Telecommunications and the Information Age ET108B LM#13. Wireless Broadband. Broadband Cellular Protocols Wi-Fi Wireless Fidelity WiMax Bluetooth

Transcription

1 Telecommunications and the Information Age ET108B LM#13 Wireless Broadband Broadband Cellular Protocols Wi-Fi Wireless Fidelity WiMax Bluetooth

2 Broadband Cellular Services Background First Cellular Broadband Standard Called 2G and started in the late 1990 s Two Leading Protocols CDMA and GSM CDMA Mostly in North and South America and Japan Code Division Multiple Access GSM Mostly in Europe, Asia, and Africa Significant market share also in US Code Division Multiple Access

3 Broadband Cellular Services Background First Cellular Broadband Standard Supported Services Simple data applications:» messaging» Web browsing Bandwidths Less than 20 kbps Reference Motorola Whitepaper:» mputers/handheld%20computers/_documents/staticfile/3g_whitepa per_0608.pdf

4 Broadband Cellular Services Background 3G Broadband Higher Speeds Minimum for fixed locations 2Mbps Minimum for Urban Mobile 384kbps Services All 2G services MMS (Multimedia Message Service) Web browsing Real-time location-based services such as directions Basic multimedia, including support for short audio and video clips, games and images

5 Broadband Cellular Services Background 3G Broadband Protocols defined per ITU s International Mobile Telecommunications-2000 standard Table 24-1 on page 669 Two most widely used ones» Universal Mobile Telecommunications System (UMTS)» CDMA2000 Universal Mobile Telecommunications System aka, UMTS Characteristics Often called 3GSM

6 Broadband Cellular Services UMTS Characteristics Often called 3GSM or WCDMA Uses Wideband Code Division Multiple Access (WCDMA) and the GSM voice network UMTS protocols under 3.5G (the next proposed standard) promises speed of up to 14Mbps Channels Up stream or Uplink 5Mhz channel in the 1900 MHz band Down stream or Downlink 5Mhz channel in the 2100 MHz band

7 Broadband Cellular Services UMTS Network Structure Segmented into two domains User Equipment Infrastructure User Equipment Subdivisions» Universal Subscriber Identity Module (USIM)» Mobile Equipment Domain Infrastructure Subdivisions» Network» Core Network See Figure 24-2 on page 670

8 Broadband Cellular Services UMTS Network Structure Cell Sizes Range» Macro, micro, pico, umbrella Macro» Antennas on towers and project out over buildings» Antennas on towers and project out over buildings» 6-12 miles in diameter Micro» Covers smaller areas and are usually below rooftops Pico» Usually found inside of buildings Umbrella» Used to fill gaps between other cells

9 Broadband Cellular Services CDMA200 Characteristics Most often deployed by companies that have had a 2G cdmaone /IS95 network Qualcomm s 2G system Transition to CDMA200 is an upgrade not a totally new network Handles packet data protocols such as IP Uses frequency hopping for transmissions Minimizes effect of interference Hops across the 450 MHz, 800MHz, 1700 MHz, and 2100 MHz bands Network Structure See Figure 24-3 on page 672

10 Broadband Cellular Services CDMA200 Network Structure Key Segments Mobile Phone Access» Phone» Base Transceiver Station (BTS) Access Network Access Network» Base Station Controller (BSC)» Traffic is aggregated Metro Network Core Network» MTSO which is sometimes called MSC» Connections to PSTN and data networks

11 Characteristics Wi-Fi Wi-Fi is actually a trademark owned by the Wi-Fi Alliance Devoted to spreading the use of Wi-Fi technologies Falls under IEEE standard Wireless Ethernet Wireless Ethernet Originally called WLAN Wi-Fi Network Hot Spots Area served by one or more WLAN access point Can be as small of a Home or the seating area of a Starbucks Can be as large as the terminal area of a major airport» Uses multiple networked access points with auto handoffs

12 Wi-Fi Network Hot Spots Wi-Fi Per minute charges in commercially owned public areas are common. Such as: Starbucks McDonald s And many Airports Access point transceiver range Factors effecting Range Depends upon signal strength and antenna characteristics Depends upon obstructions Distances per standard 100 meters (approx 330 ft)

13 Wi-Fi Network Wi-Fi Access point transceiver range Actual distances ft indoors As high as 2000 feet outside with minimal interference and no physical obstructions Network Components Wi-Fi Network Interface Many times it is built into the computer» May be replace by better PCMCIA based Wi-Fi NIC Accessory cards for Desk-top computers PCMCIA cards for Lap-tops USB based Wi-Fi NICs

14 Wi-Fi Wi-Fi Network Network Components Wi-Fi Network Access Points Part of a SHO router along with switch pots Wi-Fi Protocol is actually a series of standards is actually a series of standards See Table 24-2 on page 675 Notes: Frequency Spectrum for g listed as 5 GHz, it should be 2.4GHz. last line referenced r should be n Max Bandwidth should read 600Mbps Error all current standards use CSMA/CA not CSMA/CD

15 Wi-Fi Security Three methods Wi-Fi Wired Equivalent Privacy (WEP) Wi-Fi Protected Access (WPA) Wi-Fi Protected Access 2 (WPA2) MAC filtering WEP Weakest method Only good to stop casual access by typical users WAP Minimum security level that should be implemented Must implement encryption

16 Wi-Fi Security WAP2 Use if available MAC filtering Wi-Fi Provides additional security Not sufficient security but helps the others Should be implemented if possible Not for public networks

17 Characteristics WiMax IEEE Standard for Worldwide Interoperability for Microwave Access Sometimes Called Wireless Metropolitan Area Network WiMax Network Key Factors Line of Site (LOS) or Near LOS networks Max of 31 miles Frequency LOS 2 11 GHz under a NLOS 5 to 6 MHz under a GHz under

18 WiMax Protocols WiMax Data Link access method uses a scheduling method WiMax Multiplexing Schemes Uses Orthogonal Frequency Division Multiplexing Uses Orthogonal Frequency Division Multiplexing (OFDM)

19 Bluetoothx Electronics industry standard Developed to link devices such as: PC s and Keyboards Cellular phones and headsets Etc Uses 2.45 GHz radio frequencies Uses Spread Spectrum Hops over 79 frequencies Range: 30 ft or approx 10 meters Networks are also called Personal Networks or pico networks Bandwidth 1 Mbps with 700kbps through-put