Cellular Wireless Communication Systems
A cellular mobile communications system use a large number of low-power wireless transmitters to create cells [the basic geographic service area of a wireless communications systems. Variable power levels allow cells to be sized according to the subscriber density and demand within particular regions. As mobile users travel from one cell to cell, their conversations are "handed off" between cells in order to maintain seamless service. Channels (frequencies) used in one cell can be reused in another cell some distance away. Cell can be added to accommodate growth, creating new cells in un-served areas or overlaying cells in existing areas.
There are many tutorials / books available to let you understand about Cellular Systems, GSM, and UMTS etc. We will summarise these topics to understand generations and jump to main topic 3GPP LTE.
1st Generation
• Analog speech communication
• Analog FDMA
• Example: AMPS (Advanced Mobile Phone Services), NAACS(North American Analog Cellular Systems) and NAMPS (Narrowband Analog Mobile Phone Service)
2nd Generation
• Digital modulation of speech communications.
• Advanced security and roaming.
• TDMA and narrowband CDMA.
• Example: GSM, IS-95 (cdmaOne), and PDC
3rd Generation
• Global harmonization and roaming
• Wideband CDMA
• Example: UMTS, cdma2000, and TD-SCDMA
Beyond 3G
• International Mobile Telecommunications (IMT)-2000 introduced global standard for 3G
• Systems beyond IMT-2000 (IMT-Advanced) is set to introduce evolutionary path beyond 3G
o Mobile class targets 100 Mbps with high mobility and nomadic / local area class targets 1 Gbps with low mobility
• 3GPP and 3GPP2 are currently developing evolutionary / revolutionary systems beyond 3G
o 3GPP Long Term Evolution (LTE)
o 3GPP2 Ultra Mobile Broadband (UMB)
• IEEE 802.16-based WiMAX is also evolving towards 4G through 802.16m
We will discuss about beyond 3G evolutions in three parallel technical bodies.
• 3GPP Evolution
• 3GPP2 Evolution
• IEEE 802.16 Evolution
A: What is 3GPP? http://www.3gpp.com/
The 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations, to make a globally applicable third-generation (3G) mobile phone system specification within the scope of the International Mobile Telecommunications-2000 project of the International Telecommunication Union (ITU). 3GPP specifications are based on evolved Global System for Mobile Communications (GSM) specifications. 3GPP standardization encompasses Radio, Core Network and Service architecture.
The groups are the European Telecommunications Standards Institute, Association of Radio Industries and Businesses/Telecommunication Technology Committee (ARIB/TTC) (Japan), China Communications Standards Association, Alliance for Telecommunications Industry Solutions (North America) and Telecommunications Technology Association (South Korea). The project was established in December 1998
B: What is 3GPP2? http://www.3gpp2.com/
The 3rd Generation Partnership Project 2 (3GPP2) is a collaboration between telecommunications associations to make a globally applicable third generation (3G) mobile phone system specification within the scope of the ITU's IMT-2000 project. In practice, 3GPP2 is the standardization group for CDMA2000, the set of 3G standards based on earlier 2G CDMA technology.
The participating associations are ARIB/TTC (Japan), China Communications Standards Association, Telecommunications Industry Association (North America) and Telecommunications Technology Association (South Korea). The agreement was established in December 1998. In November 2008, Qualcomm, UMB's lead sponsor, announced it was ending development of the technology, favouring LTE instead.
C: IEE802.16 http://grouper.ieee.org/groups/802/16/
IEEE 802.16 is written by a working group established by IEEE Standards Board in 1999 to develop standards for the global deployment of broadband Wireless Metropolitan Area Networks. The Workgroup is a unit of the IEEE 802 LAN/MAN Standards Committee.
Although the 802.16 family of standards is officially called WirelessMAN in IEEE, it has been commercialized under the name “WiMAX” (from "Worldwide Interoperability for Microwave Access") by the industry alliance called the WiMAX Forum. The mission of the Forum is to promote and certify compatibility and interoperability of broadband wireless products based on the IEEE 802.16 standards.
IEEE 802.16 is a series of Wireless Broadband standards authored by the IEEE. The current version is IEEE 802.16-2009 amended by IEEE 802.16j-2009.
Tip:
IEEE 802.16 Wireless Networking - WiMax
IEEE 802.11 Wireless Networking - WiFi
IEEE 802.15.1 Bluetooth
IEEE 802.15.4 Wireless sensor / Control Network – ZigBee
In following paragraph we will discuss about progress of each technical vertical.
