PSCR Update
Public Safety Communications Research
Dr. Rob Stafford
Project Engineer – NTIA/ITS
PS Broadband Project
Department of Commerce – Boulder Labs
1
Outline
• PSCR Testing – Phase 1
– Application Testing
– Interference Into eNodeB
– Sector Characterization Test
• The Move to 10 MHz
– C-Block/D-Block Interference
– PSNB Interference
– Other Issues
• What’s Next
2
Public Safety Communications Research Program
Located at the
Department of Commerce
Boulder Labs in Colorado
The PSCR Program is a joint
effort between:
NIST’s
Office of Law
Enforcement Standards
(OLES)
and
NTIA’s
Institute for
Telecommunication
Sciences
(ITS)
3
PSCR Sponsors
Department of Homeland Security
Department of Justice
Office for Interoperability and
Compatibility
Office of Community Oriented
Policing Services
4
LTE Architecture
RAN = Radio Access Network
Ue’s
EPC = Evolved Packet Core
eNodeB’s
eNB
MME
Mobility Management Entity
HSS
Home Subscriber Server
eNB
SGW
PGW
Serving Gateway
PDN Gateway
eNB
Internet
5
eNodeB Antennas
6
eNBs
7
eNBs
8
Cell on Wheels (COW)
9
Microwave Link
10
Testing
11
Phase One
Public Safety Communications Research
LTE Demonstration Network Test Plan
Phase 1: Basic Functionality Tests
Version 1.22
September 12, 2011
12
The Phase One Tests
• eNodeB Receiver/Transmitter Tests (4)
– Interference Immunity
– Out-of-Band Emissions
• Messaging/Protocol Tests (3)
– Attach, Detach, IP Connectivity
• Applications Tests (9)
– Various applications
• Sector Characterization Test (1)
– Radiated, Real World Environment
13
Applications Tests
•
•
•
•
•
•
•
Web Browser
File Transfer (Up/Down)
Email
VPN
Voice (Mobile Originate/Terminate)
Instant Message
Database
14
Adjacent Band Interference Into the eNB
Band
Frequency
Center
Frequency
Modulation
C Block UL
777 - 787 MHz
782 MHz
LTE SC-FDMA
C Block DL
746 - 756 MHz
751 MHz
LTE OFDMA
PS Narrowband UL
799 - 805 MHz
799 MHz
P25 C4FM +1011 test pattern
PS Narrowband DL
769 - 775 MHz
769 MHz
P25 C4FM +1011 test pattern
15
Typical Test Result
16
Measured Signal Spectrum
17
3GPP Test Setup
Measurement equipment
BS under
TX test
TX
18
PSCR Test Setup
Spectrum
Analyzer
RX 1
1
2
1
1
Bi-dir coupler
2
1
RX 2
Base
Station
Combiner
1
1
Mobile
Station
30 dB Tap
TX
RX 1
40 dB
Attn
1
TX 1
RX 1
2
30 dB Tap
Spirent RFI
50 ohm
50 ohm
UE
Splitter
To
IN
From
OUT
To
IN
eNB
From
OUT
50 ohm
50 ohm
30 dB Tap
Combiner
2
2
Bi-dir coupler
2
SR5500
Channel
Sim 1
SR5500
Channel
Sim 2
40 dB
Attn
2
TX 2
RX 2
30 dB Tap
Interference
Signal Generator
C, D or LMR Bands
Spectrum
Analyzer
RX 2
Spectrum Analyzer: Agilent MXA 9020A
Interference Sig Gen: R&S SMU200A
Bi-directional coupler: Anatech AM1515DC860
Circulator: Ditom D3C0780
Splitter/Combiner: AEI AM505PD1018-N
19
eNodeB Transmitter Testing
• We use a test waveform (E-TM1.1, E-TM1.2) if
possible, or a 64 QAM modulated waveform
if test waveforms are unavailable
• We test in-band channel power, out-of-band
power (edge frequency +/- 10 MHz), and
spurious emissions (> 10 MHz offset)
• Tests use 100 kHZ measurement bandwidth
• Co-existence and Co-location specifications
20
eNb 5 MHz Spectral Emissions Mask
Spurious
728-748
In Band and Out of Band
748-777
Spurious
777-798
21
eNB Spectral Emissions Limits
DL
Frequency Bands
In Band
Out-of-Band
Spurious
Co-location
DL Frequency Range
(MHz)
758-768
748-753 Lower
Power Level
(dBm/100 kHz)
Pmax
-14
3GPP TS 36.104 version 8.8.0
Reference
Clause 6.2.1
Table 6.6.3.1-3
753-753.7 Lower
-14 to -13
Table 6.6.3.1-3
753.7-758 Lower
-13
FCC rule 27.53
768-769 Upper
-7 to -8.4
Table 6.6.3.1-3
769-777 Upper
728-748 Lower
-34
-62
Table 6.6.4.3.1-3
Table 6.6.4.3.1-1 with Note 1
777-798 Upper
728-748 Lower
-96
-62
Tables 6.6.4.2-1 and 6.6.4.4.1-1
Table 6.6.4.3.1-1 with Note 1
777-788 Upper
-59
Table 6.6.4.3.1-1
788-798 Upper
-96
Table 6.6.4.2-1
Spurious
Co-existence
22
In-Band/Out-of-Band Emissions
23
In-Band Failure
24
Sector Characterization Test
• This test is designed to determine the
throughput at near, mid, and cell edge
locations. The near, mid and cell edge
locations will be determined at the 10th, 50th
and 95th percentiles of the CDF of the SNR.
