ITEC4620 Wireless and Mobile Communication Networks Vanit(18.30-21.00(Wed))

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ITEC4620Wireless and Mobile Communication
NetworksVanit(18.30-21.00(Wed))

• ??. ???????? ?????
• ?????????????????????????????
• MUT
• Email prawit_at_mut.ac.th
• ????????? F402
• ????????????????????? [phone] ??? 220
• ??????????????????????? 0865343850

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• ?????????????????? 30
• ?????????? 30
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• ?????????? 40
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• ??????????????????????????????????????????????????
  B (???????????? ?)

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???????

• O. Bertazioli, L. Favalli, GSM-GPRS 2a ed.,
  Hoepli Informatica, 2003
• T.S. Rappaport, Wireless Communications
  Principles and Practice, Prentice Hall, 1996
• M. Gast, 802.11 Wireless Networks the Definitive
  Guide, OReilly, 2005
• ??????????????????
• ????????????????????? (PowerPoint Slides)

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• ??????????????????????????? ? ?????????
• www.msit.mut.ac.th

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• ????????????????
• ?????????????????????????
• ????????????????

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????????????????????

• ?????????????????????????????????????????
• IEEE 802.11
• GSM
• CDMA
• GPRS
• Blue-Tooth
• 3G
• Wimax
• ??????????????????????????????????????????????

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?????????????????????????????

• ??????????????????????????????????????????????????
  ?? 1 (Layer 1) ??????????????????????????
• ??????????????????????????????????????????????????
  ?? 2 (Layer 2) ??????????????????????????
• ??????????????????????????????????????????????????
  ?? 3 (Layer 3) ??????????????????????????
• ??????????? Handover ????????????????????????? ?

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????????????

• ????????????????
• ?????????????????????????
• ????????????????

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????????????????

• Introduction to Wireless and Mobile
  Communication(1 lecture)
• ????????? IEEE 802.11(3 lectures)
• IEEE 802.11 Handoff(1 lecture)
• ????????? GSM(2 lectures)
• ????????? GPRSEDGE(1 lecture)
• Wimax (1 Lecture)
• Mobile IP(1 lecture)
• Network Mobility(1 lecture)
• Routing in Ad-hoc Wireless Networks(Optional)

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Trend in Wireless Communications
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?????????????????????
????????? - Ethernet - WLAN - GSM
- CDMA - 3G - PSTN - ATM -
Wi-Max - etc. ?????? -?????, ???, Text,
Email, etc.
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1G

• Early1980s
• Analog
• Circuit-switched Network
• Low voice quality
• No security (No encryption)
• Low capacity
• AMPS (Advanced Mobile Phone System 800-900MHz)
• NMT (Nordic Mobile Telephony )

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2G

• Late 1980s
• Digital encoding
• High bit rate voice
• Limited data communications (tens Kbps)
• GSM, D-AMPS (TDMA) and CDMA
• Auxiliary services (data, fax and SMS)
• Some levels of encryption

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2.5G

• Extend 2G systems (GSM)
• Packet-switched connection (GPRS)
• Higher data rate (up to hundred Kbps)
• Higher data rates (Mbps)
• More than voice...
• Support bandwidth-hungry applications

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3G

• Higher data rates (Mbps)
• Voice Video
• Full-motion video
• Video-conferencing
• Full Internet access (IP)
• UMTS
• IMT-2000
• W-CDMA
• Wimax

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4G

• An integrated wireless system that enables
  seamless roaming between technologies.
• ATT
• Combining W-OFDM and EDGE technologies
• Sun Microsystems
• The Government of Karnataka in India
• NTT DoCoMo of Japan and Hewlett-Packard Company

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WLAN
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WiMAX
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?????????????????????????????? IEEE 802.11
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Application Layer (L5, L6,L7)

• TCP/IP model
• Layer 5 -gt Application Layer
• OSI model
• Layer 7-gt Application Layer
• Layer 6 -gt Presentation Layer
• Layer 5 -gtSession Layer

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Application Layer

• The common application layer services provide
  semantic conversion between associated
  application processes
• Examples of common application services of
  general interest include the virtual file,
  virtual terminal, and job transfer and
  manipulation protocols, FTP, Mail, HTTP

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Layer 6 -gt Presentation Layer

• It responds to service requests from the
  application layer and issues service requests to
  the session layer.
• The presentation layer is responsible for the
  delivery and formatting of information to the
  application layer for further processing or
  display

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Layer 5 -gtSession Layer

• The Session layer provides the mechanism for
  managing the dialogue between end-user
  application processes
• It provides for either full duplex or half-duplex
  operation and establishes checkpointing,
  adjournment, termination, and restart procedures.

