asset lte

Copyright 2011 AIRCOM International

Asset LTE- Practical's / Demostrations


INSTRUCTOR - GRAHAM WHYLEY

WELCOME


LTE – Frequency Bands


LTE – Frequency BandsSupported Channels (non-overlapping)

E-UTRABand

DownlinkBandwidth

Channel Bandwidth (MHZ)

1.4 3 5 10 15 20

1 60 - - 12 6 4 32 60 42 20 12 6 4* 3*3 75 53 23 15 7 5* 3*4 45 32 15 9 4 3 25 25 17 8 5 2* - -6 10 - - 2 1* X X7 70 - - 14 7 4 3*8 35 25 11 7 3* - -9 35 - - 7 3 2* 1*

10 60 - - 12 6 4 311 25 - - 5 2* 1* 1*12 18 12 6 3* 1* - X13 10 7 3 2* 1* X X14 10 7 3 2* 1* X X...33 20 - - 4 2 1 134 15 - - 3 1 1 X35 60 42 20 12 6 4 336 60 42 20 12 6 4 337 20 - - 4 2 1 138 50 - - 10 5 - -39 40 - - 8 4 3 240 100 - - - 10 6 5

* UE receiver sensitivity can be relaxedX Channel bandwidth too wide for the band- Not supported


E-UTRABand

BandwidthUL (MHz)

E-ARFCN UL

BandwidthDL (MHz)

E-ARFCNDL

Duplex Mode

1 1920-1980 13000 – 13599 2110-2170 0 – 599 FDD

2 1850-1910 13600 – 14199 1930-1990 600 - 1199 FDD

3 1710-1785 14200 – 14949 1805-1880 1200 – 1949 FDD

4 1710-1755 14950 – 15399 2110-2155 1950 – 2399 FDD

5 824-849 15400 – 15649 869-894 2400 – 2649 FDD

6 830-840 15650 – 15749 875-885 2650 – 2749 FDD

7 2500-2570 15750 – 16449 2620-2690 2750 – 3449 FDD

8 880-915 16450 – 16799 925-960 3450 – 3799 FDD

9 1749.9-1784.9 16800 – 17149 1844.9-1879.9 3800 – 4149 FDD

10 1710-1770 17150 – 17749 2110-2170 4150 – 4749 FDD

11 1427.9-1452.9 17750 – 17999 1475.9-1500.9 4750 – 4999 FDD

12 698-716 18000 – 18179 728-746 5000 – 5179 FDD

13 777-787 18180 – 18279 746-756 5180 – 5279 FDD

14 788-798 18280 – 18379 758-768 5280 – 5379 FDD

... … … … … …

33 1900-1920 26000 – 26199 1900-1920 26000 – 26199 TDD

34 2010-2025 26200 – 26349 2010-2025 26200 – 26349 TDD

35 1850-1910 26350 – 26949 1850-1910 26350 – 26949 TDD

36 1930-1990 26950 – 27549 1930-1990 26950 – 27549 TDD

37 1910-1930 27550 – 27749 1910-1930 27550 – 27749 TDD

38 2570-2620 27750 – 28249 2570-2620 27750 – 28249 TDD

39 1880-1920 28250 – 28649 1880-1920 28250 – 28649 TDD

40 2300-2400 28650 – 29649 2300-2400 28650 – 29649 TDD

LTE – Frequency Bands


Frame Structures


LTE – Frame Structure


Frame Structures-TDD

0 1 2 3 19

10 ms


Frame Structures-TDD


Frame Structures-FDD

0 1 2 3 19

One Sub-

frame = 1 mS

10 ms

In half-duplex FDD operation, the UE cannot

transmit and receive at the same time while there

are no such restrictions in full-duplex FDD.


