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Introduction to LTE (Part 2)
The webinar will start shortly
2
About the Presenters
Graham Whyley Technical Master Trainer
AIRCOM Technical Master Trainer since 2005
Currently responsible for all LTE training
course creation and delivery
Over 20 years of training experience at
companies including British Telecom and
Fujitsu
Adam Moore Learning & Development Manager With AIRCOM since 2006
Member of CIPD
3
Webinar - Introduction to LTE (Part 2)
Approximate Duration – 1 hour
Agenda LTE Carriers
Re-farming
Phased Service Deployment
LTE performance requirements & Network Architecture
Summary
Q&A
4
Frequency-division duplexing(FDD)
Frequency-division duplexing (FDD) means that the transmitter and
receiver operate at different carrier frequencies.
E-UTRA Band
Bandwidth UL (MHz)
Bandwidth DL (MHz)
Duplex Mode
1 1920-1980 2110-2170 FDD
Band 1
2110-2170 MHz
1920-1980 MHZ
60Mhz 60Mhz
Bandwidth (MHz)
1.4 3 5 10 15 20
# of RBs
6 15 25 50 75 100
Subcarriers 72 180 300 600 900 1200
FOR LTE REL’8
receiver
transmitter
REL’8
5
Frequency-division duplexing(FDD)
E-UTRA Band
Bandwidth UL (MHz)
Bandwidth DL (MHz)
Duplex Mode
1 1920-1980 2110-2170 FDD
2 1850-1910 1930-1990 FDD
3 1710-1785 1805-1880 FDD
4 1710-1755 2110-2155 FDD
5 824-849 869-894 FDD
6 830-840 875-885 FDD
7 2500-2570 2620-2690 FDD
8 880-915 925-960 FDD
9 1749.9-1784.9 1844.9-1879.9 FDD
10 1710-1770 2110-2170 FDD
11 1427.9-1452.9 1475.9-1500.9 FDD
12 698-716 728-746 FDD
13 77-787 746-756 FDD
14 788-798 758-768 FDD
Band 8:is currently used mostly by GSM.
The band is attractive from a coverage
point of view due to the lower propagation
losses.
Europe:
Band 7: The 2.6 GHz auctions have been
running in a few countries
6
FDD
0 1 2 3 19
One Sub-
frame = 1 mS
10 ms
• The frame duration is 10 ms
• Each frame consists of 10 sub-frames
2110-2130 MHz
20Mz
What is meant by TTI?
1920-1940 MHZ
0 1 2 3 19
10 ms
What is TTI
Rel’99?
What is TTI
Rel’5?
What is TTI LTE?
What is
meant by
Full Duplex?
7
Frequency-division duplexing(FDD)
E-UTRA Band
Bandwidth UL (MHz)
Bandwidth DL (MHz)
Duplex Mode
1 1920-1980 2110-2170 FDD
2 1850-1910 1930-1990 FDD
3 1710-1785 1805-1880 FDD
4 1710-1755 2110-2155 FDD
5 824-849 869-894 FDD
6 830-840 875-885 FDD
7 2500-2570 2620-2690 FDD
8 880-915 925-960 FDD
9 1749.9-1784.9 1844.9-1879.9 FDD
10 1710-1770 2110-2170 FDD
11 1427.9-1452.9 1475.9-1500.9 FDD
12 698-716 728-746 FDD
13 77-787 746-756 FDD
14 788-798 758-768 FDD
Band 8:is currently used mostly by GSM. The
band is attractive from a coverage point of view
due to the lower propagation losses.
Supported Channels (non-overlapping) E-UTRA
Band Downlink
Bandwidth Channel Bandwidth (MHZ)
1.4 3 5 10 15 20
1 60 - - 12 6 4 3
2 60 42 20 12 6 4* 3*
3 75 53 23 15 7 5* 3*
4 45 32 15 9 4 3 2
5 25 17 8 5 2* - -
6 10 - - 2 1* X X
7 70 - - 14 7 4 3*
8 35 25 11 7 3* - -
GSM Bandwidth
Available
8
Re-farming
Re-using existing 2G and 3G spectrum for LTE, operators can
make significant cost savings, extend the lifespan of existing
spectrum assets
These benefits can only be realised if operators follow a careful
planning process to minimise service degradation for existing 2G
and 3G services.
A mobile network operator that plans to roll-out its new LTE network has in
principle two options:
• buy new spectrum
• re-farm spectrum already in possession.
9
Re-farming GSM 900 MHz
The 900 MHz band It also has the benefit of increased coverage and subsequent
reduction in network deployment costs compared to deployments at higher
frequencies. (GSM900 890-960)
UMTS deployments require a full 5 MHz of spectrum to be freed up before being
deployed in that band.