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Transport Layer (UDP/TCP (L4))

• The transport layer provides transparent transfer
  of data between hosts.
• It is usually responsible for end-to-end
  connection, error recovery, flow control, and
  ensuring complete data transfer
• Examples of Transport Layer
• UDP (User Datagram Protocol)
• TCP (Transmission Control Protocol)

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Network layer(IP(L3))

• The network layer is responsible for end to end
  (source to destination) packet delivery
• The network layer provides the functional and
  procedural means of transferring variable length
  data sequences from a source to a destination via
  one or more networks while maintaining the
  quality of service requested by the transport lay
  
• The Network layer performs network routing, flow
  control, network segmentation/desegmentation, and
  error control functions.

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Data link Layer(MACLLC(L2))

• This is the layer which transfers data between
  adjacent network nodes in a wide area network or
  between nodes on the same local area network
  segment
• The data link layer provides the functional and
  procedural means to transfer data between network
  entities and might provide the means to detect
  and possibly correct errors that may occur in the
  Physical layer
• Examples of data link protocols are Ethernet for
  local area networks and PPP, HDLC and ADCCP for
  point-to-point connections.

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Physical (L1)

• The bit stream may be grouped into code words or
  symbols, and converted to a physical signal,
  which is transmitted over a physical transmission
  medium.
• The physical layer provides an electrical,
  mechanical, and procedural interface to the
  transmission medium
• The physical layer determines the bit rate in
  bit/s, also known as channel capacity, digital
  bandwidth, maximum throughput or connection speed
  

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Physical Layer (cont.)

• Bit-by-bit node-to-node delivery
• Providing a standardized interface to physical
  transmission media, including
• Mechanical specification of electrical connectors
  and cables, for example maximum cable length
• Electrical specification of transmission line
  signal level and impedance
• Radio interface, including electromagnetic
  spectrum frequency allocation and specification
  of signal strength, analog bandwidth, etc.
• Specifications for IR over optical fiber or a
  wireless IR communication link
• Modulation
• Line coding
• Bit synchronization in synchronous serial
  communication
• Start-stop signalling and flow control in
  asynchronous serial communication
• Circuit mode multiplexing
• Carrier sense and collision detection utilized by
  some level 2 multiple access protocols
• Equalization filtering, training sequences, pulse
  shaping and other signal processing of physical
  signals
• The physical layer is also concerned with
• Point-to-point, multipoint or point-to-multipoint
  line configuration
• Physical network topology, for example bus, ring,
  mesh or star network
• Serial or parallel communication
• Simplex, half duplex or full duplex transmission
  mode
• Autonegotiation

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Characteristics of Wireless Networks

• Links
• Higher error rates
• Variable data rates
• Variable delay
• Devices
• Limited power
• Easy mobility

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Mobility

• Users can move great distances, at great speed,
  or both
• personal mobility vs. terminal mobility
• Move at high speeds while communicating
• cellular voice
• Travel large distances between communication
• Cellular
• messaging/paging
• Limited Mobility
• wireless LANs
• fixed wireless/wireless local loops

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Coverage Area

• Pico-cell O(10m)
• covers a room
• Micro-cell O(100m)
• covers a floor/street
• Macro-cell O(10 Kms.)
• big towers
• Satellites
• regions/countries

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Mobility Terminology

• Mobile Location
• finding a mobile to deliver a connection/packet
• usually requires finding the cell in which a user
  is located
• Mobile Tracking
• following the approximate location of a mobile as
  it moves while not in an active session
• usually involves some sort of registration
• Handoff (Handover)
• transferring/forwarding a connection as a user
  moves while in an active session

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Antenna

• An antenna is an electrical conductor or system
  of conductors
• Transmission - radiates electromagnetic energy
  into space
• Reception - collects electromagnetic energy from
  space
• In two-way communication, the same antenna can be
  used for transmission and reception

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Types of Anntenas

• Radiation Pattern
• Omni-directional Antennas
• Directional Antennas
• Others
• Dipole Antenna
• Half Wave Dipole Antennas
• Yagi Antena

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???????? Antennas
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???????? AntennaHyper Link (RE11DP)
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???????? Antenna
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???????? Antenna
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Signal Attenuation

• Strength of signal falls off with distance over
  transmission medium
• Attenuation factors for unguided media
• Received signal must have sufficient strength so
  that circuitry in the receiver can interpret the
  signal
• Signal must maintain a level sufficiently higher
  than noise to be received without error
• Attenuation is greater at higher frequencies,
  causing distortion

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Basic Propagation Models
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Watt And dB (Decibel)
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Free space model

• Pr ??????????????
• Gt ??????????????????????????????
• Gr ??????????????????????????????
• Lamda????????????
• D ??????????? AP
• L????????????????

