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Overview of Wireless Networks

Overview of Wireless Networks. Speaker: Jerry Gao Ph.D. San Jose State University email: jerrygao@email.sjsu.edu URL: http://www.engr.sjsu.edu/gaojerry. Topic: Overview of Wireless Network. Presentation Outline.

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Overview of Wireless Networks

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  1. Overview of Wireless Networks Speaker: Jerry Gao Ph.D.San Jose State Universityemail: jerrygao@email.sjsu.eduURL: http://www.engr.sjsu.edu/gaojerry

  2. Topic: Overview of Wireless Network Presentation Outline - Overview of wireless networking- WANs (Wide Area Network)- Wireless LANs - PAN (Personal Area Network)- Challenges and Limitations Jerry Gao Ph.D.8/02 All Rights Reserved

  3. LAN 100 meters WAN 2500 meters PAN 10 meters Power Topic: Overview of Wireless Network Classifications of Wireless Networks Types of wireless networks: - Wireless analog network - based on analog circuit-built connections - Wireless digital network - based on package-switched connectionsThree types of Wireless Internet Networks: - Wide Area Network (WAN) - Wireless Local Area Network (Wireless LAN) - PAN (Personal Area Network), such as Bluetooth, InfraredOther classifications: - large, public, cellular phone networks - private in-building wireless networks - room-wide networks Jerry Gao Ph.D.8/02 All Rights Reserved

  4. Topic: Overview of Wireless Network Landscape of Wireless Networks Jerry Gao Ph.D.8/02 All Rights Reserved

  5. Topic: Overview of Wireless Network Overview of Wireless Networks Major components and elements of a wireless network: (a) Different range of wireless towers - Cellular towers - Basestations - Access points (APs) - These antennaed transceivers communicate with all types of wireless devices, exchange data or voice with them. - They transmit that information through relays and cables eventually back to the wires of the Internet. (b) Different types of wireless devices - based on radios Jerry Gao Ph.D.8/02 All Rights Reserved

  6. Topic: Overview of Wireless Network Revisit of The OSI Seven-Layer Model Request 7. Application 7. Application Response 6.Presentation Peer to Peer 6.Presentation 5. Session 5. Session Gateway 4. Transport 4. Transport Router 3. Network 3. Network Bridge 2. Data Link 2. Data Link Relay 1. Physical 1. Physical Jerry Gao Ph.D.8/02 All Rights Reserved

  7. Topic: Overview of Wireless Network Wireless OSI Layers OSI Layer Internet i-mode WAP Application IE browser Net Front browser UP browser Presentation HTML cHTML WML Session HTTP/HTTPS HTTP/HTTPS WSP Transport TCP/UDP TCP/UDP WTP/WTLS/WDP Network IP IP IP Data link ATM PDC-P PPP Physical SONET RF (i.e. WCDMA) RF (i.e. CDMA) Jerry Gao Ph.D.8/02 All Rights Reserved

  8. Topic: Overview of Wireless Network Circuit-Switched and Packet-Switched Networks There are two network architectures for communicating devices:A) the telco-favored circuit-switched network connecting voice phonesB) the computer industry favored packet-switched network connecting digital computersA circuit-switched network: - builds up a circuit for a call, establishes a dedicated two-way connection of circuits between points. - a circuit connection forms a single path between the caller and listener that last the entire call time. - this circuit is guaranteed regardless of whether you are talking, sending data, or are silent.A packet-switched network: - route IP-address data packets between points on demand. - packets are routed through multiple paths. - packets are efficient at sending data immediately and are used in i-mode and paging network - Almost every industrial wireless applications uses a packet-based LAN. Jerry Gao Ph.D.8/02 All Rights Reserved

  9. Topic: Overview of Wireless Network Overview of Wireless Networks Package-switched data Internet Telco Switch Basestation Telephone Network Circuit-switched voice and data Web Phone Jerry Gao Ph.D.8/02 All Rights Reserved

  10. Topic: Overview of Wireless Network Telco and Internet Networks Internet network: It is known as a global network, which is a collection of host computers that can communication directly.Telcos: It define the telco network as a series of interconnections. In all cases, these global networks connect to terminals. Each of industry network has its own wireless air interface and protocols for data and voice.Example: If you use a web phone or make a phone call in the U.S., you access the Public Switched Telephone Network (PSTN). If you access the Post Telephone and Telegraph (PTT). Each is a combination of local, long-distance and international phone networks.Circuit-switched and package-switched networks use a telco switch to send voice calls through the telephone network, and data transactions to the Internet.When you use a pure digital system ,such as Cellular Digital Packet Data (CDPD) modem, then you are accessing the wireless Internet without switching.However, next generation wireless network is moving from a telco-defined, circuit-switched system to an entirely Internet-defined, packet-switched protocol system Jerry Gao Ph.D.8/02 All Rights Reserved

