Wireless access evolution
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Transcript of Wireless access evolution
Wireless Access Evolution
BroadbandBroadband
New ServicesNew Services
EfficiencyEfficiency
Broadband
Subscribers
Voice
CoverageCoverage
MobilityMobility
Voice QualityVoice Quality
PortabilityPortability
CapacityCapacity
BroadbandBroadband
Network Network SimplificationSimplification
Cost of Cost of OwnershipOwnership
BY
AJAL.A.J
Introduction to Mobile wireless evolution:By AJAL.A.J
Mobile wireless evolution:
Before going 2 start with wireless evolution ,
Lets review
3
7.4
Classes of transmission media
GUIDED MEDIAGUIDED MEDIA
Guided media, which are those that provide a conduit Guided media, which are those that provide a conduit from one device to another, include twisted-pair cable, from one device to another, include twisted-pair cable, coaxial cable, and fiber-optic cable.coaxial cable, and fiber-optic cable.
Twisted-Pair CableCoaxial Cable
Fiber-Optic Cable
Topics discussed in this section:Topics discussed in this section:
Figure Twisted-pair cable
Figure UTP and STP cables
Types(1) shielded twisted-pair (STP)
(2) unshielded twisted-pair (UTP).
UTP connector
Twisted pair Connectors
RJ45 connectors
Coaxial cable
Outer conductor shields the inner conductor from
picking up stray signal from the air.
For frequencies ranging from100KHz to 500MHz
BNC connectors
Types of Connectors
1) BNC connector - to connect to a TV
2) BNC T connector - in ethernet networks
3) BNC terminator - used in end of the cable to
prevent the reflection of the signal.
Coaxial cable connectors
BNC Connectors - Bayone-Neill-Concelman
Optical fiber
Propagation modes
Modes
Fiber construction
Fiber-optic cable connectors
Twisted-Pair
Coaxial cable
Use metallic conductors that accept
and transport signals in the form of
electric current.
Optical Fiber Cable that accepts and transports
signals in the form of light.
UNGUIDED MEDIA: WIRELESSUNGUIDED MEDIA: WIRELESS
Unguided media transport electromagnetic waves Unguided media transport electromagnetic waves without using a physical conductor. This type of without using a physical conductor. This type of communication is often referred to as wireless communication is often referred to as wireless communication.communication.
Radio WavesMicrowaves
Infrared
Topics discussed in this section:Topics discussed in this section:
Electromagnetic spectrum for wireless communication
Propagation methods
Table Bands
Figure Wireless transmission waves
Radio waves are used for multicast communications, such as radio and
television, and paging systems. They can penetrate through walls.
Highly regulated. Use omni directional antennas
Note
Figure Omnidirectional antenna
7.27
Microwaves are used for unicast communication such as cellular telephones,
satellite networks, and wireless LANs.Higher frequency ranges cannot penetrate
walls.Use directional antennas - point to point line
of sight communications.
Note
Figure Unidirectional antennas
Infrared signals can be used for short-range communication in a closed area using line-of-
sight propagation.
Note
Wireless Channels
Are subject to a lot more errors than guided media channels.
Interference is one cause for errors, can be circumvented with high SNR.
The higher the SNR the less capacity is available for transmission due to the broadcast nature of the channel.
Channel also subject to fading and no coverage holes.
ANY QUESTIONS ? ? ?
Else , we can start with Mobile wireless evolution:
Introduction to wireless Communications Systems
• In 1897, Guglielmo Marconi first demonstrated radio’s ability to provide continuous contact with ships sailing the English channel.
• During the past 10 years, fueled by* Digital and RF circuit fabrication improvements* New VLSI technologies* Other miniaturization technologies
(e.g., passive components)
The mobile communications industry has grown by orders of magnitude.
• The trends will continue at an even greater pace during the next decade.
Evolution of Mobile Radio Communications
Mobile Radiotelephone in the U.S.
• In 1934, AM mobile communication systems for municipal police radio systems.* vehicle ignition noise was a major problem.
• In 1946, FM mobile communications for the first public mobile telephone service* Each system used a single, high-powered transmitter and large
tower to cover distances of over 50 km.* Used 120 kHz of RF bandwidth in a half-duplex mode. (push-to-
talk release-to-listen systems.)* Large RF bandwidth was largely due to the technology difficulty
(in mass-producing tight RF filter and low-noise, front-end receiver amplifiers.)
• In 1950, the channel bandwidth was cut in half to 60kHZ due to improved technology.
• By the mid 1960s, the channel bandwidth again was cut to 30 kHZ.
• Thus, from WWII to the mid 1960s, the spectrum efficiency was improved only a factor of 4 due to the technology advancements.
• Also in 1950s and 1960s, automatic channel truncking was introduced in IMTS(Improved Mobile Telephone Service.)
* offering full duplex, auto-dial, auto-trunking
* became saturated quickly
* By 1976, has only twelve channels and could only serve 543 customers in New York City of 10 millions populations.
• Cellular radiotelephone
* Developed in 1960s by Bell Lab and others* The basic idea is to reuse the channel frequency at a sufficient distance
to increase the spectrum efficiency.* But the technology was not available to implement until the late 1970s.
(mainly the microprocessor and DSP technologies.)
• In 1983, AMPS (Advanced Mobile Phone System, IS-41) deployed by Ameritech in Chicago.
* 40 MHz spectrum in 800 MHz band* 666 channels (+ 166 channels), * Each duplex channel occupies > 60 kHz (30+30) FDMA to maximize
capacity.* Two cellular providers in each market.
• In late 1991, U.S. Digital Cellular (USDC, IS-54) was introduced.
* to replace AMPS analog channels
* 3 times of capacity due to the use of digital modulation ( DQPSK), speech coding, and TDMA technologies.
* could further increase up to 6 times of capacity given the advancements of DSP and speech coding technologies.
• In mid 1990s, Code Division Multiple Access (CDMA, IS-95) was introduced by Qualcomm.
* based on spread spectrum technology.
* supports 6-20 times of users in 1.25 MHz shared by all the channels.
* each associated with a unique code sequence.
* operate at much smaller SNR.(FdB)
4
Mobile Radio Systems Around the World
Examples of Mobile Radio Systems
First Generation (1G)
1G (First Generation Wireless Technology). Is the analog, voice-only cellular telephone standard, developed in the 1980s. It was invented by Martin Cooper of Motorola Corp in 1973.
