Associate Professor
Dept. of Electrical and Electronic Engineering
University of Dhaka
Dr.
Mohammad
J
unaebur
R
ashid (
JR
)
1
ICT3207: Cellular and Mobile Communication (3.0 Cr)
Course Teacher
Bangladesh University of Professionals
2
Cellular concepts: frequency reuse, handoff strategies, interference and system capacity, grade of service, improving capacity and coverage, call blocking probability.
Introduction to Mobile Communication: history and evolution of mobile radio systems, types of mobile wireless services/systems - cellular, WLL, paging, satellite systems, standards, and future trends in personal wireless systems. Cellular concepts and system design fundamentals/frequency management and channel Assignment: Cellular concept and frequency reuse, Multiple Access Schemes, fixed Channel assignment, non-fixed channel assignment and handoff. Interference and system capacity, Trunking and Erlang capacity calculations. Mobile radio propagation Radio wave propagation issues in personal wireless systems, Propagation models, Multipath fading and base band impulse response models, Parameters of mobile multipath channels, Antenna systems in mobile radio.
Modulations and signal processing: Analog and digital modulation techniques, Performance of various modulation techniques - Spectral efficiency, Error-rate, Power Amplification, Equalization Rake receiver concepts, Diversity and space-time processing, Speech coding and channel coding. System examples and design issues: Multiple Access Techniques – FDMA, TDMA and CDMA systems, Operational systems, Wireless networking, security in wireless networks, Design issues in personal wireless systems.
Recommended Book(s):
1. "Mobile Cellular Telecommunications: Analog and Digital Systems"- Lee W.C.Y- McGraw-Hill 2. "Mobile Communications Engineering: Theory and Applications"- Lee W.C.Y- McGraw-Hill 3. "Mobile Communications"-J. Schiller- Pearson Education Asia Ltd.
Lecture 01
ICT3207: CMC3
Lecture 01
The objectives of this course are to:
• Develop knowledge on cellular concepts
• Get idea on different wireless techniques
• Develop knowledge on different types of wireless service
• Understand the frequency reuse scheme
• To learn the channel assignment and handoff techniques
• Understand analog and digital modulation techniques
• Know the basics of multiple access techniques
Learning Objectives:
4
How this course will be conducted…
Class Lectures: 28 (Max.)
Presentation/Viva-voce: 1 Lecture
Exam System → 4 Class tests → Midterm → Final exam → Term paper → Assignments
Lecture 01
Try to develop your level of knowledge……
Lecture Materials: Recommended books and Slides
Your Attendance is Must
ICT3207: CMC
Remarks Distribution
Final Exam 50%
Midterm 20%
Class Test 10%
Assignments/Term Paper 10%
5
Lecture 01
Grading
ICT3207: CMC
Attendance Marks
90% and Above 10.0 85% to < 90% 9.0 80% to < 85% 8.0 76% to < 80% 7.0
75% 6.0
Less Than 75% 0.0
6
Lecture 01
Lecture Plan
7
Lecture 01
Lecture Plan
8
Lecture 01
Lecture Plan
9
Lecture 01
Lecture Plan
10
Lecture 01
Lecture Plan
11
Lecture 01
Introduction
• What will computers look like in ten years?
No one can make a wholly accurate prediction. Now as a general feature, most computers are portable.
• How will users access networks with the help of computers or other communication devices?
An ever-increasing number without any wires, i.e., wireless.
• How will people spend much of their time at work, during vacation?
Many people will be mobile– already one of the key characteristics of today’s society.
• Basically there are three different concepts: – Wireless transmissions
– Mobility – Portability
12
Lecture 01
Introduction
• User mobility refers to a user who has access to the same or similar telecommunication services at different places, i.e., the user can be mobile, and the services will follow him or her.
Example: simple call-forwarding solutions known from the telephone or computer desktops supporting roaming.
• With device portability, the communication device moves (with or without a user). Many mechanisms in the network and inside the device have to make sure that communication is still possible while the device is moving.
• A typical example for systems supporting device portability is the mobile phone system, where the system itself hands the device from one radio transmitter to the next if the signal becomes too weak.
13
Lecture 01
Introduction
• With regard to devices, the term wireless is used. This only describes the way of accessing a network or other communication partners, i.e., without a wire.
• A communication device can thus exhibit one of the following characteristics:
Fixed and wired: This configuration describes the typical desktop computer in an office. Neither weight nor power consumption of the devices allow for mobile usage.
Mobile and wired: Many of today’s laptops fall into this category.
Fixed and wireless: This mode is used for installing networks, e.g., in historical buildings to avoid damage by installing wires.
Mobile and wireless: No cable restricts the user, who can roam between different wireless networks.
