230 likes | 731 Views
Introduction to the Course Justin Champion Room C208 - Tel: 3273 www.staffs.ac.uk/personel/engineering_and_technology/jjc1 Introduction to the course Contents What are we looking at History Digital to analogue Mobile technology Breakdown of the course Assements
E N D
Introduction to the Course Justin Champion Room C208 - Tel: 3273 www.staffs.ac.uk/personel/engineering_and_technology/jjc1
Introduction to the course • Contents • What are we looking at • History • Digital to analogue • Mobile technology • Breakdown of the course • Assements
Introduction to the course • 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
Digital Multimedia Analogue 1990’s 1980’s 2000 + Introduction to the course • Evolution of Personal Communication System’s
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
Introduction to the course • 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!
Introduction to the course • 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 1889 • Almon 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 problems • Further the signal travels the weaker it gets • A clear signal will degrade • Loss power • Also gain interference Strength Time / Distance
Introduction to the course - Analogue H@lu Hello
+5v 1 0 -5v Introduction to the course - Digital • Digital Communications • Allows accurate sending of signals • The signal still degrades • It is possible though to still get a signal back even with loss 1100101110010 1100101110010
Introduction to the course - Digital • 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
Introduction to the course - Digital • 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
Introduction to the course • 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
Introduction to the course • 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
Introduction to the course • 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
Introduction to the course • 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
Introduction to the course • Summary • What is the Personal Communication System • What we will cover • What the assessment will be