  11. Topic: Overview of Wireless Network Phone Number and IP Addresses Major components and elements of a wireless network: (a) Different range of wireless towers - Cellular towers - Basestations - Access points (APs) - These antennaed transceivers communicate with all types of wireless devices, exchange data or voice with them. - They transmit that information through relays and cables eventually back to the wires of the Internet. (b) Different types of wireless devices - based on radios Jerry Gao Ph.D.8/02 All Rights Reserved

  12. Topic: Overview of Wireless Network Wide Area Networks (WAN) What is WAN? (Citywide Towers Serve Nationwide Networks)WAN: Radio frequency Communication Speed Range 500-1900 Mhz 9600 kbps 2500 metersWAN is one of the most powerful wide area network, which is licensed public wireless network used by Web cell phones and private radio frequency (RF) digital modems in handhelds.- In a WAN, cell phones and handhelds with radio modems have antennas that talk with towers: - macrocell (called supercells), microcell, and picocell.- The cellular WAN tower often called a Base Transceiver Station (BTS). These are different from TV and broadcast systems. Broadcast and microwave towers Cellular towers Power a lot very low powerRange hundreds of miles no more than one mile Comm. one way broadcast two way signalingfrequency of the electromagnetic spectrum. Jerry Gao Ph.D.8/02 All Rights Reserved

  13. Topic: Overview of Wireless Network Wide Area Networks (WAN) Cellular Towers:- The cellular WAN tower often called a Base Transceiver Station (BTS). These are different from TV and broadcast systems. Broadcast and microwave towers Cellular towers Power a lot very low powerRange hundreds of miles no more than one mile Comm. one way broadcast two way signalingFrequency a specific frequency a specific frequency- To minimize cost, the cellular towers are clustered and wired back to Basestation Controllers (BSC), which convert the wireless call to a telephone call.- The entire grid of towers and controllers links back to a telephone exchange called a Mobile Switching Center (MSC), also known as a Mobile Telephone Switching Office (MTSO). The MSC switch calls, and tracks and bills users. Jerry Gao Ph.D.8/02 All Rights Reserved

  14. Cellular handoff Cellular tower grids Topic: Overview of Wireless Network Wild Area Networks (WAN) Cell phones and handhelds as Radios: They work as two-way radios.The cellular Web phone operates over a moderately powerful licensed and regulated frequency to exchange voice and data with a cell tower.The typical range: city: 500 – 1000 meters rural cells: up to 25000 meters Jerry Gao Ph.D.8/02 All Rights Reserved

  15. Topic: Overview of Wireless Network Three Generations of WAN Air Interfaces 1 G FDMA Frequency Division Multiple Access 1980s - each caller has a dedicated frequency channel: three callers use three channels 2 G TDMA and GSM Time Division Multiple Access (TDMA) Group Speciale Mobile (GSM) 1990s - callers timeshare frequency channel: nine callers use three channels 3 G CDMA and WCDMA Code Division Multiple Access (CDMA) Wide Code Division Multiple Access (WCDMA) 1990s - callers use a shorter bandwidth 2000s - “spread spectrum” each call is spread, randomly broken down, and mixed. 14 callers use the full bandwidth of one channel. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Jerry Gao Ph.D.8/02 All Rights Reserved

  16. Topic: Overview of Wireless Network Network Evolution: 1G, 2G, and 3G Network evolution:1G (voice-only) analog network|2G digital network|3G high-speed data and voice network with many grand features • Each generation can handle more subscribers,generates more revenue.-One generation does not wipe out the previous, rather a 2G tower operates next to a 1G tower. Jerry Gao Ph.D.8/02 All Rights Reserved

  17. Topic: Overview of Wireless Network 1G Networks History of 1G networks:First generation analog cellular networks were built strictly for voice calls in the early 1980s.All 1G networks are based on Frequency Division Multiple Access (FDMA), an air interface that guarantees a dedicated frequency and circuit to each caller.The Japanese began national service in 1979. The U.S. service, Advanced Mobile Phone Service (AMPS), operates at 800 MHz.Each country has its own 1G air interface protocol.Major features: - Circuit-switched network - Analog signals - Voice only - AMPS in U.S. Jerry Gao Ph.D.8/02 All Rights Reserved

  18. Topic: Overview of Wireless Network 2G Networks What is a 2G network? - The 2G networks have digital cellular air interfaces. - They were all brought to market in the early 1990s. - The 2G network includes data services, fax, and email. Almost every wireless device sold in 2002 uses one of the second-generation air interfaces, i.e. TDMA, CDMA, PDC, or GSM)Major features: - Circuit-switched network - Digital signals - Voice or data overlay - 9 kbps or 19 kbps - Dial-up service Jerry Gao Ph.D.8/02 All Rights Reserved