Before 1G technology was the mobile radio telephone or 0G (Zeroth G)
1G phones have been cloned
1. Early Cell System Non-trunk radio system
Does not use multiplexing scheme Each radio channel is fixed to a specific user or a
group of users
Trunk radio system (synchronous or asynchronous) multiplexing scheme Channels are shared and available to all users Advantage: increased efficiency of spectrum usage Disadvantage: more complex architecture required
1. Early Cell System Trunk radio system (AMPS) BTS (base station): controls the air interface between
the mobile station and MTSO Mobile station: having frequency-agile machine that
allows to change to a particular frequency designated for its use by the MTSO
MTSO: responsible for switching the calls to the cells providing Interfacing with telephone network and backup Monitoring traffic Performing testing and diagnostics, network management
functions
Differences Between First and Second Generation Systems Digital traffic channels – first-generation systems are
almost purely analog; second-generation systems are digital
Encryption – all second generation systems provide encryption to prevent eavesdropping
Error detection and correction – second-generation digital traffic allows for detection and correction, giving clear voice reception
Channel access – second-generation systems allow channels to be dynamically shared by a number of users
1G45
First Generation
What we will look at 1st Generation technology Analogue signals Frequency Division Handover Infrastructure
First Generation
Early Wireless communications Signal fires Morse Code Radio
Radio Transmitter 1928 Dorchester
First Generation
1st Generation devices Introduced in the UK by Vodafone
January 1985 UK Technology (and Italy)
Total Access Cellular System (TACS) This was based on the American design of AMPS
Used the 900MHz frequency range Europe
Germany adopted C-net France adopted Nordic Mobile Telephone (NMT)
First Generation
Operates Frequency Division Multiple Access (FDMA)
Covered in next slide Operates in the 900MHz frequency range
Three parts to the communications Voice channels Paging Channels Control Channels
PCS – 1G to 2G technology
FDMA Breaks up the available frequency into 30 KHz channels
Allocates a single channel to each phone call The channel is agreed with the Base station before transmission
takes place on agreed and reserved channel The device can then transmit on this channel
No other device can share this channel even if the person is not talking at the time!
A different channel is required to receive The voice/sound is transmitted as analogue data, which means
that a large than required channel has to be allocated.
PCS – 1G to 2G technology
FDMAFrequency
PCS – 1G to 2G technology
FDMA You use this technology all of the time!
Consider your radio in the house As you want different information you change the frequency
which you are receiving
PCS – 1G to 2G technology
Voice calls Are transferred using Frequency modulation The rate at which the carrier wave undulates is changed
Encoding information More resistant to interference than AM radio
(www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0030280.html, 2004)
PCS – 1G to 2G technology
1G infrastructure
Mobile Switching Centre
PSTN
First Generation
Infrastructure Base Station
Carries out the actual radio communications with the device
Sends out paging and control signals MSC
Takes responsibility Controls all calls attached to this device Maintains billing information Switches calls (Handover)
First Generation
Cellular Architecture Allows the area to be broken into smaller cells The mobile device then connects to the closest
cell
Cell
Cell Cell
Cell Cell
Cell Cell
Cell
Cell
Cell Cell
Cell Cell
Cell Cell
Cell
First Generation
Cellular Architecture continued Cellular architecture requires the available frequency to be
distributed between the cells If 2 cells next to each other used the same frequency each
would interfere with each other
Cell
Cell Cell
Cell
Cell Frequency 900
First Generation
Cellular Architecture continued There must be a distance between adjoining cells This distance allows communications to take place
Cell
Cell Cell
CellCell
Cell
Cell
Cell Frequency 900
Frequency 920
Frequency 940
Frequency 960
First Generation
Cellular Architecture continued This is referred to as the “Minimum Frequency Reuse Factor”
This requires proper planning and can be an issue for all radio based wireless communications
Planning the radio cell and how far a signal may go
Cell
Cell Cell
Cell
First Generation
Radio Planning Logically we picture a cell as being a
Octagon In reality the shape of a transmission will
change depending on the environment In this diagram of a cell you can see this
The building are the rectangles in dark green The darker the shade of green the stronger
the signal
Cell
Cell Cell
Cell Cell
First Generation
Radio Planning Planning needs careful thought You must cover the entire area with the minimum of base
stations Base stations cost the company money They also make the potential for radio problems greater
Simulations can be used but accurate models of the area is required Best solution is to measure the signals at various points
From this a decision can be made
Cell
Cell Cell
Cell
First Generation
Cellular infrastructure why ?? Cells with different frequencies allow devices to
move between these cells The device just informing what frequency they are
communicating at Cellular communications can only travel a certain
distance Discussed in the wireless LAN’s lecture Cell sizes are flexible
Examples in the TUK TACS system were up to 50 Miles!
First Generation
Cellular infrastructure Once you get to the ‘edge’ of a cell you will need
a handover Handover allows the user to move between cells
After a certain distance the amount of data which is sent in error becomes greater than the data sent correctly at this point you need to connect to a new cell which is closer.
TACS carries this out by monitoring the amplitude of the voice signal
First Generation
Cellular infrastructure Communicating with BS1
Moving towards BS2
BS2BS1
Transmission BS2Transmission BS1
First Generation
Cellular infrastructure Power of signal now weakening
BS2BS1
First Generation
Cellular infrastructure Paging signal stronger so hand over to new MSC
BS2BS1
First Generation
Handover Once a handover is decided upon by the BS
The MSC is informed All BS in the area of the current location are informed to
start paging the device The BS with the strongest signal is then handed over to The call can continue In reality a lot of calls were dropped whilst waiting for a
handover to take place Ending a call
A 8Khz tone is sent for 1.8 seconds The phone then returns to an idle state
First Generation TACS
Problems Roaming was not applicable outside of the UK
All of Europe was using different standards Different frequencies Different frequency spacing Different encoding technologies
Security Calls were easily ‘listened’ upon Limited capacity of the available spectrum Analogue signal meant a larger than required amount of the
frequency had to be allocated to each call Expansion of the network was difficult
This was unacceptable GSM was introduced
Next weeks lecture!
