Microsoft PowerPoint - WM-13.pptNetworking and Wireless LAN
Associate Prof. Yuh-Shyan Chen Dept. of Computer Science and Information
Engineering National Chung-Cheng University
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Major Activities of Future Wireless and Mobile Communication Systems Toward the Wireless World
World Radio Conference (WRC’03) Discuss and to identify new spectrum for future systems ITU- R WP8F
• International Telecommuication Union – Radio Sector, Working Party 8F
ITU- T SSG • ITU – Telecommunication Sector, Special Study Group
Japan TTC (Telecommuication Technology Council)
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Cont.
Japanese mITF (Mobile IT Forum), 2001 Realize an early implementation of Future Mobile Communication Systems Including systems beyond IMT-2000 and mobile commerce
Research on future generation mobile systems in Europe in influenced by the EU IST program
was launched in the area beyond 3G cellular systems, wireless regional area network (WxAN) and high altitude communication platform systems (HAPS) to establish a universal radio experiment environment
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Cont.
Korea started similar activities under 4G committee to develop mobile communication technologies and services beyond IMT-2000
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Review of European Research Framework Programs
Third generation mobile radio systems are currently being deployed globally Manufactures, network operators, service and content providers are now focused on new services and applications as well as suitable business models to make 3G as economic success
The development of 3G systems started in Europe around 1988/89 nearly two years ahead of the first development of GSM
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History of Framework Programs The European Commission is partly funding since 1987 research activities in the first International Framework Program A first vision of third generation mobile radio systems was developed around 1990 in the 2nd Framework Program RACE I (Research of Advanced Communication Conference)
Preliminary estimations on the frequency spectrum demand
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The 4th Framework Program ACTS (Advanced Communication Technologies & Services), 1995
Several projects towards mobile radio systems with significant impacts on the international standardization of IMT-2000/UMTS
The 5th Framework Program IST (Information Society Technologies), 1999
Theme “Creating a User Friendly Information Society”
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Major areas of research Heterogeneous networks Convergence of mobile and broadcasting Wireless IP (IPv6) Reconfigurability of terminals and networks Broadband fixed wireless access High speed wireless local area networks Satellite personal mobile communications Satellite interactive broadband Ultra wide band Application projects (2.5G service, interoperability issues)
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The 6th Framework Program (Information Society Technologies, IST), 2002~2003
Theme “Integrating and Strengthening the European Research Area”
IST WSI Project, http://www.ist-wsi.org
Wireless World Research Forum (WWRF) and International activities towards system beyond 3G
The vision of the Wireless World is developed • From the user perspective • A high degree of international harmonization • Global cooperation will be an important prerequisite to achieve
harmonized future standards The 6th Framework Program of the European Commission (Oct. 17, 2003) will provide an important platform for international cooperation
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Wireless World Research Forum (WWRF)
Wireless World Research Forum (WWRF) was started based on the activities in the EU IST project
WWRF (http://www.wireless-world-research.org)
Objectives of WWRF
To contribute to the vision of the Wireless World To develop and maintain a consistent vision of the Wireless World To generate, identify and promote research areas and technical and society trends for mobile and wireless system towards a Wireless World To identify and assess the potential of new technologies and trends for the Wireless World To contribute to the definition of international and national research programs To inform a wider audience about research activities that are focused on the Wireless World
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The MultiSphere Level Concept
1. The PAN 2. The Immediate Environment 3. Instant Partners 4. Radio Access 5. Interconnectivity 6. CyberWorld
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Wireless World
Software Defined Radio
Nine Potential Building Blocks
1. Augmented Reality/Cyber World 2. Semantic Aware Services 3. Peer Discovery 4. End-to-End Security and Privacy 5. Co-Operative Networks and Terminals 6. Heterogeneous Ad-Hoc Networking 7. 4G Radio Interfaces 8. Smart Antennas and Base Stations 9. Software Defined Radio
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Heterogeneous Ad-Hoc Networking
The communication network of the Wireless World will include ad-hoc elements To collaborate to construct network islands of increased direct communication needs
Such configurations are supposed to appear at hotspots such as airports or shopping malls
Ad hoc communication links can be used to ensure access to the Wireless World for remote mobile stations without direct link to the Wireless World
Such a link can also comprise heterogeneous communication means to achieve global connectivity for terminal supporting only short-range communication
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http://www.elsevier.com/locate/issn/15708705
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International Requirements from ITU-R as Targets for Research and Investigation
ITU-R approved in the 8th meeting in Geneva in Oct. 2002
A draft recommendation on “Vision framework and overall objectives of the future development of IMT-2000 and of systems beyond IMT-2000”
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Wireless and Mobile Applications
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4G System
PIC
WINS NG 2.0 Sensoria, 2001 Node development platform; multi- sensor, dual radio, Linux on SH4, Preprocessor, GPS
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Sensing
Computation
Networking
New technologies have reduced the cost, size and power of micro- sensors and wireless interfaces
Systems can Embedded into environment Sense phenomena at close range
Systems will revolutionize Environmental monitoring Disaster scenarios Structure Response
Environmental Monitoring
Circulatory Net
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When You Are Mobile Today Desperately looking for a computer to check your e-mails Need to access Internet, or other information Contacting other people using pay phone, cellular phone, airphone, BB call Someone may be paging you, faxing you, … Using a laptop to do work while traveling
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Who Needs Wireless Communications Law Makers in the Congress One who needs to work with customers face-to-face
doctor/nurse clerk/salespersons adv.: paperless, less error-prone
Retail: order, pricing, sell, inventory Warehousing:
the most paper-intensive industry can incorporate with barcodes
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Health Care: personal health history blood-drawing request X-ray taking request
Hospitality: , ,
Vending Machines: need to check stocks …
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Advantages
Easy to Install: hard-to-networking environment: river, highway, historic cites fast installation: festival, assembly, Q-&-A in congress reliability: (wired cables might be cut, get rusty, …) in a company: re-organization, change office, etc.
