asdas dsdas d asdasdasd sad asdsadasd asd das

szdasda dasd asd afdsf g fdgsdfg sdgfg dfgfdgdfsdf

1. Copyright: A. Umar
Wireless Personal Area Networks

•WPANs
• Bluetooth
•Home Networking
•UWB Overview
•Wireless Sensor Networks
Amjad Umar

2. Copyright: A. Umar
WPANs
•Short range networks (< 10 meters)
•Used in homes, cars, small offices
•Can be interconnected to form large
networks
•IEEE 802.15 is the main standards
environment
•Many active areas of work: Bluetooth,
UWB, Wireless sensor networks, Zigbees

3. Copyright: A. Umar
Bluetooth Wireless LANs

•Overview
•Applications and Examples
•Piconets and Scatternets
•Standards Overview
•Core standards

4. Copyright: A. Umar
Bluetooth Overview
•Founders: Ericsson, IBM, Intel, Nokia, Toshiba; May 98
•Currently: Over 1000 companies
•Low-cost, short range radio link between mobile PCs, phones and
other portable devices
•2.4 GHz ISM band (unlicensed): Short packets, fast-hopping, and FEC
limits impacts of interference
•Software for service and device discovery
•Typical application: cellular phone to PDA or earphone
•Supports open-ended list of applications
–Data, audio, graphics, video
•Many products from Nokia, Motorala, Apple, etc.
•Bluetooth.com and palowireless.com/bluetooth have great deal of info

5. Copyright: A. Umar
Bluetooth
Cellular
Network
PSTN
Access
Point
Wired
LAN
Bluetooth Piconet
(1 Mbps, 10 meters)

6. Copyright: A. Umar
Bluetooth Application Areas
•Cable replacement
–Eliminates need for numerous cable
attachments for connection (e.g., RS232)
•Data and voice access points
–Real-time voice and data transmissions
•Ad hoc networking
–Device with Bluetooth radio can establish
connection with another when in range

7. Copyright: A. Umar
Piconets and Scatternets
•Piconet
–Basic unit of Bluetooth networking
–Master and one to seven slave devices
–Master determines channel and phase
•Scatternet
–Device in one piconet may exist as master or slave in
another piconet
–Allows many devices to share same area
–Makes efficient use of bandwidth

8. Copyright: A. Umar
Bluetooth Configurations
A
F
B
HG
E CD
Master
Slave/Master
Slave Slave
Slave
Slave Slave Slave
•2.4 GHZ ISM band supports around 80 physical channels with 1 MHz. bandwidth
•These 80 channels are managed through piconets and scatternets
•All radios in a scatternet share the same frequency hopping (FHSS)

9. Copyright: A. Umar
Bluetooth Piconets
Master
Slave Slave
Slave
/Master
Slave
Slave
Piconet1
(Cubicle 1)
Piconet3
(Cubicle3)
PC
Cellular
Phone
Ear
Phone
PC
PC
printer
Master
Slave
SlavePiconet2
(Cubicle2)
PC
PC
printer

10. Copyright: A. Umar
Bluetooth versus Wi-Fi
Table 7 2: Bluetooth versus Wi-Fi
‑
Factor Wi-Fi Bluetooth
Data Rate 11 Mbps 1 Mbps
Distance Covered
(range)
100 meters 10 metters
Application focus Cable replacement Connection to
corporate networks
Ease of use Piconets good for
small networks
Complex even for 2
devices
Security Short distance,
multiple levels (link
level, app level)
WEP
Power Very low power
(smaller devices such
as consumer
electronics)
High power
 

11. Copyright: A. Umar
State Transitions in Bluetooth
Standby
Inquire
Page
Active
Typical Scenario:
1.Devices initially in standby mode
2.Issue an inquire (I am available, does someone need me)
3.Devices scan the inquire list and then page the ones they want to invite
4.Devices go into an active transfer mode (Piconet)
5.If too many in a piconet, go into park-sniff-hold mode
6.After transfer go into standby mode
Park,
Sniff,
Hold-
Disconnected
State
Connecting
State
Active State
Low-Power
States

