NSA LTE - Deep-Dive Monitoring of Wireless Uu and Wireline EPC Interfaces

Transcription

1 NSA LTE - Deep-Dive Monitoring of Wireless Uu and Wireline EPC Interfaces Gain full insight into LTE and EPC networks with one all-encompassing solution Fully integrated monitoring of air and wireline interfaces for LTE radio access and EPC core network performance analysis Five correlated solutions within the same environment for top-down and bottom-up analysis of the Uu interface Rapid root cause analysis with control-plane and user-plane KPIs correlated across multiple interfaces Real-time decoding of Uu traffic for instant feedback on function and performance of the air-interface in the Downlink and Uplink Competitive pressure in the emerging 4G market is placing tough demands on reducing the time-to-market of related products. Consequently, managers are facing the challenge to reduce the time required for product test & verification. Thus, test and measurement tools are needed that help engineers avoid long searches for the needle in the haystack when problems occur by providing an end-to-end view over all critical parts of the LTE / EPC network. With the introduction of the K2Air probe for the LTE air-interface and the ability of the industry-leading Network & Service Analyzer TM (NSA TM ) to cover all key interfaces in 4G networks, Tektronix Communications is providing test engineers with exactly the tools needed to achieve today's demanding goals in 4G testing. Features & Benefits Suite of fully integrated air interface and wireline monitoring applications for 360 view of radio access and core network performance K2Air probe supporting real-time promiscuous mode air interface monitoring Spectrum and Vector Analyzer tools for the investigation of physical layer issues Analysis of MAC-layer resource allocation by the enodeb Full correlation across all protocol layers of the Uu interface, including the PHY layer Coverage of all key LTE and EPC protocols Applications Analyze the QoS interdependencies between the PHY / MAC and the service layers Determine whether the cause of QoS issues are in the air-interface or within the EPC Monitor simultaneously and in real-time the Uu and X2 interfaces for the analysis of Inter- Cell Interference Coordination Correlate User Plane KPIs across wireless and wireline LTE / EPC interfaces Analyze the performance of the MAC scheduling algorithms as a response to varying (PHY-layer) channel conditions and to (NAS-layer) UE service requests Full correlation of events and data across all interfaces, including Uu and EPC interfaces Datasheet

2 Datasheet NSA LTE - Deep-Dive Monitoring of Wireless Uu and Wireline EPC Interfaces The K2Air probe provides such insights by capturing I/Q samples exchanged via the CPRI interface between the enodeb's Remote Radio Head and its baseband processing unit. By doing so, it is able to acquire in realtime critical information about the Physical and MAC layers required for further analysis by the NSA. Tektronix Communications K2Air Probe The Network & Service Analyzer (NSA ) also provides a suite of software applications for troubleshooting and optimization of UMTS (including HSPA), WiMAX and 2.5G/2G technologies. Regardless of the technology under test, the NSA allows users to trace subscribers control and user plane traffic both in real time and offline over multiple interfaces and network elements. Identification of network issues (from the symptom down to the root cause) is tremendously fast and easy, and helps carriers and vendors alike significantly improve network testing efficiency. The NSA PHY Layer Toolbox Spectrum Analyzer allows Rx and Tx power profiles to be displayed in real-time in twoand three-dimensional graphs over the time and frequency domains. A Vector Analyzer also supports analysis of the captured I/Q samples in two- and three-dimensional constellation diagrams. With these tools, test engineers are able to investigate whether QoS issues are caused e.g. by poor channel conditions. The quality of AMC algorithms can be investigated with the Vector Analyzer by determining whether modulation schemes are switched sufficiently fast in accordance with the quality of the transmission channel. Investigating the Lower Protocol Layers of the enodeb Since LTE networks are all-ip based, handling properly user QoS requests is becoming more critical than ever before. QoS can be affected by multiple elements within the LTE/EPC network. Interference at the cell edge as well as the quality of the radio resource scheduler in the enodeb may affect the user's experience of LTE services just as well as traffic management and prioritization issues within the EPC. Thus, being able to investigate all layers of the Uu interface to determine the cause of potential QoS (and other) issues is key to successful problem resolution. Power Profile and Constellation Diagrams for the LTE Uplink and Downlink 2

3 The NSA MAC Scheduling Investigator enables test engineers to analyze the allocation by the enodeb of resource blocks to the monitored UE. With this tool, the user is able to determine whether the MAC scheduler is allocating the required resources according to the user's QoS requirements. In addition to these advanced lower layer analysis tools, down-to-the-bit protocol decoding is supported by Tektronix Communications industry leading Frame Monitor, which displays all messages down to the physical layer in a human-readable format. Radio-related channel quality parameters, such as RSRP and RSRQ measurement reports provided by the UE to the enodeb, can be represented as KPIs in dedicated Radio Charts; NSA provides the user with the necessary flexibility to rapidly add any required KPIs in such charts. All views are fully correlated with each other, allowing test engineers to draw a clear relationship between messages/procedures and the physical layer aspects of the transmission channel. 360 Performance View Solution concept for monitoring of Uu and Wireline interfaces 3

