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Wireless networks: from cellular to ad hoc

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from cellular to ad hoc 2009 Outline Wireless introduction Wireless Ad hoc networks Routing Proactive routing On-demand routing TCP Sensor networks Outline ... – PowerPoint PPT presentation

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Title: Wireless networks: from cellular to ad hoc


1
Wireless networks from cellular to ad hoc
  • 2009

2
Outline
  • Wireless introduction
  • Wireless Ad hoc networks
  • Routing
  • Proactive routing
  • On-demand routing
  • TCP
  • Sensor networks

3
The three wireless waves
  • Wave 1 cellular telephony
  • Still, biggest profit maker
  • Wave 2 wireless Internet access
  • Most Internet access on US campuses is wireless
  • Hot spots are rapidly proliferating in the US
    Europe and Asia to follow soon
  • 2.5 G, 3G and 4G trying to keep up competitive
    edge?
  • Wave 3 ad hoc wireless nets (now)
  • Set up in an area with NO infrastructure to
    respond to a specific, time limited need

4
Wireless Internet Options - Cellular
  • 2.5 G
  • GPRS Time Division based (GSM) 100Kbps
  • 1xRTT CDMA based 144Kbps
  • 3G
  • UMTS Wide Band CDMA from 384 Kbps to 2Mbps
  • Integrates packet service with connection
    oriented service (voice, video, etc)
  • 4 G ?
  • WiMAX/IEEE802.16 (100Mbps) -gtgt 3G? 4G?
  • ???? 512Kbps3Mbps
  • other

5
Wireless Internet Option WiFi (IEEE802.11)
  • Replacement for wired Ethernet
  • Unlicensed spectrum (ISM)
  • Several options and rates
  • 802.11 b
  • 11, 5.5, 2, 1 Mbps _at_ 2.4 GHz
  • 802.11 a 54 Mbps in 5.7 GHz band
  • 802.11 g 54 Mbps _at_ 2.4 GHz
  • 802.11 n, up to 500Mps with MIMO and OFDM tech.
  • Range
  • Indoor 20 - 25 meters (more)
  • Outdoor 50 100 meters (1 Km)
  • Transmit power 30 - 100 mW (200mW, 500 mW)

6
Wireless Internet options Bluetooth (IEEE
802.15.1)
  • 1998 BT SIG Ericsson, IBM, Intel, Nokia,
    Toshiba
  • A cable replacement technology
  • Max rate 700Kbps _at_2.4 Ghz
  • Range 10 meters
  • Single chip radio baseband
  • at low power (1mw) low price point (5)
  • Convergence of 802.15 and Bluetooth in a single
    PAN standard

7
Emerging Landscape
Bluetooth
802.11
Cordless headset
LAN AP
  • Both 802.11 and Bluetooth will be used for access
  • Complementary benefits

8
Which Internet access to choose?
Internet
2G/3G WAN Infrastructure
  • Wireless WAN 2G/3G cellular infrastructure
  • Wireless LAN IEEE 802.11 and Bluetooth

9
Comparisons of 3G and 802.11
  • Coverage
  • 3G large coverage
  • 802.11b/a/g/n small
  • Throughput
  • 802.11b/a/g/n up to 11/54/500 Mbps
  • 3G up to 2.4 Mbps
  • Cell size and density
  • 802.11 several hundred feet
  • 3G up to several kilometers
  • Applications supported
  • 802.11 mainly data, but may support VoIP
  • 3G data plus voice
  • Cost 802.11 cheaper 3G expensive

10
Which Internet access to choose?
  • Most portables have multiple radio interfaces
  • 802.11, Bluetooth, GPRS, 1xRTT, 3G , and 4G
  • Dynamically select best access
  • Lowest connection charge
  • Best reception
  • Best power budget (must save battery power)
  • Suitable QoS
  • Challenges
  • Integrating 2G, 3G, 4G and Wi-Fi
  • "total seamlessness" between the technologies
  • Creating one multi-speed, multimedia network

11
????????????????
  • ????????
  • ??????(QoS)??/??
  • ??????(??????????)
  • ??????,??????
  • ????????? 3G
  • ???-??????
  • ??????-2Mbit/s
  • ??????/IP????
  • ????---??
  • ??---??,???,???
  • ?????---??

12
The 3rd Wave Infrastructure vs Ad Hoc
Infrastructure Network (cellular or Hot spot)
Ad Hoc, Multihop wireless Network
13
General Ad Hoc Network Characteristics
  • Instantly deployable, re-configurable (No fixed
    infrastructure)
  • Created to satisfy a temporary need
  • Node portability (eg sensors), mobility
  • Limited battery power
  • Multi-hopping (to save power, overcome obstacles,
    enhance spatial spectrum reuse, etc.)

