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Eng.Abdallah Mahmoud 01005303717 [email protected]
Motorola Certified Instructors [For Theoretical parts].
Experienced Engineers [For Practical parts].
Our Trainers
Eng.Abdallah Mahmoud 01005303717 [email protected]
Our Employees. Our Customers. External Customers. College Students.
Our Trainees
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
Mobility .
Efficiency .
Cost & Revenue.
Wireless Comm. Vision
Eng.Abdallah Mahmoud 01005303717 [email protected]
Random Access Tech.
Eng.Abdallah Mahmoud 01005303717 [email protected]
MultiPath Fading. Doppler Shift.
Diversity. Frequency hopping. Synchronizations (time & Freq. ). Error Protection.
Wireless Comm. Challenges
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
Eng.Abdallah Mahmoud 01005303717
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
First Mobile Radio Telephone, 1924
Eng.Abdallah Mahmoud 01005303717 [email protected]
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)
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
GSM – Global System for Mobile
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
1G – Separate Frequencies
Eng.Abdallah Mahmoud 01005303717 [email protected]
2G – Time Division Multiple Access (TDMA)
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
- 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
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
Diverse Mobile Wireless Spectrum
Eng.Abdallah Mahmoud 01005303717 [email protected]
Migration Paths
Eng.Abdallah Mahmoud 01005303717 [email protected]
- 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
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
● 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
Eng.Abdallah Mahmoud 01005303717 [email protected]
- 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)
Eng.Abdallah Mahmoud 01005303717 [email protected]
-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
Eng.Abdallah Mahmoud 01005303717 [email protected]
- 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
Eng.Abdallah Mahmoud 01005303717 [email protected]
Mobile Generations Arch. Evolving
Advantages for subscriber:
• Mobility• Flexibility• Convenience
Advantages for provider:
• Efficiency• Revenue / profit margins• Easier for re-
configuration• Network expansion
flexibility
Eng.Abdallah Mahmoud 01005303717 [email protected]
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:
Eng.Abdallah Mahmoud 01005303717
Eng.Abdallah Mahmoud 01005303717 [email protected]
Typical 2G Mobile Architecture
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
- 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
Eng.Abdallah Mahmoud 01005303717 [email protected]
- 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
Eng.Abdallah Mahmoud 01005303717
Eng.Abdallah Mahmoud 01005303717 [email protected]
2.5G/3G Adds IP Data – voice unchanged
Eng.Abdallah Mahmoud 01005303717 [email protected]
2.5G Architectural Detail
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
3G rel99 Architecture (UMTS) - 3G Radios
Eng.Abdallah Mahmoud 01005303717 [email protected]
3G rel4 Architecture (UMTS) - Soft Switching
Eng.Abdallah Mahmoud 01005303717 [email protected]
3GPP rel5 Architecture - IP Multimedia
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
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
Eng.Abdallah Mahmoud 01005303717 [email protected]
IMS Story: Convergence
Eng.Abdallah Mahmoud 01005303717 [email protected]
- 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
Eng.Abdallah Mahmoud 01005303717 [email protected]
IMS Session (i.e. Call) Control
Eng.Abdallah Mahmoud 01005303717 [email protected]
- 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 !
Eng.Abdallah Mahmoud 01005303717 [email protected]
Eng.Abdallah Mahmoud 01005303717 [email protected]
Eng.Abdallah Mahmoud 01005303717 [email protected]
Eng.Abdallah Mahmoud 01005303717 [email protected]
Eng.Abdallah Mahmoud 01005303717 [email protected]
Eng.Abdallah Mahmoud 01005303717 [email protected]
Eng.Abdallah Mahmoud 01005303717