Frame Structures-FDD


LTE Carriers


LTE CarriersSupported Channels (non-overlapping)

E-UTRABand

DownlinkBandwidth


1.4 3 5 10 15 20

1 60 - - 12 6 4 32 60 42 20 12 6 4* 3*3 75 53 23 15 7 5* 3*4 45 32 15 9 4 3 25 25 17 8 5 2* - -6 10 - - 2 1* X X7 70 - - 14 7 4 3*8 35 25 11 7 3* - -9 35 - - 7 3 2* 1*

10 60 - - 12 6 4 311 25 - - 5 2* 1* 1*12 18 12 6 3* 1* - X13 10 7 3 2* 1* X X14 10 7 3 2* 1* X X...33 20 - - 4 2 1 134 15 - - 3 1 1 X35 60 42 20 12 6 4 336 60 42 20 12 6 4 337 20 - - 4 2 1 138 50 - - 10 5 - -39 40 - - 8 4 3 240 100 - - - 10 6 5


Bandwidth(MHz)

1.4 3 5 10 15 20

# of RBs 6 15 25 50 75 100

Subcarriers 72 180 300 600 900 1200

Since the appropriate LTE Frequency Band

and LTE Frame Structure have been

selected or defined then the Carriers can

be defined.


LTE CarriersSupported Channels (non-overlapping)

E-UTRABand

DownlinkBandwidth


1.4 3 5 10 15 20

1 60 - - 12 6 4 32 60 42 20 12 6 4* 3*3 75 53 23 15 7 5* 3*4 45 32 15 9 4 3 25 25 17 8 5 2* - -6 10 - - 2 1* X X7 70 - - 14 7 4 3*8 35 25 11 7 3* - -9 35 - - 7 3 2* 1*

10 60 - - 12 6 4 311 25 - - 5 2* 1* 1*12 18 12 6 3* 1* - X13 10 7 3 2* 1* X X14 10 7 3 2* 1* X X...33 20 - - 4 2 1 134 15 - - 3 1 1 X35 60 42 20 12 6 4 336 60 42 20 12 6 4 337 20 - - 4 2 1 138 50 - - 10 5 - -39 40 - - 8 4 3 240 100 - - - 10 6 5


Bandwidth(MHz)

1.4 3 5 10 15 20

# of RBs 6 15 25 50 75 100

Subcarriers 72 180 300 600 900 1200

Since the appropriate LTE Frequency Band

and LTE Frame Structure have been

selected or defined then the Carriers can

be defined.

Assign Carrier to Frequency

Band


LTE – Carriers


LTE – Carriers

E-UTRABand

BandwidthUL (MHz)

E-ARFCN UL

BandwidthDL (MHz)

E-ARFCNDL

Duplex Mode

1 1920-1980 13000 – 13599 2110-2170 0 – 599 FDD


LTE – Carriers


Slot Structure and Physical Resources


•ONE slot = 12

consecutive

subcarriers

•One slot = 0.5mS

•6 or 7 OFDM symbols

(depending upon cyclic

perfix size), thus a

single resource block is

containing either 72 or

84 OFDM symbols

•12x 7 = 84 OFDM

symbols


LTE – Carriers

Bandwidth(MHz)

1.4 3 5 10 15 20

# of RBs 6 15 25 50 75 100

Subcarriers 72 180 300 600 900 1200


LTE – Carriers

E-UTRABand

BandwidthUL (MHz)

E-ARFCN UL

BandwidthDL (MHz)

E-ARFCNDL

Duplex Mode

... … … … … …

33 1900-1920 26000 – 26199 1900-1920 26000 – 26199 TDD

34 2010-2025 26200 – 26349 2010-2025 26200 – 26349 TDD

35 1850-1910 26350 – 26949 1850-1910 26350 – 26949 TDD

36 1930-1990 26950 – 27549 1930-1990 26950 – 27549 TDD

37 1910-1930 27550 – 27749 1910-1930 27550 – 27749 TDD

38 2570-2620 27750 – 28249 2570-2620 27750 – 28249 TDD

39 1880-1920 28250 – 28649 1880-1920 28250 – 28649 TDD

40 2300-2400 28650 – 29649 2300-2400 28650 – 29649 TDD


LTE – CarriersR0

R0

R0 R0

R0

R0

R0

R0

R0

R0

R0 R0

R0

R0

R0

R0

R0

R0

R0 R0

R0

R0

R0

R0

R0

R0

R0 R0

R0

R0

R0

R0


LTE – CarriersR0

R0

R0 R0

R0

R0

R0

R0

R1 R1

R1

R1 R1

R1 R1

R1

Configuration of

Carrier- 2 antenna


LTE – Carriers


REUSE 1(PRIORITISATION)

Carrier 1

Carrier 1Carrier 1

15 Mhz

5

Mhz

A1

A2A3

A1

A2

A3

Each sector divides the available bandwidth into prioritised

(one third) and non-prioritised (two third) sections.