14
The Battlefield
  • DoD was first to understand the value of ad hoc
    networks for the automated battlefield
  • In 1971 (two years after ARPANET), DARPA starts
    the Packet Radio project
  • ONR (Office of Naval Research) sponsors MINUTEMAN
    - a 5 year program at UCLA (20002005)
  • Goal develop an unmanned , airborne ad hoc
    architecture

15


SATELLITE
COMMS
SURVEILLANCE

MISSION
UAV-UAV NETWORK
COMM/TASKING
COMM/TASKING
Unmanned
UAV-UGV NETWORK
Control Platform
COMM/TASKING
Manned
Control Platform
Minuteman Algorithms and Protocols for Network
of Autonomous Agents
16
Transferring Battlefield technology to civilian
applications - Disaster recovery
  • Flood, mud slide, earthquakes, eruption, chemical
    or nuclear plant disaster, snow .
  • Several rescue teams involved, with different
    functions
  • Autonomous vehicle swarms (ground/airborne) are
    deployed (with sensors/actuators)
  • Manned and unmanned teams cooperate in rescue
  • Ad Hoc networking will be central to make the
    operation work

17
Ad Hoc Network Applications - Commercial
  • Sport events, festivals, conventions
  • Patient monitoring
  • Ad hoc collaborative computing (Bluetooth)
  • Networked video games at amusement parks, etc
  • Ad Hoc extensions (of Wireless Internet)
  • Opportunistic Evolution
  • Vehicle Communications and Urban Surveillance
  • Urban Homeland Defense
  • Mobile sensor platforms vs Cable TV
  • Sensors on cars (car navigation safety)
  • Car to car communications
  • P2P applications
  • Car Torrent, MobEyes, Autonomous evacuation
  • Commercial Killer Application? .stay tuned!

18
Vision Opportunistic Evolution of Ad Hoc
Networking
  • Key issue wired-wireless convergence
    Commercial ad hoc nets must coexist with the
    Internet
  • They will NOT follow the military model as
    isolated, self configured
  • Rather, they will emerge as a no cost extension
    of the infrastructure
  • Examples of Ad Hoc extensions (of Wireless
    Internet)
  • Indoor W-LAN extended coverage
  • Mesh Networks (Hot spot extensions)
  • Rural networks
  • Group of friends sharing 3G access via Bluetooth

19
Alternative All Wireless Networks
  • All wireless architecture Multihop wireless
    networking
  • Potential benefits
  • anytime, anywhere network setup
  • Self-organized, small to large scales
  • Minimized wiring cost
  • Three architectural paradigms from resource
    perspective
  • Low-end resource-constrained wireless sensor
    networks
  • Middle-ground mobile ad-hoc networks
  • High-end wireless mesh networks

20
Multihop Wireless Networks
Low-End
Middle-Ground
Wireless Sensor Networks
Mobile Ad-Hoc Networks
  • Resource-constrained sensors
  • Potentially large population
  • Nodes with reasonable amount of resources
  • Data rates upto 10s Mbps

21
High-End Wireless Mesh Networks 802.11s

Mesh Portal

Mesh Links 802.11 MAC/PHY
Distribution System
  • High-speed wireless backbone at gt100Mbps
  • Resource abundant
  • Promises to have both wide coverage and high rate

802.11 ESS
STA

Mesh AP Mesh router

22
Wireless Mesh Networks
23
Urban surveillance
  • CCTV surveillance
  • Cameras cannot be installed at all locations
  • Cameras can be taken out by terrorists
  • The central data collection facility can be
    sabotaged
  • Mobile video collection/storage platforms
  • Vehicles, People, Robots
  • Mobile eyes are an complement to CCTV
  • New challenges on VEHICLES
  • wireless communications medium
  • wireless data protocols/architectures
  • distributed storage strategy
  • search of the distributed, mobile data base

24
Urban opportunistic ad hoc networking
From Wireless to Wired network Via Multihop
25
The Urban Vehicle Grid
  • Ad hoc networking to prevent/contain accidents

26
Opportunistic piggy rides in the urban mesh
Pedestrian transmits a large file block by block
to passing cars, busses The carriers deliver the
blocks to the hot spot
27
More generally New Vehicle Roles on the road
  • Vehicle as a producer of geo-referenced data
    about its environment
  • Pavement condition
  • Probe data for traffic management
  • Weather data
  • Physiological condition of passengers, .
  • Vehicle as Information Gateway (Telematics)
  • Internet access, infotainment, dynamic route
    guidance,
  • These roles demand efficient communications