LTE will be able to be deployed in spectrum bands as small as 1.4MHz and it provides
good initial deployment scalability as it can be literally “squeezed” in as the GSM
spectrum is freed-up, and grow as more spectrum becomes available
GSM/DCS (Digital Cellular System)
– 900, 1800 MHz
HSPA/HSPA+
– 800, 900, 1700, 1800, 1900, 2100 MHz
LTE (Long Term Evolution – 3G, 4G)
– 800, 900, 1800, 2100, 2600 MHz (Europe)
• 900MHz offers improved building
penetration
GSM FREQUECIES 5 Mhz
10
LTE1800: LTE Deployments in 1800MHz Band
1800 MHz band widely
available throughout Europe,
APAC, MEA, and some regions
of South America
For many operators, it’s also
a way to launch next-gen
mobile broadband services
without having to waiting for
local governments to allocate
4G spectrum
LTE to be deployed in this spectrum enables the possibility to provide networks
for fast mobile broadband services with a substantially wider coverage at a
lower cost than when using 2.6 GHz, which requires a considerably larger
number of base stations.
11
64 bit QAM
SINR+19dB
m
QPSK
SINR-4dBm
Po
we
r 4
1.4
6
Path Loss 150dB
Tx Power
42 dBm
Rx
Sensitivity
-108
Path Loss
12
Phased Service Deployment
A service provider may choose to deploy LTE for selected geographical areas to serve high traffic hot zones.
LTE mobile terminals will also leverage existing 2G and 3G networks, thus allowing service to be offered in a phased deployment.
LTE may at first be deployed to serve high density urban areas and strategic indoor locations
(e.g. airports, business parks etc.).
high traffic zones
LTE CELL
LTE provides only a PS core network domain so is not able to
support traditional CS domain voice services
I need to make CS
voice call
13
Time-Division Duplexing (TDD)
TDD means the transmission and reception occur on the same frequency
Same frequency
TDD in unpaired
spectrum,
whereby the
same frequency
channel is used
for both downlink
and uplink
communication
33 1900-1920 1900-1920 TDD
34 2010-2025 2010-2025 TDD
35 1850-1910 1850-1910 TDD
36 1930-1990 1930-1990 TDD
37 1910-1930 1910-1930 TDD
38 2570-2620 2570-2620 TDD
39 1880-1920 1880-1920 TDD 40 2300-2400 2300-2400 TDD
E-UTRA Band
Bandwidth UL (MHz)
Bandwidth DL (MHz)
Duplex Mode
Special Down Down Down Down Down Down Down Up Up
E-UTRA Band
Bandwidth UL (MHz)
Bandwidth DL (MHz)
Duplex Mode
1 1920-1980 2110-2170 FDD
2 1850-1910 1930-1990 FDD
3 1710-1785 1805-1880 FDD
4 1710-1755 2110-2155 FDD
5 824-849 869-894 FDD
6 830-840 875-885 FDD
7 2500-2570 2620-2690 FDD
8 880-915 925-960 FDD
9 1749.9-1784.9 1844.9-1879.9 FDD
10 1710-1770 2110-2170 FDD
11 1427.9-1452.9 1475.9-1500.9 FDD
12 698-716 728-746 FDD
13 77-787 746-756 FDD
14 788-798 758-768 FDD
14
Type 2 LTE Frame Structure
Special Down Up Down Up Up Up Up Up Special
Special Down Down Up Up Up Up Special Down Down
Special Down Down Up Up Special Down Down Down Down
Special Down Up Down Down Down Up Up Down Down
Special Down Down Down Down Down Down Down Up Up
Special Down Down Down Down Down Down Down Up Down
Special Down Up Up Up Up Up Special Down Down
Frame 0 and frame 5 (always downlink in TDD)
Frame 0 Frame 5
Frame 1 and frame 6 is always used as for synchronization in
TDD
Frame 1 Frame 6
Frame allocation for Uplink and Downlink is settable in TDD
15
Questions
What limits Bit Rate in LTE?
Give 2 answers
Bandwidth 20MHz 15MHz
10MHz
5MHz
3MHz
1.4MHz
SINR
SINR ave = S
I + N
I = Iown + Iother
spatial multiplexing
MIMO (2x2) (4x4)
Privileged and confidential. The information contained in this material is privileged and confidential, and is intended
only for the use of the individual to whom it is addressed and others who have been specifically authorized to receive
it. If you are not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this
material is strictly prohibited. If you have received this material in error, please destroy it immediately.
LTE performance
requirements & Network
Architecture
17
LTE performance requirements
Evolved
Node B
(eNB)
LTE-Uu
Air-Interface
Bandwidth (MHz)
1.4 3 5 10 15 20
Data Rate: MAX Peak data rates target
150 Mbps (downlink 2x2)) and 75 Mbps
(uplink 1x1) for 20 MHz spectrum
allocation, assuming 2 receive antennas
and 1 transmit antenna at the terminal.