This test will be conducted between a
loaded and unloaded, single sector of an
eNB and a nomadic UE in the presence of cochannel interference.
25
Public Safety Broadband Demo Network
26
Drive Test Route
27
Typical Throughput versus SNR
PDSCH PHY Throughput vs SNR
30000
y = 0.0279x4 + 0.2526x3 + 4.475x2 + 305.76x + 2082.4
R² = 0.7939
25000
20000
15000
10000
5000
0
-10
-5
0
5
10
15
20
25
30
-5000
28
Near, Mid and Far Cell Locations
29
Downlink, Network Unloaded
30
Downlink , Network Loaded
31
Downlink Comparison
32
Uplink, Network Unloaded
33
Uplink, Network Loaded
34
700 MHz 3GPP Spectrum
Public Safety Broadband Spectrum is dedicated
by Congress and can only be used by PS
Public Safety Broadband
PS Narrowband
D Block was legislated by Congress for commercial
Use and was never dedicated to PS
D Block
D Block
Public Safety
Ch
51
A
B
C
D
E
A
B
C
Ch
52
Ch
53
Ch
54
Ch
55
Ch
56
Ch
57
Ch
58
Ch
59
698
704
710
716
722
728
734
740
C
Ch
60
746
D PS G PS
BB768B769 NB
763
A
Ch
61
752
757
Ch
62
758
Ch
63
764
A
B
C
D
E
A
B
C
Ch
52
Ch
53
Ch
54
Ch
55
Ch
56
Ch
57
Ch
58
Ch
59
Cavalier
Wireless
710
716
775
770
757
704
C
Ch
65
776
D PS G PS
BB798B799 NB
793
A
Ch
66
782
787
Ch
67
788
Ch
68
794
B
Ch
69
805
800
806
Upper Band
Lower Band
698
Ch
64
Public Safety
B
722
728
734
740
746
746
?
752
768 769
PS
A D
PublicBB
C
Ch
60
763
Ch
61
Ch
Safety
62
758
764
G
B
775
PS
NB
Ch
63
Ch
65
776
?
782
793
798 799
PS
A D
PublicBB
C
B
Ch
64
770
787
Ch
66
Ch
Safety
67
788
G
B
P
N
Ch
68
794
800
Cavalier
Wireless
35
2
10 MHz eNB Spectral Emission Mask
Spurious
728-748MHz
20
In-Band and Out-of-Band
748-777MHz
0
dBm/100kHz
(748,-14)
-20
(753.7,-13)
(753,-14)
(758,-13)
Spurious
777-798MHz
(768,-7)
(769,-8.4)
(769,-34)
(777,-34)
-40
(728,-62)
-60
-80
(748,-62)
(788,-59)
(777,-59)
Coexistence Limit
Colocation Limit
-100
720
730
740
(798,-96)
(777,-96)
750
760
770
Frequency (MHz)
(788,-96)
780
790
800
36
10 MHz Test
37
The D-Block Experiment
• Band 13 signal within FCC limits
• Simulation: User is close to Band 13 site, far
from PSBB site
– User is about 8 km from PS site, 300 m from
Band 13 site in this experiment
38
D Block Radiated Signal (1)
39
D Block Radiated Signal (2)
40
Map of Band 13 Signal Level
41
Effect of D-Block Interference
42
PSNB Testing
43
Our “Dispatch”
44
Radios & Test Equipment
45
Other Interferers!
• PSBB uplink = 788 to 798 MHz
– GPS L1 = 1575.42 MHz
– 2*788 MHz = 1576 MHz!
• Leakage from cable TV repeaters
• Wireless microphones
46
What Is Next?
• 10 MHz Regression Results
• Phase 3
– Being modified to heavily address
interoperability (IOT)
• The New Legislation
– http://www.ntia.doc.gov/files/ntia/publications/
ntia_public_safety_communications_slidedeck
.pdf
47
Generic PSCR Network Diagram
48
New Mobiles
49
For Additional Information:
http://www.pscr.gov
Dr. Rob Stafford
stafford@its.bldrdoc.gov
50