First Generation
Summary 1G systems
TACS Frequency Use Infrastructure Handover Problems
Cellular standards
• Analog cellular: G1 cellular systems– AMPS: AT&T and Motorola; rapidly giving
way to digital technology worldwide.– N-AMPS: narrow-band AMPS; Motorola.– NMT (Nordic mobile telephone) in scandinavia– TACS (Total access communication system)
developed in England.
TDMA Design Considerations Number of logical channels per physical channel
(number of time slots in TDMA frame): 8 Maximum cell radius (R): 35 km Frequency: region around 900 MHz Maximum vehicle speed (Vm):250 km/hr Maximum coding delay: approx. 20 ms Maximum delay spread (m): 10 s Bandwidth: Not to exceed 200 kHz (25 kHz per
channel)
2G
2G73
Cellular standards continued
• Digital cellular: G2 cellular systems– GSM (Global System for Mobile communication): dominates
worldwide; adopted in 1987 for pan-Europe systems; operates in the 800 and 900 MHz ranges and is ISDN compatible; 4-cell reuse plan and each cell is divided into 12 sectors; used CDMA; supporting roaming from country to country.
– D-AMPS (Digital AMPS): AKA US TDMA is the N. Am. Standard; operates in the same 800 MHz band as AMPS and uses the same 30 kHz bands as AMPS; 3:1improvement on band utilization over AMPS; co-exists with AMPS; data rate up to 28.8 bps.
• Others: PDC (Japanese Digital Cellular), PCS (Personal digital system).
Spectrumonomics !
Cellular Communications
• Mobile telephone service - a system for providing telephone services to multiple, mobile receivers using two-way radio communication over a limited number of frequencies.
• Mobile wireless evolution:– First generation– Second generation– Third generation
Evolution of Mobile Radio Communications
• Major Mobile Radio Systems– 1934 - Police Radio uses conventional AM mobile communication system.– 1935 - Edwin Armstrong demonstrate FM– 1946 - First public mobile telephone service - push-to-talk– 1960 - Improved Mobile Telephone Service, IMTS - full duplex– 1960 - Bell Lab introduce the concept of Cellular mobile system– 1968 - AT&T propose the concept of Cellular mobile system to FCC.– 1976 - Bell Mobile Phone service, poor service due to call blocking– 1983 - Advanced Mobile Phone System (AMPS), FDMA, FM– 1991 - Global System for Mobile (GSM), TDMA, GMSK– 1991 - U.S. Digital Cellular (USDC) IS-54, TDMA, DQPSK– 1993 - IS-95, CDMA, QPSK, BPSK
Example of Mobile Radio Systems
• Examples
– Cordless phone
– Remote controller
– Hand-held walkie-talkies
– Pagers
– Cellular telephone
– Wireless LAN• Mobile - any radio terminal that could be moves during operation
• Portable - hand-held and used at walking speed
• Subscriber - mobile or portable user
• Classification of mobile radio transmission system– Simplex: communication in only one direction
– Half-duplex: same radio channel for both transmission and reception (push-to-talk)
– Full-duplex: simultaneous radio transmission and reception (FDD, TDD)
• Frequency division duplexing uses two radio channel– Forward channel: base station to mobile user
– Reverse channel: mobile user to base station
• Time division duplexing shares a single radio channel in time.
Forward Channel
Reverse Channel
Paging Systems
• Conventional paging system send brief messages to a subscriber
• Modern paging system: news headline, stock quotations, faxes, etc.
• Simultaneously broadcast paging message from each base station (simulcasting)
• Large transmission power to cover wide area.
Cordless Telephone System• Cordless telephone systems are full duplex communication
systems.
• First generation cordless phone– in-home use
– communication to dedicated base unit
– few tens of meters
• Second generation cordless phone– outdoor
– combine with paging system
– few hundred meters per station
Cellular Telephone Systems
• Provide connection to the PSTN for any user location within the radio range of the system.
• Characteristic – Large number of users , - Large Geographic area
– Limited frequency spectrum , - Reuse of the radio frequency by the concept of “cell’’.
• Basic cellular system: mobile stations, base stations, and mobile switching center.
• Communication between the base station and mobiles is defined by the standard common air interface (CAI)
– forward voice channel (FVC): voice transmission from base station to mobile
– reverse voice channel (RVC): voice transmission from mobile to base station
– forward control channels (FCC): initiating mobile call from base station to mobile
– reverse control channel (RCC): initiating mobile call from mobile to base station
Cellular Call Completion
• Components of a signal:– Mobile Identification Number (MIN) - an enclosed
representation of the mobile telephone’s 10-digit telephone number.
– Electronic Serial Number (ESN) - a fixed number assigned to the telephone by the manufacturer.
– System Identification Number (SID) - a number assigned to the particular wireless carrier to which the telephone’s user has subscribed.
Cellular Call Completion
Call Completion
How Cellular Telephony Works (continued)
Advanced Mobile Pone Service (AMPS)
• A first generation cellular technology that encodes and transmits speech as analog signals.
Time Division Multiple Access (TDMA)
Code Division Multiple Access (CDMA)
• Each voice signal is digitized and assigned a unique code, and then small components of the signal are issued over multiple frequencies using the spread spectrum technique.
Global System for Mobile Communications (GSM)
• A version of time division multiple access (TDMA) technology, because it divides frequency bands into channels and assigns signals time slots within each channel.
• Makes more efficient use of limited bandwidth than the IS-136 TDMA standard common in the United States.
• Makes use of silences in a phone call to increase its signal compression, leaving more open time slots in the channel.
Wireless Local Loop (WLL)
• A generic term that describes a wireless link used in the PSTN to connect LEC central offices with subscribers.
• Acts the same as a copper local loop.
• Used to transmit both voice and data signals.
Local Multipoint Distribution Service (LMDS)
• A point-to-multipoint, fixed wireless technology that was conceived to supply wireless local loop service in densely populated urban areas and later on a trial basis to issue television signals.
• A disadvantage is that its use of very high frequencies limits its signal’s transmission distance to no more than 4km between antennas.
Multipoint Multichannel Distribution System (MMDS)
• Uses microwaves with frequencies in the 2.1 to 2.7 GHz range of the wireless spectrum.
• One advantage is that because of its lower frequency range, MMDS is less susceptible to interference.
