overview of wireless networks anuj puri. outline projections of wireless growth cellular networks...
Post on 22-Dec-2015
222 views
TRANSCRIPT
![Page 1: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/1.jpg)
Overview of Wireless Networks
Anuj Puri
![Page 2: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/2.jpg)
Outline
Projections of wireless growthCellular NetworksWireless LANs and BluetoothWAPAd Hoc wireless networks
![Page 3: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/3.jpg)
0
200
400
600
800
1,000
1,200
1998 1999 2000 2001 2002 2003
PCs
TV households
Mobile phone subscribers
Millions of subscribers worldwide
HUGE EXPECTATIONS AND INVESTMENT IN M-DATA
46
17
98
35
U.K. licenses
German licenses
French licenses
UMTS license fee to date (not ex-haustive)
European UMTS spectrum auctions
$ Billions
![Page 4: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/4.jpg)
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
SUCCESS OF I-MODE IN JAPAN
Feb 22,1999 start
Aug 8
Nov 18
Dec 23
May 31,
2000
i-Mode has already exceeded 12 million subs
Number of i-mode subscribersThousands
![Page 5: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/5.jpg)
Outline
Projections of wireless growthCellular NetworksWireless LANs and BluetoothWAPAd Hoc wireless networks
![Page 6: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/6.jpg)
Cellular Networks
Mobile phones (internet access) Cellular concept Frequency reuse Handoffs
![Page 7: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/7.jpg)
Organization of Cellular Networks
BS(base station)
MSC (mobile switching center)
HLR (home locationregister)
VLR (visitorlocation register)
BS – modulation, antennaMSC – switchingHLR – information (location) about “home” usersVLR – information about visiting users
![Page 8: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/8.jpg)
How does a call get to the mobile ?
Suppose (510) 643 - 1111 is roaming in the (703) area code Cell phone registers with the (703) MSC, which adds it to (703) VLR and informs the (510) HLR of the location of the cell phoneA call comes in for (510) 643 – 1111. Then (510) MSC queries its HLR, and directs the call to the (703) MSCThe (703) MSC forwards the call to the mobile
![Page 9: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/9.jpg)
Handoff
MSC
HLR
VLR
BS B
BS A
• Mobile is associated with BS A• It continuously monitors the signal strength from BS A, and BS B• When the signal strength from BS B becomes stronger, it associates with BS B
![Page 10: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/10.jpg)
Evolution of cellular industry
First Generation
Analog Voice
AMPS
Second Generation
Digital Voice
GSM, IS-95, IS-136, PDC
Third Generation
Packet data
W-CDMA, EDGE,CDMA2000
![Page 11: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/11.jpg)
MULTIPLE MIGRATION PATHS ARE AVAILABLE
2G
*FootnoteSource: Sources
2.5G 3G 3+G 4G
PDC
GSM
TDMA (IS-136)
CDMA
(IS-95A/B)
WCDMA HSPDA
OFDM
Software radio
Array antennas
GPRS
EDGE
CdmaOne1XRTT
1XEVDO/HDR1 xtreme
cdma2000MC-3X
![Page 12: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/12.jpg)
3G Networks
BS B
BS A
SGSN
SGSN
GGSN
Access NetworkPhysical layer/ MAC IP based Core Network
Routing/network handoff
![Page 13: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/13.jpg)
Mobile IP
Home Agent (HA) – keeps track of where the mobile is (similar to GGSN)Foreign Agent (FA) – delivers packets to the mobile in the foreign network (similar to SGSN) All packets for mobile arrive at HA which “tunnels” them to mobile’s FAWhen mobile moves to a new location, it informs its HA of the new FA
![Page 14: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/14.jpg)
Outline
Projections of cellular growthCellular NetworksWireless LANs and BluetoothWAPAd Hoc wireless networks
![Page 15: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/15.jpg)
Wireless LANs and Bluetooth
For indoor use or operation over small areasOperates in ISM (Industrial Scientific and Medical) BandSpread Spectrum techniques
![Page 16: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/16.jpg)
Main Components of 802.11
Roaming
Medium AccessControl
Physical Layer
![Page 17: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/17.jpg)
Physical Layer
Operate in unlicensed bands In U.S., 900 MHz, 2.4 GHz, 5.7GHz Various restrictions on use
Spread Spectrum techniques Direct Sequence Spread Spectrum Frequency Hopping Spread Spectrum
