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IEEE 802.16 and 802.15 - PowerPoint PPT Presentation


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IEEE 802.16 and 802.15. Outline. An overview An insight into IEEE 802.16 WiMAX An introduction to Bluetooth. Local Area Networks (e.g. 802.11). Satellite Global Area Network. Background: Wireless Landscape. High-Speed Connectivity & Hierarchy of Networks. Low Cost & Complexity.

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outline
Outline
  • An overview
  • An insight into IEEE 802.16 WiMAX
  • An introduction to Bluetooth
background wireless landscape

Local Area Networks

(e.g. 802.11)

Satellite

Global Area Network

Background: Wireless Landscape

High-Speed Connectivity

&

Hierarchy of Networks

Low Cost &

Complexity

Personal Area

Network

Fixed Broadband Wireless (e.g.802.16)

Cellular Mobile Networks (e.g. GPRS,3G)

High Cost &

Complexity

Increasing Coverage Area

background wireless technologies
Background: Wireless Technologies

WAN

(Wide Area Network)

MAN

(Metropolitan Area Network)

LAN

(Local Area Network)

PAN

(Personal Area Network)

what is wimax
What is WiMAX?
  • WiMAX (Worldwide Interoperability for Microwave Access)
    • BWA (Broadband Wireless Access) Solution
    • Standard (IEEE 802.16 is the standard) for constructing Wireless Metropolitan Area Networks (WMANs)
    • Can go places where no wired infrastructure can reach
    • Backhauling Wi-Fi hotspots & cellular networks
    • Offers new and exciting opportunities to established and newly emerging companies
      • Incorporate cable (wired technology) standard
      • Comply with European BWA standard
wimax overview
WiMAX Overview
  • Complement the existing last mile wired networks (i.e. xDSL, cable modem)
  • Fast deployment, cost saving
  • High speed data, voice and video services
  • Fixed BWA, Mobile BWA
benefits of wimax
Benefits of WiMAX
  • Speed
    • Faster than broadband service
  • Wireless
    • Not having to lay cables reduces cost
    • Easier to extend to suburban and rural areas
  • Broad coverage
    • Much wider coverage than WiFi hotspots
ieee 802 16 evolution
IEEE 802.16 Evolution
  • Fixed BWA at 10-66hz
  • Line of sight
  • Fixed BWA at 2-11hz
  • None line of sight
  • Revision of 802.16
  • Combine previous 802.16 standards
  • Mobile BWA based on 802.16-2004 (802.16a)
  • Roaming with vehicular speed
ieee 802 16 specifications
IEEE 802.16 Specifications
  • 802.16a
    • use the licensed and license-exempt frequencies from 2 to 11Ghz
    • Support Mesh-Network
  • 802.16b
    • Increase spectrum to 5 and 6GHz
    • Provide QoS (for real-time voice and video service)
  • 802.16c
    • Represents a 10 to 66GHz system profile
  • 802.16d
    • Improvement and fixes for 802.16a
  • 802.16e
    • Addresses on Mobile
    • Enable high-speed signal handoffs necessary for communications with users moving at vehicular speeds
ieee 802 16 operation
IEEE 802.16 Operation
  • WiMAX consists of two parts
    • A WiMAX tower, similar in concept to a cell-phone tower - A single WiMAX tower can provide coverage to a very large area -- as big as 3,000 square miles
    • A WiMAX Receiver The receiver and antenna could be a small box or PCMCIA card, or they could be built into a laptop the way WiFi access is today
how wimax works
How WiMax Works
  • WiMax can provide 2 forms of wireless services:

- Non-LOS, Wi-Fi sort of service, where a small antenna on a computer connects to the tower. Uses lower frequency range (2 to 11 GHz).

- LOS, where a fixed antenna points straight at the WiMax tower from a rooftop or pole. The LOS connection is stronger and more stable, so it is able to send a lot of data with fewer errors. Uses higher frequencies, with ranges reaching a possible 66 GHz.