• MMDS does not require a line-of-sight path between the transmitter and receiver.
Short Message Service (SMS)• Globally accepted wireless service that enables the transmission of
alphanumeric messages between mobile devices and external systems• Available in US on GSM-based PCS as well as TDMA and CDMA
based cellular systems
• Short Message Service Center (SMSC) acts as a relay and store and forward system for messages
• Point to point delivery of messages• Active mobile handset is able to receive or send a short message at any
time, independent of whether a voice or data call is in progress• Utilizes out-of-band packet delivery and low-bandwidth message
delivery• Guarantees delivery of the short message by the network. Temporary
transmission failures are identified, and the message is stored in the network until the destination becomes available
2.5G103
2.5G, which stands for "second and a half generation," is a cellular wireless technology developed in between its
predecessor, 2G, and its successor, 3G.
"2.5G" is an informal term, invented solely for marketing purposes, unlike
"2G" or "3G" which are officially defined standards based on those
defined by the International Telecommunication (ITU). The
term "2.5G" usually describes a 2G cellular system combined with
General Packet Radio Services (GPRS )
A 2.5G system may make use of 2G system infrastructure, but it implements a
packet-switched network domain in addition to a circuit-switched domain.
2.5 G 2G (GSM standard)—GPRS (General Packet
Radio Service )was introduced in 2001. It added packet switching protocols to mobile communications technology and TCP/IP thus making possible the reading and sending of e-mails, instant messaging (IM), and browsing the Internet. SMS or short message service is heavily used.
2.5 G added MMS.
MMS
Multimedia Message Service, a store-and-forward method of transmitting graphics, video clips, sound files and short text messages over wireless networks using the WAP protocol. Carriers deploy special servers, dubbed MMS Centers (MMSCs) to implement the offerings on their systems.
MMS also supports e-mail addressing, so the device can send e-mails directly to an e-mail address. The most common use of MMS is for communication between mobile phones. MMS, however, is not the same as e-mail. MMS is based on the concept of multimedia messaging. The presentation of the message is coded into the presentation file so that the images, sounds and text are displayed in a predetermined order as one singular message. MMS does not support attachments as e-mail does.
To the end user, MMS is similar to SMS.
2.5G
An enhancement to 2G networks that allows them to operate in a "packet switched" manner
2.5G networks incorporate 2G technology with GPRS' higher speeds to support data transport. 2.5G is a bridge from the voice-centric 2G networks to the data-centric 3G networks.
GPRS (General Packet Radio Service) is a radio technology for GSM networks that adds packet-switching protocols. As a 2.5G technology, GPRS enables high-speed wireless Internet and other data communications. GPRS networks can deliver SMS, MMS, email, games, and WAP applications.
GPRS
GPRS (General Packet Radio Service) is a specification for data transfer on TDMA and GSM networks.
The theoretical limit for packet switched data is approx. 170 kb/s.
A realistic bit rate is 30-70 kb/s. . GPRS supports both TCP/IP and X.25 communications. It provides moderate speed data transfer, by using unused TDMA
channels on a GSM network. GSM circuit switch connections are still used for voice, but data is
sent and received in "packets" in the same way as it would be in the fixed internet environment.
The advantage is that network resources are used more efficiently. Rather than maintaining a circuit for the duration of the connection, which ties up resources regardless of whether anything is actually being sent or received, GPRS only consumes resource when information packets are transmitted.
HSCSD
HSCSD (High Speed Circuit Switched Data) is a specification for data transfer over GSM networks. HSCSD utilizes up to four 9.6Kb or 14.4Kb time slots, for a total bandwidth of 38.4Kb or 57.6Kb.
14.4Kb time slots are only available on GSM networks that operate at 1,800Mhz. 900Mhz GSM networks are limited to 9.6Kb time slots. Therefore, HSCSD is limited to 38.4Kbps on 900Mhz GSM networks. HSCSD can only achieve 57.6Kbps on 1,800Mhz GSM networks.
HSCSD vs. GPRS
HSCSD has an advantage over GPRS in that HSCSD supports guaranteed quality of service because of the dedicated circuit-switched communications channel. This makes HSCSD a better protocol for timing-sensitive applications such as image or video transfer.
GPRS has the advantage over HSCSD for most data transfer because HSCSD, which is circuit-switched, is less bandwidth efficient with expensive wireless links than GPRS, which is packet-switched.
For an application such as downloading, HSCSD may be preferred, since circuit-switched data is usually given priority over packet-switched data on a mobile network, and there are few seconds when no data is being transferred.
Industrial, Scientific, and Medical (ISM) spread spectrum modulation 902-928 MHz 2.4-2.4835 GHz (home of
microwave oven band) 5.725-5.850 GHz
under 1 watt transmitter output power
more bandwidth with higher frequencies, which support higher data rates.
ISM Frequency BandsThe three ISM frequency bands are the only ones available for unlicensed wireless transmission in the US. Only one band has world-wide availability.
Lifi….the latest technology in wireless communication
• LiFi is a new class of high intensity light source of solid state design bringing clean lighting solutions to general.
• With energy efficiency, long useful lifetime, full spectrum and dimming , LiFi lighting applications work better compared to conventional approaches.
• This technology gives the general construction of LiFi lighting systems and the basic technology building blocks behind their function.
Advantages• Using this innovative technology 10,000 to 20,000
bits per second of data can be transmitted simultaneously in parallel using a unique signal processing technology and special modulation
• As communication technology is expanding at a rapid pace we are running out of radio frequency spectrum but this new visible light spectrum has 10,000 times more capacity than radio frequency.
•
• Cellular masts or base stations worldwide uses a lot of energy particularly for cooling and it operates at only five percent efficiency whereas LiFi technology can transmit data through the 14 billion light bulbs already installed worldwide. So it is virtually free .
• The whole process of transmitting data through light is more energy efficient than using radio frequency.
Applications
• Can be used in the places where it is difficult to lay the optical fiber like hospitals. In operation theatre LiFi can be used for modern medical instruments.
• In traffic signals LiFi can be used which will communicate with the LED lights of the cars and accident numbers can be decreased.
• Thousand and millions of street lamps can be transferred to LiFi lamps to transfer data.
Conclusion
• The design and construction of the LiFi light source enable
• efficiency,• long stable life, • full spectrum intensity • that is digitally controlled • and easy to use.
