Introduction to the Course Justin Champion Room C208 - Tel: 3273 .

Introduction to the Course

Justin Champion

Room C208 - Tel: 3273www.staffs.ac.uk/personel/engineering_and_technology/jjc1

Introduction to the course

ContentsWhat are we looking atHistory

Digital to analogue

Mobile technology Breakdown of the course Assements


What we are looking at Mobile devices using cellular communications Looking at how they work Uses of this technology We are not considering

Mobile voice technology Wireless Technology

Wi-Fi Bluetooth These do not support any roaming


Evolution of Personal Communication System’s

Analogue Digital Multimedia

1980’s 1990’s 2000 +

Introduction to the course History

1876 Graham bell creates the phone 1878 First exchange in Connecticut, USA.

Gradual spread Analogue Publicly Switched Telephone Network

Used throughout the world 1979

(ISDN) Digital Communications started on the PSTN 1985 Mobile phones start in the UK 1993 ADSL introduced 2001 GPRS service started 2004 EDGE predicted to start 200? 3G service starting

This is ongoing if ever to happen as discussed in lectures

Introduction to the course History of the phone

Created by Graham Bell in 1875 He created what we know as a microphone In 1876 the patent for a telephone was submitted 1878 first telephone exchange was created

In New Haven, Connecticut, USA


Publicly Switched Telephone Network (PSTN)Also know as Plain Old Telephone System

(POTS)This is the telephone network we all use every

day Wired Controlled by British Telecom in the UK Parts of the network are Analogue

Increasingly using Digital Communications Last mile is still analogue today!


Communicating To allow communication a circuit must be completed

between two phone devices This circuit will then allow the analogue signals to

travel between them Voice in the early days

Introduction to the course Switching

The first automated exchange was created in 1889Almon Strowger a undertaker created this

exchange He was annoyed that a opposition undertaker who’s wife

worked in the exchange was getting all the burial work

Introduction to the course - Analogue

Analogue problemsFurther the signal travels the weaker it getsA clear signal will degrade

Loss power Also gain interference

Time / Distance

Strength

Introduction to the course - Analogue

HelloH@lu

Introduction to the course - Digital

Digital CommunicationsAllows accurate sending of signalsThe signal still degrades It is possible though to still get a signal back

even with loss

1100101110010 1100101110010

1

0

+5v

-5v


Analogue to Digital Conversion (ADC)Regular samples are taken from the signal

Each given a value depending on the number of bits Example shown uses 8 bits

127

-127


Analogue to Digital Conversion (ADC)Regular samples are taken from the signal

Each given a value depending on the number of bits Example shown uses 8 bits storing values between 127 & -127

127

-127

Introduction to the course Sampling Rate

Needs to be sufficient to gain all of the analogue signal

If it is not a lot of the signal is lost as in the example shown in the previous example

Nyquist’s law tells us the minimum sampling rate Sampling Rate = Highest Frequency * 2

Telephones use 3.4 KHz sampling rate for voice calls 8 KHz for digital calls 1 KHz = 1000 cycles a second


PSTN Modular The PSTN is a modular design New parts can be added to the network as required

Mobile communications Satellite Communications

SS7 allows this as discussed in a future week


Mobile Communications Started with Mobile phones

Which were voice only Limited battery life Limited roaming capability Limited quality Unsecured

Advent of Digital phones Allowed for better use of this phone technology Allowed the user to roam and receive calls anywhere Call were encrypted The use of digital communications also allowed for data calls

Introduction to the course Roaming capability

Brought forward technology Dual/Tri Band phones Satellite phones

Expensive about £1.20 a minute for a world phone call This allowed the user to move from the office/home

environment and still be connected. Laptops

As computers got smaller it was now possible to carry it with you

As the computer is available the data was required for it

Introduction to the course Data Use

GSM phones allowed 9.6 Kbps data communications Enough for email and simple file transfers

SMS messaging is the most popular data use Voice calls are coming to the peak of the popularity

Additional avenues of revenue are required Increased data is a obvious choice Charge the user for the packet received Charge for the services they are accessing i.e. Football results service

Introduction to the course Personal Communication Services (PCS)

We will soon have the ability for anyone to access digital information like the Internet.

Unlike the Internet, there will be value added service from day one Video on Demand Paying your credit card bill Ordering services

Value added services will be the primary goal of the PCS This will be needed to pay for the infrastructure and licenses paid for

Each user will be able to view the information as they want it Central control will not be put upon on the users Differing levels of hardware capability will effect the end presentation


Weekly Breakdown 1 – This lecture 2 – 1G & 2G technology 3 – Device Technology 4 – General Packet Radio Service 5 – Enhanced Data GSM Environment 6 – Universal Mobile Telecommunication System (UMTS) 7 – CDMA 2000 8 – I-Mode and WAP 9 – 2G and 3G Handover methods 10 – PCS 11 – 4G, the future


Assessment Assignment 50%

This will be one piece of written work of about 4000 words This work will need independent research by the student to discuss

the topic of WCDMA Examination 50%

This will be a formal examination during the faculties exam period Weighting

The weighting of each part will be evenly split


Summary What is the Personal Communication System What we will cover What the assessment will be

Introduction to the Course Justin Champion Room C208 - Tel: 3273 .

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