Transcript Session Title

Testing Wireless Devices and Systems
Session 1: Introduction
9-July-2012
Fanny Mlinarsky
octoScope, Inc.
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Contents
Evolution of wireless technology
Test challenges
Test applications
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Brief History of Wireless
5G
4G
Wireless capacity / throughput
IEEE 802
3G
2G
802.16e
802.11a/b/g
LTE
LTE-A Key wireless
802.11n/ac technologies
WCDMA/HSxPA
GPRS
Analog
CDMA
GSM IS-54
First cell
phones
1970
IS-136
TACS
AMPS
NMT
1980
1990
3
2000
2010
G = generation
2015
OFDM (Orthogonal Frequency Division Multiplexing)
Voltage
Multiple orthogonal carriers
Frequency
• OFDM is the most robust signaling scheme for a hostile wireless channel
– Works well in the presence of multipath thanks to multi-tone signaling and
cyclic prefix (aka guard interval)
• OFDM is used in all new wireless standards, including
– 802.11a, g and draft 802.11ac, ad
– 802.16d,e; 802.22
– DVB-T, DVB-H, DAB
• LTE is the first 3GPP standard to adopt OFDM
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DVB = digital video broadcasting
DVB-T = DVB terrestrial
DVB-H = DVB handheld
DAB = digital audio broadcasting
LTE = long term evolution
FDMA vs. OFDMA
• OFDMA is more frequency efficient
than traditional FDMA
– Orthogonal subcarriers require no guard bands
Guard
band
Channel
FDMA
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OFDMA
OFDMA
Resource Block (RB)
Time
Time
LTE
Frequency allocation per
user is constant vs. time
User 1
User 2
User 3
Frequency per user is dynamically
allocated vs. time slots
User 4
User 5
OFDM = orthogonal frequency division multiplexing
OFDMA = orthogonal frequency division multiple access
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LTE Resource Block
A resource block (RB) is a basic unit of access allocation. RB bandwidth per
slot (0.5 ms) is 12 subcarriers times 15 kHz/subcarrier equal to 180 kHz.
Subcarrier (frequency)
…
1 slot, 0.5 ms
Resource block
12 subcarriers
…
…
7
1 subcarrier (15 kHz)
v
…
Resource Element
1 subcarrier
QPSK: 2 bits
16 QAM: 4 bits
64 QAM: 6 bits
Time
Multiple Antenna Techniques
•
SISO (Single Input Single Output)
Traditional radio
•
MISO (Multiple Input Single Output)
Transmit diversity (STBC, SFBC, CDD)
•
SIMO (Single Input Multiple Output)
Receive diversity, MRC
•
MIMO (Multiple Input Multiple Output)
SM to transmit multiple streams simultaneously; can be used
in conjunction with CDD; works best in high SNR
environments and channels de-correlated by multipath
TX and RX diversity, used independently or together; used to
enhance throughput in the presence of adverse channel
conditions
•
Beamforming
SM = spatial multiplexing
SFBC = space frequency block coding
STBC = space time block coding
CDD = cyclic delay diversity
MRC = maximal ratio combining
SM = Spatial Multiplexing
SNR = signal to noise ratio
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MIMO vs. SISO Throughput
Draft 802.11n vs. Legacy - Home
Draft 802.11n vs. Legacy - Office
180
160
140
120
100
80
60
40
20
0
Mbps
Mbps
Draft-802.11n
Legacy 802.11g
Draft-802.11n
6 ft
110
40
Measured by octoScope
150
180
200
180
160
140
120
100
80
60
40
20
0
25
feet
Vendor 1
Legacy 802.11g
35
45
50
feet
Vendor 2
MIMO = multiple input multiple output
SISO = single input single output
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IEEE 802.11a,b,g,n Data Rates
20 MHz Channel
1 stream
2 streams
3 streams
40 MHz Channel
4 streams
1 stream
2 streams
3 streams
4 streams
Data Rate, in Mbps
802.11b
2.4 GHz
1, 2, 5.5,
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802.11a
5 GHz
6, 9, 12,
18, 24, 36,
48, 54
802.11g
2.4 GHz
1, 2, 6, 9,
12, 18, 24,
36, 48, 54
802.11n
2.4 and
5 GHz
6.5, 13,
19.5, 26,
39, 52,
58.5, 65
13, 26, 39,
52, 78,
104, 117,
130
19.5, 39,
58.5, 78,
117, 156,
175.5, 195
26, 52, 78,
104, 156,
208, 234,
260
13.5, 27,
40.5, 54,
81, 108,
121.5, 135
27, 54, 81,
108, 162,
216, 243,
270
40.5, 81,
121.5, 162,
243, 324,
364.5, 405
54, 108,
162, 216,
324, 432,
486, 540
802.11n, SGI
enabled
2.4 and
5 GHz
7.2, 14.4,
21.7, 28.9,
43.3, 57.8,
65, 72.2
14.4, 28.9,
43.3, 57.8,
86.7,
115.6, 130,
144.4
21.7, 43.3,
65, 86.7,
130, 173.3,
195, 216.7
28.9, 57.8,
86.7,
115.6,
173.3,
231.1, 260,
288.9
15, 30, 45,
60, 90,
120, 135,
150
30, 60, 90,
120, 180,
240, 270,
300
45, 90,
135, 180,
270, 360,
405, 450
60, 120,
180, 240,
360, 480,
540, 600
SGI = short guard interval
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802.11ac – Next Generation Wi-Fi
•
•
•
•
Up to 6.9 Gbps of PHY data rate
Higher order MIMO (> 4x4)
8 spatial streams
Multi-user (MU) MIMO
– Up to 4 users; up to 4 streams per user
• Higher bandwidth channels (20, 40, 80,
80+80 and 160 MHz)
MU-MIMO
Multiple beamformed
streams in the same channel
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Wireless Topologies
•
•
•
•
2G/3G/LTE and most Wi-Fi
networks are infrastructure
based
Mesh networks (e.g. 802.11s) are
sometimes used to interconnect
APs or base stations to the
central carrier or corporate
network or to the internet
With the spread of LTE, the trend
is towards smaller base stations
and smaller cells interconnected
via microwave (sometimes Wi-Fi)
mesh networks
Wireless backhaul is starting to
displace traditional expensive
fiber or copper cabling
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Infrastructure network
Mesh network
Small 2G/3G/LTE base
stations are
interconnected via
microwave links.