A: 3GPP Evolution
B: 3GPP2 Evolution
C: IEEE802.16 Evolution
A: 3GPP Evolution
Release 99 (March 2000): UMTS/WCDMA
Release 5 (March 2002): HSDPA
Release 6 (March 2005): HSUPA
Release 7 (2007): DL MIMO, IMS, Optimized real-time services (VoIP, Gaming, & PTT)
Release 8 (LTE):
• 3GPP work on the Evolution of the 3G Mobile System started in November 2004
• Standardized in the form of Rel-8
• Spec finalized and approved in January 2008
• Target deployment in 2010
• LTE-Advanced study phase in progress
B: 3GPP2 Evolution
CDMA2000 1X (1999)
CDMA2000 1xEV-DO (2000)
EV-DO Rev. A (2004): VoIP
EV-DO Rev. B (2006): Multi-carrier
UMB (EV-DO Rev C):
• Based on EV-DO, IEEE 802.20, and FLASH-OFDM
• Spec finalized in April 2007.
• Commercially available in early 2009.
C: IEEE802.16 Evolution
802.16 (2002): Line-of-sight fixed operation in 10 to 66 GHz
802.16a (2003): Air interface support for 2 to 11 GHz
802.16d (2004): Minor improvements to fixes to 16a
802.16e (2006): Support for vehicular mobility and asymmetrical link
802.16m (in progress): Higher data rate, reduced latency, and efficient security mechanism
Till now we have learnt about technical vertical bodies, working in cellular wireless network areas (3gpp, 3gpp2 & IEEE802.16). I hope you have understanding of these bodies and work area now. Few technologies mentioned above still not clear to you (eg: MIMO etc) and you are looking for more information about these. No problem, everything will cover later. Now onwards I will focus on 3GPP LTE and technologies which are enabling LTE network.
First question come our mind, why we require another generation of network? What are the requirements for LTE?
Requirement s for LTE
• Peak Data Rate: 100 Mbps DL/ 50 Mbps UL within 20 MHz bandwidth
• Up to 200 active users in a cell (5 MHz)
• Less than 5 ms user-plane latency
• Mobility
o Optimized for 0 ~ 15 km/h.
o 15 ~ 120 km/h supported with high performance
o Supported up to 350 km/h or even up to 500 km/h
• Enhanced multimedia broadcast multicast service (E-MBMS)
• Spectrum flexibility: 1.25 ~ 20 MHz
• Enhanced support for end-to-end QoS
LTE Enabling Technologies
• OFDM (Orthogonal Frequency Division Multiplexing)
• Frequency domain equalization
• SC-FDMA (Single Carrier FDMA)
• MIMO (Multi-Input Multi-Output)
• Multicarrier channel-dependent resource scheduling
• Fractional frequency reuse
• Single Carrier FDMA (SC-FDMA)
o SC-FDMA is a new single carrier multiple access technique which has similar structure and performance to OFDMA
Utilizes single carrier modulation and orthogonal frequency multiplexing using DFT-spreading in the transmitter and frequency domain equalization in the receiver
o A salient advantage of SC-FDMA over OFDM/OFDMA is low PAPR
Efficient transmitter and improved cell-edge performance
Key features of LTE
• Multiple access scheme
o DL: OFDMA with CP.
o UL: Single Carrier FDMA (SC-FDMA) with CP.
• Adaptive modulation and coding
o DL/UL modulations: QPSK, 16QAM, and 64QAM
o Convolutional code and Rel-6 turbo code
• Advanced MIMO spatial multiplexing techniques
o (2 or 4)x(2 or 4) downlink and uplink supported.
o Multi-user MIMO also supported.
• Support for both FDD and TDD
• H-ARQ, mobility support, rate control, security, and etc.
3GPP specification for LTE standards, which you refer for detail study.
Specification index Description of contents
TS 36.1xx Equipment requirements: Terminals, base stations, and repeaters
TS 36.2xx Physical layer
TS 36.3xx Layers 2 and 3: Medium access control, radio link control, and radio resource control
TS 36.4xx Infrastructure communications (UTRAN = UTRA Network) including base stations and mobile management entities
TS 36.5xx Conformance testing
Glossary:
AMPS: Advanced Mobile Phone Services
NAACS: North American Analog Cellular Systems
NAMPS: Narrowband Analog Mobile Phone Service
UMTS: Universal Mobile Telecommunications System
WCDMA: Wideband Code Division Multiple Access
HSDPA: High-Speed Downlink Packet Access
HSUPA: High-Speed Uplink Packet Access
MIMO: Multiple Input and Multiple Output
IMS: IP Multimedia Subsystem
PTT: Push to talk
UMB: Ultra Mobile Broadband
OFDM: Orthogonal Frequency Division Multiplexing
FDMA: Frequency Division Multiplexing Access
SC-FDMA: Single Carrier FDMA
H-ARQ: Hybrid automatic repeat request
Bibliography
A cellular mobile communications system use a large number of low-power wireless transmitters to create cells [the basic geographic service area of a wireless communications systems. Variable power levels allow cells to be sized according to the subscriber density and demand within particular regions. As mobile users travel from one cell to cell, their conversations are "handed off" between cells in order to maintain seamless service. Channels (frequencies) used in one cell can be reused in another cell some distance away. Cell can be added to accommodate growth, creating new cells in un-served areas or overlaying cells in existing areas.