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Vision: Ubiquitous Computing / Nomadic Computing
computers everywhere; information anywhere anytime
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Features of Wireless Communication
One global bandwidth shared by all users fortunately channels, such as (frequency, time-slot) pairs, can be reused
Radio-based low bandwidth high latency radio communication links higher bit error rate (BER)
Fading short-term multipath fading (Rayleigh effect)
due to same signal taking different paths and arriving at the receiver shifted in phase
long-term fading (radio shadow) topology of the terrain (like mountains) can cause signal dropouts solution: deploying multiple antenna sites
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Limited resources: limited energy (battery life) limited CPU speed limited memory
Less reliable, less secure
Cellular-based Ad hoc Relaying link Wireless ATM Packet Radio Network
*** (refer to the earlier figures...)
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Wireless information services: Pico-service: local parking lot availability, layout of a building Micro-service: train and bus station information, local traffic information Macro-service: weather information, local news service Wide Area Service: stock market information
Real-time multimedia applications tele-medicine tele-computing collaborative environments
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New Dimensions in Mobile Computing
wide variations of available resources heterogeneity how to adapt to changes in the environment multiple administrative domains scalability
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Power saving display, LCD low-voltage CPUs
AT&T's Hobbit chip: 5,000 times less power consumption in doze mode than active mode
radio: IEEE 802.11 power consumption example:
• transmit: 1400 mW • receive: 1000 mW • idle: 830 mW • sleep: 130 mW
Size, user interface (wearable computers)
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Mobile communication protocols WAP wireless TCP Mobile IP MAC protocols
Energy-efficient protocol related to the above send/receive/idle/sleep model
... and many others
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context includes user's location environment (e.g., noise level, communication b/w, communication cost etc.) social situation (e.g., with boss, with co-worker etc.)
context-aware applications context-sensitive information access (e.g. where are the bookstores in the vicinity) context-sensitive commands: in active badge system
• command format: <badge> <location> <event-type> <action>
• Ex: Coffee Kitchen arriving “play -v 50 ~/sound/rooster.au”
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History of Wireless Networks
Progress of transmission: fire and smoke used by Indians ==> messenger on horseback ==> telephone line ==> networks
Traditional networks (LAN, MAN, WAN) have provided great convenience:
in office, hotel room, or home. But you cannot utilize the service unless you are physically connected to a LAN or a telephone line.
ALOHANET by Univ. of Hawaii: 7 campuses over 4 islands; star-like structure centered at the Oahu island.
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Progress of Wireless Comm. (cont.)
In 80’s, amateur radio hobbyists built TNC (terminal node controller) to interface “hams” radio equipment and their computers.
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Progress of Wireless Comm. (cont.)
In 1985, FCC authorized the use of ISM bands for Industrial, Scientific, and Medical for commercial development. ISM bands = 902MHz and 5.85 GHz ISM is very attractive to vendors because NO obtaining FCC license is required. In 80’s, small-size computers started to appear.
laptop, palmtop, PDA Wireless LAN products populate
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Standardization and Promotion
wireless LAN: IEEE 802.11 standard was finalized in July 1997. IEEE 802.11a, b, e, g
wireless WAN: RAM, etc.
Personal Communication Service (PCS): 1.9 GHz sold $7.7 billion to TV company in 1995 by VP Al Gore. $15 billion in 1996.
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Toshiba Gets into WLAN Chips
San Jose, CA-based Toshiba America Electronic Components (TAEC), a company owned by Toshiba America, this week announced a new 5GHz chip set for high-speed 802.11a-based wireless networks.
The first of the two chips is the TC35672, a baseband large scale integration processor with dedicated circuit for processing data at 54Mbps, with 10-bit analog-to-digital and digital-to-analog converters that operate at 40MHz. The chip uses the proprietary Toshiba TX39 core and power management to reduce power consumption. The other chip, the TA32151, is an intermediate frequency (IF) integrated circuit (IC) that interfaces directly with the baseband. This IC will take signals from a radio frequency RF chip (not included as part of this set) and executes orthogonal modulation and demodulation to transmit signals to the baseband.
