LTE – More Than AcronymsLTE – More Than Acronyms
Presentation to:NPSTC
Arlington, VAJune 10, 2009
Presentation to:NPSTC
Arlington, VAJune 10, 2009
LTE – An acronym for all occasionsLTE – An acronym for all occasions• A discussion of the acronym ridden LTE
standard is timely given the United States government priority on expanding availability of broadband services to the entire population
• A number of wireless technologies will compete with or will complement wired technologies to provide universal service
• LTE is a candidate technology for public safety broadband wireless service, perhaps in a modified core network form
• A discussion of the acronym ridden LTE standard is timely given the United States government priority on expanding availability of broadband services to the entire population
• A number of wireless technologies will compete with or will complement wired technologies to provide universal service
• LTE is a candidate technology for public safety broadband wireless service, perhaps in a modified core network form
LTE Specification Managed by - 3rd
Generation Partnership ProgramLTE Specification Managed by - 3rd
Generation Partnership Program
3GPP – GSM-EDGE-UMTS-LTE3GPP2 – CDMA, 1XEVDO
LTE = Long Term EvolutionLTE = Long Term Evolution
Supported BandwidthsSupported Bandwidths• LTE supports various bandwidths to fit in
spectrum allocations in various global regions– 1.25 MHz– 1.6 MHz– 2.5 MHz– 5 MHz– 10MHz– 15 MHz– 20MHz
• LTE supports various bandwidths to fit in spectrum allocations in various global regions– 1.25 MHz– 1.6 MHz– 2.5 MHz– 5 MHz– 10MHz– 15 MHz– 20MHz
Global LTE Frequency BandsGlobal LTE Frequency Bands
3X103X20
2X121X61X221X10 (D)
MHzBlocks
OFDM= Orthogonal Frequency Division Multiplexing
OFDM= Orthogonal Frequency Division Multiplexing
• Does this sound familiar?– Used in WiMax 802.16 protocol for the
downlink (from the base station) and the uplink (to the base station)
• A variant is used in LTE – OFDMA– Only for the downlink
• Does this sound familiar?– Used in WiMax 802.16 protocol for the
downlink (from the base station) and the uplink (to the base station)
• A variant is used in LTE – OFDMA– Only for the downlink
LTE OFDM Physical Channel Structure and Modulation
LTE OFDM Physical Channel Structure and Modulation
The “comb”represents subcarriers # of bits depends
on modulation type
OFDM vs OFDMAOFDM vs OFDMA
LTE Uplink Uses SC-FDMA (Single Carrier Frequency Division Multiple Access
LTE Uplink Uses SC-FDMA (Single Carrier Frequency Division Multiple Access
• Has similarities to the OFDM• Allows simpler user equipment
transmitters by reducing the need for linearity in power amplifiers
• Conserves battery power• Retains orthogonality for intra-cell
interference control
• Has similarities to the OFDM• Allows simpler user equipment
transmitters by reducing the need for linearity in power amplifiers
• Conserves battery power• Retains orthogonality for intra-cell
interference control
OFDMA and SC-FDMA ComparisonQPSK Modulation Example and M=4 Subcarriers
OFDMA and SC-FDMA ComparisonQPSK Modulation Example and M=4 Subcarriers
MIMO (Multiple Input Multiple Output)MIMO (Multiple Input Multiple Output)• Multiple, uncorrelated,
antennas separated by greater than 10λ
• 2X2 configuration might be used to increase data rate for one user, or may increase the capacity of a cell site by permitting separate data streams
• Sophisticated coding used for reconstruction of signals
• Increases performance in multipath areas
• Multiple, uncorrelated, antennas separated by greater than 10λ
• 2X2 configuration might be used to increase data rate for one user, or may increase the capacity of a cell site by permitting separate data streams
• Sophisticated coding used for reconstruction of signals
• Increases performance in multipath areas
From Microwaves and RF Magazine
Network SimplificationNetwork Simplification
SON = Self Organizing NetworkSON = Self Organizing Network• Larger number of base
stations (eNodeB) increases network deployment, optimization and management tasks
• Reduction of tasks while following existing O&M practices was desired by network operators
• Larger number of base stations (eNodeB) increases network deployment, optimization and management tasks
• Reduction of tasks while following existing O&M practices was desired by network operators
