introduction to Broadband Comm.

1. Introduction to Broadband
Communications
Ph.D Course_ Broadband Communications
Lect#1
hikmat.abdullah@coie-nahrain.edu.iq

2. Introduction to Broadband Communication
• Broadband is wide bandwidth data transmission which transports
multiple signals and traffic types. The medium can be coaxial
cable, optical fiber, radio or twisted pair.
• In digital telecommunication, the term was mainly used for
transmission over multiple channels with reduced noise.
• In telecommunications, “broadband” and “wideband” are used
interchangeably
• Internet Broadband refers to an Internet connection that allows support
for data, voice, and video information at high speeds.

3. • In the context of Internet access, the term "broadband" is used loosely
to mean "access that is always on and faster than the traditional dial-up
access".
• A range of more precise definitions of speed have been prescribed at
times, including:
 "Greater than the primary rate" (which ranged from about 1.5
to 2 Mbit/s) —CCITT in "broadband service" in 1988.
 "Internet access that is always on and faster than the
traditional dial-up access"—US National Broadband Plan of
2009
 4 Mbit/s downstream, 1 Mbit/s upstream —FCC, 2010.
 25 Mbit/s downstream, 3 Mbit/s upstream —FCC, 2015
Introduction to Broadband Communication

4. What is our resource? Wireless Spectrum
• It is all about spectrum!!!
In USA
50MHz at
700MHz in
2008
Raised
$19B
In TR, 3G
105MHz at
2100MHz
in 2008
Raised
$1.3B

5. How we can achieve Multiple Access?
• By creating orthogonal resources
Orthogonal Codes
Frequency
Division
Mul1ple
Access
Code
Division
Mul1ple
Access
Time
Division
Mul1ple
Access

6. What is an Orthogonal Code? In CDMA

7. Wired Broadband
• DSL(Digital Subscriber line)
• Cable Modem
• Optical Fibre Technologies (PON, FTTH, FTTB,FTTC)
• PLC (Power Line Communication)
Wireless Broadband
• Mobile Broadband
• Wireless LANs

8. Mobile Broadband
• Lack of standardization

10. • Frequency allocation problem – No roaming

21. Intercarrier SeparaNon =
1/(symbol duraNon)
– No intercarrier guard bands
– Controlled overlapping of bands
– Maximum spectral efficiency (Nyquist rate)
N carriers
B
Features
f 0
B
Frequency
Data
Time-frequency grid
User
1
User
2
User
3
T=1/f 0
User
8 Carrier
One OFDM symbol
Time
What is OFDMA?
– Easy implementaNon using IFFTs
Modula0on technique
A user uNlizes some carriers to transmit its data as coded quanNty at each
frequency carrier, which can be quadrature-amplitude modulated (QAM).
ELEC 450 - Koc University

22. WLAN Broadband
• Wireless Local Area Networking
– Debut of IEEE with IEEE 801.11 and WiFi Alliance
– Operates in unlicensed frequency
– Single frequency network, multiplexing is CSMA
• ISM bands – Industrial, Scien1fic, and Medical bands
– 900MHz, 2.4GHz, and 5.8GHz
• U-NII band – Unlicensed Na1onal Informa1on Infrastructure band
– 5GHz
• WLAN is secondary user in ISM, primary in U-NII

23. IEEE 802.11 Family
– IEEE 802.11b
• Direct spread spectrum at 2.4GHz
• First standard : 3 channels : 11 Mbps :
– IEEE 802.11a
• 300Mhz of 5.9GHz only – operates with OFDM
– IEEE 802.11g
• Operates in 2.4GHz with same design of 802.11a: 54Mbps
– IEEE 802.11e
• MAC Standard : QoS support
– IEEE 802.11n
• with MIMO-OFDM: <600Mbps
– IEEE 802.11p
• DSRC for Vehicular Networks

24. ITU and IMT-2000
• International Telecommunication Union is the eldest organiza1on in the UN
family still in existence. It was founded as the International Telegraph Union in
Paris on 17 May 1865 and is today the leading United Na1ons agency for
informa1on and communica1on technology issues, and the global focal point for
governments and the private sector in developing networks and services.
– ITU-R Radio communication
– ITU-T Standardization
– ITU-D Development

25. IMT-2000
• International Mobile
TelecommunicaNons-2000 (IMT-2000)
is the global standard for third
generation (3G) wireless
communica1ons, defined by a set of
interdependent ITU Recommendations.
• IMT-2000 is particularly a framework
that defines the criteria of ubiquitous
support. The key criteria's are
– High transmission rates
– Fixed line voice quality
– Global roaming and circuit switched
services support
– Multiple simultaneous services
– Increased capacity and spectral efficiency
– Symmetric and asymmetric transmission
of data
Another
multiple
access scheme
OFDMA

26. Mobile WiMAX
• Adopts OFDMA
– Faces the challenge of mobility unlike 3G which faces the
challenge of data rate.
– Driven by WiMAX Forum
– Delivers mobility at Vehicular Speeds
•
•
•
•
•
Adaptive Modulation and Coding
Hybrid ARQ
Fast Scheduling
Bandwidth efficient handover
EV-DO and HSPA are FDD, WiMAX is first TDD now FDD is
introduced
• Operating in 2.5GHz
• 2x2 MIMO

27. Modulation Evolution

28. IMT- Advanced
• Defines the standard of 4G
• ITU-R considers data rates up to 100 Mbps for high
mobility and 1Gbps for low mobility
– WiMAX-m which is IEEE 802.16m with MIMO
– LTE with MIMO

29. Key Features of 4G
• Increased data rates
– OFDMA, higher modula1on, AMC, turbo coding, ARQ,
MIMO
• High Spectral Efficiency
– Reduce cost of per bit
• Flexible radio planning
– SON: Self-Organizing Network
• Reduced latency
– Round-trip-times 10ms or less
• All-IP architecture
– “flat” all-IP based core network
• Interworking
– Internetworking of existing technologies
• Open Interfaces
– Multivendor network operation
• Spectral flexibility
– Scalable bandwidths

46. Comparison Summary