Carrier 1

Carrier 1Carrier 1

Number of Partitions = 3

15 Mhz

5

Mh

z

A

1

A

2A

3

A

1

A

2

A

3

The simplest way to minimize ICI

within a Frequency Reuse 1 (FR 1)

scenario is by prioritisation of

resources. Reuse 1 (Prioritisation)

scheme prioritises certain portions of

the carrier bandwidth (i.e.,

number of RBs) in each cell

according to a set plan.

The whole bandwidth is still available

for transmission in all cells, but the

concept is that each cell uses its

prioritised RBs more often than its

non-prioritised RBs, so that it

minimises the interference that it may

cause to other cells.


Coordination factor

The improvement of Traffic &

Control SINR with the

deployment of Prioritisation is

dependent on the Cell Loading

and on the coordination factor.

coordination factor of 0

assumes no

coordination at all. No dB

improvement. No ICI

coordination factor of 1 means

perfect coordination.

Recommended 0.7


Soft Frequency Reuse



Soft Frequency Reuse Scheme (Power Ratio 50%, Bandwidth

Ratio 50%)


inter-cell interference control (ICIC).

The available thresholds

are “RSRP” and

“Relative RSRP”.

RSRP is self explanatory

while the latter is defined

in dBs and can be

expressed as

the difference between

the RSRPs of the

serving and the

strongest interfering cell


Global Editor


Reuse Partitioning


Reuse Partitioning

•Multiple partitions.

•Two dedicated zones, one for CCUs, the

other for CEUs.

•Each sector can only consume CE

resources from its own dedicated CE partition


Comparison


Site Data Base


Bearers


LTE – Bearers


LTE – Bearers The Default Uplink

and Downlink LTE

bearers are defined

per CQI providing 15

DL bearers and 4 UL

bearers.

CQI is a report sent

from the UE to the

eNodeB suggesting

the appropriate

Modulation and

Coding to be used by

the eNodeB


57 Copyright 2010 AIRCOM International

Channel Quality Indicator Reporting

CQI Report

PUSCH PUCCH

PDSCH

The UE may not have

PUSCH resources

CQI Modulation Actual coding rate

RequiredSINR

1 QPSK 0.07618 -4.46

2 QPSK 0.11719 -3.75

3 QPSK 0.18848 -2.55

4 QPSK 308/1024 -1.15

5 QPSK 449/1024 1.75

6 QPSK 602/1024 3.65

7 16QAM 378/1024 5.2

8 16QAM 490/1024 6.1

9 16QAM 616/1024 7.55

10 64QAM 466/1024 10.85

11 64QAM 567/1024 11.55

12 64QAM 666/1024 12.75

13 64QAM 772/1024 14.55

14 64QAM 873/1024 18.15

15 64QAM 948/1024 19.25

Each default Bearers has

Control & Traffic SINR

requirements according to

Copyright 2011 AIRCOM International57 Copyright 2010 AIRCOM International

Channel Quality Indicator Reporting

CQI Report

PUSCH PUCCH

PDSCH

The UE may not have

PUSCH resources

CQI Modulation Actual coding rate

RequiredSINR

1 QPSK 0.07618 -4.46

2 QPSK 0.11719 -3.75

3 QPSK 0.18848 -2.55

4 QPSK 308/1024 -1.15

5 QPSK 449/1024 1.75

6 QPSK 602/1024 3.65

7 16QAM 378/1024 5.2

8 16QAM 490/1024 6.1

9 16QAM 616/1024 7.55

10 64QAM 466/1024 10.85

11 64QAM 567/1024 11.55

12 64QAM 666/1024 12.75

13 64QAM 772/1024 14.55

14 64QAM 873/1024 18.15

15 64QAM 948/1024 19.25

15 Defaulf

Bearers


CQI Modulation Efficiency Actual coding rate

RequiredSINR

1 QPSK 0.1523 0.07618 -4.46

2 QPSK 0.2344 0.11719 -3.75

3 QPSK 0.3770 0.18848 -2.55

4 QPSK 0.6016 308/1024 -1.15

5 QPSK 0.8770 449/1024 1.75

6 QPSK 1.1758 602/1024 3.65

7 16QAM 1.4766 378/1024 5.2

8 16QAM 1.9141 490/1024 6.1

9 16QAM 2.4063 616/1024 7.55

10 64QAM 2.7305 466/1024 10.85

11 64QAM 3.3223 567/1024 11.55

12 64QAM 3.9023 666/1024 12.75

13 64QAM 4.5234 772/1024 14.55

14 64QAM 5.1152 873/1024 18.15

15 64QAM 5.5547 948/1024 19.25

The coding rate indicates

how many real data bits

are present out of 1024

while the efficiency

provides the number of

information bits per

modulation symbol.