  19. Topic: Overview of Wireless Network 3G Networks Purpose: 3G networks are designed to support digital packet cellular.What is 3G network? - 3G is the wireless Internet transmitting voice, data, photos, audio, and video – all bits running on a wireless packet-based cellular network.Major features: - Packet switched - TDynamic allocation of voice or data - Transport roaming - Quality sound and video - Data transmission at 2 Mbps - Identification of caller location - W-CDMA, CDMA 2000, TDD, UWC, FDD air interfaces - It is always on.Transparent roaming – the ability to continue a data or voice call over multiple networks without dropping the call. Jerry Gao Ph.D.8/02 All Rights Reserved

  20. Topic: Overview of Wireless Network LANs: Blockwide Basestations Reach Business and Home What is Wireless LAN Network?- Wireless LAN (WLAN) refers to the wireless local area network, which has a range of 100 meters. Since wired and wireless LAN protocols are interchangeable from an application viewpoint, it is simple to say LAN.- In a WLAN, LAN devices talk to a basestation, which is mounted in buildings. They include: - computers and laptops with wireless cards - handhelds and experimental cell phones- The LAN network is packet based and fully supports handhelds that can work standalone and offline.A WLAN operates on unlicensed spectrum.WLAN or LAN: 2.4. GHZ, 11 Mbps, and 100 meters.The major advantage: greater wireless data bandwidth Because WAN cell phone data trickles in at kilobits per second, while WLAN data is measured in megabits per second. Jerry Gao Ph.D.8/02 All Rights Reserved

  21. Topic: Overview of Wireless Network LANs: Blockwide Basestations Reach Business and Home Applications of Wireless LAN Network: - Provide businesses a private Wireless Network to connect computers, laptops, and wireless handhelds. - Provide wireless business applications in different areas: retailing, transportation, distribution, manufacturing, parcel and post delivery, government, health care, and education.WLAN Standards:- The most popular industrial WLAN standard is wireless Ethernet, IEEE 802.11b.- This standard is extremely compatible among vendors.- A typical basestation operates at 11 Mbps and share 255 devices. However, the individual handheld generally does not get more than 3 Mbps.- WECA (the Wireless Ethernet Capability Alliance) is helping sponsor IEEE 802.11g, a Higher Data Rate wireless Ethernet that is expected to boost speed to 22 Mbps. Jerry Gao Ph.D.8/02 All Rights Reserved

  22. Topic: Overview of Wireless Network Home Networks: HAN and SOHO Two marketing terms, Home Area Network (HAN) and Small Office Home Office (SOHO), designate any wireless LAN that has been priced and designed to work with standard office equipment.HANs and SOHOs connect home/office computers, printers, telephones, laptops,….HomeRF (Home Radio Frequency) is the popular wireless network forum led by computer and consumer electronic companies.- Key standard - the Shared Wireless Access Protocol (SWAP) specifies both voice and data.- HomeRF also operates at 2.4 GHZ and transmits data at 1 to 2 Mbps.- HomeRF has a 50-meter range and can connect up to 10 devices, including computers, telephone, home theater, and DVD.- In Sept. 2000, the FCC cleared channels for the operation of HomeRF at 10 Mbps. Jerry Gao Ph.D.8/02 All Rights Reserved

  23. Topic: Overview of Wireless Network Next Generation Wireless LAN Applications of Wireless LAN Network: - Provide businesses a private Wireless Network to connect computers, laptops, and wireless handhelds. - Provide wireless business applications in different areas: retailing, transportation, distribution, manufacturing, parcel and post delivery, government, health care, and education.WLAN Standards:- The most popular industrial WLAN standard is wireless Ethernet, IEEE 802.11b.- This standard is extremely compatible among vendors.- A typical basestation operates at 11 Mbps and share 255 devices. However, the individual handheld generally does not get more than 3 Mbps.- WECA (the Wireless Ethernet Capability Alliance) is helping sponsor IEEE 802.11g, a Higher Data Rate wireless Ethernet that is expected to boost speed to 22 Mbps. Jerry Gao Ph.D.8/02 All Rights Reserved

  24. Topic: Overview of Wireless Network PANs: Roomwide Transmitters Coordinate Nearby Devices What is PAN? (2.4 GHZ, 700 Kbps, and 10 meters)- Personnal Area Network (PAN) is at the bottom of the wireless power range, where transmitters reach about 10 meters, the width of an average room.- A PAN network operates with nearby devices to exchange data and voice, sometime automatically.- Unlike the WANs or LANs, PAN requires no tower to operate.- Wireless synchronization of voice and data is requirement of modern PAN systems. Jerry Gao Ph.D.8/02 All Rights Reserved

