Mum

1. Wireless and Mobile Communications
ECE – 403
Dr. Simranjit Singh
Assistant Professor
Department of Electronics and Communication
Punjabi University
Email: simranjit.eced@gmail.com

2. Books
TEXT BOOK
Wireless Communications: Principles and Practice
by Theodore S. Rappaport
REFERENCE BOOKS
Wireless Communications
by Andrea Goldsmith
Digital Communications
by John G. Proakis, Masoud Salehi
The syllabus can be downloaded from the following link:
http://punjabiuniversity.ac.in → Download syllabus

3. History of Wireless and Mobile Communication
• 1831: Faraday started experimenting with electromagnetic
(EM) waves
• 1864: Maxwell who had been working on a mathematical
model for EM waves publishes his first paper on the subject
• Maxwell theorized that the EM waves would travel close to the
speed of light
• Three scientists further worked on the Maxwell’s Equations:
Lodge, Tesla and Hertz
• 1887: Hertz proves the existence of EM waves (spark
transmitter generates a spark in a receiver several meters
away)
• The unit of frequency is named after Hertz !!
• 1Hertz = 1 cycle/second

4. • 1896: Guglielmo Marconi demonstrates wireless telegraph
to English telegraph office
• 1897: ``The Birth of Radio'' - Marconi awarded patent for
wireless telegraph
• 1897: First ``Marconi station'' established on Needles island
to communicate with English coast
• 1898: Wireless telegraphic connection between England
and France established
• 1901: Marconi successfully transmits radio signal across
Atlantic Ocean from Cornwall to Newfoundland
• 1902: First bidirectional communication across Atlantic
• 1909: Marconi awarded Nobel prize for physics
• 1914: First voice over radio transmission

5. Mobile phone subscribers per 100 inhabitants 1997-2007
97/100
(Developed)
49 /100
(World)
45/100
(Developing)

7. Modern Wireless Communication
• Initially, the sole purpose of the mobile phone was to transmit
voice
• However, with the development of cellular technology, the next
generation networks are supporting high speed data
communications (Internet) in addition to voice communication
• Fixed wireless networks are overtaking fiber optic and copper
cables between fixed points several kilometers apart
• Wireless networks have also been used increasingly in homes
as replacement for wires through WLANs (Wi-Fi)
• Bluetooth is also becoming increasing popular for making
wireless connections where previously cumbersome wires
were used
• Bluetooth and WLAN do not need a spectrum license

10. Second Generation (2G) Cellular Networks
• Most of today’s cellular networks use second generation (2G)
technologies
• 2G technologies conform to the second generation cellular standards
• First generation (1G) cellular systems relied on FDMA/FDD and
Analog FM
• 2G standards use digital modulation formats and TDMA / FDD and
CDMA / FDD
• Three 2G standards use TDMA :
1. GSM (Global System for Mobile communication)
2. IS-136 (Interim Standard 136) or NADC/USDC
3. PDC (Pacific Digital Cellular)
• One 2G standard uses CDMA: IS-95 (Interim Standard-95) or
cdmaOne

11. Frequency, Time and Code Division Multiple Access

12. • Global System Mobile (GSM) supports 8 time slotted users for
each 200 kHz radio channel
• Interim Standard 136 (IS-136) supports three time slotted
users each of 30 kHz each
• IS-136 is also called North American Digital Cellular or US
Digital Cellular
• Pacific Digital Cellular (PDC) is similar to IS-136
• Interim Standard 95 Code Division Multiple Access (IS-95),
also known as cdmaOne supports up to 64 users that are
orthogonally coded and simultaneously transmitted on each
1.25 MHz channel

14. cdmaOne
IS-95
GSM
NADC
IS-136
PDC
Uplink
Frequencies
824-849MHz 890-915MHz 800, 1500 MHz
Downlink
Frequencies
869-894MHz 935-960MHz 800, 1500 MHz
Duplexing FDD FDD FDD
Multiple
Access
Technology
CDMA TDMA TDMA
Modulation
BPSK with
Quadrature
spreading
GMSK with
BT=0.3
π/4-DQPSK
Carrier
Separation
1.25 MHz 200KHz
30 KHz for IS-136
25 KHz for PDC
Voice
channels per 64 8 3

