Download - A Direction Based Call Admission Control
Mobile Multimedia CommunicationsAn Emerging Technology
Presented by:
Dr. M. Mahfuzul Islam
Department of Computer Science and Engineering
Bangladesh University of Engineering and Technology
2Presented on 19 September 2007 at AIUB, Bangladesh
Presentation Objectives
What is Mobile Multimedia
Communication?
Wireless networks: An Emerging
Technology.
Research Problems
Conclusions
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Mobile Multimedia Communications
MSC
PSTN
Wireless Connection
Optic Fibre
Wired Connection
Movie Server
Base Station
Integrate voice, audio, text and video.
Connectivity
Combine Wireless and wired medium.
Allow Terminal Mobility and Personal Mobility
Combine Telecommunications and Computing Technology.
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Wireless Technology: the new vision
Current wireless uses Wireless long distance Wireless LANs Wireless local Loops
(WLLs) Personal area networks
(PANs) M-Commerce
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Wireless Technology: the new vision
Wireless Long Distance
1G AnalogAMPSTACSNMTRTMS
2G narrowband DigitalGSM
IS-54/136 TDMAISS-85/cdmaOne
PDC
2G+ or 2.5GVoice and DataGPRS, HSCDS
GSMIS-136A & 8
TDMAIS-95c cdmaOne
3G Broadband Digital
W. CDMAUWC-136cdma2000
VoiceVery small
dataAmerican Roaming
Enhanced Voice
some dataInternational
Roaming
VoiceEnhanced data
E-mail Internet
Broadband dataVideo
Fast Internet Remote Access
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Wireless Technology: the new visionWireless Long Distance: GSM
The most popular 2G cellular standard developed to cater
voice services and data delivery using digital
modulation.
Development background:
Developed by Groupe Spéciale Mobile (founded
1982) which was an initiative of CEPT (Conference
of European Post and Telecommunication).
In 1989, ETSI (European Telecommunications
Standards Institute) took the control of GSM and
defined new acronym “Global System for Mobile
Communications.”
Commercial use has been started since 1991.
Features of GSM Standards:
Supports international roaming and
handheld terminals.
Good subjective speech quality and
wide-range of new services.
Low cost (?).
Compatible with other systems, say
ISDN and PSTN.
2.5G Cellular: Extends the 2G technologies – GSM, TDMA, CDMA. GPRS (general packet
radio systems) technology is used to add data capacity.
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Wireless Technology: the new vision
Wireless Long Distance
3G Cellular: The goals of 3G are to
provide- WANs for PC and multimedia, allowing for bandwidth on demand. flexibility to support multiple standards integrate fixed wireless access services, satellite services and cellular at data rates 384 kbps for mobile, and 2 mbps for fixed.
CDMA is the universal standard for 3G, but face the same pricing issue at 2.5G (time basis charge). Court battles over the leased spectrum. costs to deploy not seen as tenable.
4G Cellular: Broadband IP could provide
4G services (since 2003).
Users pay for different kind of services.
The service is IP based and looks like wired services accessed via a browser.
New entrants arelooking for 3Galternatives.
VSAT (very small aperture terminal): Stationary wireless
Broadband is best provided by VSAT.
Many country is taking off. Small VSAT dishes, speed
0.5 mbps.
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Base Transceiver
System (BTS)
Base Transceiver
System (BTS)Base Station
Controller (BSC)
Base Station
Controller (BSC)
Base Station (BS)
VLR HLR
EIR AuC
Mobile Switching Centre
(MSC)
PSTN
Other
GSM
MobileTerminal (MT)
Wireless Connection
P2P Wireless or optic fiber connection
There are three main components of GSM networks:
Mobile Terminal (MT) Mobile equipment for transmitting and receiving signals. Subscriber Identity Module (SIM) for storing necessary permanent and temporary data.
Base Station (BS) Base Transceiver System (BTS) for
transmitting and receiving signals; and manipulating signals
Base station Controller (BSC) for assigning and managing resources, controlling handoff and power level, etc.
Mobile Switching Centre (MSC) Manage communications, mobility, and billing information.
Home Location Register (HLR): central master database for users under the MSC. Visitor location Register (VLR): Local database for the users currently under the domain of MSC. Authentication Center (AuC): Authenticate mobile terminals and encrypt user data. Equipment Identity Register (EIR): register MTs and locked stolen or malfunctioning MTs.
Wireless Technology: the new visionWireless Long Distance: GSM Network Components
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Wireless Technology: the new vision
Wireless LAN
Wireless LAN Used within a building or among buildings on a campus. Wireless LANs are not generally replacing existing wired LANs but extending
them to portable devices. Example: In hospitals, doctors and nurses can use handheld or notebook computers to record patient
data at the bedside, which is faster than using a wired computer.
WLANs use two technologies: infrared and microwave.
Cannot penetrate solids such as walls, ceiling, dust or rain. So, transmitter and receiver must be in line of sight.
Microwave and radio-frequency (RF) are the most popular WLAN technology because the signals can go through the walls.
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Wireless Technology: the new vision
Wireless LAN
Wireless LAN use two topologies: peer-to-peer and client-server. Peer-to-peer: each unit communicate with every other units.
Less expensive because the system has no central controlling unit.
Performance decreases as traffic increase because more and more collisions occur.
Client-Server: Server is the central coordinating node. It communicates with the clients wirelessly and links to a wired LAN on behalf of those clients.
