Michael Lawton
Product Planner
Mobile Broadband
Operation
Small Cell SIG, “Stretching the Limits”
April 3, 2014
1

• The case for small cells
• Heterogeneous networks
• Introduction to LTE and ICIC
• Cell range extension
• Release 10 eICIC
- Time domain based ICIC with ABS
• Release 11 FeICIC enhancements
• Test Requirements and challenges
• Progress towards commercialisation
• Summary
Small Cell SIG, “Stretching the Limits”
April 3, 2014
2

“2013, 1000 PetaBytes” = 1 Exabyte/m
“2010, 120 PetaBytes/m”
1 Petabyte = 10 15 = 1M x 1Gbyte
• Solutions to the “1000x” problem:-
More Hz? … ~3x
More bps/Hz? … ~3x
More bps/Hz/m … ~100x
- Total ~1000x
Voice Data
Source: Ericsson
• Key Drivers & Enablers for Small Cell Deployments
- Baseband costs drop with volume
- Baseband size and power consumption dropping
- New technologies
• Heterogeneous Networks & eICIC (Inter-cell Interference Co-ordination)
• SON (Self Organising Networks)
• Wifi offloading
Small Cell SIG, “Stretching the Limits”
April 3, 2014
3

HetNet Definition - HetNet is a network where a mixture of macro cells and small cells are employed together to meet the coverage and capacity needs of the network
What are small cells?
Low-power wireless access points
Operate in licensed spectrum
Operator-managed
Provide improved cellular coverage, capacity and applications for homes and enterprises as well as public spaces
Small Cell SIG, “Stretching the Limits”
April 3, 2014
4

LTE Rel 8 High level requirements
 Reduced cost per bit
 More lower cost services with better user experience
 Flexible use of new and existing frequency bands
 Simplified lower cost network with open interfaces
 Reduced terminal complexity and reasonable power consumption
DL SU-
MIMO
MU-
MIMO
Multiple Input Multiple Output
Spectral Efficiency
3-4x HSDPA (downlink)
2-3x HSUPA (uplink)
Latency
Idle  active < 100 ms
Small packets < 5 ms
SPEED!
Downlink peak data rates
(64QAM)
Antenna config
Peak data rate Mbps
Peak data rate Mbps
SISO
100
2x2
MIMO
4x4
MIMO
Uplink peak data rates
(Single antenna)
Modulation QPSK
16
QAM
64
QAM
50
172.8
57.6
326.4
86.4
Mobility
Optimized: 0–15 km/h
High performance: 15-
120 km/h
Functional: 120–350 km/h
Under consideration:
350–500 km/h
Small Cell SIG, “Stretching the Limits”
April 3, 2014
5
MHz
1.4
3
5
10
15
20

N
DL symb
OFDM symbols (= 7 OFDM symbols @ Normal CP)
2048 144 2048 144 2048 144 2048 144 2048 160 2048 144
CP 0 CP 1 CP etc.
2 3 CP 4 CP 5
144
CP
2048 (x Ts)
6
1 slot
= 15360 Ts
= 0.5 ms
The Cyclic Prefix is created by prepending each symbol with a copy of the end of the symbol
0 1 2 3 4 5 6 0 1 2 3 4 5 6
Time (Symbol)
1 sub-frame
= 2 slots
= 1 ms
RS - Reference Signal (Pilot)
P-SS - Primary Synchronization Signal
S-SS - Secondary Synchronization Signal
PBCH - Physical Broadcast Channel
PCFICH –
Physical Control Channel Format Indicator Channel
PHICH (Normal)
– Physical Hybrid ARQ Indicator Channel
PDCCH (L=3) - Physical Downlink Control Channel
PDSCH - Physical Downlink Shared Channel
#0 #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14 #15 #16 #17 #18 #19
1 frame
= 10 sub-frames
= 10 ms
Small Cell SIG, “Stretching the Limits”
April 3, 2014
6

f
1
Freq domain based
Cellular concept
(3GPP rel 8) f
2
Time domain based
(Rel 10 eICIC)
P
2
P
1
Power based
(Rel 11 FeICIC combines power and time)
Small Cell SIG, “Stretching the Limits”
April 3, 2014
7