15. • 2G cellular systems are being deployed to replace the non-
mobile fixed telephones
• In developing countries, cellular systems are being used
instead of Plain Old Telephone Service (POTS) which make
use of copper cables
• Due to use of digital signal processing techniques, the 2G
techniques provide a 3 time capacity increase over 1G
• To meet the high number of customer demands, 1G is being
gradually and totally being replaced by 2G
• In 2001, major cellular companies like AT & T, Cingular and
NTT decided to abandon IS-136 and PDC standards
• All the major companies are adopting 3GPP/3GPP2
• The 3GPP which is based on the GSM and 3GPP2 is based
on CDMA with both being backward compatible

16. Blue bands are for North America and South America
Yellow are for Europe, Asia-Pacific, Middle East and Africa
https://en.wikipedia.org/wiki/GSM_frequency_bands

17. Bands of 2G, 3G and 4G in India

18. Reliance Jio LTE Bands India

19. Network Operators in India
• Total mobile subscribers in India: 1002.05 million (May 2015)

20. 2019 Survey (Network Operators)

21. Evolution to 2.5G Mobile Radio Networks
• Since the mid 1990s the 2G standards have been widely
deployed by wireless carriers
• These standards were developed in times when internet was
not too popular
• The early 2G standards are based on circuit switching
• Circuit switching: Dedicated channel between Tx and Rx
before the transfer begins
• This limits the data users to a single circuit switched voice
channel
• Therefore, the data transmissions in 2G are limited to the data
throughput rate of an individual user
• Early 2G systems support individual data rates of 9.6 kbps

22. • The data rate of 9.6 kbps is very low for rapid email and internet
browsing applications
• Even with low data rate, the early 2G networks did support limited
internet browsing and sophisticated messaging capabilities
• Short message service (SMS) is a very popular feature of GSM
data services which allow users to send short real time messages
just by dialing their number
• With time, the demand for higher data rate kept on increasing and
new standards were forged to be overlaid upon existing 2G
technologies
• The standards are data centric and are called 2.5G
• These standards require the base station equipment to be modified
and subscriber unit (cell phone) software to be upgraded
• The higher data rates supported by 2.5G allow for faster internet
browsing, email, m-commerce and location based mobile services

23. • The 2.5G technologies also support a popular new web
browsing format language called Wireless Application Protocol
(WAP)
• WAP allows standard web pages to be viewed in compressed
format specifically designed for small, portable, hand held
wireless devices
• Japan was one of first countries to adopt commercial cellular
telephony in 1970’s and was the first country to enjoy mobile
data service and web browser capability
• NTT DoCoMo introduced a service called I-mode in 1998 even
before WAP
• I-mode supports games, colour graphics and interactive web
browsing using a modest data rate of 9.6 kbps
• In late 2001, the I-mode was being used by almost 25 million
users in Japan

24. Upgrade to 2.5G Pre-requisites
• The upgrade path to 2.5G from 2G must be compatible with
the air interface standard for original 2G
• If not, then it would require wholesale equipment changes at
the base station
• The 2.5G standards have been developed to allow each of the
major 2G technologies (GSM, CDMA, IS-136) to be upgraded
with compatibility with the earlier standards
• For GSM, the three different upgrade paths are:
1. GPRS (General Packet Radio Service)
2. HSCSD (High Speed Circuit Switched Data)
3. EDGE (Enhanced Data Rates for GSM Evolution)

25. Evolution from 2G to 3G

26. HSCSD for 2.5G GSM
• In 2G GSM, each user gets only one time slot out of the
available 8 for data communication
• HSCSD allows the user to use consecutive time slots in order
to obtain higher data rate
• Also, the channel coding in HSCSD is relaxed so the data rate
of one time slot is 14.4 kbps
• If 4 consecutive time slots are allocated to the same user, the
data rate of up to 14.4 × 4 = 57.6 kbps can be achieved by
HSCSD
• The service providers are allowed to bill HSCSD as a
premium service and charge extra for it
• It can be implemented by simply changing the software at the
GSM base station