12. Copyright: A. Umar
Bluetooth Standards Documents
•Standards specifications
–Details of various layers of Bluetooth protocol
architecture (more than 1500 pages)
•Bluetooth is a layered protocol architecture
–Core protocols (5 layer) - required
–Cable replacement and telephony control protocols
–Adopted protocols (PPP, WAP,,) .
•Profile specifications
–Use of Bluetooth technology to support various
applications

13. Copyright: A. Umar
Protocol Architecture
•Core protocols
Radio layer - Bluetooth transceiver operating in the 2.4 GHz
Baseband layer -Bluetooth Link Controller (LC) low-level link
routines (complex).
Link Manager Protocol (LMP) is used by the Link Managers (on
both side) for link
Host Controller Interface (HCI) a command interface to access to
hardware status and control registers.
Logical Link Control and Adaptation Protocol (L2CAP) supports
higher level protocol multiplexing
Service Discovery Protocol (SDP) applications to discover which
services are provided by a Bluetooth device

14. Copyright: A. Umar
Bluetooth Stack
Bluetooth Radio
Baseband
Logical Link Control and Adaptation Protocol ( L2CAP)
Link Management Protocol (LMP)
RFCOMM
Audio
SDP
TCS
Bin
AT-
Commands
PPP
IP
TCP UDP
WAP
WAE
OBEX
vCard/vCal
Host Controller Interface
Shaded areas (see legend) represent different families of Bluetooth Protocols

Core
Cable
replacement
Telephony
control
Adopted
Legend

15. Copyright: A. Umar
Protocol Architecture (cont.)
Cable replacement protocol: provides emulation of serial ports over
the L2CAP protocol (e.g., emulates EIA RS232 communications over
the Bluerooth baseband layer.
•Telephony control protocols: (TCS BIN) defines the signalling and
control sequences needed for telephone conversations over
Bluetooth.
•Adopted protocols: minimize new by Bluetooth:
PPP: used to transport IP packets over point-to-point links such as dial-up lines.
TCP/UDP/IP. foundation protocols for the Internet
OBEX: The object-exchange protocol developed for the exchange of objects
(similar to HTTP, vCard and vCalendar)
WAE/WAP: The Wireless Application Protocol and Wireless Application
environment are included in Bluetooth.

16. Copyright: A. Umar
Usage Models
File transfer: to transfer files over Bluetooth. protocols used can be
SDP or OBEX.
Internet bridge (Dial-Up networking): to wirelessly connect a PC with
a cordless modem or a cellular phone uses PPP and AT protocols
LAN access: connect a piconet device to access a LAN. uses SDP
and PPP-IP protocols.
Synchronization: synchronize device-to-device PIM (personal
information management) information such as calendars and phone
books. The model uses OBEX and IrMC (infrared mobile
communications)
Three-in-one phone: Telephone headsets and handsets can be used
in this model as audio input and output devices. This model uses
Audio, SDP, and AT commands.

17. Copyright: A. Umar
Usage Models
L2CAP
File Transfer Application
SDP
OBEX
RFCOMM
a) File Transfer
L2CAP
Modem Emulation or Driver Application
SDP
AT Commands
RFCOMM
b) Dial-Up Networking
L2CAP
LAN Access Application
SDPPPP
RFCOMM
c) LAN Access
PPP
IP
L2CAP
Synchronization Application
SDPOBEX
RFCOMM
c) LAN Access
IrMC

18. Copyright: A. Umar
Radio Specification
•2.4 GHZ ISM band that can support around 80 physical channels with 1
MHz. bandwidth
•These 80 channels are managed through piconets and scatternets.
•Several classes of transmitters
–Class 1: Outputs 100 mW for maximum range
•Power control mandatory
•Provides greatest distance
–Class 2: Outputs 2.4 mW at maximum
•Power control optional
–Class 3: Nominal output is 1 mW
•Lowest power
•Much less powerful than cellular phones (GSM operates at 1
to 3 Watts)