Any Questions ?
Or else lets EDGE
Going through the Going through the Edge,Edge,
from 2.5G to 3G from 2.5G to 3G
Going through the Going through the Edge,Edge,
from 2.5G to 3G from 2.5G to 3G
2.75 G124
2G/2.5G Voice & Data Handset still dominates the market while 2.75G is
trying to fill the technology gap before 3G is mature.
Advancement of Cellular TechnologyAdvancement of Cellular Technology
•GSM ANSI 136 Interoperability Team•GERAN – GSM EDGE Radio Access Network•UTRAN –UMTS Terrestrial Radio Access Network
All IP RAN
GSM
TDMA
GAIT*
GP
RS EDGE
Classic
EDGECompact
ED
GE
GP
RS
-136
HS
IMT2000
FDD:WCDMA
TDD:WCDMA
TD:CDMA
TD:SCDMA
UMTS
2G 2.5G 2.75G 3G
<9.6kbps <115kbps <384kbps <2Mbps
Western Europe
ED
GE
Ph
ase
II
<384kbps
EGPRSEDGE
Phase1Rel99
EDGEPhase2Rel4,5, 6
and beyond
UTRANGERANiDEN
cdma2000™1XEV-DV
cdma2000™1xEV-DO
cdma2000™1XRTTCDMA
PDC
>2Mbps
4G
UWBSDRHSDPA….
20022002 20032003 2004200420012001
Bluetooth™ WLAN
EDGE• Enhanced Data Rates for Global Evolution (EDGE) is a bolt-on
enhancement to 2G and GPRS networks. This technology is compatible with TDMA and GSM networks. EDGE uses the same spectrum allocated for GSM850, GSM900, GSM1800 and GSM1900 operation.
• Instead of employing GMSK (Gaussian minimum-shift keying) EDGE uses 8PSK (8 Phase Shift Keying) producing a 3bit word for every change in carrier phase. This effectively triples the gross data rate offered by GSM. EDGE, like GPRS, uses a rate adaptation algorithm that adapts the modulation and coding scheme (MCS) used to the quality of the radio channel, and thus the bit rate and robustness of data transmission. It introduces a new technology not found in GPRS, Incremental Redundancy, which, instead of retransmitting disturbed packets, sends more redundancy information to be combined in the receiver. This increases the probability of correct decoding.
EDGE provides data speed three times that of GPRS
• EDGE is a mobile network radio technology that allows current GSM networks to offer 3G services within existing frequencies. As an evolution of GSM/GPRS, EDGE is an upgrade to GPRS' data and GSM's voice networks..
3G129
Why 3G?
Why 3G?• Higher bandwidth enables a range of new applications!!• For the consumer
– Video streaming, TV broadcast– Video calls, video clips – news, music, sports– Enhanced gaming, chat, location services…
• For business– High speed teleworking / VPN access– Sales force automation– Video conferencing– Real-time financial information
3G
• 3G networks promise next-generation service with
transmission rates of 144Kbps and higher that can support multimedia applications, such as video, video conferencing and Internet access. Both UMTS (WCDMA) and EDGE will support 3G services. 3G networks operate on a different frequency than 2G networks.
Emerging Third Generation (3G) Technologies
The promise of these technologies is that a user can access all her telecommunication services from one mobile phone.
• CDMA2000 - a packet switched version of CDMA.
• Wideband CDMA (W-CDMA) - based on technology developed by Ericson, is also packet-based and its maximum throughput is also 2.4 Mbps.
3G 3G—UMTS (Universal Mobile
Telecommunications System)--Can reach 384 kbps. The technology made video phones, watching streaming video, downloading music and getting broadband access possible. UMTS can be used on both mobile phones and computers. It is capable of transferring 385 kbps for mobile systems and up to 2Mbps for stationary systems.
3G services in Asia• CDMA (1xEV-DO)
– Korea: SKT, KTF– Japan: AU (KDDI)
• WCDMA / UMTS– Japan: NTT DoCoMo, Vodafone KK– Australia: 3 Hutchinson– Hong Kong: 3 Hutchinson
IS-95 (CdmaOne) IS-95: standard for the radio interface IS-41: standard for the network part Operates in 800MHz and 1900MHz bands Uses DS-CDMA technology (1.2288 Mchips/s) Forward link (downlink): (2,1,9)-convolutional code,
interleaved, 64 chips spreading sequence (Walsh-Hadamard functions)
Pilot channel, synchronization channel, 7 paging channels, up to 63 traffic channels
Reverse link (uplink): (3,1,9)-convolutional code, interleaved, 6 bits are mapped into a Walsh-Hadamard sequence, spreading using a user-specific code
Tight power control (open-loop, fast closed loop)
Advantages of CDMA Cellular Frequency diversity – frequency-dependent
transmission impairments have less effect on signal
Multipath resistance – chipping codes used for CDMA exhibit low cross correlation and low autocorrelation
Privacy – privacy is inherent since spread spectrum is obtained by use of noise-like signals
Graceful degradation – system only gradually degrades as more users access the system
Drawbacks of CDMA CellularSelf-jamming – arriving transmissions from
multiple users not aligned on chip boundaries unless users are perfectly synchronized
Near-far problem – signals closer to the receiver are received with less attenuation than signals farther away
Soft handoff – requires that the mobile acquires the new cell before it relinquishes the old; this is more complex than hard handoff used in FDMA and TDMA schemes
CDMA Design ConsiderationsRAKE receiver – when multiple versions of
a signal arrive more than one chip interval apart, RAKE receiver attempts to recover signals from multiple paths and combine themo This method achieves better performance than
simply recovering dominant signal and treating remaining signals as noise
Soft Handoff – mobile station temporarily connected to more than one base station simultaneously
RAKE Receiver RAKE Receiver has to estimate:
o Multipath delayso Phase of multipath componentso Amplitude of multipath componentso Number of multipath components
Main challenge is receiver synchronization in fading channels
Principle of RAKE Receiver
Forward Link Channels Pilot: allows the mobile unit to acquire timing
information, provides phase reference and provides means for signal strength comparison
Synchronization: used by mobile station to obtain identification information about cellular system
Paging: contain messages for one or more mobile stations
Traffic: the forward channel supports 55 traffic channels
Forward Traffic Processing StepsSpeech is encoded at a rate of 8550 bpsAdditional bits added for error detectionData transmitted in 2-ms blocks with
forward error correction provided by a convolutional encoder
Data interleaved in blocks to reduce effects of errors
Data bits are scrambled, serving as a privacy masko Using a long code based on user’s electronic
serial number
Forward Traffic Processing Steps Power control information inserted into traffic
channel DS-SS function spreads the 19.2 kbps to a rate of
1.2288 Mbps using one row of 64 x 64 Walsh matrix
Digital bit stream modulated onto the carrier using QPSK modulation scheme
Reverse Traffic Processing Steps Convolutional encoder at rate 1/3 Spread the data using a Walsh matrix
o Use a 6-bit piece of data as an index to the Walsh matrixo To improve reception at base station
Data burst randomizer Spreading using the user-specific long code mask
Third-Generation Capabilities
Voice quality comparable to the public switched telephone network
144 kbps data rate available to users in high-speed motor vehicles over large areas
384 kbps available to pedestrians standing or moving slowly over small areas
Support for 2.048 Mbps for office use Symmetrical/asymmetrical data transmission rates Support for both packet switched and circuit
switched data services
Typical application: road traffic
ad ho
cUMTS, WLAN,DAB, GSM, TETRA, ...
