xxx. előadás
Oláh András
2009. 03. 25.
i.) Trendek ii) Kognitív rádió (hálózat) iii) Vezeték nélküli érzékelő hálózat iv.) Kooperáció Wiener szűrés esetén
1

2

Product
TV stations
Route to home phone broadcast TV broadcast radio
Display
TV radio stereo
Local storage
Cassette/ 8-track
Vinyl album
Local news mail
Advertising newspaper delivery
Radio Stations phone non-electronic
Tom Wolzein, Sanford C. Bernstein & Co

Product
TV stations
Info
“Daily me” content
Cable Nets
Web sites
Local news
Content from individuals
Route to home cable phone/DSL wireless broadcast TV broadcast radio satellite mail express delivery iPod / storage
Display
TV radio
PC stereo monitor headphones pager
Local storage
VCR
DVD
Web-based storage
Server/ TiVo (PVR)
PC
CD/CD-ROM
MP3 player / iPod
Peer-to-peer subcarriers / WIFI cell phone
Advertising newspaper delivery phone
Radio stations
Satellite radio pagers - PDAs cable box
PDA/Palm game console game console non-electronic Storage sticks/disks
Adopted from Tom Wolzein, Sanford C. Bernstein & Co

5

2007 Potential
Mobile phones, PDAs, scanners, Web Tablets,
GPS, etc.
PC’s, servers, etc.
Vehicle cargo containers, tankers, supply chain assets (SKU)s…
Medical Device, HVAC, industrial machinery, distributed generation…
Industrial controllers, appliance controllers…
Accelerometers, pressure gauges, flow, position, speed, temp biosensors, etc.
8-, 16-, 32-, 64-bit chips, etc.
Mobile info appliances
Static info appliances
Mobile devices
Static devices
Controllers
Smart sensors
Microprocessors & Microcontrollers
1.5 billion
500 million
350 million (SKUs: trillions)
375 million
500 million
750 million
35 billion
6

RFID antenna
Smart dust communications mote flexible fuel cell
7

Source: Institute for the Future 8

1.
IP Will Eat Everything! – Next Generation Internet
2.
Security Is Critical
3.
Convergence of Communications & Applications Will Be A
Reality – Network Will Be The Computer
4.
Wireless Internet Will Be Big – Driving Mobility
5.
Sensor Networks Will Be Everywhere
6.
e-Collaboration Will Dominate The Workplace – next generation speech recognition
7.
Broadband Will Be Common – Death of Locality
8.
Wireless & Wired Lines Will Converge – Accelerating
Virtualization
9.
Knowledge Mining Will Transform the Way We Do Business
10.
Home LANs Will Proliferate – Ethernet Will Be Everywhere
9

2005
2005
IP Devices
Application-aware network 2010
Perpendicular storage
Flexible
Storage virtualization
Grid networks
Self-healing
Infobots
Wearable
2015 networks network
Intelligent optical chip
3-D printing
Nano computers display
Fuel cells proliferate
Quantum
Private on-demand Virtual Reality reconfigurable Communications
Computing
Holographic
100 Gbyte mobile storage
1 Tbyte mobile networks storage storage
2010 2015 2020 2015 2010
Mobile
Cognitive radio Speech
Tele-immersion
Next Generation
Mesh sensory video
IP Mobility
Dialing
Internet networks
Over-the-air
Emergence of
Cloaking
Biometrics programming Dominant
RFID
Pallets
Physical & Semantic
Location-aware services
Interactive video
Wireless
VoIP
Items mobility
2015
Seamless
Speech-to-speech
Composite
2010
Sensory Internet translation
Video search applications
RFID web
Wireless Content
2005
2005
10

Here Now
 Voice over IP
 P2P

Integrated GPS
 WiFi

RFID
 3G Mobile
 Satellite Radio / DAB

Mobile TV / IP-TV / Web TV
 DTV / HDTV

PVR
 Video on Demand
 WiMAX

Mesh Networks
 Broadband Power Line (BPL)
Coming Soon
 3G+ Mobile
 Ultra Wide Band (UWB)