There are many tutorials / books available to let you understand about Cellular Systems, GSM, and UMTS etc. We will summarise these topics to understand generations and jump to main topic 3GPP LTE.
1st Generation
• Analog speech communication
• Analog FDMA
• Example: AMPS (Advanced Mobile Phone Services), NAACS(North American Analog Cellular Systems) and NAMPS (Narrowband Analog Mobile Phone Service)
2nd Generation
• Digital modulation of speech communications.
• Advanced security and roaming.
• TDMA and narrowband CDMA.
• Example: GSM, IS-95 (cdmaOne), and PDC
3rd Generation
• Global harmonization and roaming
• Wideband CDMA
• Example: UMTS, cdma2000, and TD-SCDMA
Beyond 3G
• International Mobile Telecommunications (IMT)-2000 introduced global standard for 3G
• Systems beyond IMT-2000 (IMT-Advanced) is set to introduce evolutionary path beyond 3G
o Mobile class targets 100 Mbps with high mobility and nomadic / local area class targets 1 Gbps with low mobility
• 3GPP and 3GPP2 are currently developing evolutionary / revolutionary systems beyond 3G
o 3GPP Long Term Evolution (LTE)
o 3GPP2 Ultra Mobile Broadband (UMB)
• IEEE 802.16-based WiMAX is also evolving towards 4G through 802.16m
We will discuss about beyond 3G evolutions in three parallel technical bodies.
• 3GPP Evolution
• 3GPP2 Evolution
• IEEE 802.16 Evolution
A: What is 3GPP? http://www.3gpp.com/
The 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations, to make a globally applicable third-generation (3G) mobile phone system specification within the scope of the International Mobile Telecommunications-2000 project of the International Telecommunication Union (ITU). 3GPP specifications are based on evolved Global System for Mobile Communications (GSM) specifications. 3GPP standardization encompasses Radio, Core Network and Service architecture.
The groups are the European Telecommunications Standards Institute, Association of Radio Industries and Businesses/Telecommunication Technology Committee (ARIB/TTC) (Japan), China Communications Standards Association, Alliance for Telecommunications Industry Solutions (North America) and Telecommunications Technology Association (South Korea). The project was established in December 1998
B: What is 3GPP2? http://www.3gpp2.com/
The 3rd Generation Partnership Project 2 (3GPP2) is a collaboration between telecommunications associations to make a globally applicable third generation (3G) mobile phone system specification within the scope of the ITU's IMT-2000 project. In practice, 3GPP2 is the standardization group for CDMA2000, the set of 3G standards based on earlier 2G CDMA technology.
The participating associations are ARIB/TTC (Japan), China Communications Standards Association, Telecommunications Industry Association (North America) and Telecommunications Technology Association (South Korea). The agreement was established in December 1998. In November 2008, Qualcomm, UMB's lead sponsor, announced it was ending development of the technology, favouring LTE instead.
C: IEE802.16 http://grouper.ieee.org/groups/802/16/
IEEE 802.16 is written by a working group established by IEEE Standards Board in 1999 to develop standards for the global deployment of broadband Wireless Metropolitan Area Networks. The Workgroup is a unit of the IEEE 802 LAN/MAN Standards Committee.
Although the 802.16 family of standards is officially called WirelessMAN in IEEE, it has been commercialized under the name “WiMAX” (from "Worldwide Interoperability for Microwave Access") by the industry alliance called the WiMAX Forum. The mission of the Forum is to promote and certify compatibility and interoperability of broadband wireless products based on the IEEE 802.16 standards.
IEEE 802.16 is a series of Wireless Broadband standards authored by the IEEE. The current version is IEEE 802.16-2009 amended by IEEE 802.16j-2009.
Tip:
IEEE 802.16 Wireless Networking - WiMax
IEEE 802.11 Wireless Networking - WiFi
IEEE 802.15.1 Bluetooth
IEEE 802.15.4 Wireless sensor / Control Network – ZigBee
In following paragraph we will discuss about progress of each technical vertical.