AP = access point
LTE = long term evolution
Wireless Protocols and Applications
Voice, video, ...
IMS
Internet
EPC
LTE, Wi-Fi, ...
IMS = IP multimedia subsystem
EPC = evolved packet core
LTE = long term evolution
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Contents
Evolution of wireless technology
Test challenges
Test applications
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Many Things To Test
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Lots of Knobs
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Wireless Test Standards of Note
2G/3G/LTE
Wi-Fi
Data transport
Applications
Smart Grid
3GPP RAN5 →ETSI
→PTCRB/GCF
(conformance,
interoperability)
Wi-Fi Alliance
(WMM, WPA, etc.)
IETF RFC 2285,
2544, 2889 (packet
loss, latency, jitter)
ITU-T Voice Quality
P.800 (MOS); P.862
(PESQ); G.107 (RFactor)
NIST SEP 2
interoperability
CTIA (TIS/TRP
MIMO-OTA
SAR)
IEEE 802.11.2
(range, throughput,
latency)
3GPP = 3rd generation partnership project
RAN = radio access network
IETF = internet engineering task force
RFC = request for comments
GCF = global certification forum
ITU = international telecommunication union
ETSI = European Telecommunications Standards Institute
CTIA = cellular telecommunications internet association
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IETF video quality
RFC 4445 (MDI
MLR, DF)
TIS = total isotropic sensitivity
TRP = total radiated power
MIMO = multiple input multiple output
OTA = over the air
SAR = specific absorption ratio
WMM = wireless multimedia
WPA = wireless protected access
NIST = national institute of standard and technology
SEP = smart energy profile
MOS = mean opinion score
PESQ = perceptual speech quality measure
R-Factor = rating factor
MDI = Media Delivery Index
MLR = media loss rate
DF = delay factor
MIMO/OTA Test Standards
•
3GPP (International)
– MIMO/OTA specification development
– RAN WG4 in collaboration with CTIA & COST
•
CTIA (US)
– SISO OTA certification standard
– MIMO/OTA Sub-Working Group (MOSG) is driving effort
to update current standard SISO TIS/TRP standard
•
COST (Europe)
– ICT COST IC1004 Action: “Cooperative Radio
Communications for Green Smart Environments”;
Formerly COST 2100 Action: “Pervasive Mobile & Ambient
Wireless Communications”
– Contributions driven by SWG2.2: “Compact Antenna
Systems for Terminals”
MIMO = multiple input multiple output
OTA = over the air
3GPP = 3rd generation partnership project
CTIA = cellular telecommunications industry association
COST = European Cooperation in Science and Technology
3GPP Groups
Now working on LTE-A
•
•
•
•
•
•
RAN1-4 develop the functionality
standards
RAN4 feeds RAN5 RF group with test
requirements
RAN1 feeds RAN5 RF group through RAN4
RAN2 feeds RAN5 Signaling group with
test requirements
ETSI develops TTCN code per RAN5
standards and makes code available as
open source
Test equipment manufacturers are active
contributors to the TTCN effort
TTCN makes signaling certification
uniform; RF certification is different
among test equipment vendors
RAN1
TX/RX DSP
RAN4
RF and channel
RAN5
RF Cert
3GPP = 3rd generation partnership project
RAN = radio access network
GCF = global certification forum
ETSI = European Telecommunications Standards Institute
TTCN = Testing and Test Control Notation
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RAN2
Signaling
RAN5
Signaling Cert
ETSI
(TTCN)
GCF
PTCRB
Test Equipment
eNB emulators
•
SEP 2 Architecture
Smart Grid application 1
Smart Grid application 1
…
Applications
IP layer
…
Radio
technologies
www.homeplug.org
www.wi-fi.org
www.zigbee.org
The interoperability test spec is targeted to be completed in Q4-2012
•
•
SEP 2 was selected in 2009 by the NIST as a standard profile for smart energy
Smart Grid Interoperability Panel (SGIP) sets guidelines for smart grid testing and
certification programs.
SEP = smart energy profile
NIST = national institute of standards and technology
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Contents
Evolution of wireless technology
Test challenges
Test applications
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Test Applications
R&D
QA
Production
Deployment
RX sensitivity
TX spectrum
Throughput vs. range
Adaptive modulation
MIMO modes
Roaming, handover
Mesh algorithms
Throughput
Delay
Packet error rate
Test automation
Regression testing
Conformance
Interoperability
Regulatory compliance
Reproducing field failures
Parametric testing
- Speed
- Coverage
- Yields
Pre-deployment lab test
Field survey
Deployment test
Monitoring
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Next Session
Part II: R&D Test
When: July 10th at 2 p.m.
Thank you!
Please see more info and white papers at
www.octoscope.com
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