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Wireless Technology: the new vision
Wireless LAN
Wi-Fi is the 802.11b wireless Ethernet standard that transmits up to 11 Mbps connection is easy. Wi-Fi networks run in unlicensed bandwidth. Appear in a place where people congregate such as airports, hotels, conference centers, and coffee houses. For many people, WLAN services could be equivalent to 3G at about 1/13th the current cost.
Self-organizing Mesh is a new idea in WLAN arena Operate in peer-to-peer mode A message is routed to the nearest access point – the closest device – which routes it to the next nearest point, and so on. The unusual phenomenon is that the more users, the more capacity. This technology could strongly influence the future of wireless.
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Wireless Technology: the new vision
Wireless Local Loop: With the goal of replacing the wireline link. This “fixed wireless” solves “the last mile” problem. Use RF technology between a home or business and a telephone company’s central office. One approach is to place antennas on light posts to form a wireless mesh. Fixed wireless is being used in developing countries and remote locations in place of wire because these networks are more rapidly deployed and less costly that buying cables.
Some developing countries are bypassing wiring altogether.
Wireless PAN (Personal Area Network): A short distance network – about 30 feet (10 meters).The main technologies used are infrared and Bluetooth. This new kind of network could be used to synchronize laptop and a PDA, link several laptops in a rooms, etc.
M- Commerce: Conduct commerce digitally from wireless devices.
Location-based services and personalization are important part of wireless economy. Due to small antennas and low power, the handheld device can’t send signals to satellite for measuring location using GPS.
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Research Challenges
Wireless Resources
…………….Bandwidth in wired media
600 Mbps for 1 ATM line 600 Mbps for 1 ATM line
Bandwidth in wireless media384 Kbps for cell radius 10 km ( 2G / 2.4G) /
2 Mbps for cell radius < 100 m (Pico-cell, 3G)
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Most GSM Networks operate at 900 MHz and/or 1800MHz, 850 MHz and/or 1900MHz in Parts of Americas (including USA and Canada).
900 MHz Frequency Band
Uplink
Downlink
124 carriers
890MHz 915MHz 935MHz 960MHz
Downlink Uplink
124 carriersEach Carrier has 200KHz Frequency band
TDMA divides each RF channel (i.e., carrier) to 8 voice Channel
t1 t1 t2
t2 t3 t3 t4
t4 t5 t5 t6
t6 t7 t7 t8
t8
Time-slots
Time slot duration 577 µs
TDMA Frame: Each frame contains 8 time slots. Channel data rate: 270.833 kbps Frame duration: 4.615 mS
There are two types of logical channels: Traffic channels
Signaling Channels – for broadcasting, common control, and dedicated control.
Research ChallengesWireless Resources: GSM
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Research Challenges
Wireless Resources
When an active mobile moves from one cell to another (handoff call), then resources must be available at that cell to continue the call, otherwise the call will dropped.
From the users perspective,
“Dropping an ongoing call is more undesirable to the user than blocking a new call.”
Reserving resourcesReserving resources in neighbouring cells is the only in neighbouring cells is the only solution to this problem.solution to this problem.
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Research Challenges
Open Research Problem on Wireless Resources
Resources can be increased by using Smart Antenna.
Efficient use of bandwidth by exploiting mobility information.
Developing efficient resource allocation algorithms.
Efficient use of Radio frequency waves.
Exploration of new radio frequencies for communication.
The Cell Structure for K = 7
12
34
5
67
12
34
5
67
12
34
5
67
D
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Research Challenges
Is Wireless Secured?
In favor of Security Both wired and wireless use the IP protocol. Signals fade fast when they travel through the air. Eavesdroppers need
special equipment to pick up radio signals from far away. Data are encrypted before sending.
Not Secured Data inside the handheld device is not in encrypted format. Hackers may
successful in remote login and collect data. Data sent spread in air, open to all (how can we get 100% secured encryption
technique).
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Research Challenges
Is Wireless Safe ?
Microwave frequencies are more dangerous than radio-wave frequencies, because microwave cause molecule to vibrate faster, causing heat as the molecules rub against each other. The power limit on cell-phones, wireless modems, and WLANs (3 watts) aims to protect people from this short-term microwave heating phenomenon. Some studies shows that long-term effects from low-level vibration do not raise body temperature, but damage to DNA, which may cause disease like cancer.
Electromagnetic radiation from power lines, electronic appliances, and computers can interfere with the body’s bio-electromagnetic fields, causing an imbalance. These imbalances leave people feeling drained, fatigued, and stressed out. Although our body can rebalance disruptions caused by occasional exposure to electromagnetic radiation, frequent exposure will lower body’s immunity and causes diseases.
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Research Challenges
Other Open Research Problems on Cellular Network
Development of Localization Algorithms
Handoff Management and Data Migration Policies
Device Registration and Call Delivery.
Security
Architecture for Providing Internet Services
Developing smart devices
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Research Challenges
Other Areas for Research
Development of Smart Devices: Developing smart-devices for reducing communications.
Wireless Ad-hoc Network: Designing Ad-hoc network along with tackling its IP addressing, routing and security problem.
Wireless Sensor Network: Designing Wireless sensor networks along with its data transferring, security and localization problem.
Wireless LAN and WAN: Development of Infrastructure, smart devices and reliable and secured policies for data communication.
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Conclusions
Mobile Multimedia Communication is the most emerging wireless
technology.
Wireless Networks are going to replacing its counterpart wired network
rapidly.
Introduction of Smart Devices and continuing development of algorithms
enable tremendous growth of mobile communications.
Wireless Network provides moderate level of security.
Capacity is the main limitation of Wireless networks.
Indeed !
Wireless and Optical Network will survive only in the next generation !
Indeed !
Wireless and Optical Network will survive only in the next generation !