  • Through stronger LOS antennas, WiMax transmitting stations would send data to WiMax enabled computers or routers set up within 30 (3,600 square miles of coverage) mile radius.
wimax spectrum
WiMax Spectrum
  • Broad Operating Range
  • WiMax Forum is focusing on 3 spectrum bands for global deployment:
  • Unlicensed 5 GHz: Includes bands between 5.25 and 5.85 GHz. In the upper 5 GHz band (5.725 – 5.850 GHz) many countries allow higher power output (4 Watts) that makes it attractive for WiMax applications.
  • Licensed 3.5 GHz: Bands between 3.4 and 3.6 GHz have been allocated for BWA in majority of countries.
  • Licensed 2.5 GHz: The bands between 2.5 and 2.6 GHz have been allocated in the US, Mexico, Brazil and in some SEA countries. In US this spectrum is licensed for MDS and ITFS.
technical similarities and differences between licensed and license exempt bands
Technical Similarities and Differences Between Licensed and License-Exempt Bands
  • Both solutions are based on IEEE 802.16-2004 standard, which uses OFDM in the physical (PHY) layer.
  • OFDM provides benefits such as increased SNR of subscriber stations and improved resiliency to multi-path interference.
  • For creating bi-directional channels for uplink and downlink, licensed solutions use FDD while license exempt solutions use TDD.
time division duplexing tdd20
Time Division Duplexing (TDD)
  • In case of TDD both uplink and downlink transmissions share the same frequency but are separated on time
  • A TDD frame has a fixed duration and also consists of one uplink and one downlink frame
  • TDD framing is Adaptive
frequency division duplexing fdd22
Frequency Division Duplexing (FDD)
  • In case of FDD both uplink and downlink channels are on separate frequencies
  • The capability of downlink to be transmitted in bursts simultaneously supports two different modulation types
    • Full Duplex SS's (which can transmit and receive simultaneously
    • Half Duplex SS's (which cannot)
architecture
Architecture
  • P2MP (Point to Multi point)
    • Wireless MAN
    • BS connected to Public Networks
    • BS serves Subscriber Stations (SS)
    • Provides SS with first mile access to Public Networks
  • Mesh Architecture
    • Optional architecture for WiMAX
p2mp architecture

Base

Station

P2MP Architecture

Non Line-of-Sight

Point to Multi-Point

Line-of-Sight Backhaul

802.16d

802.16

Telco Core Network or Private (Fiber) Network

INTERNET

BACKBONE

reference model
Reference Model
  • Supports multiple services (e.g. IP, voice over IP, video) simultaneously, with different QoSpriorities
  • Covers MAC layer and PHY layer
mac layer
MAC Layer
  • Wireless MAN: Point-to-Multipoint and optional mesh topology
  • Connection-oriented
    • Connection ID (CID)
  • MAC layer is further subdivided into three layers
    • Convergence sub-layer (CS)
    • Common part sub-layer (CPS)
    • Privacy sub-layer
mac addressing
MAC Addressing
  • SS has 48-bit 802.3 MAC address
  • BS has 48-bit base station ID
    • Not a MAC address
  • Connection ID (CID)
    • 16 bit
    • Used in MAC PDU
    • Connection Oriented Service
mac pdu
MAC PDU
  • Each MAC packet consists of the three components,
    • A MAC header, which contains frame control information.
    • A variable length frame body, which contains information specific to the frame type.
    • A frame check sequence(FCS), which contains an IEEE 32-bit cyclic redundancy code (CRC).
mac pdu types
MAC PDU Types
  • Data MAC PDUs
    • HT = 0
    • Payloads are MAC SDUs/segments, i.e., data from upper layer (CS PDUs)
    • Transmitted on data connections
  • Management MAC PDUs
    • HT = 0
    • Payloads are MAC management messages or IP packets encapsulated in MAC CS PDUs
    • Transmitted on management connections
  • BW Req. MAC PDUs
    • HT = 1; and no payload, i.e., just a Header
mac pdu transmission
MAC PDU Transmission
  • MAC PDU’s are transmitted on PHY bursts
  • The PHY burst can contain multiple FEC blocks
  • Concatenation
    • Multiple MAC PDU's can be concatenated into a single transmission in either uplink or downlink direction
  • Fragmentation
    • Each MAC SDU can be divided into one or more MAC PDU's
  • Packing
    • Packs multiple MAC SDU's into a single MAC PDU
mac cs sub layer
MAC CS Sub-layer
  • Interoperability requires convergence sub-layer to be service specific
  • Separate CS layers for upper layer (ATM & packet) protocols
  • CS Layer:
    • Receives data from higher layers
    • Classifies data as ATM cell or packet
    • Forwards frames to CPS layer
mac cps sub layer
MAC CPS Sub-layer
  • Performs typical MAC functions such as addressing
    • Each SS assigned 48-bit MAC address
    • Connection Identifiers used as primary address after initialization
  • MAC policy determined by direction of transmission
    • Uplink is DAMA-TDM
    • Downlink is TDM
  • Data encapsulated in a common format facilitating interoperability
    • Fragment or pack frames as needed
    • Changes transparent to receiver
mac privacy sub layer
MAC Privacy Sub-layer
  • Provides secure communication
    • Data encrypted with cipher clock chaining mode of DES
  • Prevents theft of service
    • SSs authenticated by BS using key management protocol
how it works
How It Works