MACRO
PICO
C B A
VICTIM
AGGRESSOR
UE Rx sensitivity
C B A
UE is able to use both the picocell and the macro cell
• A: UE is connected to picocell
• B: UE reports higher signal strength for the macrocell but with ICIC it can continue to use the picocell
• C: The network hands the UE over to the macrocell
Small Cell SIG, “Stretching the Limits”
April 3, 2014
8

MACRO
CSG
AGGRESSOR
VICTIM
A B C
UE Rx sensitivity
A B C
• UE is not a member of the CSG Picocell
• A: UE is connected to the Macrocell
• B/C: UE reports a stronger signal strength for the CSG but with ICIC it can continue to use the macrocell
Small Cell SIG, “Stretching the Limits”
April 3, 2014
9

Regular Subframe ABS Subframe
0 1 2 3 4 5 6 0 1 2 3 4 5 6
0 1 2 3 4 5 6 0 1 2 3 4 5 6
1 sub-frame
= 2 slots
= 1 ms
1 sub-frame
= 2 slots
= 1 ms
Time (Symbol)
Time (Symbol)
#0 #1 #2 #3 #4 #5 #6 #7 #8 #9
RS - Reference Signal (Pilot)
P-SS - Primary Synchronization Signal
S-SS - Secondary Synchronization Signal
PBCH - Physical Broadcast Channel
PCFICH –
Physical Control Channel Format
Indicator Channel
PHICH (Normal) – Physical Hybrid ARQ Indicator Channel
PDCCH (L=3) - Physical Downlink Control Channel
PDSCH - Physical Downlink Shared Channel
#10 #11 #12 #13 #14 #15 #16 #17 #18 #19
1 frame
= 10 sub-frames
= 10 ms
RS - Reference Signal (Pilot)
P-SS - Primary Synchronization Signal
S-SS - Secondary Synchronization Signal
PBCH - Physical Broadcast Channel
SIB1, Paging signal, associated PDCCH
Small Cell SIG, “Stretching the Limits”
April 3, 2014
10

Macro
Pico
AGGRESSOR
UE1
UE2
PICO - UE1
Macro with ABS
Pico
ABS
Pico schedules data in ABS and non ABS subframes
MACRO with ABS
PICO
– UE2
Macro with ABS
ABS
Macro Pico
AGGRESSOR
CSG
Pico
Protected subframe providing CRE for PICO
UE3 MACRO – UE3
Femto with ABS
MACRO without ABS
Improved Macro coverage
• “Aggressor” creates protected subframes to support CRE for the victim
Pico with ABS
Macro
ABS
Protected subframe providing improved Macro coverage
Small Cell SIG, “Stretching the Limits”
April 3, 2014
11

MACRO
AGGRESSOR
C B A
PICO
VICTIM
Rx sensitivity cell border based on DL signal strength
ABS subframe non ABS subframe
C B A
Small Cell SIG, “Stretching the Limits”
April 3, 2014
12

ABS cell #3
ABS cell #1 cell #5
UE
CSG cell #4
ABS cell #2
• UE is connected to Macro cell (#2)
• UE is not a member of a nearby CSG cell (#4)
• Network seeks to mitigate intercell interference using cell #4 ABS subframe to send data to UE
• UE seeks to cancel CRS interference from CSG cell (#4) and other neighbours
• To facilitate this cell #2 gives the UE information about neighbour cell CRS info
• Cell #2 can also use dedicated RRC messages to send it’s SIB1 data to the UE
• Power control can be used to adjust the interference between cells
Small Cell SIG, “Stretching the Limits”
April 3, 2014
13

Test Category Test Purpose No. of
Tests
Section 8 (Performance Test) RCT
(RF conformance Test)
3GPP 36.521
RRM
(Radio Resource Mgt)
3GPP 36.521
PCT
Protocol Signalling Test
3GPP 36.523
Section 9 (Reporting Tests)
Section 7: Radio link Monitoring
Section 8: Reporting
Section 9: RSRP and RSRQ
Section 8: Measurement config control and reporting
Comments
16
Rx demod performance test in the presence of an aggressor cell with
ABS
Demod subframe and provide reporting with overlaps and aggressor cell ABS
22 Radio link monitoring and reporting in ABS and non ABS subframes
3 Protocol signaling for eICIC procedures
• 3GPP conformance test cases written
• Certification bodies (GCF and PTCRB) now developing a certification regime
Small Cell SIG, “Stretching the Limits”
April 3, 2014
14