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???????? Free space model

• Pr 100mW
• Gt 1 ????
• Gr 1 ????
• Lamda3e8/2.4e9
• d ??????????? AP
• L1
• AP ????????????????? 100 ????

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Two-ray ground Model

• Pr ??????????????
• Gt ??????????????????????????????
• Gr ??????????????????????????????
• ht????????????????????????????
• hr????????????????????????????
• d ??????????? AP
• L????????????????

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???????? Two-ray ground Model

• Pr ??????????????
• Gt 1 ????
• Gr 1 ????
• ht2 ????
• hr2 ????
• d ??????????? AP
• L 1 ????

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Shadowing Model

• Due to multipath propagation
• Due to fading effects.

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Multi-path

• The desired signal reaches the receiving antenna
  via multiple path
• A Difference propagation delay and path loss
• Each of these received paths are summed at the
  antenna

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Fading

• A time varying change in the path loss of a link
• For Free Space

• For Fading

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Shadowing Model
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Wall Attenuation
Parameters Light wall Loss Heavy Wall Loss Floor Loss (dB)
Value 3.4 6.9 18.3
COST action 231, Digital mobile radio towards
future generation systems final report, European
Commission Brussels 1999.
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????????????????????????????????

• ????????????? point-to-point ??????????????????
  IEEE 802.11 ?????? directional antena
  ??????????????????????????????????????????????????
  ?????????????? 54 Mbps ??????????? 1 km ?????????
  ??????????????????????????????????????????????????
  ??????????????????????????????????????
• Ptx20 dBm
• Sentivity -72 dBm

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??????????????????????
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????????????????

• Antenna AP ??????? Omni-directional
• Antenna Wireless Adapter ??????? Directional

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Antenna
Gain 11 dBi
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????????????????
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?????????????????????????????????????

• Laptop 2 ?????????? IEEE 802.11b
  ??????????????????????? Throughput ??????????????
  ????????????.
• ??? UDP ?????????????????????? payload 100, 500,
  ??? 1500 bytes
• ????????? RTS/CTS
• PLCP preamble and header 24 bytes
• MAC/LLC header and trailer (FCS) length 42
  bytes
• ACK 14 bytes
• SIFS 10s
• DIFS 50s
• Average backoff time between transmissions 310s
• PLCP and control packets ??????????????? 1Mbps.

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?????????????????????????????????????

• VoIP ??? PCM ???????????????????????? RTP/UDP/IP
  ?????????????????????????????????? (packet
  departure-interval time) ???? 20 ms
• ?????????????? VoIP ??????????????????????????????
  ?
• ?????????????? VoIP ???????????????? IEEE
  802.11b??? ?

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Coverage

• Laptop ??????????????? IEEE 802.11b (Silver
  Orinco) ?????????? Access point (Netgear)
  ??????????????????????????????????????????????????
  ?? Beacon ??? Laptop ?????? ??????????????????????
  ??????? ????????? Laptop ?????????????????????? 1
  m/s

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????

• ?????
• ???????????????

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??????????????????????????

• ?????????? servers ???????? GSM ??? GPRS (1 ??)
• ?????????????????????????? GSM ??? GPRS (1 ??)
• WLAN handover performance analysis and proposed
  algorithms (1 ??)
• Mobile IP performance analysis and proposed
  algorithms (1 ??)
• Performance study of Linux-bad Firewall (1 ??)
• Performance study of VoIP Over GPRS (1 ??)
• A study of SCADA(Supervisory Control And Data
  Acquisition) system (1 ??)
• An empirical Study of QoS of WiMax (1 ??)
• An empirical Study of MPLS (1 ??)
• An empirical Study of WLAN Security (1 ??)
• An implement of secure VoIP (3 ??)
• An implement of Crypto mobile Phone (3 ??)
• others

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??????????????????????????????????????????

• IEEE 802.11 or
• GSM or
• Blue-Tooth or
• CDMA or
• GPRS