Cell range up to 100km??
64QAM 6bits/Hz
16QAM 4bits/Hz
QPSK 2 bts/hz
dynamic adaptive modulation
Radio Conditions SINR
What is bit/s/Hz?
What is the average bit/s/Hz?
bit/s/Hz
18
Cell range
Cell range up to 100km??
Cell range is limited by a number of items:
Frequency
Path Loss
Timing Advance
Prach Parameters
• Preamble format
• Root Sequence Index (RSI)
• zeroCorrelationZoneConfig
Height of the enodeB
Cell range
19
Spectrum Efficiency
Spectrum efficiency is 1.7-2.7bps/Hz/cell in the downlink and 0.7bps/Hz/cell
in the uplink when inter-site distance (ISD) is 500m.
64QAM 6bits/Hz
16QAM 4bits/Hz
QPSK 2 bts/hz
dynamic adaptive modulation
Radio Conditions SINR
What is bit/s/Hz?
What is the average bit/s/Hz?
bit/s/Hz
20
Key Features
Evolved NodeB
– No RNC is provided anymore
– The evolved Node Bs take over all radio management functionality.
– This will make radio management faster and hopefully the network
architecture simpler
Admission
control
Load
control
Packet
Scheduling
Evolved Node B (eNB)
Evolved Node B handles all physical
resource via a scheduler and
assigns them dynamically to users and
channels
64QAM
16QAM
QPSK
dynamic adaptive modulation
Radio Conditions SINR
DATA
21
Key Features
Admission
control
Load
control
Packet
Scheduling
Evolved Node B (eNB)
QoS awareness
– The scheduler must handle and distinguish
different quality of service classes
– Otherwise real time services would not be
possible via EUTRAN DATA
Qo
S C
lass I
den
tifi
er
22
Questions
What is the cell range for LTE?
What limits the cell range?
23
LTE-UE
S6a
Serving
Gateway
S1-U
S11
Evolved Packet Core (EPC)
S1-MME
PDN
Gateway
Internet/IMS
S5
Evolved UTRAN (E-UTRAN)
Evolved
Node B
(eNB)
X2
LTE-Uu
HSS
MME: Mobility Management Entity
LTE Network Architecture
SGSN
S4
S3 interface connects MME directly to SGSN for signaling to
support mobility across LTEand UTRAN
S3 DATA DATA DATA DATA
Signalling
Connection to
3G network
UMTS Terrestrial Radio
Access Network ALL IP NETWORK
MME
24
LTE: Key Performance Indicators for E-UTRAN
An EPS bearer uniquely identifies traffic flows that receive a common QoS
treatment between a UE and a PDN GW
Serving
Gateway
P-
Gateway
S1-U S5 LTE-Uu
PDN
End to End Bearer
EPS Bearer External Bearer
Radio Bearer S1 - Bearer S5 - Bearer
25
LTE: Key Performance Indicators for E-UTRAN
Radio Bearer
Serving
Gateway
MME: Mobility Management Entity LTE
S1 - Bearer
S5 - Bearer
IDLE
TRACKING
AREA UPDATE
S1 – Bearer handover rate
26
LTE: Key Performance Indicators for E-UTRAN Seamless mobility experience
subscribers to remain connected via any access technology
Serving
Gateway
DATA
MME: Mobility Management Entity
SGSN
RNC
3G
LTE
27
LTE devices will be backward compatible with GSM and UMTS, even at early
stage of LTE deployment, LTE subscribers will be able to roam worldwide
irrespective of the country they are in.
LTE Broadcast will give operators an opportunity to achieve new revenues
Evolved NodeB
– No RNC is provided anymore
Admission
control
Load
control
Packet
Scheduling
Evolved Node B (eNB)
DATA
Max Spectrum efficiency
about 5 bits/Hz
Target : Spectrum efficiency
is 1.7-2.7bps/Hz/cell in the
downlink
Target :
Spectrum
efficiency is 1.7-
2.7bps/Hz/cell in
the downlink
28
Data
Spectrum
(MHz)
Data
Efficiency
(bit/s/Hz)
Sectors Total
Bandwidth
(Mbps)
LTE
Down link
(1x2)
5 1.7 3 25
LTE
2x2
5 3.4 3 50
LTE
Down link 2x2
10 3.4 3 102
LTE
Down link 4x4
20 6.8 3 408
Assumption – 1.7 bits/Hz
Backhaul (IP/Ethernet)
LTE - enodeB
64
QAM 16
QAM QPSK
29
Any Questions?