  25. Topic: Overview of Wireless Network PANs: Roomwide Transmitters Coordinate Nearby Devices Objective: - PAN systems are designed to link local devices without using a wire or having to plug in anything. - A PAN system creates and builds on peer-to-peer transfer of information without cables.PAN Applications Examples: - Remote control of devices and information exchanges. - A PAN web phone transparently passes voice or email between handhelds and laptops. - A radio pen (by the Swedish company Anoto with 3M) that transmits, as it is being written, text or graphics to a nearby transmitter.Other interesting PAN devices: - sensors, scanners, printers, monitors, magnetic cards readers - wireless cameras, wireless GPS antennas Jerry Gao Ph.D.8/02 All Rights Reserved

  26. Topic: Overview of Wireless Network Bluetooth Network What is a Bluetooth network?The BluetoothTM2 network is a low-power, personal, wireless voice and data network that has a range of 10 meters.Bluetooth wierless technology is positioned to displace infrared data and is a good mechanism to synchronize devices, transfer files, and replace data cables.- The Bluetooth name and trademarks are owned by Bluetooth SIG, Inc., U.S.A.- A Bluetooth network, called a piconet, can connect up to 8 Bluethooth devices.- Major features: - automatic synchronization, passthrough of a data/ voice stream for all devices. - a fast-hopping, spread-spectrum radio that operates with 1 milliwatt of power. Bluetooth Special Interest Group (SIG) is a consortium that includes the funding members IBM, Ericsson, Nokia, Intel, and Toshiba.Now it has grown to include 2000 other companies, including Mcirosoftware Corp.. Palm, Inc, and other phone and computer vendors Jerry Gao Ph.D.8/02 All Rights Reserved

  27. Topic: Overview of Wireless Network Bluetooth Network Bluetooth Network Standard --> IEEE 802.15IEEE 902.15 is the IEEE version of the Bluetooth specification. It serves two purposes:- specify a version of the Bluetooth network complementary to 802.11 wireless Ethernet.- amplify the Bluetooth ability to transmit 20 Mbps. (driven by Eastman Kodak Company, which required a wireless format to support downloading photes from a digital camera).A Bluetooth PAN is convenient for passing conventional voice and small data streams.The Bluetooth device forecast in 2001 is a $950 million market.According to Gartner Research in 2000: By 2003, one billion Bluetooth devices are expected to create a $4.5 billion market. Jerry Gao Ph.D.8/02 All Rights Reserved

  28. Topic: Overview of Wireless Network Wireless 2.4 GHz Protocols IEEE 802.11b HomeRF Bluethooth Speed 11 Mbps 1,2, 10 Mbps 30 to 700 kbps Use Office or campus LAN Home, office, house Personal Area Network Range 100 meters 50 meters 10 meters Frequency Direct sequence Wideband frequency Narrowband frequency sharing spread spectrum hopping hopping Backer Cisco, Lucent, 3Com Apple, Compaq, Dell Ericsson, Motorola,Intel, Apple, Intel, WECA Motorola, Proxim Nokia, Bluetooth Special HomeRF working interest group group URL: www.wirelessethernet.com www.homerf.org www.bluetooth.com Jerry Gao Ph.D.8/02 All Rights Reserved

  29. Generation Wireless Technology 1G AMPS advanced mobile phone system 2G TDMA time division multiple accessCDMA code division multiple accessGSM global system for mobile comm. 2.5G Enhanced TDMA, CDMA, GSM 3G Cdma2000 QualcomW-CDMA wideband CDMA Topic: Overview of Wireless Network Wireless Network Evolution Jerry Gao Ph.D.8/02 All Rights Reserved

  30. Technology Speed CDPD 19.2 Kbps Infrared IRDA 115 Kbps (1-4 Mbps extension) Bluetooth 723 Kbps 802.11b 11 Mbps 802.11a 54 Mbps Topic: Overview of Wireless Network Wireless Network Speed Comparison Jerry Gao Ph.D.8/02 All Rights Reserved

  31. Technology Function CDPD Short text bursts – stock quotes sports scores Infrared Device interconnect, data sync Bluetooth Device interconnect, voice 802.11b Lan replacement, multimedia 802.11a High Speed Lan replacement Topic: Overview of Wireless Network Wireless Network Uses Jerry Gao Ph.D.8/02 All Rights Reserved

  32. Topic: Overview of Wireless Network Challenges and Issues • Aggressive pricing – a by-product of increased competition – has reduced average airtime revenue per subscriber. • Second generation network technologies are short on bandwidth and QoS (quality of service) assurances. • Wireless network coverage is not as robust in the US as elsewhere, many US users may become frustrated trying to access the Web when they need information. • Up-front costs of wireless networking, both at the service provider and corporate levels, are steep. Jerry Gao Ph.D.8/02 All Rights Reserved

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