Software-Defined Radio (SDR)
 Grid Computing
 Sensor Networks
 Nanotechnology
 Internet Protocol Version 6 (IPv6)

Quantum Cryptography
On the Horizon
 Gigabit WiMax

User Controlled Light Paths (UCLP)
 Semantic Web
 Bio Computing

Quantum Computing
Access to anything, anywhere, anytime

Top-down: What the network thinks you want, when they think you want it and in the format they want
 TV content on cable, or over the air
 Radio show on radio
 Books in the bookstore or library
 Snail mail rain or shine
 Voice by monopoly phone provider
Choice: What you want, when you want it, from anywhere
 All content and services available online:
Music, Movies, TV Shows, Books, podcasts, Voice, TV, Radio…
 Choice of receptors: Personal Computers, cellphones, Blackberry, iPods…
The Consumer’s Revenge!

It has revolutionized communications
 Mobile is supplanting wireline for telephony
 The mobile web is beginning to make in-roads
 Smaller, cheaper, more powerful devices
 Faster, smarter radiocommunications
 Result is ‘Un-tethered’ access
Global Vision
Mobile Internet For All
ICMB 09.07.07 - 13

Placing new pressures on spectrum use…
Spectrum challenges are now global
 Global and regional harmonization

Technology neutrality

Licence-exempt spectrum and standards

Public safety & security
 Implications
 Greater effort required to build consensus (i.e. preparations for
WRC)

Nations can no longer operate in isolation
 Regional (minimum) – Global
(desired)
New pressures on spectrum management
 Cognitive Radio
 Challenge: develop new regulations to accommodate cognitive performance
 UHF White Spaces
 Challenge: Develop standards for use of unused broadcast spectrum for wireless broadband
 UWB
 Challenge: Develop internationally harmonized rules addressing potential interference

Where everyone and everything is connected
Ecosystem of the Internet
 R adioF requency
ID entification (RFID) tags + Smart Computing
 Wireless sensors
 Personal Area Networks
(PANs)
Economic System
Lead Users
International
Agencies
Producers &
Suppliers
Consumer
Advocacy
Groups
Internet of
Things
Gov’t &
Regulators
Legal System
R&D organization s
Social System
Internet
Things
3G+ mobile
Human Body
Human Being
2G mobile
Satellite
Source: ITU, 2005
WiMAN
WiLAN Cable xDSL

‘The Internet of Things’ is a concept originally coined and introduced by MIT, Auto-ID Center and intimately linked to RFID and electronic product code (EPC)
“… all about physical items talking to each other..”
Like RFID it is a concept that has attracted much rhetoric, misconception and confusion as to what it means and its implications in a social context
16

The Internet of Things * (2007 Commission view):
The Internet of Things viewed as a network for communicating devices and based upon four degrees of sophistication, involving:



Purely passive devices (RFID) that yield fixed data output when queried
Devices with moderate processing power to format carrier messages, with the capability to vary content with respect to time and place
Sensing devices that are capable of generating and communicating information about environment or item status when queried
 Devices with enhanced processing capability that facilitate decisions to communicate between devices without human intervention – introducing a degree of intelligence into networked systems
* European Commission (2007) From RFID to the Internet of Things – Pervasive networked systems
17

Wireless Paradigm

Evolution Path
18
18

Wireless Paradigm
 Adaptive Wireless Broadband Network 구현
19
19

Wireless Paradigm
20
20

Wireless Paradigm
21
21





New radios for heterogeneous access



Low-power sensor radios
High-speed WLAN and 4G/802.16
Faster 4G cellular, 802.16, etc.
Spectrum-sharing for dense networks


Dynamic spectrum / cognitive radio for frequency coordination
Spectrum etiquette protocols
Ad-hoc wireless networks


Self-organizing networks capable of scaling organically
Discovery, MAC and routing protocols for reliable ad-hoc services
Pervasive computing software