27. GPRS for 2.5G GSM and IS-136
• General Packet Radio Service is a packet based data network
which is well suited for non real time internet usage
• GPRS is based on packet switching
• Packet switching means there is no dedicated channel and
the packets are sent to the network with small amounts of
data and a header
• In packet switching, individual packets determine their own
route
• Unlike circuit switching, GPRS supports multi user sharing of
individual channels and time slots
• GPRS can support much more users than HSCSD but in a
bursty manner

28. • With all 8 time slots of GSM radio channel dedicated to
GPRS, an individual user is able to achieve up to 171.2 kbps
• 21.4 × 8 = 171.2 kbps (21.4 kbps uncoded data rate)
• In GPRS, applications are required to provide their own error
correction scheme
• As in the case of any packet network, the data throughput
experienced by an individual GPRS user decreases as more
and more users attempt to use the network
• Implementation of GPRS requires installation of new routers
and internet gateways at the base station
• Also, a new software is required which redefines the base
station air interface standard for GPRS channels and time
slots
• GPRS uses the same 2G TDMA standards as GSM as it was
originally designed for GSM but later used with IS-136 also

29. EDGE for 2.5G GSM and IS-136
• Enhanced Data Rates for GSM Evolution (EDGE) is a more
advanced upgrade to GSM standard
• EDGE requires the addition of new hardware and software at
the base stations
• EDGE introduces a new digital modulation format 8-PSK
(Octal PSK) along with the existing GMSK
• EDGE allows 9 different air interface standards called multiple
modulation and coding (MCS) with varying degrees of error
control coding
• Each interface may use GMSK (low data rate) or 8-PSK (high
data rate) depending upon the demands and the operating
conditions
• Adaptive capability of EDGE to select the “best” air interface is
called incremental redundancy

30. • Transmission starts with maximum error control and it is then
constantly reduced until unacceptable outage is obtained
• Rapid feedback between the mobile and base station restores
the previous acceptable interface
• Incremental redundancy ensures that the radio link for each
user will quickly reach a condition that uses minimum amount
of overhead while maintaining acceptable link quality
• When EDGE uses 8-PSK without any error control and all 8
time slots are dedicated to a single user the raw achievable
data rate is 547.2 kbps
• Raw uncoded data rate with 8-PSK = 68.4 kbps
• Some kind of error control and overhead is always required,
so the actual achievable data rate with EDGE for a single
channel is 384 kbps
• Using MCS, EDGE can combine different channels and
achieve a data rate of several Mbps

31. IS 95B for 2.5G CDMA
• Unlike TDMA standards, CDMA has a single upgrade path for
eventual 3G operation
• The interim data solution for CDMA is called IS 95B
• Like GPRS, it is being deployed worldwide and provides high
speed packet and circuit switched data access
• IS 95 did not have any data access
• IS 95A had a throughput rate of 14.4kbps
• IS 95B supports MDR (medium data rate) service by allowing
a dedicated user to use upto 8 different codes simultaneously
• 8 × 14.4 =115.2 kbps
• Due to the overhead, only 64 kbps are available to the user for
personal data

33. Third Generation(3G): The Vision
• Universal global roaming
• Increased data rates
–384 kbps while moving
–2 Mbps when stationary at specific locations
• Multimedia (voice, data & video)
• Symmetrical and asymmetrical data transmission
• Circuit and packet switched services
• Speech quality comparable to wireline
• Increased capacity (more spectrally efficient)
• IP architecture

34. 3G: Third Generation Networks
• 3G is the third generation of mobile phone standards and
technology superseding the 2.5G
• It is based on the ITU (International Telecommunications
Union) family of standards under the International Mobile
Telecommunications (IMT-2000) program
• IMT-2000 program, together with the main industry and
standardization bodies worldwide targets to implement a
global frequency band that would support a single wireless
communication standard for all countries
• Several radio access technologies have been accepted by
ITU as a part of IMT-2000
• Radio Access Network – Network between core network and
the mobile station