A: 3GPP Evolution
B: 3GPP2 Evolution
C: IEEE802.16 Evolution
A: 3GPP Evolution
Release 99 (March 2000): UMTS/WCDMA
Release 5 (March 2002): HSDPA
Release 6 (March 2005): HSUPA
Release 7 (2007): DL MIMO, IMS, Optimized real-time services (VoIP, Gaming, & PTT)
Release 8 (LTE):
• 3GPP work on the Evolution of the 3G Mobile System started in November 2004
• Standardized in the form of Rel-8
• Spec finalized and approved in January 2008
• Target deployment in 2010
• LTE-Advanced study phase in progress
B: 3GPP2 Evolution
CDMA2000 1X (1999)
CDMA2000 1xEV-DO (2000)
EV-DO Rev. A (2004): VoIP
EV-DO Rev. B (2006): Multi-carrier
UMB (EV-DO Rev C):
• Based on EV-DO, IEEE 802.20, and FLASH-OFDM
• Spec finalized in April 2007.
• Commercially available in early 2009.
C: IEEE802.16 Evolution
802.16 (2002): Line-of-sight fixed operation in 10 to 66 GHz
802.16a (2003): Air interface support for 2 to 11 GHz
802.16d (2004): Minor improvements to fixes to 16a
802.16e (2006): Support for vehicular mobility and asymmetrical link
802.16m (in progress): Higher data rate, reduced latency, and efficient security mechanism
Till now we have learnt about technical vertical bodies, working in cellular wireless network areas (3gpp, 3gpp2 & IEEE802.16). I hope you have understanding of these bodies and work area now. Few technologies mentioned above still not clear to you (eg: MIMO etc) and you are looking for more information about these. No problem, everything will cover later. Now onwards I will focus on 3GPP LTE and technologies which are enabling LTE network.
First question come our mind, why we require another generation of network? What are the requirements for LTE?
Requirement s for LTE
• Peak Data Rate: 100 Mbps DL/ 50 Mbps UL within 20 MHz bandwidth
• Up to 200 active users in a cell (5 MHz)
• Less than 5 ms user-plane latency
• Mobility
o Optimized for 0 ~ 15 km/h.
o 15 ~ 120 km/h supported with high performance
o Supported up to 350 km/h or even up to 500 km/h
• Enhanced multimedia broadcast multicast service (E-MBMS)
• Spectrum flexibility: 1.25 ~ 20 MHz
• Enhanced support for end-to-end QoS
LTE Enabling Technologies
• OFDM (Orthogonal Frequency Division Multiplexing)
• Frequency domain equalization
• SC-FDMA (Single Carrier FDMA)
• MIMO (Multi-Input Multi-Output)
• Multicarrier channel-dependent resource scheduling
• Fractional frequency reuse
• Single Carrier FDMA (SC-FDMA)
o SC-FDMA is a new single carrier multiple access technique which has similar structure and performance to OFDMA
Utilizes single carrier modulation and orthogonal frequency multiplexing using DFT-spreading in the transmitter and frequency domain equalization in the receiver
o A salient advantage of SC-FDMA over OFDM/OFDMA is low PAPR
Efficient transmitter and improved cell-edge performance
Key features of LTE
• Multiple access scheme
o DL: OFDMA with CP.
o UL: Single Carrier FDMA (SC-FDMA) with CP.
• Adaptive modulation and coding
o DL/UL modulations: QPSK, 16QAM, and 64QAM
o Convolutional code and Rel-6 turbo code
• Advanced MIMO spatial multiplexing techniques
o (2 or 4)x(2 or 4) downlink and uplink supported.
o Multi-user MIMO also supported.
• Support for both FDD and TDD
• H-ARQ, mobility support, rate control, security, and etc.
3GPP specification for LTE standards, which you refer for detail study.
Specification index Description of contents
TS 36.1xx Equipment requirements: Terminals, base stations, and repeaters
TS 36.2xx Physical layer
TS 36.3xx Layers 2 and 3: Medium access control, radio link control, and radio resource control
TS 36.4xx Infrastructure communications (UTRAN = UTRA Network) including base stations and mobile management entities
TS 36.5xx Conformance testing
Glossary:
AMPS: Advanced Mobile Phone Services
NAACS: North American Analog Cellular Systems
NAMPS: Narrowband Analog Mobile Phone Service
UMTS: Universal Mobile Telecommunications System
WCDMA: Wideband Code Division Multiple Access
HSDPA: High-Speed Downlink Packet Access
HSUPA: High-Speed Uplink Packet Access
MIMO: Multiple Input and Multiple Output
IMS: IP Multimedia Subsystem
PTT: Push to talk
UMB: Ultra Mobile Broadband
OFDM: Orthogonal Frequency Division Multiplexing
FDMA: Frequency Division Multiplexing Access
SC-FDMA: Single Carrier FDMA
H-ARQ: Hybrid automatic repeat request
Bibliography
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