19. Copyright: A. Umar
Baseband Specification
•Very complicated
•Specifies
–Frequency hopping
–Physical Links
–Bluetooth Packet Fields
–Error correction
–Logical Channels
–Bluetooth Audio
–Bluetooth Security

20. Copyright: A. Umar
•Frequency Hopping in Bluetooth. FH occurs by jumping from one
channel to another (80). (all devices on a piconet share same).
•Physical Links between Master and Slave.
Synchronous connection oriented (SCO). point-to-point connection of
master and slave. Mainly for voice
Asynchronous connectionless (ACL). Point-to-multipoint link between
master and all slaves is also supported.
Bluetooth Packet Fields. Single slot & multiple slot
consist of three fields:
Access code – used for timing synchronization, offset compensation, paging,
and inquiry
Header – used to identify packet type and carry protocol control information
Payload – contains user voice or data and payload header, if present
Baseband Specification

21. Copyright: A. Umar
•Error Correction Schemes:. different types of error correction
codes that includes ARQ.
•Logical Channels and Channel Control: Bluetooth defines five
types of channels for different types of payload such as Link
control (LC), Link manager (LM), User asynchronous (UA), User
isochronous (UI), and User synchronous (US).
•Bluetooth Audio. choice of two
– pulse code modulation (PCM)
–continuously variable slope delta (CVSD) modulation.(variable step)
–The choice is made by link manager
•Bluetooth Link Security. includes Authentication, Encryption
(privacy) and Key management.
Baseband Specification (cont.)

22. Copyright: A. Umar
Link Management Protocol (LMP)
•LMP manages the radio links between Bluetooth
masters and slaves.
•LMP specifies exchange of LMP PDUs
•PDUs supported by the LMP:
–General response
–Security Service
•Authentication
•Pairing: establish a key between authenticated pairs
•Change link key
•Change current link key
•Encryption

23. Copyright: A. Umar
L2CAP
•Provides a link-layer protocol between entities with
a number of services
•Similar to LLC
•Relies on lower layer for flow and error control
•Makes use of ACL links, does not support SCO links
•Provides two alternative services to upper-layer
protocols
–Connection service
–Connection-mode service

24. Copyright: A. Umar
Cordless Systems and
Wireless Local Loop

•Cordless networks
•Wireless MANs (Wireless Local
Loops)

25. Copyright: A. Umar
Cordless Phone
Base UnitHandset
Public
Switched
Telephone
Network
(PSTN)
•Basically a cellular phone with no location services
•Typical coverage is 100-300 meters
•User owns handset and base unit -- no initial need for standards

26. Copyright: A. Umar
Cordless System Operating
Environments
•Residential – a single base station can
provide in-house voice and data support
•Office
–A single base station can support a small office
–Multiple base stations in a cellular
configuration can support a larger office
•Telepoint – a base station set up in a public
place, such as an airport

27. Copyright: A. Umar
Time Division Duplex (TDD)
•Also known as time-compression multiplexing
•Data transmitted in one direction at a time, with transmission
between the two directions
–Simple TDD: Bit stream is divided into equal segments, compressed in time to a
higher transmission rate, and transmitted in bursts
–Wireless TDD typically used with TDMA
•A number of users receive forward channel signals in turn and then transmit
reverse channel signals in turn, all on same carrier frequency
•TDMA/TDD used more often :
•Improved ability to cope with fast fading (base station can detect strongest signals
and send at the same)
•Improved capacity allocation (can assign more slots to forward channel for
improved forward traffic)

28. Copyright: A. Umar
TDD
A1 A2B1 B2
A1 A2B1 B2
Base
Station
Handset
•Base station sends data blocks A1, A2
•Handset sends data blocks B1, B2
Time