602/1024 = 0.5879

QPSK = 2bits

Efficiency=

2x0.5879=1.1758 data

bits per symbol

coding rate


Coding rate


Bearers


MIMO - Multiple Input Multiple Output


MIMO - Multiple Input Multiple Output

•The propagation channel is the air interface, so that transmission antennas are handled as input to the channel, whereas receiver antennas are the output of it

MIMO Types Number of Antennas

SISO(Single Input

Single Output)

MISO(Multiple Input

Single Output

…

SIMO(Single Input

Multiple Output)

…

MIMO(Multiple Input

Multiple Output)

……


MIMO

LTE supports downlink transmission on 1, 2 or 4 cell specific antenna ports

corresponding either to 1, 2 or 4 cell-specific reference signals.

On their turn each one of the RS corresponds to one antenna port.

R0

R0

R0 R0

R0

R0

R0

R0

R0

R0

R0 R0

R0

R0

R0

R0

R0

R0

R0 R0

R0

R0

R0

R0

R0

R0

R0 R0

R0

R0

R0

R0

each antenna is uniquely

identified by the position

of the reference signals

R0

R0

R0R0

R0

R0

R0

R0

R0

R1 R1

R1

R1 R1

R1 R1

R1

On their turn each one of the RS

corresponds to one antenna port.


MIMO

• Single antenna port; port 0

• Single User – MIMO

• Transmit diversity

• Open loop spatial multiplexing

• Closed loop spatial multiplexing

• Multi User – MIMO

• Closed-loop Rank=1 pre-coding


Tx diversity:

The first and simplest downlink LTE multiple antenna scheme is :

Open-loop Tx diversity.

It is identical in concept to the scheme introduced in UMTS Release 99.

Closed loop Tx diversity

The more complex, closed loop Tx diversity techniques from UMTS have not

been adopted in LTE, which instead uses the more advanced MIMO, which

was not part of Release 99.

T

X

R

X010100

010100

010100

SU-MIMO


Open-loop spatial multiplexing, no UE feedback required

•In open loop in which no feedback is provided from UE

configuration collapse’s to time diversity and relies on

Cyclic Delay Diversity (CDD)

•Creates multi-path on the received signal. Prevents

signal cancellation

In case of UEs with high velocity, the quality of the feedback

may deteriorate.

Thus, an open loop spatial multiplexing mode is also

supported which is based on predefined settings for spatial

multiplexing and precoding.

SU-MIMO includes :

conventional techniques such as Delay

(cyclic for OFDM) Diversity


Closed loop Tx diversity

PUSCH

Data

Transport Blocks Code Block Segmentation

Turbo Coding

Rate Matching

Data and Control Multiplexing

CQI4 bit

16 CS

PMI RI

The UE asks for two

layersRank Indicator 2

from the enodeB.

UE feels it can distinguish

between to different layers

Layer Mapping

Layer 0 Layer 1

Pre Coding

Physical Uplink Shared Channel

(PUSCH): This physical channel

found on the LTE uplink is the Uplink

counterpart of PDSCH

SU-MIMO includes :Spatial Multiplexing

and Precoded Spatial Multiplexing.


SU-MIMO-Spatial Multiplexing

Spatial multiplexing allows to transmit different streams of data simultaneously on the same resource block(s)

Two code-word streams 2x2 SU-MIMO

T

X

R

X010 100

010

100

SU-MIMO

CW0 CW1

Depending on the pre-coding used, each

code word is represented at different

powers and phases on both antennas.

