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Testing Wireless Devices and Systems Session 1: Introduction. 9-July-2012 Fanny Mlinarsky octoScope, Inc. Contents. Evolution of wireless technology Test challenges Test applications. Brief History of Wireless. 5G. 4G. Key wireless technologies. LTE-A. IEEE 802. 802.11n/ac. LTE.
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Testing Wireless Devices and SystemsSession 1: Introduction 9-July-2012 Fanny Mlinarsky octoScope, Inc.
Contents Evolution of wireless technology Test challenges Test applications
Brief History of Wireless 5G 4G Key wireless technologies LTE-A IEEE 802 802.11n/ac LTE 3G 802.16e 802.11a/b/g 2G WCDMA/HSxPA GPRS Wireless capacity / throughput Analog CDMA GSM Increasing throughput and capacity IS-54 IS-136 TACS AMPS NMT First cell phones 2015 1970 1980 1990 2000 2010 G = generation
OFDM (Orthogonal Frequency Division Multiplexing) Multiple orthogonal carriers Wi-Fi WiMAX LTE • 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 Voltage Frequency 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 OFDMA
OFDMA Resource Block (RB) LTE Time Time Frequency allocation per user is constant vs. time Frequency per user is dynamically allocated vs. time slots User 1 User 2 User 3 User 4 User 5 OFDM = orthogonal frequency division multiplexing OFDMA = orthogonal frequency division multiple access
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. 1 slot, 0.5 ms … Resource block 12 subcarriers … … Subcarrier (frequency) Resource Element 1 subcarrier QPSK: 2 bits 16 QAM: 4 bits 64 QAM: 6 bits 1 subcarrier (15 kHz) v … 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
MIMO vs. SISO Throughput Measured by octoScope Vendor 1 Vendor 2 MIMO = multiple input multiple output SISO = single input single output
IEEE 802.11a,b,g,n Data Rates SGI = short guard interval
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
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 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
Contents Evolution of wireless technology Test challenges Test applications
Many Things To Test Interference Throughput Range Routing Power Consumption Roaming Frame error rate Mesh networking Adjacent channel rejection Conformance Backwards compatibility Interoperability Data rate adaptation
Lots of Knobs Data traffic Motion Interference Multipath Noise MIMO modes Attenuation QoS Security
Wireless Test Standards of Note 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 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 TX/RX DSP • 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 RAN2 Signaling RAN4 RF and channel RAN5 RF Cert RAN5 Signaling Cert ETSI(TTCN) Test EquipmenteNB emulators 3GPP = 3rd generation partnership project RAN = radio access network GCF = global certification forum ETSI = European Telecommunications Standards Institute TTCN = Testing and Test Control Notation GCFPTCRB
SEP 2 Architecture … • 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. Smart Grid application 1 Smart Grid application 1 Applications IP layer • www.homeplug.org • www.wi-fi.org • www.zigbee.org Radio technologies … The interoperability test spec is targeted to be completed in Q4-2012 SEP = smart energy profile NIST = national institute of standards and technology
Contents Evolution of wireless technology Test challenges Test applications
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