35. GSM and CDMA (No single standard ???)
• An organization called 3GPP continued the work by ITU by
defining a mobile system that fulfils the IMT-2000 standard
• This is called Universal Mobile Telecommunications System
(UMTS)
• After trying to establish a single 3G standard, ITU finally
approved of a family of five 3G standards which are part of IMT-
2000:
▪ W-CDMA (UMTS)
▪ CDMA2000
▪ TD-SCDMA
• Europe, Asia and Japan have agreed upon a 3G standard
called UMTS which is W-CDMA operating at 2.1GHz
• In USA and other parts of America, W-CDMA will have a
different spectrum

36. 3G W-CDMA (UMTS)
• W-CDMA uses DS-CDMA in which the user bits are spread over a
wide spectrum by using a spreading code of chip rate 3.84 Mcps

37. • The channel BW in WCDMA is 5MHz as opposed to normal
CDMA which uses a channel BW of 1.25 MHz
• Due to wider bandwidth, it is called Wideband CDMA and
therefore it can support a higher data rate as compared to the
conventional CDMA
• Also, conventional CDMA supports 64 users but WCDMA due
to higher channel BW supports 100 to 350 users
• The actual channel BW used by the operator depends on the
200KHz grid
• W-CDMA is backward compatible with GSM, IS-136 and PDC
• As W-CDMA requires a minimum spectrum allocation of 5
MHz, the wider air interface bandwidth requires a complete
change of RF equipment at the base station
• This is a cumbersome process and that is the reason why W-
CDMA is taking time to implement all over the world

38. • World’s first commercial W-CDMA service, called FoMA was
launched by NTT DoCoMo in Japan in 2001
• FoMA – Freedom of Mobile Multimedia Access
• FoMA is a brand name for 3G in Japan
• W-CDMA provides backward compatibility with the GSM/IS-
136 and PDC TDMA technologies as well as 2.5G TDMA
technologies
• The network structure and bit level packaging of GSM was
retained by W-CDMA with additional capacity provided by the
CDMA air interface

39. 3G cdma2000
• cdma2000 is a natural evolution of IS-95 (cdmaOne)
• cdma2000 includes additional functionality that increases spectral
efficiency and data rate capability
• CDMA allows many users on the same frequency channel by using
different codes
• CDMA can support more users as compared to FDMA/TDMA so it
has a huge economic advantage
• The 3G standard for CDMA was developed by Telecommunications
Industry Association (TIA) and standardized by 3GPP2
• The main cdma2000 air interface standards approved by ITU for
IMT2000 are:
▪ cdma2000 1xRTT
▪ cdma2000 1xEV
▪ cdma2000 EV-DV

40. cdma2000 1xRTT
• cdma2000 1xRTT is the first 3G CDMA air interface
• 1xRTT implies that only one 1.25 MHz channel is used in this
interface
• RTT – Radio Transmission Technology
• 1x implies one times the original cdmaOne channel BW which
is 1.25MHz
• Supports instantaneous data rate of 307 kbps and typical
throughput rate of 144 kbps per user
• Supports upto 2 times the users as IS-95 standard
• Allows two times the standby time for better battery life of the
subscriber unit

41. • It use adaptable chipping rates and signaling rates by
incremental redundancy
• No additional RF equipment is required because it does not
need a new spectrum unlike W-CDMA
• Only changes in the baseband hardware and software are
required
QUESTION:
What is baseband ??
Difference between broadband and baseband ??

42. cdma2000 1xEV
• EV stands for Evolutionary Advancement initially developed by
Qualcomm as a HDR (high data rate) standard to be overlaid
upon IS 95, IS-95B and cdma2000
• Later ITU recognized cdma2000 1xEV as a part of IMT2000
• This standard provides the option of installing radio channels
with data only (cdma2000 EV-DO) and with data and voice
(cdma2000 EV-DV)
• cdma2000 EV-DO supports instantaneous data rate at speeds
greater than 2.4 Mbps however the user data rate is much
lower and depends on a lot of factors
• cdma2000 EV-DV supports data and voice both and gives a
data rate of about 144kbps and twice the voice channels as
IS-95B