R0

R0

R0 R0

R0

R0

R0

R0

R0

R0

R0 R0

R0

R0

R0

R0

R0

R0

R0 R0

R0

R0

R0

R0

R0

R0

R0 R0

R0

R0

R0

R0

Each antenna is uniquely




Single user MIMO principle

4 Closed-loop spatial multiplexing

Closed-loop spatial multiplexing. Here the UE reports both the RI

and index of the preferred pre-coding matrix.

Rank Indicator (RI) is the UE’s recommendation for the number of layers, i.e.

streams to be used in spatial multiplexing. RI is only reported when the UE is

operating in MIMO modes with spatial multiplexing

Spatial Multiplexing does

increase throughput but

this comes at an expense

of higher SINR

requirements as shown on

the LTE bearers


Spatial Multiplexing - Rate Gain

Spatial Multiplexing (SM) targets increasing users’ throughput.

Depending on the number of TX and RX antennae the user

experiences a Rate Gain



SU-MIMO Tx DiversitySU-MIMO

+22dB

Roughly speaking Diversity is used

to improve coverage

This is the coverage area

for SU-MIMO

Spatial

Multiplexing does

increase

throughput but

this comes at an

expense of higher

SINR

requirements as

shown on the LTE

bearers




+22dB

SM is used to

increase single

users’ throughput

Roughly speaking Diversity is used

to improve coverage

When applying diversity

What changes, are the SINR

requirements for the bearers that are

reduced.

This is the coverage area

for SU-MIMO

Spatial Multiplexing (SM) targets increasing

users’ throughput. Depending on the number of

TX and RX antennae the user experiences a

Rate Gain


Achievable DL Bearer without and with –MIMO Coverage Improvement

(2TX by 2 RX)

By increasing the coverage for each bearer respectively the

result will be larger areas with higher CQI bearers.


Achievable DL Bearer without and with –MIMO Coverage Improvement

(2TX by 2 RX)

So from a system perspective Diversity not only increases

coverage but network throughput as well.


SU-MIMO – Diversity

What changes, are the SINR

requirements for the bearers that are

divided by the corresponding table

value


+22dB

SM is used to increase single

users’ throughput

Roughly speaking

Diversity is used to

improve coverage


How do we set this up on Asset


Bearers-LTE Parameters

SU-MIMO DiversitySU-MIMO

+22dB

Above this threshold

switch to SU-MIMO

Below this threshold

switch to SU-MIMO

Diversity

If

enabled


Multi User – MIMO


Multi User – MIMO

MU-MIMO is used

to increase the

cells’ throughput.

This is achieved by

co-scheduling

terminals on

the same Resource

Blocks.

Spatial Multiplexing does increase throughput but this comes at an

expense of higher SINR requirements as shown on the LTE bearers


Multi User – MIMO Applying MU-

MIMO will make no

obvious changes to

a network unless it

is overloaded.

In order for MU-

MIMO to be used

there is a higher

Traffic & Control

SINR requirement

defined




MU-MIMO

MU-MIMO increases cell throughput and number of terminals


MU-MIMO

Applying MU-MIMO will make no obvious changes to a

network unless it is overloaded.

To demonstrate the use of MU-MIMO we will spread terminals

and run the SIM in snapshot mode.

The density of terminals will be high enough for many of them

to fail due to insufficient capacity.

Then we will enable MU-MIMO and observe how the network

is now capable to serve more of the terminals


MU-MIMO

RSRQ changes when MU-MIMO is deployed because the number of

served terminals changes.


large improvements close to the cell edge

DL Data Rate without and with MU-MIMO


DL Cell Throughput without and with MU-MIMO

effect of the eNodeB now being

capable to serve a higher

number of users by scheduling

them on the same resources

DL Cell Throughout (per cell) when MUMIMO

is enabled.


The following table indicates how a highly loaded network can accommodate extra users by deploying MU-MIMO.




MU-MIMO is used to

increase the cells’

throughput.

In order for MU-MIMO to

be used there is a higher

Traffic & Control SINR

requirement defined

BearersBearers


How do you set MU-MIMO in Asset




+22dB

Above this threshold

switch to SU-MIMO

Below this threshold

switch to SU-MIMO

Diversity

If

enabled



SU-MIMO DiversityMU-MIMO

+18dB

If

enabled



DiversityMU-MIMOSU-MIMO

+22dB +18dB

Above this

threshold switch to

MU-MIMO

Below this

threshold switch to

SU-MIMO

Diversity

If

enabled


Diversity

As previously mentioned Diversity’s main purpose is to increase coverage and

this is done by decreasing the bearers’ SINR requirements.