Dynamic binding of application agents and sensors
Real-time orchestration of sensors and actuators
2007-05-09
22
22

23




Going wireless more and more...
Lack of interoperability bw. different technologies
Lack of spectrum (???)
24

 Fixed Spectrum Assignment (Existing spectrum policy forces spectrum to behave like a fragmented disk )

Bandwidth is expensive and good frequencies are taken

Unlicensed bands
– biggest innovations in spectrum efficiency
 Recent measurements by the
FCC in the US show 70% of the allocated spectrum is not utilized
 Time scale of the spectrum occupancy varies from msecs to hours
SOLUTION


More clever radio
Frequency Agility----SPECTRUM SHARING
25

Joseph Mitola 1992
Software Defined Radio(SDR) radio primarily defined in software, which supports a broad range of frequencies, and its initial configurations can be modified for user requirements.
Joseph Mitola 1999
Cognitive Radio(CR)
SDR + Intelligence
26




Existing techniques for spectrum sharing:

Unlicensed bands (WiFi 802.11 a/b/g)




Underlay licensed bands (UWB)
Opportunistic sharing
Recycling (exploit the SINR margin of legacy systems)
Spatial Multiplexing and Beamforming
Drawbacks of existing techniques:



No knowledge or sense of spectrum availability
Limited adaptability to spectral environment
Fixed parameters: BW, Fc, packet lengths, synchronization, coding, protocols, …
New radio design philosophy: all parameters are adaptive

Cognitive Radio Technology
27





Measurement of the spectrum usage in frequency, time, and space
Wideband channel

Common with UWB
Spatial channel model


Clustering approach
Interference correlation
Derive statistical traffic model of primary users

Power level



Bandwidth
Time of usage
Inactive periods
120
90
60
150
180
30
0
210
240 300
270
Angular domain
330
Time (min)
28

 Sensing Radio
 Wideband Antenna, PA and LNA
 High speed A/D & D/A, moderate resolution
 Simultaneous Tx & Rx
 Scalable for MIMO
 Physical Layer
 OFDM transmission

Spectrum monitoring
 Dynamic frequency selection, modulation, power control

Analog impairments compensation
 MAC Layer
 Optimize transmission parameters
 Adapt rates through feedback

Negotiate or opportunistically use resources
PA D/A
LNA A/D
IFFT MAE/
POWER CTRL
FFT
ADAPTIVE
LOADING
CHANNEL
SEL/EST
INTERFERENCE
MEAS/CANCEL
TIME, FREQ,
SPACE SEL
LEARN
ENVIRONMENT
QoS vs.
RATE
FEEDBACK
TO CRs
RF/Analog Front-end Digital Baseband MAC Layer
29

Functionality
Multiple channels for agility
WiFi
27 fixed 20MHz channels
Cognitive Radio
Variable # and BW
Sensing collisions/interference WiFi interference only Any interference
Simultaneous spectrum sensing and transmission
Not possible Necessary
Modulation scheme, rate
Packet length, preamble
Fixed per packet
Fixed
Adaptive bit loading
More flexible
Power level Fixed per packet Adaptive control
Interference mitigation
Spatial processing
QoS, rate, latency
WiFi interference only Any interference
Some (802.11n)
Lots…
Limited Sophisticated
30

31

Concept of SDR
Termed coined by Mitola in 1992
Radio’s physical layer behavior is primarily defined in software
Accepts fully programmable traffic & control information
Supports broad range of frequencies, air interfaces, and application software
Changes its initial configuration to satisfy user requirements
SDR: use software routines instead of ASICs for the physical layer operations of wireless communication system
ASICs
(PHY)
Software
Routines
Programmable
Hardware
32/37 2007-05-09
32
NETLAB Seminar 7 March 2007
32/37

33/37
Reconfigurable
Easily Upgradeable
Responds to the changes in the operating environment
Lower maintenance cost
NETLAB Seminar 7 March 2007
33/37