![Page 18: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/18.jpg)
Medium Access Layer
Why not use Ethernet protocol ? Sender cannot detect collision
senders power overwhelms other transmitters
carrier sense does not necessarily mean collision
Receiver has a better idea of whether a collision is happening
Hidden Terminal / Exposed Terminal Problem
![Page 19: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/19.jpg)
Hidden and Exposed Terminals
A B C
A and B can hear each otherB and C can hear each otherA and C can not hear each other
Both A and C want to transmit to B (Hidden Terminal)B wants to transmit to A when C is transmitting to someone else (Exposed Terminal)
![Page 20: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/20.jpg)
MACA
A wants to transmit to B- A sends a RTS to B- B replies with a CTS- A sends data to B
RTS: contains the length of dataCTS: also contains the length of data
Everyone hearing RTS stays quiet for CTSEveryone hearing CTS remains quiet for RTS
![Page 21: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/21.jpg)
802.11 MAC
CSMA/CA (Carrier Sense / Collision Avoidance) Carrier Sense (check to see if
someone is transmitting) Collision Avoidance (RTS-CTS-Ack)
Acknowledgments at link levelFragmentation and Reassembly
![Page 22: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/22.jpg)
Basic Scheme
RTS
CTS
Data
ACK
NAV (RTS)NAV (CTS)
Defer Access
Back-off Window
![Page 23: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/23.jpg)
Some Terminology
AccessPoint
AccessPoint
Basic Service Set (BSS)
Extended Service Set (ESS)
DistributionSystem
![Page 24: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/24.jpg)
Bluetooth
Master-slave architectureFrequency hopping systemSystem design for cheap production
![Page 25: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/25.jpg)
Outline
Projections of cellular growthCellular NetworksWireless LANs and BluetoothWAPAd Hoc wireless networks
![Page 26: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/26.jpg)
WAP (or the web for small wireless devices)
Why not use wired web infrastructure (html, http, tcp) ? HTML too feature rich for small devices TCP may have too much overhead for low
bandwidth wireless links
WAP (Wireless Application Protocol) An optimized stack for wireless applications Mobile talks with the WAP gateway WAP gateway talks with the web server on
the internet
![Page 27: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/27.jpg)
WAP Architecture
WAP Gateway
Internet
Web Server
WAP HTTP/TCP
![Page 28: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/28.jpg)
WAP Stack
Bearer ServicesSMS, CSD
WDP (DatagramProtocol)
WTP (TransactionProtocol)
WSP (SessionProtocol)
WML, etc
IP
TCP/UDP
HTTP
HTML
![Page 29: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/29.jpg)
Gateways/Proxies for Wireless Devices ?
Gateway Internet
Web Server
2nd Generation: Low speed data, small displays WAP3rd Generation: Higher speed, IP address for each station Proxy/ Gateway ?
![Page 30: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/30.jpg)
Outline
Projections of wireless growthCellular NetworksWireless LANs and BluetoothWAPAd Hoc wireless networks
![Page 31: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/31.jpg)
Ad Hoc Wireless Networks
No base stations or infrastructure requiredMulti-hop wireless networks Each node can talk with a neighbor
Applications Sensor networks Intelligent control applications (i.e,
IVHS)
![Page 32: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/32.jpg)
Ad Hoc Wireless Networks
MAC schemesAddressingRouting
![Page 33: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/33.jpg)
Geographical Routing Algorithm
Assumptions:• Each node knows its own position and its neighbors’ position• Nodes don’t know the global topology• Destination address is a geographical position to which the packet is to be delivered
Geographicalnetwork
![Page 34: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/34.jpg)
A Simple Routing Algorithm
Routing Decision: Route to the neighbor which is nearest to the packet destination
Source
Destination
![Page 35: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/35.jpg)
Problem with Simple Routing
Source
Destination
• Simple routing doesn’t always work• The Geographical routing algorithm is an extension of the simple routing algorithm.