The bearers with the decreased SINR requirements are easier to achieve.

When applying diversity the RSRP plot and the

SCH/BSC SINR plot stay the same. RSRQ

stays the same as well.

What changes, are the SINR requirements for

the bearers that are divided by the

corresponding table value.

R0

R0

R0 R0

R0

R0

R0

R0

R0

R0

R0 R0

R0

R0

R0

R0

R0

R0

R0 R0

R0

R0

R0

R0

R0

R0

R0 R0

R0

R0

R0

R0

each antenna is uniquely




RSRPRSRP is not affected by cell loads. This is the reason why a network is usually

firstly dimensioned to provide adequate signal strength at the desired areas.

WHY?


RSRQ

RSRQ on the other hand is affected by cell loads

WHY?

Especially with MU-

MIMO


Comparing all different options for SU-MIMO and how they affect Data Rates.


Summary


Terminal Types


Terminal Types

Path Loss


Path Loss


Terminal Types

Ref Sens = KTB + NF + SINR

kTB :thermal noise level , in

units of dBm, in the specified

bandwidth

The receiver Noise Figure

(NF) is a measure of the

degradation of the SINR

caused by components in the

RF signal chain. This

includes the antenna filter

losses, the noise introduced

by the analogue part of the

receiver

SINR (IN) SINR (OUT)


Bandwidt

h (Δf)

Thermal noise

power

1 Hz −174 dBm

10 Hz −164 dBm

100 Hz −154 dBm

1 kHz −144 dBm

10 kHz −134 dBm

100 kHz −124 dBm

180 kHz −121.45 dBm One LTE resource block

360Mhz -118.4 Two LTE resource blocks

200 kHz −120.98 dBm

1 MHz −114 dBm

2 MHz −111 dBm

6 MHz −106 dBm

20 MHz −101 dBm

Link Budget- Up link-Thermal noise

Terminal noise can be

calculated as:

“K (Boltzmann constant) x

T (290K) x bandwidth”.

k = Boltzman constant (1.38*10-23

Joules/Kelvin)

T = Temperature in degrees Kelvin

R = Resistance in ohms

B = Bandwidth in Hz

http://en.wikipedia.org/wiki/3GPP_Long_Term_Evolution


Bandwidt

h (Δf)

Thermal noise

power

180 kHz −121.45 dBm One LTE resource block

Terminal noise can be calculated as:

“K (Boltzmann constant) x T (290K) x bandwidth

1.38*10-23 x 290000 x 180000=0.0000 0000 000072034

Convert to dBm = 10 log 0.0000 0000 000072034

-121.45 dBm for one resource block (180kHz)

k = Boltzman constant (1.38*10-23 Joules/Kelvin)

T = Temperature in degrees Kelvin

R = Resistance in ohms

B = Bandwidth in Hz

Terminal Types


Terminal Types

Downlink Reference Signal

DLRS TX Power

Reference Signal Received Quality (RSRQ)

RSRQ is defined as the ratio N×RSRP / (E-UTRA carrier RSSI), where N is the number of RB’s of the

E-UTRA carrier RSSI measurement bandwidth. The measurements in the numerator and denominator

shall be made over the same set of resource blocks.


Terminal Types


Traffic Raster


Services


Intoduction

QoS differentiation, i.e. prioritisation of different services

according to their requirements becomes extremely

important when the system load gets higher.

The most relevant parameters of QoS classes

are:

•Transfer Delay

• Guaranteed Bit rate:

Delay sensitive QoS Classes have guaranteed bit rate

requirements.

.


Intoduction

Allocation and Retention Priority (ARP):

Within each QoS class there are different allocation and

retention priorities.

The primary purpose of ARP is to decide whether a bearer

establishment / modification request can be accepted or

needs to be rejected in case of resource limitations .

In addition, the ARP can be used (e.g. by the eNodeB) to

decide which bearer(s) to drop during exceptional resource

limitations


Intoduction

Users within the same QoS class and ARP class will share

the available capacity.

If the number of users is simply too high, then they will suffer

from bad quality.