Lower costs
Platform longevity, higher volume
SW has lower development costs
Time to market
Future protocols will have complex implementations
Overlap testing/development cycles
Adaptability
Standards change over time
Multi-mode operation
Sharing hardware resources
Open architecture allows multiple vendors
Maintainability enhanced
34/37 2007-05-09
34
NETLAB Seminar 7 March 2007
UWB
802.16a
EDGE
SDR
802.16a
Bluetooth
802.11b
WCDMA 802.11n
34/37

W-CDMA Physical Layer Processing
Transmitter
D
/
A
Receiver
A
/
D
...
1. Filtering: suppress signals outside frequency band
2. Modulation: map source information onto signal waveforms
3. Channel Estimation: Estimate channel condition for transceivers
4. Error Correction: correct errors induced by noisy channel
35/37
35
NETLAB Seminar 7 March 2007
35/37

36/37
NETLAB Seminar 7 March 2007
36/37

Primary User (Licensed User) the user which has an exclusive right to a certain spectrum band.
In other words, the license holders...
No need to be aware of cognitive users
No additional functionalities or modifications needed
Secondary User (Unlicensed User)
Cognitive-radio enabled users
Lower priority than PUs
37

 A spectrum hole is a band of frequencies assigned to a primary user, but, at a particular time and specific geographic location, the band is not being utilized by that user.
38



The term “cognitive radio” was first coined by Mitola in 1999 and can be defined as in 2006 by IEEE: “ A type of radio that can sense and autonomously reason about its environment and adapt accordingly.
This radio could employ machine learning mechanisms in establishing, conducting or concluding communication and networking functions with other radios ”
Two CR-related standards are under development:

IEEE 802.22: high rate access (1.5 Mb/s) in rural areas up
 to 100 km in coverage
IEEE 802.11h: WLANs with dynamic frequency selection transmit power control capabilities
39

 In the 1999 paper that first coined the term
“cognitive radio”, Joseph Mitola III defines a cognitive radio as

“A radio that employs model based reasoning to achieve a specified level of competence in radio-related domains .”
40

 Simon Haykin defines a cognitive radio as “ An intelligent wireless communication system that is aware of its surrounding environment
(i.e., outside world), and uses the methodology of understanding-bybuilding to learn from the environment and adapt its internal states to statistical variations in the incoming RF stimuli by making corresponding changes in certain operating parameters (e.g., transmit-power, carrierf requency, and modulation strategy) in realtime, with two primary objectives in mind:


· highly reliable communications whenever and wherever needed;
· efficient utilization of the radio spectrum.
41

 Cognitive radios are a powerful tool for solving two major problems:
1) Access to spectrum (finding an open frequency and using it)
2) Interoperability (talking to legacy radios using a variety of incompatible waveforms)
42

Cognitive radio requirements co-exists with legacy wireless systems uses their spectrum resources does not interfere with them
 Cognitive radio properties




RF technology that "listens" the spectrum
Knowledge of primary users’ spectrum usage as a function of location and time
Rules of sharing the available resources (time, frequency, space)
Embedded intelligence to determine optimal transmission
(bandwidth, latency, QoS) based on primary users’ behavior
43

44

Radio Environment
(Outside World)
Transmitted signal
RF Stimuli
Transmit-power control, and spectrum management
Spectrum Holes,
Noise-floor statistics
Traffic statistics
Radio-scene
Analysis
(Spectrum sensing)
Interference temperature
Quantized
Channel capacity
Channel-state estimation, and predictive modeling
Transmitter
Receiver
Spectrum Holes
: A band of frequencies that are not being utilized by the primary user at a particular time and in a particular geographic location.
- Black/Grey/White Holes
Interference temperature
: To quantify and manage the sources of interference in a radio environment
45

External
Sources
Orient
Establish Priority
Pre-process
Immediate
Normal
Plan
Generate Alternatives
(Program Generation)
Evaluate Alternatives
Urgent
Parse
Read Buttons
Outside
World
Register to Current Time
Observe
Receive a Message
Learn
New
States
Prior
States
Act
Send a Message
Set Display
Save Global
States
Decide
Alternate Resources
Initiate Process(es)
(Isochronism Is Key)
OODA loop The Cognition Cycle
OBSERVE-ORIENT-DECIDE-ACT
46