29. Copyright: A. Umar
Cordless Standards
•DECT (Digital Enhanced Cordless Telecommunications) developed in
Europe
•PWT (Personal Wireless telecomm) developed in US
•DECT is most commonly used standard (mainly
•DECT Architecture (suited for voice)
– Physical layer – data transmitted in TDMA-TDD frames over one of 10
RF carriers
–Medium access control (MAC) layer – selects establishes/releases
connections on physical channels; supports three services:
•Broadcast
•Connection oriented
•Connectionless
–Data link control layer – provides for the reliable transmission of
messages using traditional data link control procedures

30. Copyright: A. Umar
Home R/F
Wireless LAN2
(Master/slave)
First Floor
= Wireless Adapter
Wireless connection
Wireless connection
Second Floor
Printer
Baby
Monitor
TV
Phone
Laptop
Laptop
xDSL, cable,
ISDN, or other
Main PC
Internet
Gateway

31. Copyright: A. Umar
Home R/F Specification
HomeRFHomeRFPHYSICAL LAYERPHYSICAL LAYER
IPIP
TCPTCP UDPUDP
INTERNETINTERNET
APPLICATIONSAPPLICATIONS
VOICEVOICE
APPLICAPPLIC--
ATIONSATIONS
HomeRFHomeRFMAC LAYERMAC LAYER
DECTDECT
150 feet,
10 Mbps
www.homerf.org

32. Copyright: A. Umar
How SWAP (Shared Wireless Application
Protocol) Supports Voice and Data
SWAP Frame
DECT
Uses TDMA
Good for voice
802.11
Uses CSMA/CA
Good for data
SWAP Frame = CSMA/CA + TDMA
Good for voice and data

33. Copyright: A. Umar
UWB -- Overview
•Ultra Wideband (UWB) is emerging as a new wireless personal
area network technology.
•Originally developed in the 1960s for the military.
•FCC approved the commercial implementation of UWB in
February 2002, within limits.
•UWB provides high data rates (around 50 Mbps) in very short
distances (10 meters).
•UWB is a radio system that uses narrow pulses (millions of pules
per second) for communication and sensing by using short-range
radar.
•UWB radio sends data in millions of pulses across a wide
frequency band
•Lgal in the US as long as it uses less power than normal radio
frequency leakage.

34. Copyright: A. Umar
Wireless Sensor Networks
(Overview)
•WSNs) typically consist of small, low-powered devices
(sensors)
•Sensors can be developed to measure temperature,
humidity, motion, color changes in a painting, or any other
measurable thing.
•Most WSNs consist of millions of tiny processors
communicating over slow wireless networks,
•WSNs may consist of devices with a wide range of
computation, communication, and sensing capabilities.
•The WSNs may use Bluetooth or IEEE 802.11 networks

35. Copyright: A. Umar
Sensor Node (Mote)
CPU
Sensor
Interface
Radio
Interface
Sensor Node (Mote)
Battery

36. Copyright: A. Umar
WSN Hierarchy
Network of
Tiny
Sensors
Network of
Tiny
Sensors
Network of
Powerful
Sensors
Powerful
server

37. Copyright: A. Umar
WSN Design
A
C
B
E
D
Access
Point
General
Network
(Corporate
LAN,
Internet)
X Y
Not Used
WSN

38. Copyright: A. Umar
WSN Protocol Stack
PHYSICAL LAYER
•Frequency Allocations
•Transmission and Propagation (Fading, Scattering, etc.)
•Signal Encoding (Modulation/Demodulation)
DATA LINK LAYER
•Error Detection and Correction
•Contention Management (Multiple Access Control)
•Power Management
NETWORK LAYER
•Addressing
•Network Routing
TRANSPORT LAYER
•End-to-End Message Delivery
•End-to-End Error Control
HIGHER LAYERS (APPPLICATION, PRESENTATION, SESSION),
•Data Applications
•Voice applications

39. Copyright: A. Umar
Summary

•WPANs
• Bluetooth
•Home Networking
•UWB Overview
•Wireless Sensor Networks