In that case it is better to block a few users to guarantee the

quality of existing connections, like streaming videos.


Services

When running a simulation,

ASSET first attempts to serve

the GBR demands of both

Real Time and Non-Real

Time services, taking into

account the Priority values of

the different services.

Resources are first allocated

to the service with the highest

priority, and then to the next

highest priority service, and

so on. Allocation and Retention Priority (ARP)

If resources are still available after the GBR demands have been met, then different

scheduling algorithms can be employed to attempt to serve the MBR of real time

services.


LTE QoS


Services When running

a simulation,

ASSET first

attempts to

serve the GBR

demands of

both Real Time

and Non-Real

Time services,

taking into

account the

Priority values

of the different

services.

After defining the General Service Parameters one or more Carriers can be related

to the Service. Since a supporting Carrier has been assigned to the Service, all UL

and DL Bearers will be available for selection as the Supporting Bearers.

No carrier

defined OR

BEARER


Services

A Minimum Bit Rate (Min-GBR) and a Maximum Bit Rate (Max-MBR) have been

specified for the service.

If a terminal achieves connection to one or more of the available bearers then the

eNodeB will firstly allocate enough resources to it in order to achieve the Min-

GBR.

It will keep allocating more resources to it until the terminal either reaches the

Max-MBR ceiling or until there not more resources available due to cell loading.


LTE – Bearers

The Default Uplink and Downlink LTE bearers are defined per CQI providing 15 DL bearers

and 4 UL bearers.

The most preferable bearer is DL-CQI-15 and the least preferable bearer is DL-CQI-1


Services

The Default Uplink and Downlink LTE

bearers are defined per CQI providing 15

DL bearers and 4 UL bearers


Services

After defining the General Service Parameters one or more Carriers can be related

to the Service. Since a supporting Carrier has been assigned to the Service, all UL

and DL Bearers will be available for selection as the Supporting Bearers.


Packet Scheduler


Packet SchedulerIf resources are still available

after the GBR demands have

been met, then different

scheduling algorithms can be

employed to attempt to serve

the Max Bit Rate.


UE 1 Data

sent

UE 2 Data

sent

UE 1

UE 6

UE 5

UE 4

UE3

UE 2

UE 3 Data

sent

UE 4 Data

sent

UE 5 Data

sent

UE 6 Data

sent

UE 1 Data

Request

UE 2 Data

Request

UE 3 data

Request

UE 4 Data

Request

UE 5 Data

Request

UE 6 Data

Request

NodeB Packet

Scheduler

Round Robin Scheduler

NodeB Buffers

The aim of this

scheduler is to

share the

available/unused

resources equally

among the RT

terminals

The Round Robin approach is completely

random asit simply allocates the same

resources to all terminals in turns.


Proportional Fair

If resources are still available after the GBR

demands have been met:

Terminals with higher data rates get a larger

share of the available resources.

Each terminal gets either the resources it

needs to satisfy its RT-MBR demand.


Proportional Demand

The aim of this scheduler is to allocate the remaining

unused resources to RT terminals in proportion to their

additional resource demands.

If resources are still available after the GBR

demands have been met:

Proportional Demand completely ignores RF

conditions


Max SINR

Terminals with higher bearer rates(and consequently higher SINR) are preferred

over terminals with lower bearer rates (and consequently lower SINR).

This means that resources are allocated first to those terminals with better

SINR/channel conditions, thereby maximising the throughput.

where S is the average received signal

power,

I is the average interference power,

and N is the noise power.

Best RF conditions are served first.


Max SINR

Own-signal interference in LTE an occur due to :

•Inter-symbol interference due to multipath power exceeding cyclic prefix length

•Inter-carrier interference due to Doppler spread (large UE speed)

In LTE, orthogonality is often assumed unity for simplicity:

a = 1 is assumed for LTE and hence Iown = 0.

where S is the average received signal

power,

I is the average interference power,

and N is the noise power.



The effect of different schedulers on a fairly loaded network



The effect of schedulers on a heavily loaded network

Max SINR Scheduling will maximise the network

throughput as terminals with the best RF

conditions are served first.