“Reading the Meters”


Monitors its own performance continuously
“Turning the Knobs”

Responds to the operator’s commands by configuring the radio
 The Cognitive Engine tells the radio how to control the knobs and meters.
2007-05-09
47
47
47

2007-05-09
48
48
48

 Hidden node problem
 Heterogeneous System Design
2007-05-09
49
49

 Frequency Assignment
 Negotiation of Resources (Game theory)
2007-05-09
50
50

 Hardware






Learning Mechanisms
Routing and Upper layer Issues (Networking, QoS)
Developing spectrum sharing behaviors
Sensitive detection
Frequency assignment negotiation
Resource allocation


Security (Unintentional config..)
Integration with “spectrum market”
51

Routing, System
Management, QoS and other upper layer issues...
Application Layer
Transport Layer
Network Layer
MAC Layer
Physical Layer
• Optimize transmission parameters
• Adapt rates through feedback
• Negotiate or opportunistically use resources
OFDM transmission
Spectrum monitoring
Dynamic frequency selection, modulation, power control
Analog impairments compensation
52

53

camera mic accelerometer gyro
 pressure thermal
GPS
Also the biomedical sensors: EMG, EKG, pulses, emotions, etc
54

Külvilág
(megfigyelt rendszer)
Intelligens szenzorok
(hálózat)
Elektromos jel
Előfeldolg. dig. folyam
Jelfedolgozás, monitorozás, döntés
(közp. adatfeld.)
Rádiós kapcsolat
Érzékelés, jelfeldolgozás, kommunikáció
KOMM. PROT. ???
55

MICA, 2001-2002
5.7cm X 3.18cm
4 MHz CPU
128K ROM 512K RAM
40kbps Radio range x00 feet
Sensors, battery not included
Spec, March 2003
2mm X 2.5mm
CPU, memory, RF transceiver
Sensors, battery, antenna not included
< 1 dollar if mass-produced
56

57

Alkalmazás
Hálózati réteg
Jelfeldolgozási réteg
Érzékelési réteg
Optimális protokollok
Optimális erőforrásmenedzsment
(energy aware routing)
???
tradicionális hálózati protokollok nem alkalmazhatóak
Max. élettartam
58

Ekvivalens modell
Érzékelt mennyiség (forgalom) továbbítása a bázis állomás felé
N d
N
N-1 N-2 d
N-1 d
N-2
N-3 szenzorok
???
Új protokollok:
Optimális csomagtovábbító eljárások
Energia hatékonyság !!
1 d
1
BS
Maximális élettartam!
59

LEGHOSSZABB ÉLETTARTAM
Energia- és lokalizáció kényszerek
Statisztikai forgalmi modellek
Csomagtovábbítási algoritmus
N max ugrások száma, optimális node elhelyezkedés vagy optimális útvonal
Statisztikai módszerek, nagy eltérések elmélete
Eddigi (determinisztikus) eredmények:
A. J. Goldsmith (2002), I.F. Akyildiz (2002), F. L. Lewis (2004), Haenggi (2005)
Nyitott kérdés és a dolgozat új eredmény ei:
Élettartam optimalizálása statisztikus forgalom esetén
60

● Szenzorok száma : N
● Szomszédos elemek közötti távolság: d
1
, d
2
● y i
   csomag.
… d
N
; valószínűségi változó jelöli, hogy egy node-on generálódik -e
● az on-off forgalmi modellben egy node csomagot.
 y
   y
1
( k ),...., y
N
( k )
 p i valószínűséggel forgalmi állapotvektor generál
● Egy csomag szomszédos node nak továbbításához energiaszükséglete: g i
.
A Rayleigh terjedési modell alapján:
P
0
= g i
P r
:

P
 
N g i
 d
 
N
0
 ln P r e


N

0

K ét node távolságából előállíthatjuk egy csomag d távolságba küldéséhez szükséges energiát. 61