43. cdma2000 3x
• Also knows as cdma2000 EV-DO Rev B is a multi carrier
evolution
• It uses up to 3 adjacent carriers to obtain data rates much
greater than 2Mbps
• It enhances the user experience and enables new services
such as high definition video streaming
• Either 3 adjacent channels of 1.25 MHz are combined into one
channel into 3.75 MHz (no new RF equipment is required)
• Three individual non adjacent channels can be combined into
3.75 MHz channel but requires a new RF equipment is
required
• The advantage over W-CDMA is that it requires no new
spectrum and no new RF equipment

44. TD-SCDMA (China)
• In 1998 Chinese Academy of Telecommunications Technology
(CATT) proposed a 3G scheme called Time Division
Synchronous CDMA
• This proposal was adopted by ITU in IMT2000 in late 1999
• TD-SCDMA uses TDD instead of FDD as used by W-CDMA
• By using TDD, the system can more easily accommodate
asymmetric traffic with different data rate requirements
• The S word in TD-SCDMA stands for synchronous
• It means that the signals received at the base station are
synchronized to minimize the interference by continuous
timing adjustments

45. • Using synchronization reduces the interference between the
users using the same time slot but different codes
• Although this improves the performance but the hardware
complexity increases due to the synchronizing equipment
• It provides a data rate of 384 kbps (indoor/mobile) and 2Mbps
(outdoor/stationary) and uses a channel spacing of 1.6 MHz

46. Wireless Local Loop (WLL)
• Wireless local loop (WLL) or Fixed Radio Access (FRA) is
used as a wireless communications link for ‘The Last Mile’
• WLL is used as the communication link for ‘The Last Mile’
connection for providing POTS and/or broadband internet to
the customers
• WLL provides an easy solution for those countries where there
is inadequate telecommunication infrastructure
• WLL provides an inexpensive, reliable and rapidly deployable
solution for such countries
• VoIP (Voice over internet protocol) is increasingly becoming
popular
• The vision is that one day a single broadband connection can
provide telephone, television, radio, fax and internet

47. • Fixed wireless systems are not like cellular systems which
have high mobility
• WLL is able to take advantage of the time invariant nature of
the channel between the fixed transmitter and fixed receiver
• WLL systems are usually operated in the microwave or
millimeter wave range which is around 28 GHz
• As compared to the bandwidth offered by 3G cellular systems
(2.1 GHz range), microwaves offer up to 10 times bandwidth
• Since the frequency is very high, the distance travelled is
approximately close to 4 Km
• If there is a LOS between the Tx and Rx, the radio links
actually almost like an optical channel and can be used for
transmitting large data rates reliably
• So, fixed wireless networks at very high frequencies are more
suitable for rural or flat sub-urban setting

49. QUESTION
What is the difference between
• DSL
• Cable
• Fiber ??
• Which one would you prefer for constant speed
access of 10 Mbps ???

50. Advantages of WLL
• Easy to install
• Takes no time to install
• Once installed, there is no extra money to be paid
• The cable companies generally take wires on lease on a
monthly basis
• One recent examples of Fixed Wireless Access is WiMAX
• What is the full form of WiMAX ?????

51. LMDS
• LMDS is a WLL
• Local Multipoint Distribution Service is a broadband wireless
point to multipoint system that provides reliable digital two-way
voice, data and internet services
1. ‘Local’ – Local tells you that the signal range is limited,
typically of the order of 5 Km
2. ‘Multipoint’ – point – multipoint transmission (Broadcast) and
the return path is point – point
3. ‘Distribution’ – refers to the wide variety of data that can be
transmitted such as voice, video or internet
4. ‘Service’ – refers to the nature of relationship between the
operator and subscriber and the choice of services entirely
depends on the operator

54. • In 1995 the auction of PCS bands (150 MHz) yielded $30
billion
• In 1998, the auction of LMDS bands of 1300 MHz yielded only
$500 million
• One reason is that this service is relatively new and vastly
unproven
• Second, it uses millimeter waves whose equipment is still very
expensive
• This encourages the researchers to look for cheap RF
equipment in the millimeter range
• One of the very important applications of LMDS is the Local
Exchange Carrier (LEC)

55. If the base station has a LOS with the customers, LMDS allows
the LECs to install wireless equipment for rapid connectivity
without requiring any cables or physical connection

