mobile technology session

Mobile Technologies

Overview

Eng.Abdallah Mahmoud 01005303717

[email protected]

Eng.Abdallah Mahmoud 01005303717 [email protected]

Motorola Certified Instructors [For Theoretical parts].

Experienced Engineers [For Practical parts].

Our Trainers


Our Employees. Our Customers. External Customers. College Students.

Our Trainees


No need for any Communication Systems.

Simple Communication System. Wired Telecommunication System

1. Traffic .2. Signaling .3. Circuit switching Technology .

Toward Wireless Communication.

Life Before Wireless Communications


Mobility .

Efficiency .

Cost & Revenue.

Wireless Comm. Vision


Random Access Tech.


MultiPath Fading. Doppler Shift.

Diversity. Frequency hopping. Synchronizations (time & Freq. ). Error Protection.

Wireless Comm. Challenges


Antenna diversity Cellular concept Frequency reuse● typically every 7 cells Handoff as caller

moves Modified CO switch● HLR, paging Sectors improve reuse● every 3 cells possible

Cellular Mobile Telephony


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1864: James Clark Maxwell● Predicts existence of radio waves 1886: Heinrich Rudolph Hertz● Demonstrates radio waves 1895-1901: Guglielmo Marconi● Demonstrates wireless communications over

increasing distances Also in the 1890s● Nikola Tesla, Alexander Stepanovich Popov, JagdishChandra Bose and others, demonstrate forms of wireless communications

Origins of Wireless Communications


First Mobile Radio Telephone, 1924


Advanced Mobile Phone Service (AMPS)US trials 1978; deployed in Japan (’79) & US

(’83)800 MHz; two 20 MHz bands; TIA-553 Nordic Mobile Telephony (NMT)Sweden, Norway, Demark & FinlandLaunched 1981450 MHz; later at 900 MHz (NMT900) Total Access Communications System (TACS)British design; similar to AMPS; deployed 1985

First Generation (nearly all retired)


Leverage technology to increase capacity● Speech compression; digital signal processing Utilize/extend “Intelligent Network” concepts● Improve fraud prevention; Add new services Wide diversity of 2G systems● IS-54/ IS-136 North American TDMA(D-AMPS ); &

PDC (Japan)[PDC dominant 2G cellular system in Japan].

● DECT and PHS; iDEN● IS-95 CDMA (cdmaOne)● GSM

2nd Generation “2G” – digital systems


GSM – Global System for Mobile


Originally “Groupe Spécial Mobile ”● joint European effort beginning in 1982 focused on seamless roaming across Europe Services launched 1991● time division multiple access (8 users per 200KHz)● 900 MHz band; later extended to 1800 MHz; then 1900

MHz● Quad-band “world phones” support 850/900/1800/1900

MHz GSM – dominant world standard today● well defined interfaces; many competitors; lowest cost

to deploy● network effect (Metcalfe’s law) took hold in late 1990s

GSM – Global System for Mobile


1G – Separate Frequencies


2G – Time Division Multiple Access (TDMA)


Spread spectrum modulation● originally developed for the military● resists jamming and many kinds of interference● coded modulation hidden from those w/o the

code All users share same (large) block of spectrum● one for one frequency reuse● soft handoffs possible All 3G radio standards based on CDMA● CDMA2000, W-CDMA and TD-SCDMA

2G & 3G – Code Division Multiple Access


Universal global roaming (1 standard, not 7)● 3GSM leads, but with CDMA 2000 & China TD-SCDMA Multimedia (voice, data & video) Increased data rates (384 Kbps to ? Mbps) Increased capacity (more spectrally efficient) Data-centric architecture (ATM at first, then IP) But deployment took longer than expected● No killer data app; new spectrum costly; telecom bubble burst; much of the vision was

vendor-driven

The 3G Vision


- General packet radio service● first introduction of packet technology- Aggregate radio channels● support higher data rates (115 Kbps)● subject to channel availability- Share aggregate channels among

multiple users- All new IP-based data infrastructure- No changes to voice network

GPRS - 2.5G for GSM


ITU (International Telecommunication Union)● Radio standards and spectrum IMT-2000● ITU’s umbrella name for 3G which stands for International Mobile Telecommunications 2000 3G Partnership Projects (3GPP & 3GPP2)● focused on evolution of access and core

networks● National and regional standards bodies

collaborating, i.e., ARIB, TIA, TTA, TTC, CWTS. T1, ETSI

3G Standardization


EDGE – GSM evolution, i.e. TDMA● Legacy; sometimes referred to as 2.75G CDMA 2000 – Multi Carrier CDMA● Evolution of IS-95 CDMA UMTS/3GSM (W-CDMA, HSPA) – Direct Spread CDMA● Defined by 3GPP TD-SCDMA – Time Division Synchronous CDMA● Defined by Chinese Academy of Telecommunications Technology under the Ministry of Information Industry Paired spectrum bands Single spectral band with time division duplexing

3G Radio technology deployed today


GSM evolution path: W-CDMA, HSDPA, HSPA, …

● leverages GSM’s dominant position Legally mandated in Europe and elsewhere● 5 MHz each way (symmetric) Requires substantial new spectrum Slow start (behind CDMA 2000) but now

leading● Network effect builds on GSM’s 80% market

share

UMTS (3GSM) now market leader


Diverse Mobile Wireless Spectrum


Migration Paths


- 4G not formally defined, projected to provide● 100 Mbps (moving) & 1 Gbps (stationary)● Seamless roaming across heterogeous networks- Pre-4G standards sometimes promoted as “4G”● WiMAX – ~6 million units by 12/2008?● Flash-OFDM - ~13 million subscribers in 2010 ?● 3GPP Long Term Evolution (LTE) – 2010 launch● UMB in 3GPP2 – extent of adoption is uncertain● IEEE 802.20 - adoption uncertain