Megvalósítás: Az 1 dimenziós lánc felállítása a bázis
állomás távolságának függvényében
(PEGASIS,PEDAP)
2
BS
3
4
D
1
Újraindexelés a bázisállomástól való „távolság” alapján
G
62


Eseményvezérelt adatgyűjtés (Event-driven data gathering) statisztikus forgalom

Annak a valószínűsége, hogy egy adott y forgalom képződik a hálózaton:
N p ( )
 i


1 p i y i (1
 p i
)
1
 y i
Például: Az aktív node -ok y = (1,
N d
N
0, 1,
N-1 N-2 d
N-1 d
N-3
1, …,
N-3 1
1) d
1
BS
63


Valószínűségben optimalizálunk:
Pr

 
, , ,
 
A ,

 e
 
Két eset:

A hálózatban egy node átlagos fogyasztása K ütemre összegezve:
 
1
: k
K
N
N i   

1 i

1 y g i j

0 j
 A maximális fogyasztású node K ütemre összegzett energia felhasználása:
 
2
: max k
K 

1 i


 g i
N  y j



64

Adott:  - konfidencia
K:
K:
A a rendelkezésünkre álló telep energia esetén
Pr
Pr


 
 
2
A

A



Pr


 k
K

1

1
N i
N

1
Pr

 k
K

1 max i y i j i   




0 g
 j

A



 e
  g i
N y j




A



 e
 
A hálózat élettartama az az ütemszám, amelyre a fenti egyenlőség fennáll.
Kihívás: A „K” élettartam meghatározása polinomiális időben.
65

Az összenergia fogyasztás farokeloszlásának becslése
Chernoff határ
Union határ
Optimális csomag továbbítás kombinatorikus optimalizációval
66

Pr
  
A

 e
 i
 
 s

A farokeloszlás becslése > nagy eltérések elmélete > Chernoff határ

Az onoff modell logaritmus momentum generáló függvénye:
 i s
 log{ p e i sG i (1 p i
)}

A Chernoff határ minden s inf
> 0-
 ra felülről becsül, ezért mi azt az keressük, melyre a célfüggvényünk, azaz a lemerülési valószínűség minimális: s

: s i
N

1
 i
 
 sAN s*ot
Megoldás: Minimum keresés gradiens módszerrel:

      sgn


 i
N 

1 d
 i
  ds

A



A lemerülési valószínűség Chernoff határa:
Polinomiális időben megtalálja a minimumot!
Pr


1

A

 e i
N 

1
 i
 
 sAN

Az élettartam:
Pr

 k
K 

1
1
N
 k

A


 e
K
N  i

1
 i
( s
*
)
 s AN
~
K

 N i

1 log{
NAs
  p e i sG i
  p i
),
67

Optimális szenzorszám meghatározása lánc protokoll esetén
68

Az élettartam növelése komplex csomagtovábbítási stratégiák szerint (single hop és lánc kiterjesztései)


„Random shortcut” (véletlen rövidzár) protokoll
„HAPW – hop ahead in any possible way”
(bárki bárkinek küldhet előre) protokoll
Az élettartam meghatározása analitikus kifejezéssel, valamint polinomiális idejű optimumkereső algoritmus
69

A „Random shortcut”
(véletlen rövidzár) protokoll
A protokoll:
Csomag érkezik az i. node -ra „érmefeldobás” a i
:= Pr ( fej := a láncban a következőnek küldi a csomagot)
1-a i
:= Pr ( írás := rövidre zár a bázisállomás felé)
Motiváció:
“Pénz feldobás”
N d
N
N-1 N-2 d
N-1 d
N-3
N-3
Fej : a szomszéd csomópontnak küldi a csomagot g i energiával
Írás : rövidre zár, egyből a bázis állomásnak küldi a csomagot G i energiával
1
BS d
1
Bottleneck node
Cél: a opt
 arg max