56. • Unfortunately, maintaining a LOS connection is not enough for
communication
Atmospheric factors such as
1. rain
2. hail
3. snow (flakes)
can affect the transmission of millimeter wave severely

58. Wireless Local Area Network (WLAN)
• In 1997, FCC allocated 300 MHz of unlicensed spectrum in
the Industrial Scientific and Medical (ISM) bands of 5.150-
5.350 GHz and 5.725-5.825 GHz
• ISM was allocated for supporting low-power license free
spread spectrum data communications
• This allocation is called the Unlicensed National Information
Infrastructure (UNII) band
• Earlier in 1980s, FCC has also allocated unlicensed bands in
the 902-928 MHz, 2400-2483.5 MHz and 5.725-5.825 MHz
• In 1987, the IEEE 802.11 Wireless LAN group was founded to
begin standardization of spread spectrum WLANs for use in
ISM bands

59. 902 928 2400 2484 5150 5350 5470 5725 f/MHz
26 MHz 83.5 MHz 200 MHz 255 MHz
The ISM bands

61. Evolution of WLAN (802.11)

62. • WLAN movement did not gain momentum until the late 1990s
when the popularity of internet combined with the wide scale
acceptance of portable, laptop computers finally caused
WLAN to become important
• IEEE 802.11 was finally standardized in 1997
• Initial standards used 11 Mcps DS-SS and provided 2 Mbps
(QPSK) data rates reducing to 1 Mbps (BPSK) in noisy
conditions
• QUESTION: How can reducing the data rate in noisy
conditions help your transmission ??
• As WLAN became popular, new improved 802.11 High Rate
Standard called 802.11b was approved in 1999
• 802.11b supported data rates of 11 Mbps and 5.5 Mbps in
addition to 2 Mbps and 1 Mbps which were retained from the
original 802.11 standard

63. • Initially the standard 802.11 included an infrared standard
during its evolution which was later discontinued
• Also initially both FH-SS and DS-SS were used with the
original 802.11 standard but only the DS-SS was standardized
for higher data rate standards
• Another standard 802.11a was proposed which provides a
data rate of up to 54 Mbps and uses the 5 GHz band
• The DS-SS 802.11b standard has been names Wi-Fi by the
Wireless Ethernet Compatibility Alliance (WECA)
• IEEE 802.11g is based on Complimentary Code Keying
OFDM standards and supports both 802.11b (2.4 GHz) and
802.11a (5 GHz) with dual band support
• Recently a new standard has been proposed called 802.11n
which provides data rates up to 600 Mbps using multiple
antennas (MIMO) with a channel spacing of 40 MHz

64. WLAN:802.11b (Wi-Fi)
• The most popular 802.11 standard currently in deployment.
• Supports 1, 2, 5.5 and 11 Mbps data rates in the 2.4 GHz
ISM (Industrial-Scientific-Medical) band

65. WLAN:802.11a
• Operates in the 5 GHz UNII (Unlicensed National
Information Infrastructure) band
• Incompatible with devices operating in 2.4GHz
• Supports Data rates up to 54 Mbps

66. WLAN:802.11g
• Supports data rates as high as 54 Mbps on the 2.4 GHz
band
• Provides backward compatibility with 802.11b equipment

67. WLAN: 802.11n
• Provides data rates up to 600 Mbps
• Uses multiple input multiple output technology (MIMO)
• Evolution started in 2002 and finalized in 2009

68. • Frequency hopping spread spectrum proponents of IEEE
802.11 have formed HomeRF standard that supports
frequency hopping equipment
• In 2001 HomeRF developed a 10 Mbps FH-SS standard
called HomeRF 2.0
• FH-SS and DS-SS WLANs operate in the same unlicensed
bands as cordless phones, Bluetooth devices and other
WLAN users
• All WLANs are manufactured to operate on any one of the
specified channels and assigned a channel when the WLAN is
first installed
• So the channelization scheme used by the network installer
becomes very important because if a lot of the WLANs use
the same channel, the performance is degraded due to
interference