Personal Travel Assistant,DAB, PDA, laptop, GSM, UMTS, WLAN, Bluetooth, ...
1.4.1
Overlay Networks - the global goal
regional
metropolitan area
campus-based
in-house
verticalhand-over
horizontalhand-over
integration of heterogeneous fixed andmobile networks with varyingtransmission characteristics
1.23.1
Influence of mobile communication to the layer model
service location new applications, multimedia adaptive applications congestion and flow control quality of service addressing, routing,
device location hand-over authentication media access multiplexing media access control encryption modulation interference attenuation frequency
Application layer
Transport layer
Network layer
Data link layer
Physical layer
3G Standards• 3G Standard is created by ITU-T and is called as IMT-
2000.• The aim of IMT-2000 is to harmonize worldwide 3G
systems to provide Global Roaming.
IS-95 IS-136 & PDCGSM-
EDGE
GPRS
HSCSDIS-95B
Cdma2000-1xRTT
Cdma2000-1xEV,DV,DO
Cdma2000-3xRTT
W-CDMA
EDGE
TD-SCDMA
2G
3G
2.5G
3GPP3GPP2
Upgrade paths for 2G Technologies
3G: Winners & Losers ?? UMTS
Huge delays (terminals availability) Very expensive license fees Clear evolution path
HSxPA (Peak Data Rates), LTE (Long Term Evolution) (Network Simplification)
WCDMA Compelling peak data rates (EV-DO) Unclear evolution path
3xRTT? WIMAX?
• UMTS Band : 1900-2025 MHz and 2110-2200 MHz for 3G transmission.
• Terrestrial UMTS (UTRAN) : 1900-1980 MHz, 2010-2025 MHz, and 2110-2170 MHz bands
UMTS Frequency Spectrum
CDMA was commercially introduced in 1995 with IS-95A or cdmaOne. IS-95A is the CDMA-based second generation (2G) standard for mobile communication. The following
are the key aspects of this standard:
• Support for data rates of upto 14.4 kbps
• IS-95A has been used exclusively for circuit-switched voice
• Convolutional Channel coding used
• Modulation technique used is BPSK
IS-95A
IS-95B or cdmaOne is the evolved version of IS-95A and is designated as 2.5G. IS-95B maintains the Physical Layer of IS-95A, but due to an enhanced MAC layer, is capable of providing for higher speed data services. The following are the key aspects of the standard:
• Theoretical data rates of upto 115 kbps, with generally experienced rates of 64 kbps
• Additional Walsh codes and PN sequence masks, which enable a mobile user to be assigned up to eight forward or reverse code channels simultaneously, thus enabling a higher data rate
• Code channels, which are transmitted at full data rates during a data burst
• Convolutional Channel coding
• Binary Phase Shift Keying (BPSK) as the Modulation technique used
IS-95B
•Supports theoretical data rates of upto 307 kbps, with generally experienced rates of 144 kbps
• The newly introduced Q-PCH of CDMA 2000 enables the mobile to be informed about when it needs to monitor F-CCCH and the Paging Channel, thus improving on the battery life
• Introduction of Radio Configurations – Transmission formats characterized by physical layer parameters such as data rates, modulation characteristics, and spreading rate. RCs help in providing for additional data rates.
• Quality and Erasure indicator bits (QIB and EIB) on the reverse power control sub channel. These help in indicating to the BS about bad frames or lost frames received at the mobile station, so that they can be retransmitted
• Code channels are transmitted at full data rates during a data burst
• Convolutional and Turbo coding techniques used
• Modulation technique used is QPSK
CDMA 2000 1X
• Offering data speeds up to 2 Mbps
• Using three standard 1.25 MHz channels within a 5 MHz band
• Leveraging deployment experiences, and manufacturers’ learning curves of today’s widely adopted, commercially available CDMA systems
• Using Convolutional and Turbo coding techniques
• Using QPSK as the Modulation technique
CDMA 2000 3X
• Supporting data rates of up to 2.4 Mbps
• Having no backward-compatibility with CDMA 2000
• Including two inter-operable modes: an integrated 1x mode optimized for voice and medium data speeds, and a 1xEV mode optimized for non real-time high capacity/high speed data and Internet access
• Providing Adaptive Rate Operation with respect to channel conditions
• Providing Adaptive modulation and coding
• Providing Macro diversity via radio selection
• Providing an always-on operation of 1xEV-DO terminals in the active state
• Using a multi-level modulation format (QPSK, 8-PSK, 16-QAM)
1X EV-DO
1xEV-DV
• Backward compatible with CDMA 2000.
• EV-DV can be easily extended to operate in 3x mode under the framework of current system.
• Forward peak data rate : 3.072 Mbps.
• Reverse peak data rate: 451.2 kbps.
• Addition of three new channels to f/w link and reverse link for packet data operation and its support.
• Adaptive modulation and coding : QPSK, 8- PSK, 16-QAM
• Variable frame duration
• Mobile station can select one of N base stations.