K

70

1
N i i-1 l i
BS

λ i valószínűségi változó a láncban megtett út hosszát fejezi ki,
 iλ i az a node, amelyik az i ből induló csomagot rövidrezárja a bázisállomás felé,
 p
  i
 l i
 
1 a
 i
 i  a j annak a valószínűsége, hogy az iedik nodej i l i
1 on generált csomag l i hosszú úton marad a láncban.
Az iedik nodeon generált csomag energia szükséglete:
 i
:
 y i

 i  j i

1 g

G j i
  i


71

Pr



 k
K

1 i
N y i



 i   
N

1 j i

1 g j

G i
  i 




A




 l
1
...
Pr l
N



K k

1
N
N i

1
 i

A
  l
1 1
,...,

N
 l
N



Pr
   l
1 1
,...,

N
 l
N

Pr


A Pr


K k

1
N k
K

1
N i

1
N
 i i
N  

1
 i


A



A

 valószínűség Chernoff határának kifejezése: l
1 l
N e
N  i

1
 i
( , )
 sA
N
K
Pr
 
1
 l
1
,...,

N
 l
N
  e
 sA i
N 

1


 l i e
 i p
  i
 l i



Tömörebben a következő felső határ adható meg: ahol  i


 l i e
 i

1
 a l i
 l i j

1


1 a j

 a kiterjesztett logaritmus generáló függvény.
Pr

 i
N 

1
 i

A

 e
N  i

1
 i
( , )
 sA
K

N i

1


 l i e
 i
* s A
 

1
 a l i
 l i j

1


1 a j


72


Az energiafogyasztás farokeloszlása és annak Chernoff határa:

Pr max i

 k
K N 

1 j i y j
 g i
 
( ) i j
Ahol Li-Silvesterbecsléssel számítva:  i

G is
 
( ) i j 1
 




A


 e
K max i
 i
  
As
,
 log
 
 log





1 p y e g i



  y
   N p y e g i
A költség függvény kiszámítása az adott node átlagos terhelése és a várható fogyasztásának szorzata: g i y
 n i y a g i
  a G is
 ahol a terhelést a következő rekurzió adja meg: n i
  i n a i

1 i

1 i N 1,...,1
~
K

As max


 i

  
 max log i







1
As
  p y e n
( ) i y
 a i g i
  a i G is






73

74

Az élettartam növelése random shortcut (véletlen rövidzár) modell használatával
Random shortcut
Lánc
Szenzorok elhelyzése
1. Determinisztikusan egyenletes
2. Exponenciális
3. Normális
4. Egyenletesen véletlen eloszlás
75

A vizsgált protokollokkal elérhető élettartam javulás a single hophoz képest:
HAPW
Random shortcut (véletlen rövidzár)
Véletlenszerű energia tudatos
Energia tudatos
Lánc
4.7x
4x
3.5x
3x
2x
76

Berkeley Crossbow Motes
Érzékelés: hőm., fény, szeizmikus, mágneses tér
RF 916 MHz
Hatósugár : 30-100ft
Processszor: microcontroller, 40Mhz, 128 kB flash

Vizsgált protokollok:

Lánc



Singlehop
Véletlen Rövidzár
Energia Tudatos
77

Szenzoriális elemek (mote)
• Hőmérséklet
• Nyílászárók
• Villanykapcsolók
• Bioszenzor
(pulzoximéter)
Mobil/statikus hálózati elemek
RF kommunikáció (433MHz)
Vezetéknélküli adatgyűjtő bázisállomás
Mote
0
Adatfeldolgozó/ve zérlő/ archiváló egység
Hálózati hozzáférés (GSM,
GPRS, Internet)
Energiaérzékeny protokollok és adatközlési módok
Kommunikációs protokollok optimalizálása!
Adatfúzió, profildefiníció, döntések és beavatkozások vezérlése
Szabványos hálózati protokollok, adatbázis kezelése és a hálózat távvezérlése
78

„Energia tudatos”
Élettartam növekedés
2,8x
„Véletlen rövidzár”
„Single hop”
„Lánc”
2,6x
2x
1x
79