14
Lecture 01
Applications
15
Lecture 01
Applications
• In Vehicles
ICT3207: CMC
• Today’s cars already comprise some, but tomorrow’s cars will comprise many wireless communication systems and mobility aware applications.
• Music, news, road conditions, weather reports, and other broadcast information are received via digital audio broadcasting (DAB) with 1.5 Mbit/s.
• For personal communication, a universal mobile telecommunications system (UMTS) phone might be available offering voice and data connectivity with 384 kbit/s.
16
Lecture 01
Applications
ICT3207: CMC
• Cars driving in the same area build a local ad-hoc network for the fast exchange of information in emergency situations or to help each other keep a safe distance.
• In case of an accident, not only will the airbag be triggered, but the police and ambulance service will be informed via an emergency call to a service provider.
• In the future, cars will also inform other cars about accidents via the ad-hoc network to help them slow down in time, even before a driver can recognize an accident.
17
Lecture 01
Applications
ICT3207: CMC
• Just imagine the possibilities of an ambulance with a high-quality wireless connection to a hospital. Vital information about injured persons can be sent to the hospital from the scene of the accident. All the necessary steps for this particular type of accident can be prepared and specialists can be consulted for an early diagnosis.
• Wireless networks are the only means of communication in the case of natural disasters such as hurricanes or earthquakes.
• In the worst cases, only decentralized, wireless ad-hoc networks survive.
18
Lecture 01
Applications
ICT3207: CMC
• A travelling salesman today needs instant access to the company’s database: to ensure that files on his or her laptop reflect the current situation, to enable the company to keep track of all activities of their travelling employees, to keep databases consistent etc. With wireless access, the laptop can be turned into a true mobile office, but efficient and powerful synchronization mechanisms are needed to ensure data consistency.
19
Lecture 01
Applications
ICT3207: CMC
• Replacement of wired networks :
In some cases, wireless networks can also be used to replace wired networks, e.g., remote sensors, for tradeshows, or in historic buildings.
– Due to economic reasons, it is often impossible to use wired remote sensors for weather forecasts, earthquake detection, or to provide environmental information. Wireless connections, e.g., via satellite, can help in this situation.
– Tradeshows need a highly dynamic infrastructure, but cabling takes a long time and frequently proves to be too inflexible.
20
Lecture 01
Applications
ICT3207: CMC
• Internet everywhere? Not without wireless networks! Imagine a travel guide for a city. Static information might be loaded via Pen drive, DVD, or even at home via the Internet.
• But wireless networks can provide up-to-date information at any appropriate location. The travel guide might tell you something about the history of a building downloading information about a concert in the building at the same evening via a local wireless network.
• Another growing field of wireless network applications lies in entertainment and games to enable, e.g., ad-hoc gaming networks as soon as people meet to play together.
• Infotainment and more
21
Lecture 01
Applications
ICT3207: CMC
• Location aware services
• what services, e.g., printer, fax, phone, server etc. exist in the local environment.
• Follow-on services
• automatic call-forwarding, transmission of the actual workspace to the current location.
• Information services
• push: e.g., current special offers in the supermarket.
• pull: e.g., where is the Black Forrest Cherry Cake?
• Support services
• caches, intermediate results, state information etc. follow the mobile device through the fixed network.
• Privacy
• who should gain knowledge about the location
22
Lecture 01
Applications
ICT3207: CMC
23
Lecture 01
Applications
ICT3207: CMC
• Effects of device portability
• Power consumption
• limited computing power, low quality displays, small disks due to limited battery capacity.
• CPU (Samsung Glalxy S7 Edge: Qualcomm Snapdragon 820 or Exynos 8890 - quad-core 2.3 et quad-core 1.6 GHz; Huawei Honor 8: HiSilicon Kirin 950)
• Loss of data
• higher probability, has to be included in advance into the design.
• Limited user interfaces
• compromise between size of fingers and portability.
• integration of character/voice recognition, abstract symbols.
• Limited memory
• limited value of mass memories with moving parts.
24
Lecture 01
Applications
ICT3207: CMC
• Wireless networks in comparison to fixed networks :
• Higher loss-rates due to interference
• emissions of, e.g., engines, lightning.
• Restrictive regulations of frequencies
• frequencies have to be coordinated, useful frequencies are almost all occupied.
• Low transmission rates
• local some Mbit/s, regional currently 9.6 kbit/s with GSM.
• Higher delays, higher jitter
• connection setup time with GSM in the second range, several hundred milliseconds for other wireless systems.
• Lower security, simpler active attacking
• radio interface accessible for everyone, base station can be simulated, thus attracting calls from mobile phones
