DAYANANDA SAGAR COLLEGE OF ENGINEERING
(An Autonomous Institute Affiliated to VTU, Belagavi)
Shavige Malleshwara Hills, Kumaraswamy Layout, Bengaluru-560078
Department of Information Science and Engineering
(Accredited by NBA & NAAC with ‘A’ Grade)
WIRELESS AND MOBILE NETWORKS
17IS8SEWMN
Faculty Name:
Mrs. Radhika T V
Assistant professor
Dept. of ISE,DSCE
Dept of ISE,DSCE
Module 4
Wireless Personal Area Networks
Dept of ISE,DSCE
Learning objectives
•Tounderstandthemainphysical,architecturalandnetworkingissuesof
WPAN.
•To know about the design considerations of WPAN.
•To study the MAC and routing protocols of WPANs.
•To know about the WPAN technologies.
•To illustrate the applications of WPANs.
Dept of ISE,DSCE
Wireless Personal Area
Network(WPAN)
• A personal, short distance area wireless network for
interconnecting devices centered around an individual person's
workspace.
• Address wireless networking of mobile computing devices
such as PCs, PDAs, peripherals, cell phones, pagers and
consumer electronics.
• Are also called short wireless distance networks.
• Extends to 33 feet (10 meters) or less.
• Major technologies of WPAN are Bluetooth (802.15.1), and
ZigBee (802.15.4)
Dept of ISE,DSCE
Network architecture
Consists of the Master-Slave configuration.
Dept of ISE,DSCE
WPAN topologies
A Two connectivity topologies are defined in WPAN.
• Piconet
• scatternet.
Dept of ISE,DSCE
Piconet
• A piconet is a WPAN formed by a device serving as a master
and one or more devices serving as slaves in the network.
Piconet Master/Slave configuration.
Dept of ISE,DSCE
Scatternet
• A scatternet is a collection of operational
piconets overlapping in time and space.
• A device that is a member of two or more
piconets is said to be involved in a scatternet.
WPAN components
• WPAN components are in a range from very low power
devices with very low communication possibilities to high-end
devices covering the full range of communication standards.
• Requirements
– The devices in a WPAN must be low cost.
– The devices must operate for a long time from simple
battery.
– Because of their large number, they must be small such that
the user is hardly aware of their presence.
– The devices are small in size.
– Ease of use.
WPAN technologies
• The IEEE 802.15 is the IEEE working group established in
January 1999 to develop standards for WPAN.
Bluetooth (IEEE 802.15.1)
• Protocol stack
Physical layer
• The Baseband is the physical layer of the Bluetooth.
• When the data is received, baseband checks for
accuracy and extract the information from the packet.
It compresses the data, packetizes using identifiers
and error correction information.
• The received packet is checked for errors and
decompressed.
Physical layer (Contd..)
• The Bluetooth standard supports two types of link:
– synchronous connection oriented links (SCO)
– asynchronous connectionless links (ACL)
• SCO is used primarily for voice communications and
ACL is used for packet data. 13 different packet types
are defined for the baseband layer of the Bluetooth
system.
Physical layer (Contd..)
• The packets are
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
ID
NULL
POLL
Frequency hopping synchronization(FHS)
Data-medium rate 1(DM1)
Data-high rate 1(DH1)
AUX1
DM3
DH3
DM5
DH5
HV1
HV2
HV3
Data voice (DV)
Physical layer specifications of 802.15
Problem 1
Problem 2
Link layer
• Link
management (LM) is
the
fourth layer
of Bluetooth specification.
• Each Bluetooth device has it own link manager.
• It is responsible for the following functions:
– To send and receive data and it is able to identify the
sending device and perform authentication and ciphering
functions.
– It will determine what type of frame to use on a slot-by-slot
• basis.
– It directs how devices will listen for transmissions from
other devices or put devices into various power-save modes
according to the Bluetooth-specified procedures.
Application software
• The last basic part of Bluetooth system is application
software.
• The application software is set in the device that
operates an application over the Bluetooth protocol
stack.