0 1 2 3 4 5 6 7 8 9
ABS ABS ABS ABS ABS
ABS ABS
ABS ABS
ABS ABS symbol noise to emulate noise form other cells
CELL 2
AGGRESSOR
Fading
Fading
CELL 1
SERVING
UE reporting
2.5 µs
• Test the ability for the UE to receive data from CELL 1 in the subframes that overlap with the
ABS subframes from CELL 2
• Noise is added to OFDM symbols in CELL1 in order to emulate neighbour cell interference
(differs based on ABS/non ABS, CRS symbol or not)
• Measure fraction of max Tput for data sent during the aggressor ABS subframes
• Test limit 70% of Max Tput
Small Cell SIG, “Stretching the Limits”
April 3, 2014
15

0 1 2 3 4 5 6 7 8 9
ABS ABS ABS ABS ABS
ABS ABS
ABS ABS
ABS ABS
CELL 2
AGGRESSOR
Fading
3 µs symbol noise to emulate noise form other cells
Fading
CELL 3
AGGRESSOR
Fading
CELL
SERVING
0 1 2 3 4 5 6 7 8 9
ABS ABS ABS ABS ABS
ABS ABS
ABS ABS
ABS ABS
UE reporting
-1 µs
• Add a second Aggressor cell
• Signal CRS (Cell Specific Reference Signals) info to the UE
• Repeat max Tput measurement
Small Cell SIG, “Stretching the Limits”
April 3, 2014
16

0 1 2 3 4 5 6 7 8 9
ABS ABS ABS ABS ABS
ABS ABS
ABS ABS
ABS ABS
CELL 2
AGGRESSOR
Fading symbol noise to emulate noise form other cells
Fading
CELL 1
SERVING
UE reporting
2.5 µs
• Test the CQI reporting for the UE during ABS subframes and non-ABS subframes
• Set the modulation to equate to the median CQI/ CQI-1/ CQI+1 and measure BLER
• Check the BLER =10% point fall between CQI-1 and CQI+1 for both ABS and non-ABS cells
Small Cell SIG, “Stretching the Limits”
April 3, 2014
17

0 1 2 3 4 5 6 7 8 9
ABS ABS ABS ABS ABS
ABS ABS
ABS ABS
ABS ABS
CELL 2
AGGRESSOR
Fading
3 µs symbol noise to emulate noise form other cells
Fading
CELL 3
AGGRESSOR
Fading
CELL
SERVING
0 1 2 3 4 5 6 7 8 9
ABS ABS ABS ABS ABS
ABS ABS
ABS ABS
ABS ABS
UE reporting
-1 µs
• Add another Aggressor cell
• Signal CRS (Cell Specific Reference Signals) info to the UE
• Perform tests as per eICIC section 9
- Test the CQI reporting for the UE during ABS subframes and non-ABS subframes
- Set the modulation to equate to the median CQI/ CQI-1/ CQI+1 and measure BLER
- Check the BLER =10% point fall between CQI-1 and CQI+1 for both ABS and non-ABS cells
Small Cell SIG, “Stretching the Limits”
April 3, 2014
18

1. Standardization
The Committee
Room
2. Regulation
The Test
House
3. Physics
Maxwell’s
Place
4. Commerce
The Shopping
Mall
Where engineers consume lots of coffee while creating wireless law standards
Where Devices are put on trial to prove their conformance
And then there was light…
Where electro- magnetic law determines if it actually works currently here!
Where commercial law determines whether anyone actually buys it certification IOT Field trials Deployment
Rel 10: WI eICIC_LTE-Core
Completed June 11

Rel 11: WI eICIC_enh_LTE-Core
Completed Dec 12

PTCRB: RFT 116:
Enhance for ICIC for LTE.
Now ready for validation
GCF – No WI yet.
No public info
Coming in
2015???
Small Cell SIG, “Stretching the Limits”
April 3, 2014
19

• The case for small cells … addressing the “1000x” problem
• Heterogeneous networks
• Introduction to LTE and ICIC
• Cell range extension
• Release 10 eICIC
- Time domain based ICIC with ABS
• Release 11 FeICIC enhancements
• Test Requirements and challenges
• Progress towards commercialisation
• Summary
Small Cell SIG, “Stretching the Limits”
April 3, 2014
20