• DTX transmission supported for saving battery life.
3G: Technology Summary Technology Convergence on Wideband-CDMA WCDMA
Successor to CDMA, 4 core standards – 1xRTT, 1x EV-DO, 1x EV-DV, 3xRTT
1xRTT provides 2x voice capacity increase over CDMA and a peak data rate of 144kbps
EV-DO Rev A provide peak data rates of 3.1 downlink / 1.8 uplink (800kbps typical)
UMTS (Universal Mobile Telephone System) Successor to GSM, based on W-CDMA Peak data rates of up to 1920kbps (384kbps typical) HSDPA peak data rate of up to 14.4Mbps
Global Subscriber Counts
0
0.5 Bn
1 Bn
1.5 Bn
2 Bn
2.5 Bn
2006 2007 2008 2009 2010 2011
CDMA
GSM
W-CDMA
The future of cellular radio: G3?
• Market increases quickly over the years worldwide, often beyond projection.
• Cost continues to drop: $.45/minute in the early 90s to 9.4 cents in 2000.
• G3 proposals are under consideration– Calls for data rate from 144 kbps (fast moving)
to 384 kbps (pedestrian).– Supports global roaming
3. 5 G162
(HSPA)
3.5G (HSPA)High Speed Packet Access (HSPA) is an amalgamation of two mobile telephony protocols,
High Speed Downlink Packet Access (HSDPA)
and
High Speed Uplink Packet Access (HSUPA),
that extends and improves the performance of existing WCDMA protocols
3.5G features
3.5G introduces many new features that will enhance the UMTS technology in future. 1xEV-DV already supports most of the features that will be provided in 3.5G. These include:
- Adaptive Modulation and Coding
- Fast Scheduling
- Backward compatibility with 3G
- Enhanced Air Interface
HSDPA EVOLUTION
3.5G (HSDPA)
High Speed Downlink Packet Access
Why HSDPA?
Comparison Between 3G & 3.5G.Data Rate ( 2Mbps -----> 10 Mbps)
Modulation ( QPSK -----> QPSK&16QAM)
TTI( 10ms ----> 2ms )
HSDPA FeaturesHSDPA Features
Hybrid Automatic Repeat Request Hybrid Automatic Repeat Request Fast cell site selection Fast cell site selection Adaptive Modulation and CodingAdaptive Modulation and Coding
Reducing delay ” T T I ”.Reducing delay ” T T I ”.
3.5G
3.5G or HSDPA (High Speed Downlink Packet Access) is an enhanced version and the next intermediate generation of 3G UMTS. It comprises the technologies that improve the Air Interface and increase the spectral efficiency, to support data rates of the order of 30 Mbps. 3.5G introduces many new features that will enhance the UMTS technology in future. 1xEV-DV already supports most of the features that will be provided in 3.5G. These include:• Adaptive Modulation and Coding• Fast Scheduling• Backward compatibility with 3G• Enhanced Air interface
IS-95B
IS-95BUses multiple code channelsData rates up to 64kbpsMany operators gone direct to 1xRTT
CDMAIS-95A
IS-95A14.4 kbpsCore network re-used inCDMA2000
1xRTT
CDMA2000 1xRTT: single carrier RTTFirst phase in CDMA2000 evolutionEasy co-existence with IS-95A air interfaceRelease 0 - max 144 kbpsRelease A – max 384 kbpsSame core network as IS-95
1xEV-DO
CDMA2000 1xEV-DO: Evolved Data Optimised Third phase in CDMA2000 evolutionStandardised version of Qualcomm High Data Rate (HDR)Adds TDMA components beneath code componentsGood for highly asymmetric high speed data appsSpeeds to 2Mbps +, classed as a “3G” systemUse new or existing spectrum
1xEV-DVCDMA2000
3xRTT
CDMA2000 1x Evolved DVFourth phase in CDMA2000 evolutionStill under developmentSpeeds to 5Mbps+ (more than 3xRTT!)Possible end game.
CDMA2000 evolution to 3G
What next after 3G?What next after 3G?
1990 2000 2010
GSM(2G)
W-CDMA(3G)
GPRS/EDGE(2.5G)
• The future path has fractured into a number of possibilities• Operators and vendors must create viable strategies to prosper within this complexity
4G
3G+
3G &WLAN
3G &WLAN &Brdcst
3G+ &WLAN
3G &WLAN &Ad-hoc
3G+ &WLAN &Ad-hoc
4G &WLAN
4G &WLAN &Brdcst
4G &WLAN &Ad-hoc
2.5G &WLAN
3.9G172
LTE (3.9G)
and
LTE-Advanced (4G)
Long-Term Evolution
After comparison the LTE-Advanced (4G) is better than LTE (3.9G) in some
specifications such as:• LTE-Advanced 4G have Data rates up to 1Gbps in stationary
scenarios, Coverage enhancements for high• frequency bands, LTE-Advanced will be a smooth evolution of
LTE, Numerology and access technologies will be the same, Bandwidth up to 100MHz supported, Contiguous and non-contiguous carrier aggregation,
• New technologies are being proposed, Enhanced MIMO, cooperative transmission, relaying etc.
• LTE-Advanced is a very flexible and advanced system, further enhancements to exploit spectrum availability and advanced multi-antenna techniques.
LTE/WIMAX Overview
Two Key technologies are evolving to meet the Wireless Broadband Requirements
802.11n(smart antennas)802.11Mesh extns.
Lo
cal A
rea
Fix
ed
Wid
e A
rea
Mo
bile
Co
vera
ge/
Mo
bili
ty
Met
ro A
rea
No
mad
ic
802.16(Fixed LOS)
802.16a/d(Fixed NLOS)
802.11b/a/g
Mobile Industry
Fixed Wireless Industry
4G Air Interfaces
Data Rates (kbps)100,000 +
3GPP2CDMA
2000-1X
HRPDA1x
EVDO
1x EVDV Rel. C
1x EVDVRel. D
GSM UMTS HSPAGPRS EDGE LTE 3GPP
MOBILE BROADBAND
DSL ExperienceDial Up
Higher Data Rate / Lower Cost per Bit
802.16e(Mobile WIMAX)
4G (LTE)
• LTE stands for Long Term Evolution• Next Generation mobile broadband
technology• Promises data transfer rates of 100 Mbps• Based on UMTS 3G technology• Optimized for All-IP traffic
4G179
Why 4G?