• SON automates some processes needed to extend, change, optimize:– New cells– Coverage – Capacity– Cell radius– Frequency allocation– Bandwidth– Neighbor lists, roaming
parameters– Border areas
• May be centralized, distributed or hybrid
• SON automates some processes needed to extend, change, optimize:– New cells– Coverage – Capacity– Cell radius– Frequency allocation– Bandwidth– Neighbor lists, roaming
parameters– Border areas
• May be centralized, distributed or hybrid
LTE Reduces Network Components and Cost Compared to Existing Technology
LTE Reduces Network Components and Cost Compared to Existing Technology
• Supports both FDD (Frequency Division Duplexing) and TDD (Time Division Duplexing) to allow use in unpaired bands
• Frame mount radios, tower top radios (40W at ant.), remote radio heads
• Radio network controllers eliminated from architecture – IP connectivity
• Supports both FDD (Frequency Division Duplexing) and TDD (Time Division Duplexing) to allow use in unpaired bands
• Frame mount radios, tower top radios (40W at ant.), remote radio heads
• Radio network controllers eliminated from architecture – IP connectivity
eNode B (Base)Courtesy of Motorola
Comparison UMTS vs LTEComparison UMTS vs LTERequirement Current HSxPA 6 LTE E-UTRA
Peak Data Rate 14 Mbps Down5.76 Mbps Up
100 Mbps Down50 Mbps Up
Spectral Efficiency .6 - .8 DL.35 UL
3-4X DL; 2-3X UL improvement
Averaged User Throughput
900 Kbps UL;150 Kbps DL
3-4X DL; 2-3X UL improvement
User Plane Latency 50ms 5 msCall Set Up Time 2 sec 50 msMobility 250 km/h 350 km/hBandwidth 5 MHz Scalable to 20 MHz
LTE Advantages Gigantic Economies of Scale
LTE Advantages Gigantic Economies of Scale
• Market size over a billion units worldwide• Simplified air protocols allows manufacture of
inexpensive subscriber devices that are power efficient
• Lower cost deployment of fixed infrastructure– Elimination of circuit switched components– Direct IP from base station to Mobility Management
Entity– IP networking standardized components– Network core allows gateways to other IP
technologies – earlier generations, trusted and untrusted sources
• Market size over a billion units worldwide• Simplified air protocols allows manufacture of
inexpensive subscriber devices that are power efficient
• Lower cost deployment of fixed infrastructure– Elimination of circuit switched components– Direct IP from base station to Mobility Management
Entity– IP networking standardized components– Network core allows gateways to other IP
technologies – earlier generations, trusted and untrusted sources
Uses for the LTE Throughput Capabilities
Uses for the LTE Throughput Capabilities
• HDTV 720i/H• Interactive Gaming• Video Blogging/Communities/Uploads• Permanent Synch (ex: Photos to home
PC, Outlook, etc.)• Music• And, Voice over IP Calls
• HDTV 720i/H• Interactive Gaming• Video Blogging/Communities/Uploads• Permanent Synch (ex: Photos to home
PC, Outlook, etc.)• Music• And, Voice over IP CallsINCREASES ARPU & # OF SUBSCRIBERS FOR CARRIERS
So Why is All This Important?So Why is All This Important?• Introduction of LTE, a so-called 3.5 Generation
technology (with 4G performance) is the most meaningful step toward Fixed-Mobile Convergence
• Our society, and especially the younger generation, values the always-on personal access (replacing the home phone)
• Whatever media and content is available at home on a wired connection is desired in the mobile environment –the “personalized media experience”
• Intense use of bandwidth straining existing 3G systems• Opens possibilities of advanced applications for public
safety and taking advantage of economies of scale
• Introduction of LTE, a so-called 3.5 Generation technology (with 4G performance) is the most meaningful step toward Fixed-Mobile Convergence
• Our society, and especially the younger generation, values the always-on personal access (replacing the home phone)
• Whatever media and content is available at home on a wired connection is desired in the mobile environment –the “personalized media experience”
• Intense use of bandwidth straining existing 3G systems• Opens possibilities of advanced applications for public
safety and taking advantage of economies of scale
AcknowledgementsAcknowledgementsRobert LopezMoanley LormejustePalaniappan MuthukaruppanVikas PatelRenato Sunga