairs with identical numbers of twists.

2.3.1 Twisted pair

28

Wearable Technology

2.3.2 Coaxial cable:

It has an inner conductor surrounded by tubular insulating layer, surrounded by tubular conducting shield.

The have insulating outer jacket.

Used as transmission line Radio frequency signal Feed lines connecting radio transmitters and receivers Internet connection

Advantages

Sufficient frequency range to support multiple channels, which allows for much greater throughput.

Lower error rates. Because the inner conductor is in a Faraday shield, noise immunity is improved, and coax has a lower error rates and therefore slightly better performance than twisted pair.

Greater spacing between amplifiers coax's cable shielding reduces noise and crosstalk, which means amplifiers can be spaced farther apart than with twisted pair.

Disadvantages

More expensive to install compare to twisted pair cable.

The thicker the cable, the more difficult to work with.

Figure 2.3.2 Coaxial cable

29

Wearable Technology

2.3.3 Wireless Transmission:

Transfer of information between two or more point not connected by electrical conductor.

The most commonly wireless Technologies use electromagnetic wireless telecommunication, such as radio.

It encompasses various types of fixed, mobile, and portable application, including two-way radios, cellular telephone, personal digitals assistants (PDAs), and wireless networking.

Advantages:

Mobility - user device can be moved easily within the wireless range.

Neat and easy Installation - since no cable running here and there, just start up the wireless device and you're ready to rumble.

Less cost for cabling infrastructure and device.

More users supported - cable device have limited slots whereas wireless does not.

Disadvantages

Relatively lower bandwidth speed - example: although currently 802.11/n could reach 128 Mbps, UTP cable can reach 1 Gbps. And more user mean each bandwidth get smaller. That is why currently wired backbone network is still preferred.

Ease of access means more security also necessary to protect data and/or bandwidth, since people can connect anywhere within range without seeking network plug.

Figure 2.3.3 Wireless Transmission.

30

Wearable Technology

Shared Media:

The Ethernet standard comprises several wiring and signaling variants of the OSI physical layer in use with Ethernet. The original 10Base5 Ethernet used coaxial cables a shared medium. Later the coaxial cable where replaced by twisted pair and fiber optic links in conjunction with hubs or switches. Data rates where periodically increased from the original 10Mbits/s to 100Gbits/s.

Ethernet was originally based on the idea of computers communicating over a shared coaxial cable acting a s a broadcast transmission medium. The methods used where similar to those used in radio systems with the common cable providing the communication channel.

Threw the 1st half of the 1980 s, Ethernets 10Base5 implementation used a coaxial cable 0.375 inches (9.5 MM) in diameter, later called “thick Ethernet” or “thick net”. Its successor 10Base2, called “thin Ethernet” or “thin net”, used a cable similar to cable television cable of the area. The emphasis was on making installation of the cable easier and less costly.

31

Wearable Technology

CHAPTER 3: Types of Ethernet

The Ethernet physical layer evolved over a considerable time span and encompasses coaxial, twisted pair and fiber optic physical media interfaces and speeds from 10 Mbit to 100 Gbit. The first introduction of twisted pair CSMA/CD was 802.3 1BASE5. While 1BASE5 had little market penetration, it did define the physical apparatus (wire, plug/jack, pin out, and wiring plan) which would be carried over to 10BASE-T. The most common forms used are 10BASE-T, 100BASE-TX, and 1000BASE-T. All three utilize twisted pair cables and 8P8C modular connectors. They run at 10 Mbit/s, 100 Mbit/s, and 1 Gbit/s, respectively. Fiber optic variants of Ethernet offer high performance, electrical isolation and distance (tens of kilometers with some versions). In general, network protocol stack software will work similarly on all varieties.

Type of Ethernet:

Fast Ethernet Gigabit Ethernet 10 gig Ethernet

3.1 Fast Ethernet:

100 Mbps bandwidth.

Uses CSMA/CD media access protocol and packet format as in Ethernet.

100BaseTX (UTP) and 100BaseFX (fiber) standards.

Full duplex/half duplex operation.

32

Wearable Technology

Figure 3.1 Fast Ethernet

33

Wearable Technology

3.2 Gigabit Ethernet:

1 Gbps bandwidth.

Uses CSMA/CD media access protocol as in Ethernet and is backward compatible

1000BaseT (UTP), 1000BaseSX(multimode fiber) and 1000BaseLX standards.

Figure 2.3.3 Wireless Transmission

34

Wearable Technology

3.3 10Gig Ethernet:

10 Gbps bandwidth.

Uses CSMA/CD media access protocol as in Ethernet.

Propositioned for metro-Ethernet.

Maximum link distances cover 300 m to 40 km.

Full-duplex mode only.

Uses optical fiber only.

35

Wearable Technology

CHAPTER 4: Challenges and Future

4.1 Challenges:

Instead of creating a completely new protocol, the IEEE decided to keep all the old pocket formats, interfaces and procedural rules and simply reduce the bit time from 100 nsec to 10 nsec. This effectively increased the bandwidth to 100 mbps. The protocol was officially known as 802.3 u, but was more commonly called called Fast Ethernet.

The change in bit time presented a number of challenges a number of challenges to the designers of Fast Ethernet. The reduction in bit time increases thenumber of bits sent within a set time period, however these bits still take the same amount of time to travel across a length of wire (i.e. the propagation delay is the same over a given length). This means that more bits will be send during the 2* propagation Delay used as the collision window (see Broadcast Network Operation). Either the minimum frame size needs to be increased, or the propagation delay (i.e. cable length) needs to be backward compatibility of this standard, so the maximum network size was reduces, with typically maximum cable lengths of 100m.

4.2Future Ethernet

10 Gigabits Ethernet has already been ratified, and is being use for a part of the internet backbone and for large scientific clusters. 1 Gigabit Ethernet is now a common network interface upon new PCs, replacing fast Ethernet. The next standards will be 40Gigabit Ethernet, which has already been demonstrated by switching platforms.

36

Wearable Technology

Reference

1. "IEEE 802.3 'Standard for Ethernet' Marks 30 Years of Innovation and Global Market Growth" (Press release). IEEE. June 24, 2013. Retrieved January 11, 2014.

2. "Ethernet Prototype Circuit Board". Smithsonian National Museum of American History. 1973. Retrieved September 2, 2007.

3. EEE Standard for Ethernet" (PDF). ieee.org. IEEE Standards Association. 2012-12-28. Retrieved 2014-02-08.

Website reference:

1. Wikipedia.2. Figure from google images.3. Ehow.com.

37