4G: Anytime, Anywhere Connection
• Also known as ‘Mobile Broadband everywhere’• ‘MAGIC’
– Mobile Multimedia Communication– Anywhere, Anytime with Anyone– Global Mobility Support– Integrated Wireless Solution– Customized Personal Service
• According to 4G Mobile Forum, by 2008 over $400 billion would be invested in 4G mobile projects.
• In India, communication Minister Mr. Dayanidhi Maran, has announced a national centre of excellence to work in 4G arena.
4G
4G—The fourth generation cell phone is being championed in Japan. It will boost the data rates to 20 Mbps. These speeds enable high quality video transmission and rapid download of large music files. The first 4G phones appeared in 2006.
4G: Data rate Facts Transmission at 20 Mbps 2000 times faster than mobile data rates 10 times faster than top transmission rates planned in final
build out of 3G broadband mobile 10-20 times faster than standard ADSL services. Companies developing 4G technology
Cellular phone companies: Alcatel, Nortel, Motorola, IT Companies: Hughes,HP,LG Electronics
…and Beyond Technology Convergence on OFDM (Orthogonal
Frequency Division Multiple Access)
HSOPA Improved bandwidth, latency over UMTS/HSxPA Radio technology based on MIMO-OFDM, peak data
rates of up to 70Mbps Network simplification
Operator Objectives
Voice+Growth to Wireless
Data+ Growth to
Broadband
Network Goals are SimilarDifferentiation on Access & Business goals
Mobile Operators Subscriber growth Wireless Data / 3G Wireline Substitution
Fixed Operators Broadband Line Growth Revenue Protection
Cable, Satellite, ISP Network Leverage New Markets Video Play
Evolution of Cellular Networks
1G 2G 3G 4G2.5G
Advantages of LTE
3G/HSDPA vs. WIMAX/LTE Network Architecture
Traditional Cellular Architecture
Base Stations
Carrier Access Point (CAP) Architecture
=
Operator’sIP Network
MSSSGSN
GGSN MediaGateway
CAPController
VoIP Gatewayor IMS
DataGatewayor IMS
Internet PSTN Internet PSTN
Base StationControllers
Access Points
Lower Cost!Any off-the-shelf IP network with
Mobile IP support=
outdoor CPE
“By 2012, 18 million laptops will have WIMAX
built-in” - Intel
digital cameras
set top boxes
WIMAX technology will in most consumer devices
CHANGING THE WAY WE:
laptops
Gaming consoles
pdas
televisions
MP3 player
vehicles
Videocameras
indoor CPE
handsets
Comparison of LTE Speed
LTE Architecture
Higher frequency selectivity
Severer power limited condition
Under these conditions, system should be optimized with considering the trade-off between cell throughput and cell coverage
Example 1: Self-deployment of eNodeBs • More autonomous deployment becomes
obviously more interesting – Without planning of radio parameters– Also useful study item for home NodeB deployment
• Start with minimal coverage and gradually increase cell size• Radio scanning to find unused resources• Negotiation with neighbor cells about spectrum resource usage
Example 2: Self Neighbor Scanning HeNB
• Operator will have many thousands/millions of home eNB.– Human operation based configuration of each hEB is not
economical.
• Home eNB frequently scan – All neighbors of own or other PLMN ID
• heNB capable of scanning neighboring macro cells/frequencies
– All neighbors of other RAT• heNB capable of scanning neighboring UMTS/WIMAX cells
– Scan results are sent to the central server
Home eNB frequently scan…
Example 3: Self Coordinating Interference Management
• To coordinate scheduling in interfering cells, – Alt1: Semi-static restrictions for users close to cell
borders• Self coordination between cells set by rules • Agreed in Release 8 as HII
– Alt2: Short time-scale coordination • Very high speed of coordination for re-optimization
based on load in different cells
Self Coordinating Interference Management
Example 4: HO Parameterization Optimization
• Handover parameter optimization triggered by “performance problems”
• Optimization of individual neighbor-to-neighbor parameters– E.g. HO hysterisis control
• Slow optimization loop – Cautiously change parameter to avoid user
perceivable degradation– Evaluate results through performance monitoring
HO hysterisis control
Example 5: UE Measured Performance Reporting
Example 6: Common Channel Self Optimization
RACH, PCH, BCH Power optimizations
• Instead of drive tests: slow optimization based on UE reports– received signal strength, channel quality, neighbor
signal strength– Ideally also location of UE
• Cautious adjustment of power in one cell, monitoring of effects– search optimal settings, e.g. gradient descent
Example 7: Reduction of Energy Consumption by RAN
Reduction of Energy Consumption by RAN
• Partial or complete eNB power down during low load, e.g. at night
• Stored profiles used to reconfigure radio parameters for the new topology
• Wake up based on timers or external triggers
Advantages in Femto cell deployment in a Radio Aspect
interference scenarios
LTE vs UMTS• Functional changes compared to the current
UMTS architecture
NGN Context
Evolved hardware technologies+
Improved network bandwidth=
Entertainment apps on mobile
208
209
When you are NOT mobile, you use
210
When you are mobile, you use
211
Millions of passengers per day!
Market promoters
January 16- 2010China Star Optoelectronics Technology (CSOT)’s
8.5-generation LCD panel project was officially launched
2005The sales volume of TCL color TV sets
ranked first place in the world.
world's 25th-largest consumer electronics producer and sixth-largest television producer (after Samsung, LG, Sony, Panasonic and Sharp).
also Refer ….1. Erik Dahlman, Stefan Parkvall, and Johan Skold, 4G
LTE/LTE-Advanced for Mobile Broadband, Elsevier Ltd., 2011, pp.11-12,379-380.
2. Christian Mehlfuhrer, Martin Wrulich, Josep Colom �Ikuno, Dagmar Bosanska, Markus Rupp, SIMULATING THE LONG TERM EVOLUTION PHYSICAL LAYER, 17th European Signal Processing Conference (EUSIPCO 2009) Glasgow, Scotland, August 24-28, 2009,pp.1.
3. FAROOQ KHAN, LTE for 4G Mobile Broadband Air Interface Technologies and Performance, Cambridge University Press, New York, 2009, pp.3.