• This software allows the mobile phone, PDA or
keyboard to do its job.
• In order to interoperate with each Bluetooth devices,
all of them must have compatible sections in their
Bluetooth stack.
IEEE 802.15.2 (Coexistence)
• Concerned with coexistence issues that arise when
two wireless systems share an environment of
operation.
• It has two goals:
– to quantify the effects of mutual interference
between WPAN and WLAN devices, and
• to establish mechanisms for coexistence of WPAN
and WLAN (e.g. IEEE 802.15.1 and IEEE 802.11b)
at both the MAC and PHY layer.
IEEE 802.15.2 (Contd..)
• Mechanisms can be broadly categorized as
collaborative or non-collaborative.
– A collaborative mechanism that facilitates
coexistence needs to have coordinated scheduling
efforts, such as TDMA or CSMA.
• Adaptive frequency hopping, MAC scheduling, and
transmit power control schemes are noncollaborative mechanisms for coexistence
HR-WPAN (IEEE 802.15.3)
• IEEE 802.15.3 is a standard for high-rate (11 to 55
Mb/s) WPANs.
• HR-WPAN mainly focus on power management, QoS
and security.
• The main purpose of IEEE 802.15.3 is to provide low
cost, low complexity, low power consumption, and high
data rate connectivity for wireless personal devices.
• It is designed to support at least 11 Mbps data rate
within at least 10 meters range.
• The vision of HR-WPAN is “to promote wireless
multimedia connectivity and interoperability
between devices in a personal area network”.
IEEE 802.15.3 Channels
Reference model-IEEE 802.15.3
LR-WPAN (IEEE 802.15.4):
ZigBee
• IEEE 802.15.4 task group investigates low
data rate WPAN solutions with a battery life
ranging from months to several years and a
very low complexity.
• The spectrum allocation for this standard is as
follows: 1 channel at 868 MHz, 10 channels in
the 915 MHz band, and 16 channels in the 2.4
GHz band.
Topology models
ZigBee stack
ZigBee stack (Contd..)
• Physical layer: The physical layer defines radio
characteristics and supports the 2.45GHz and
868/915MHz radio bands.
• MAC layer uses CSMA-CA (carrier sense multiple
access with collision avoidance) channel access
mechanism.
• Network layer performs tasks include starting the
network (coordinator), assigning network addresses,
adding and removing network devices, routing
messages, applying security, and implementing route
discovery.
• Application layer consists of the Application
Framework, ZigBee Device Object (ZDO), and
Application Support (APS) Sublayer.
IEEE 802.15.5: Mesh WPAN
• A mesh WPAN employs one of two connection
arrangements, full mesh topology or partial
mesh topology Mesh networks have the
capability to provide extension of network
coveragewithout increasing transmit power or
receive sensitivity, enhanced reliability via
route redundancy, easier network configuration
and better device battery life due to fewer
retransmissions.
WPAN applications
• Automotive
– The use of a WPAN is most suitable for vehicles as the distances
between devices within the vehicles will be limited to an
acceptable range and the use of cables to connect devices are
cumbersome. For this reason the WPAN can be used.
• Information sharing
– The use of IEEE 802.15 devices has been developed for
workplace use with le sharing, printing, and multimedia
communications.
• Home automation
– The interconnectivity within the home with an increase in
digitally based devices will see data transfer much more
prominent. Currently using infrared communications, owners of
personal digital assistants can download software to use the
device as a remote control. In such application scenarios the
WPAN technology is the most suitable one.
WPAN applications (Contd..)
• Health monitoring
– With many advantages including low-power consumption, small size,
simple protocol, wide compatibility, and so on, WPAN is applied to
many medical applications including telemedicine system, pervasive
and continuous patients monitoring and wireless-integrated medical
devices.
• Office automation
– Notebook, printer, PDA, desktop computer, fax machine, mouse,
keyboard - all can be instantly connected via Bluetooth technology.
Stay completely up-to-date, at any where and any time.
• RFID applications
– Some of the RFID applications, using WPAN technologies finds the
applications like asset tracking, people tracking, inventory tracking, etc.