http://www.networkworld.com/news/tech/2001/0903tech.html

802 16 network entry
802.16 Network Entry
  • Scanning
    • Scan for BS downlink channel
    • Synchronize with BS
    • Specifies channel parameters
  • Ranging
    • Set PHY parameters correctly
    • Establish the primary management channel (for negotiation, authentication, and key management)
  • Registration
    • Result in establishment of secondary management connection (for transfer of standard based management messages such as DHCP, TFTP )
  • Establishment of transport connection
ieee 802 16 features
IEEE 802.16 Features
  • Scalability
  • QoS
  • Range
  • Coverage
  • WiMAX vs. Wi-Fi
ieee 802 11 vs ieee 802 16 1 4
IEEE 802.11 vs. IEEE 802.16 (1/4)
  • Scalability
    • 802.11
      • Channel bandwidth for 20MHz is fixed
      • MAC designed to support 10’s of users
    • 802.16
      • Channel b/w is flexible from 1.5 MHz to 20 MHz.
      • Frequency re-use.
      • Channel bandwidths can be chosen by operator (e.g. for sectorization)
      • MAC designed to support thousands of users.
ieee 802 11 vs ieee 802 16 2 4
IEEE 802.11 vs. IEEE 802.16 (2/4)
  • Quality Of Service (QoS)
    • 802.11
      • No QoS support today (802.11e working to standardize )
      • Contention-based MAC (CSMA/CA) => no guaranteed QoS
    • 802.16
      • QoS designed in for voice/video
      • Grant-request MAC
      • Supports differentiated service levels.
        • e.g. T1 for business customers; best effort for residential.
      • Centrally-enforced QoS
ieee 802 11 vs ieee 802 16 3 4
IEEE 802.11 vs. IEEE 802.16 (3/4)
  • Range
    • 802.11
      • Optimized for users within a 100 meter radius
      • Add access points or high gain antenna for greater coverage
      • Designed to handle indoor multi-path delay spread of 0.8μ seconds
    • 802.16
      • Optimized for typical cell size of 7-10km
      • Up to 50 Km range
      • No “hidden node” problem
      • Designed to tolerate greater multi-path delay spread (signal reflections) up to 10.0μ seconds
ieee 802 11 vs ieee 802 16 4 4
IEEE 802.11 vs. IEEE 802.16 (4/4)
  • Coverage
    • 802.11
      • Optimized for indoor performance
      • No mesh topology support within ratified standards
    • 802.16
      • Optimized for outdoor NLOS performance (trees, buildings, users spread out over distance)
      • Standard supports mesh network topology
      • Standard supports advanced antenna techniques
bluetooth
Bluetooth
  • named after a Danish Viking and King, Harald Blåtand
  • it is a cable-replacement technology: new technology using short-range radio links, intended to replace the cable(s) connecting portable and/or fixed electronic devices
  • conceived initially by Ericsson in 1994, set to commercially come out in bulk around 2002
  • a standard for a small , cheap radio chip to be plugged into computers, printers, mobile phones, etc
  • The Bluetooth Special Interest Group (SIG) was founded by Ericsson,IBM,Intel,Nokia and Toshiba in February 1998, to develop an open specification for short-range wireless connectivity
bluetooth44
Bluetooth
  • Bluetooth radio modules operate in the unlicensed ISM band centered at at 2.45GHz. RF channels:2402+k MHZ, k=0..78.
  • Bluetooth devices within 10m of each other can share up to 720kbps of capacity
  • Projected cost for a Bluetooth chip is ~$5. Plus its low power consumption, means you could literally place one anywhere.
  • Can operate on both circuit and packet switching modes, providing both synchronous and asynchronous data services
  • It is intended to support an open-ended list of applications, including data, audio, graphics and even video.
bluetooth45
Bluetooth
  • Bluetooth must be able to:
  • Recognize any other Bluetooth device in radio range
  • Permit easy connection of these devices
  • Be aware of the device types
  • Support service discovery
  • Support connectivity aware applications
  • Examples of Bluetooth uses:
  • Briefcase email: access email while the PC is still in the briefcase; when PC receives an email, you are notified thru the mobile phone. Use the mobile phone to browse the email.
  • Cordless desktop: connect your desktop/laptop cordlessly to printers, scanner, keyboard, mouse, etc.
ieee 802 15
IEEE 802.15
  • In 1999, IEEE established a working group for wireless personal area networks (WPAN)
    • Contains multiple subgroups
  • IEEE 802.15.1
    • Standardizes the lower layers of the Bluetooth (together with the Bluetooth consortium)
    • Bluetooth also specifies higher layers
  • IEEE 802.15.2
    • Focuses on the coexistence of WPAN and WLAN
    • Proposes the adaptive frequency hopping (used since version 1.2) that requires a WPAN device check for the occupied channels and exclude them from their hopping list
  • IEEE 802.15.3
    • For high-rate at low-power low cost
  • IEEE 802.15.4
    • Low-rate low-power consumption WPAN enabling multi-year battery life
    • Zigbee consortium tries to standardize the higher layers of 802.15.4
bluetooth is a pan technology
Bluetooth is a PAN Technology
  • Offers fast and reliable transmission for both voice and data
    • Can support either one asynchronous data channel with up to three simultaneous synchronous speech channels or one channel that transfers asynchronous data and synchronous speech simultaneously
    • Support both packet-switching and circuit-switching
bluetooth is a standard that will
Bluetooth is a standard that will …
  • Eliminate wires and cables between both stationary and mobile devices
  • Facilitate both data and voice communications
  • Offer the possibility of ad hoc networks and deliver synchronicity between personal devices
characteristics of bluetooth technology
Characteristics of Bluetooth Technology