69. Unique WLAN channels specified by IEEE 802.11b
India (1-13)

70. Placement of Access Points for WLAN
• The placement of WLAN access points is very important
• The correct placement can provide orders of improvement in
cost and data rate in a high interference environment
• Earlier, a hit and trial method was used
• Nowadays, using softwares based on computer aided design
(CAD) measurement and prediction such as SitePlanner by
Wireless Valley, the WLAN deployments can be made rapidly
• One just needs to load the blueprint of the building in the
software and the proper placements of the WLAN access
points can be found without even setting foot inside the
building
• The CAD prediction design was counter checked with actual
measurements and it matched closely

73. HiperLAN
• High Performance Radio LAN
• European alternative for IEEE 802.11 by ETSI
• ETSI – European Telecommunications Standards Institute
• Developed in Europe in the mid 1990s and similar to capability
in IEEE 802.11
• The goal was to provide data rate higher than 802.11
• Uses the 5.2 GHz and 17.1 GHz bands
• Two versions of HiperLAN are:
1. HiperLAN/1
2. HiperLAN/2

74. HiperLAN/1
• HIPERLAN/1 was the first version whose development started
in 1991
• This standard was approved in 1996
• Range – 50m
• Slow mobility – 1.4m/s
• Supports synchronous and asynchronous data
• Sound – 32 kbps
• Video – 2 Mbps
• Data – 1-20Mbps
• HiperLAN/1 does not conflict with microwave and appliances
which use 2.4 GHz band

75. HiperLAN/2
• HiperLAN/2 is the second version of HiperLAN
• Approved in February 2000
• Supported data rates up to 54 Mbps for a variety of networks
such as UMTS core, ATM and IP networks
• Operates in the 5 GHz band
• Backward compatible with HiperLAN/1
• Uses BPSK, QPSK, 16-QAM and 64-QAM
• Also offers security services using DES/triple-DES algorithms
• DES – data encryption standard
• Similar to IEEE 802.11a which supports 54 Mbps and also
operates in the 5 GHz band

76. HiperLAN: Failure in The Market
• HiperLAN never received much commercial implementation
• The reason was competition from IEEE 802.11 which was
simpler to implement and made it faster to the market
• Most of the work done on HiperLAN/2 survives in the PHY
layer of the 802.11a standard whose PHY layer is almost
similar to HiperLAN/2

77. Future of WLANs
• As wireless data rates increase and worldwide standards
begin to converge a new application for WLANs becomes
evident: The Public LAN concept (pubLAN)
• In pubLAN a nationwide Wireless Internet Service Provider
(WISSP) builds a nationwide infrastructure of WLAN access
points in selected hotels, restaurants, airports etc.
• The WISP charges monthly fee to users who wish to have
always-on Internet access in those selected locations
• Another application is that WLANs could be used to provide
the last 100m access for homes/businesses in competetion to
fixed wireless access
• The unlicensed band in limited, so if careful planning is not
done, the spectrum can quickly become saturated

80. Bluetooth and Personal Area Networks
• Due to the rapid strides made by the wireless technology in
the past two decades, electronics manufacturers realize that
there is huge consumer appreciation for ‘removing the wire’
• Printer cables
• Headphone cables
• Mouse cables
• All the cables in these devices are being replaced by low
power short range wireless connection
• Wireless offers convenience and flexibility
• Removing the wire allows collaborative communication

82. • Bluetooth is an open standard that has been embraced by
over 1000 manufacturers of electronic appliances
• It provides an ad-hoc approach for enabling various devices to
communicate with one another in a nominal 10 meter range
• Named after King Harald Bluetooth, the 10th century Viking
who united Denmark and Norway, Bluetooth aims to unite all
the appliances within the personal workspace of an individual
• It operates in the 2.4 GHz ISM band and uses a frequency
hopping TDD scheme for each radio channel
• It divides data into chunks and transmit it on up to 79 different
frequencies
• The hopping rate is 1600 hps
• The standard for Bluetooth has been designed to operate in a
very high interference levels and relies on a number of FEC
and ARQ schemes to support a raw BER of 10-3

84. • The 802.15 standards committee has been formed to provide
an international forum for developing Bluetooth and other
PANs that interconnect
1. pocket PCs
2. PDAs
3. cell phones
4. Light projectors and other appliances