PCI Planning


PCI


GeneralPCI GROUP CODE CELL

SPECIFIC

FREQ SHIFT

0 0 0 0

1 0 1 1

2 0 2 2

3 1 0 3

4 1 1 4

5 1 2 5

6 2 0 0


PCIPCI GROUP CODE CELL

SPECIFIC

FREQ SHIFT

0 0 0 0

1 0 1 1

2 0 2 2

3 1 0 3

4 1 1 4

5 1 2 5

6 2 0 0


GeneralPCI GROUP CODE CELL

SPECIFIC

FREQ SHIFT

0 0 0 0

1 0 1 1

2 0 2 2

3 1 0 3

4 1 1 4

5 1 2 5

6 2 0 0


General


Minmise Groups


Minmise Codes


LTE Network Performance- Coverage and Capacity Predictions


Cell Loads

Option 1 - Cell loads

Site Database and specifically under the LTE Parameters tab in the fields of

Downlink Load (as a percentage) and Mean UL Interference Level (in dB)..


Cell Loads

The second option is to create a traffic raster spreading the defined LTE

Terminal Type(s) and then the cell load levels get calculated by running

Simulator Snapshots. In both cases a reference terminal type has to be

specified for the calculation process.

Cell load levels get calculated

by running Simulator

Snapshots.


Cell Loads

The second option is to create a traffic raster spreading the defined LTE

Terminal Type(s) and then the cell load levels get calculated by running

Simulator Snapshots. In both cases a reference terminal type has to be

specified for the calculation process.

You must run a traffic raster first


Creating a Traffic Raster

Creating a

Traffic Raster

This is usually

done per

clutter type by

assigning a

terminal

density or a

relative weight

to each one of

the clutters.


Traffic


Creating a Traffic Raster


LTE Simulation - Resolution

The decision on what

resolution should be

used for the simulations

is based on what

propagation models are

assigned to the cell

antennas.

• Firstly, it is suggested

to use a propagation

model at the resolution

it has been tuned for.


Resolution

Secondly, it is suggested to

use two propagation

models.

•The first one (Primary)

should be calculated at high

resolution (2-20 meters) and

for a relatively small radius

(1-3 km).

• The second one

(Secondary) should be

calculated at relatively lower

resolution (20-100 meters)

and for a larger radius (3-

30km).


Array Setting


Path Loss•The first one (Primary)

should be calculated at

high resolution (2-20

meters) and for a

relatively small radius

(1-3 km).

The second one

(Secondary) should

be calculated at

relatively lower

resolution (20-100

meters) and for a

larger radius (3-

30km).


Number of covering cells

The number of

covering cells mainly

affects the accuracy of the

interference based

calculations.

The more cells taken

into account, the more

accurate the interference

values are.


Results


Best RSRP


Path Loss


Simulator Results


Simulator Results

Default

Beares


BCH/SCH SINR

BCH/SCH SINR is not affected by the cell load.

BCH and SCH channels are positioned in the 6 central RBs of the Band Width

and effect from interference is small.


RSRQ

RSRQ on the other hand is affected by cell loads. WHY?


Diversity

When applying diversity the RSRP plot and the SCH/BSC SINR plot stay the

same. RSRQ stays thesame as well.

What changes, are the SINR requirements for the bearers that are divided by

the corresponding table value.


+22dB


Diversity

When applying diversity the RSRP plot and the SCH/BSC SINR plot stay the

same. RSRQ stays thesame as well.

What changes, are the SINR requirements for the bearers.

As previously mentioned Diversity’s main purpose is to increase coverage

and this is done by decreasing the bearers’ SINR requirements.

By increasing the coverage for each bearer respectively the result will be

larger areas with higher CQI bearers.

So from a system perspective Diversity not only increases coverage but

network throughput as well.


+22dB


Diversity

What changes, are the SINR requirements for the bearers that

are divided by the corresponding table value.


Diversity


DL Data Rate Improvement with Spatial Multiplexing


+22dB


Adaptive SwitchingDiversity and Spatial Multiplexing provide significant gains

to the network.

Both of them can be deployed at the same time in Adaptive Switching mode by

eNodeBs so as to provide higher throughput to users close to the cell and

extended coverage to users at cell edge.

SU-MIMO Diversity SU-MIMO

+22dB


Simulator Results


Cell Edge Threshold


Cell Edge Threshold (Global Editor)

asset lte

Documents

relaxedx channel bandwidth

ue receiver sensitivity