79 frequencies, each channel is used

for 625 microseconds

2M is expected for Bluetooth 2

bluetooth topology
Bluetooth Topology
  • Two or more piconet interconnected to form a scatternet
    • Only one master for each piconet
    • A device can’t be masters for two

piconets

  • Bluetooth-enabled devices can automatically locate each other
  • Topology is established on a temporary and random basis
  • Up to eight Bluetooth devices may be networked together in a master-slave relationship to form a piconet
    • One is master, which controls and setup the network
    • All devices operate on the same channel and follow the same frequency hopping sequence
    • The slave of one piconet can be the master of another piconet
piconet
Piconet
  • Master sends its globally unique 48-bit id and clock
    • Hopping pattern is determined by the 48-bit device ID
    • Phase is determined by the master’s clock
  • Why at most 7 slaves?
    • Active member address is 3-bit
  • Parked and standby nodes
    • Parked devices can not actively participate in the piconet but are known to the network and can be reactivated within some milliseconds
    • 8-bit for parked nodes
    • No id for standby nodes
    • Standby nodes do not participate in the piconet
scatternet
ScatterNet
  • FH-CDMA to separate piconets within a scatternet
  • More piconets within a scatternet degrades performance
    • Possible collision because hopping patterns are not coordinated
  • A device participating in more than one piconet
    • At any instant of time, a device can participate only in one piconet
    • If the device participates as a slave, it just synchronize with the master’s hop sequence
    • The master of a piconet can join another piconet as a slave; in this case, all communication within in the former piconet will be suspended
    • When leaving a piconet, a slave notifies the master about its absence for certain amount of time
  • Communication between different piconets takes place by devices jumping back and forth between these nets
frequency selection
Frequency Selection
  • FH is used for interference mitigation and media access; TDD is used for separation of the transmission directions
    • In 3-slot or 5-slot packets, why frequency does not change? Why some frequencies are skipped?

fk

fk+1

fk+2

fk+3

fk+4

fk+5

fk+6

M

S

M

S

M

S

M

fk

fk+3

fk+4

fk+5

fk+6

M (3-slot packet)

S

M

S

M

fk

fk+1

fk+6

M

S (5-slot packet)

M

physical links
Physical Links
  • Synchronous Connection Oriented (SCO) : allocates a fixed bw between a point-to-point connection involving the master and one slave.
    • The master reserves slots periodically.
    • It primarily supports time-bounded information like voice.
    • SCO packets do not include a CRC and are never retransmitted.
    • The master can support up to 3 simultaneous SCO links
  • Asynchronous connectionless (ACL) : a point-to-multipoint link between the master and all slaves in the piconet.
    • Packet-switch style of connection
    • No bw reservation possible
    • Delivery may be guaranteed thru error detection and retransmission
    • Only single ACL link can exist
physical links57
Physical Links
  • Synchronous connection-oriented link (SCO)
    • Reserve two consecutive slots at fixed intervals
  • Asynchronous connectionless Link (ACL)
    • Polling scheme – master polls each slave
  • Error recovery
    • ACK a packet in the slot following the packet
    • Negative ACK or timeout signals a retransmission
benefits
Benefits
  • Cable Replacement
    • Replace the cables for peripheral devices, USB 1.1 and 2.0, printers, etc
  • Ease of file sharing
    • Panel discussion, conference, etc.
  • Wireless synchronization
    • Synchronize personal information contained in the address books and date books between different devices such as PDAs, cell phones, etc.
  • Bridging of networks
    • Cell phone connects to the network through dial-up connection while connecting to a laptop with Bluetooth.