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Intel Inside
TI isn't alone in its enthusiasm over embedded wireless networking. Intel will begin manufacturing its own dual-band 802.11a/802.11b chipset this fall, for laptops and desktops, according to Russ Craig, an analyst tracking the semiconductor industry for the Aberdeen Group.
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802.11a: Wait until next year! By Steven J. Vaughan-Nichols
No one doubts that 802.11a, with its top data throughput rate of 54Mbps
with up to 72Mbps or 108Mbps possible if you use one of a variety of proprietary and non- standard double-speed mode beats the pants off 802.11b, which only has 11Mbps on a good day with the wind blowing the right way. 802.11a averaged four times faster than 802.11b
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5GHz frequency 802.11a avoids the interference slow- downs that b must suffer with microwave ovens, high-end wireless phones, and other 802.11b networks
If speed was everything, 802.11a cards and access points should be flying off store shelves right? Wrong. Speed isn't everything
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802.11a, although it's been on the market since late 2001, has had trouble finding buyers. Cost has been an important factor.
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Ad hoc applications provide truly wireless solutions
Ad hoc mode allows users to spontaneously form a wireless LAN.
For example, a group of people with 802.11-equipped laptops may gather for a business meeting at their corporate headquarters. In order to share documents such as presentation charts and spreadsheets, they could easily switch their NICs to ad hoc mode to form a small wireless LAN within their meeting room. Another example is when you and your associates are waiting for a flight at the airport, and you need to share a relatively large PDF file. Through ad hoc mode, you can easily transfer the file from one laptop to another. With any of these applications, there's no need to install an access point and run cables.
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The ad hoc form of communications is especially useful in public-safety and search-and-rescue applications. Medical teams require fast, effective communications when they rush to a disaster to treat victims. They can't afford the time to run cabling and install networking hardware. The medical team can utilize 802.11 radio NICs in their laptops and PDAs and enable broadband wireless data communications as soon as they arrive on the scene.
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Some product vendors are beginning to base their solutions on ad hoc mode. As an example, MeshNetworks offers a wireless broadband network system based on 802.11 ad hoc mode and a patented peer-to-peer routing technology.
http://www.meshnetworks.com/
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MeshNetworks and ViewSonic Collaborate to Integrate Mobile Broadband Networking Technology with Mobile Computing Devices Companies’ Initiatives Poised To Bring Customers Improved Information Access
“MeshNetworks shares ViewSonic’s vision that consumers will demand a fully connected mobile computing platform that offers high-speed data and Internet access,” said Masood Garahi, Chairman and CEO of MeshNetworks.
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Wireless Network ArchitectureWireless Network Architecture General functions of networks:
bit pipe of data MAC for sharing of a common medium synchronization and error control routing
OSI reference model: Fig. 1.2 wireless LAN/MAN/WAN layers: Fig. 1.3
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Functionality: modulation: translate baseband signal to a suitable analog form amplification: raise signal strength synchronization: carrier sense (Fig. 1.6) error checking:
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Antenna Concept
propagation pattern: radiation power: typically less than a few watts gain: degree of amplification
omni-directional = 1 directional > 1 (good for longer distance) example: watering your lawn
direction: omnidirectional or directional
Communication Channel
Air Pure nitrogen and oxygen are effective for transmission. rain, fog, snow are obstacles.
Space
Water
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Mobility: Example: talking on a cordless phone vs. cord phone.
Installation in Difficult-to-Wire Areas: rivers, freeways, old building Hazard materials (such as asbestos particles) when drilling. Right-of-way restrictions in some city to dig ground.
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Benefits of Wireless Networks (cont.)
Reduced Installation Time: It may take months to receive right-of-way approvals.
Increased Reliability: cable vs. cable-less
Long-term savings: never need re-cabling
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Wireless Network Concerns (cont.)
Power Management Electricity in battery is a limited resource. modes control:
System Interoperability e.g., IEEE 802.11 standard
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Security Concerns Security Threats:
Radio waves can easily penetrate walls. One can passively retrieve your radio signal without being noticed (Fig. 1.10). Electronic sabotage: someone maliciously jam your wireless network
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Installation Issues Wireless coverage as a contour: Fig. 1.12 Intra-system interference:
e.g., between 802.11 access points
Inter-system interfernce:
e.g., from external Bluetooth, which is also on 2.4 GHz
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Health Risks So far, no conclusive answer yet!!
Radio is safer than cellular phones!! Wireless network is even safer as it operates at 50~100 milliwatts, compared to 600mw~3w of cellular phones.
US Detp. of Food and Drug classifies risks into 4 classes:
class I: wireless LAN, supermarket scanner class III: wireless MAN (could damage eyes if watching directly) class IV: laser scalpel
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Future of Wireless Networks The outlook is very good (Fig. 1.14).
curve of standardization curve of hardware costs