Wall
![Page 36: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/36.jpg)
Routing Tables
Routing Table for Station n:
(x,y) position Neighbor
a(12,4)
b
Position of n -
Position of neighbor a a Routing Algorithm:
• Packet arrives for position p at node n• Node n finds the position to which p is closest and forwards to the corresponding neighbor
Position of neighbor b
Routing Tables:• Routing tables contain some additional entries beside neighbors
![Page 37: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/37.jpg)
Route Discovery
Packet gets “stuck” when a node does not have a neighbor to which it can forward the packetWhen a packet is stuck, a Route Discovery is started to destination DA path p = s(0) s(1)...s(k) is found to DEntry [ position(D), s(i+1) ] is added to the routing table of s(i)
![Page 38: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/38.jpg)
ExamplePos(A) = (1,1)Pos(B) = (2,2)Pos(C) = (3,1)
Links:A ---- BB ---- C
A
B
C
Pos(A) ---
Pos(B) B
Pos(B) ---
Pos(A) APos(C) C
Pos(C) ---
Pos(B) B
• A gets a packet for Pos(C)• A forwards it to B because pos(B) is closer to pos(C)• B forwards it to C because pos(C) is closer to pos(C)
Pos(C)
Pos(C)
Pos(C)
![Page 39: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/39.jpg)
Route Discovery
Pos(A) = (1,1)Pos(B) = (2,2)Pos(C) = (3,1)Pos(D) = (2.5,0)Links:A ---- BB ---- CC ---- D
B
C
• A gets a packet for Pos(D)• Packet gets stuck at A because Pos(A) is closest to Pos(D)• Initiate route discovery for D from A• Update the routing tables and forward the packet
Pos(D)
Pos(D)
A
D
Pos(A) ---
Pos(B) B
Pos(D) ---
Pos(C) C
Pos(B) ---
Pos(A) A
Pos(C) C
Pos(C) ---
Pos(B) B
Pos(D) D
Pos(D) B
Pos(D) C
Pos(D)
Pos(D)
Pos(D)
![Page 40: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/40.jpg)
Theorem: There are no cycles in the routing tables.
--- Think of the routing entry [ position(D), a] as a path with end point D. Then we are always following a path whose end point is closer to the destination then the end point of the previous path.
![Page 41: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/41.jpg)
A Geometrical View
Routing Table for Station n:
(x,y) position Neighbor
a(12,4)
b
Position of n -
Position of neighbor a a
Position of neighbor b
Vornoi View:
n
a
b
(12,4)
• Route discovery is initiated if packet destination falls within the cell containing station n• Each route discovery causes the cell with station n to get split
![Page 42: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/42.jpg)
Routing Table Size
How many “splits” before station n is alone in its cell ?• Each split reduces the cells area ~ 1/2• The cell’s area when station n is alone in the cell ~ 1/N where N is the number of stations in a unit area => log(N) splits before station n is alone in its cell
Each split causes a route discovery
Each route discovery causes L entries to be added to the routingtables where L is the average route discovery path length=> O( L log(N) ) entries in routing table of each station
![Page 43: Overview of Wireless Networks Anuj Puri. Outline Projections of wireless growth Cellular Networks Wireless LANs and Bluetooth WAP Ad Hoc wireless networks](https://reader035.vdocuments.net/reader035/viewer/2022081519/56649d775503460f94a59698/html5/thumbnails/43.jpg)
Outline
Projections of wireless growthCellular NetworksWireless LANs and BluetoothWAPAd Hoc wireless networks