3.5G and 4G


Sophisticated multiple access schemes● DL: OFDMA with Cyclic Prefix (CP)● UL: Single Carrier FDMA (SC-FDMA) with CPAdaptive modulation and coding● QPSK, 16QAM, and 64QAM● 1/3 coding rate, two 8-state constituent

encoders, and a contention-free internal interleaverAdvanced MIMO spatial multiplexing techniques● (2 or 4) x (2 or 4) downlink and uplink

LTE highlights


Orthogonal Frequency Division Multiple Access● Supercedes CDMA used in all 3G variantsOFDMA = Orthogonal Frequency Division Multiplexing (OFDM) plus statistical multiplexing● Optimization of time, frequency and code

multiplexingAlready deployed in 802.11a & 802.11g WiFi● Ups WiFi from 11 Mbps to 54 Mbps & beyond

4G Technology – OFDMA


● Many closely-spaced sub-carriers, chosen to be orthogonal, thus

eliminating cross-talk & guard bands● Vary bits per sub-carrier based on

instantaneous received power

OFDM – Orthogonal Frequency Division Multiplexing


- Dynamically allocate user data to sub-carriers based on instantaneous data rates and varying sub-carrier capacities

- Highly efficient use of spectrum- Robust against fading, e.g. during mobile operation

Statistical Multiplexing (in OFDMA)


-Multiple Input Multiple Output smart antenna technology

-Multiple paths improve link reliability and increase spectral efficiency (bps per Hz), range and directionality

4G Technology - MIMO


- Single carrier multiple access● Used for LTE & UMB uplinks● Being considered for 802.16m uplink- Similar structure and performance to OFDMA● Single carrier modulation with DFT-spread

orthogonal frequency multiplexing and FD equalization

- Lower Peak to Average Power Ratio (PAPR)● Improves cell-edge performance● Transmit efficiency conserves handset battery

life

4G Technology – SC-FDMA


Mobile Generations Arch. Evolving

Advantages for subscriber:

• Mobility• Flexibility• Convenience

Advantages for provider:

• Efficiency• Revenue / profit margins• Easier for re-

configuration• Network expansion

flexibility


IMT-2000 Vision (from 1992) includedLAN, WAN and Satellite Services

Frequency reuseA2

A3A1A

D2

D3D1D

B2

B3B1B

C2

C3C1

A2

A3A1A

A2

A3A1A

CB2

B3B1B

D2

D3D1D

B2

B3B1B

D2

D3D1D

C2

C3C1C

C2

C3C1C

4 site / 3 cell frequency re-use pattern:


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Typical 2G Mobile Architecture


Hand Over

BTS

BTS

BTS

BTS

BTS

BTS

BTSBT

SBTS

BTS

PSTN MSC MSC

BSCXCDR

BTS

BSCXCDR

BTS

Mobile is handed over from serving cell to neighbor cell


- Like PSTN, 2G mobile networks have one network plane for

voice circuits and another network plane for signaling- Some elements reside only in the signaling plane● HLR, VLR, SMS Center, …

Separation of Signaling & Transport


- Based on SS7● ISUP and specific Application Parts- GSM MAP and ANSI-41 services● mobility, call-handling, O&M, authentication, supplementary services, SMS, …- Location registers for mobility management● HLR: home location register has permanent

data● VLR: visitor location register – local copy for

roamers

Signaling in Core Network

PSTN-to-Mobile Call


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2.5G/3G Adds IP Data – voice unchanged


2.5G Architectural Detail


Enhanced Data rates for Global EvolutionIncreased data rates with GSM compatibility● still 200 KHz bands; still TDMA● 8-PSK modulation: 3 bits/symbol give 3X data rate● shorter range (more sensitive to

noise/interference)Migration path: IS-136 TDMA to GSM/EDGE● GAIT - GSM/ANSI-136 interoperability team● Allowed operators like AT&T and Cingular to

migrate to GSM/EDGE using an evolved ANSI-41 core network

EDGE


3G rel99 Architecture (UMTS) - 3G Radios


3G rel4 Architecture (UMTS) - Soft Switching


3GPP rel5 Architecture - IP Multimedia


Defines migration from GSM to UMTS/ 3GSM

3G Partnership Project (3GPP)

W-CDMA – Wideband CDMA modulationHSxPA – High Speed (Download/Upload) Packet AccessMBMS – Multimedia Broadcast Multicast ServiceGAN – Generic Access NetworkPoC – Push-to-talk over CellularLTE – Long Term Evolution, a new air interface based on OFDM modulation


One core network for “any access”● Based on IP● Wireline and wireless transparency● Based on IETF standards, with extensionsAccess and bandwidth will be commodities; services are the differentiator● Per-session control supports per-application

quality of service (QoS) guarantees and per-application billingVoice is just application● “Easily” integrated with other applications…

IMS / NGN Vision


IMS Story: Convergence


- Generate new revenue from new services● Per-session control allows IMS to

guarantee QoS for each IP session, and enables differential billing for applications & content

- Reduce capital spending● Converge all services on common

infrastructure● Focus limited resources on core

competencies

IMS / NGN Value Proposition


IMS Session (i.e. Call) Control


- Most major mobile operators have deployed a SIP

infrastructure of some sort● CSCFs per strict IMS or otherwise● In use for new applications like Push to

Talk (PTT)- Fixed operators moving to softswitches for conventional voice, butMobile voice calls still use circuit switching

So far, only for New Applications !


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mobile technology session

Education

abdallah mahmoud01005303717

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g radio standards

tdscdma eng

cdma cdmaone gsm eng

g systems

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