28
Vehicle Roles Vehicular Sensor Apps
  • Vehicle Vehicle, Vehicle Roadway as
    collaborators
  • Cooperative Active Safety
  • Forward Collision Warning, Blind Spot Warning,
    Intersection Collision Warning.
  • In-Vehicle Advisories
  • Ice on bridge, Congestion ahead,.
  • Environment
  • Traffic congestion monitoring
  • Urban pollution monitoring
  • Civic and Homeland security
  • Forensic accident or crime site investigations
  • Terrorist alerts

29
Urban Ad Hoc net in action Safe Driving
Vehicle type Cadillac XLR Curb weight 3,547
lbs Speed 65 mph Acceleration -
5m/sec2 Coefficient of friction .65 Driver
Attention Yes Etc.
Vehicle type Cadillac XLR Curb weight 3,547
lbs Speed 75 mph Acceleration
20m/sec2 Coefficient of friction .65 Driver
Attention Yes Etc.
Alert Status None
Alert Status None
Alert Status Inattentive Driver on Right
Alert Status Slowing vehicle ahead
Alert Status Passing vehicle on left
Vehicle type Cadillac XLR Curb weight 3,547
lbs Speed 45 mph Acceleration -
20m/sec2 Coefficient of friction .65 Driver
Attention No Etc.
Vehicle type Cadillac XLR Curb weight 3,547
lbs Speed 75 mph Acceleration
10m/sec2 Coefficient of friction .65 Driver
Attention Yes Etc.
Alert Status Passing Vehicle on left
30
Vehicular Sensor Network (VSN) IEEE Wiress
Communications 2006 Uichin Lee, Eugenio
Magistretti (UCLA)
31
Accident Scenario storage and retrieval
  • Designated Cars
  • Continuously collect images on the street (store
    data locally)
  • Process the data and detect an event
  • Classify the event as Meta-data (Type, Option,
    Location, Vehicle ID)
  • Post it on distributed index
  • Police retrieve data from designated cars

Meta-data Img, -. (10,10), V10
32
How to retrieve the data?
  • Epidemic diffusion
  • Mobile nodes periodically broadcast meta-data of
    events to their neighbors
  • A mobile agent (the police) queries nodes and
    harvests events
  • Data dropped when stale and/or geographically
    irrelevant
  • Mobility-Assist Meta-Data Harvesting
  • Assumption
  • N disseminating nodes each node ni advertises
    event ei , k-hop relaying
  • v average speed, R communication range
  • ? network density of disseminating nodes
  • Discrete time analysis (time step ?t)
  • Metrics
  • Average event percolation delay
  • Average delay until all relevant data is harvested

33
You are driving to Vegas You hear of this new
show on the radio Video preview on the web (10MB)
CarTorrent Opportunistic Ad Hoc networking to
download large multimedia files

34
Highway Infostation downloading
Problem Stopping at gas station to download is a
nuisance Observation many other
drivers are downloading the same files (like in
the Internet) Solution Co-operative P2P
Downloading using the Car to Car ad hoc nets
(Car-Torrent)
35
Partial download from Infostation
Internet
Download
36
Co-operative P2P Download
Internet
P2P Exchange of Pieces
Vehicle-Vehicle Communication
37
U-Ve T Ucla - Vehicular Testbed - Project Goals
  • Provide
  • A platform to support car-to-car experiments in
    various traffic conditions and mobility patterns
  • A shared virtualized environment to test new
    protocols and applications
  • Remote access to U-VeT through web interface
  • Extendible to 1000s of vehicles through WHYNET
    emulator
  • potential integration in the GENI
    infrastructure
  • Allow
  • Collection of mobility traces and network
    statistics
  • Experiments on a real vehicular network

38
Big Picture
  • We plan to install our node equipment in
  • 50 Campus operated vehicles
  • on a schedule and random campus fleet
    mobility patterns
  • 50 Communing Vans
  • Measure freeway motion patterns
  • Hybrid cross campus connectivity using 10 WLAN
    Access Points
  • The U-Box Node
  • Laptop/PC (Linux) (Windows), 2 x WLAN Interfaces,
    1 Software Defined Radio (FPGA based) Interface,
    1 Control Channel , 1 GPS, OLSR Used for the
    Demo

39
The C2C testbed
40
Future of Commodity Ad Hoc Nets
  • Commercial ad hoc networks will happen as
    opportunistic extensions
  • They will NOT follow the military model
  • New research (beyond military) critical
  • Integration of wired-wireless solutions
  • Soft handoff
  • Third Party forwarding incentives
  • P2P protocols
  • New measurement/modeling tools ( eg, Capacity
    estimation)
  • Security/privacy
  • Key issue wired-wireless convergence
    Commercial ad hoc nets MUST COEXIST with the
    Internet
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