4 Datasheet NSA LTE - Deep-Dive Monitoring of Wireless Uu and Wireline EPC Interfaces Troubleshooting the higher protocol layers of the LTE / EPC Network In addition to gaining deep insights into the function of the lower protocol layers of the Uu interface, test engineers must be able to analyze the higher protocol layers, including the Radio Resource Control (RRC) and NAS (Non-Access Stratum) signaling protocols on the Uu interface as well as a multitude of EPC specific protocols such as S1-AP, GTPv2-C and DIAMETER. These are the layers at which network performance issues become most apparent. These occur especially under loaded conditions, i.e. when network elements need to handle a large number of calls. Within such an environment, being able to easily and quickly filter out those calls that have failed (for whatever reason) becomes a critical requirement for efficient root cause analysis. The NSA LTE and EPC troubleshooting suites enable engineers to conveniently filter out from thousands of calls displayed in appropriate Call Tables that small portion that has caused trouble, e.g. by filtering the call tables according to EMM (EPS Mobility Management) cause values returned by the network. The Session Analyst application allows statistics to be displayed in a convenient manner that help the engineer identify how often specific cause values occur and therefore help focus on the most problematic calls. Multiple interface call trace with easy access to down-to-the-bit protocol details After identifying a particular call of interest, the engineer can then analyze the call flow end-to-end from one interface to another, and drill-down to the details of individual messages to determine the cause of call failures. If a specific reason for call failure has been determined (e.g. due to a particular problematic parameter value being signaled to the network), it is then a straightforward task to 'drill-up' to identify all calls with identical or similar parameter values. This drill-up approach helps determine if these calls have also a similar behavior in the end-to-end calls flows. 4

5 Investigating Network Level Behavior with KPIs For more specific LTE performance monitoring, the NSA provides a comprehensive set of Key Performance Indicators (KPIs) that map complex relationships between multiple parameters and call phases. The LTE KPI set allows users to determine the performance of multiple service aspects such as mobility management (attach failures, handover, tracking and location update success/failure), service management (radio bearer analysis, throughput analysis) and radio performance (connection setup times, retransmissions, resource allocation). Message statistics and KPIs provide insight into network and node performance 5

6 Datasheet NSA LTE - Deep-Dive Monitoring of Wireless Uu and Wireline EPC Interfaces K2Air Probe Characteristics Features: Reception of downlink OFDMA and uplink SC-FDMA traffic in real-time via CPRI interface. 2 x 2 MIMO reception Real-time decoding of PHY and MAC/RLC protocol layers. Lossless decoding of all specified LTE bandwidths: 1.4, 3, 5, 10, 15 and 20 MHz Interfaces: 4 x CPRI V4 optical and electrical 1 x 1GBit Ethernet Interface (connection to NSA and remote access) USB Interface/MMC Card Slot (firmware update and maintenance) Physical characteristics Dimensions mm inch Height Width Depth Weight kg lbs. Net Power supply AC Input: 200W VAC 50/60Hz Fuse Data: 4A 2A Regulatory Safety: EN : 2001 EMC: EN Class A or B Environmental characteristics Temperature: +5 ºC to +40 ºC. Altitude Operating: 6,561 ft. (2,000 m). Uu Interface Analysis Tools: Spectrum and Vector Analyzer MAC Scheduling Investigator Frame Monitor for down-to-the-bit protocol decoding Uu call trace; full correlation of Uu call trace with other EPC interfaces Customizable Control-plane and User-Plane KPIs Radio Chart Analysis LTE and EPC Analysis Tools Tektronix Communications K2Air Probe NSA LTE/EPC Application Features Protocol Decode and (Single Interface and Multi-Interface) Call trace capabilities for X2, S1, S3, S4, S6a, S10, S11, S12 and interfaces Customizable Control-plane and User-Plane KPIs Analysis of message statistics Analysis of cause value statistics Drill-down from Call Table down due individual message parameter value Drill-up from parameter value to all related calls LTE and EPC Interface Support Uu, R8 3GPP X2, R8 3GPP S1, R8 3GPP S3, R8 3GPP S4, R8 3GPP S6a, R8 3GPP S10, R8 3GPP S11, R8 3GPP S12, R8 3GPP

7 Datasheet NSA LTE - Deep-Dive Monitoring of Wireless Uu and Wireline EPC Interfaces About Tektronix Communications: Tektronix Communications provides network operators and equipment manufacturers around the world an unparalleled suite of network diagnostics and management solutions for fixed, mobile, IP and converged multi-service networks. This comprehensive set of solutions support a range of architectures and applications such as LTE, fixed mobile convergence, IMS, broadband wireless access, WiMAX, VoIP and triple play, including IPTV. Tektronix Communications is headquartered in Richardson, Texas. Learn more about the company's test, measurement and network monitoring solutions by visiting: For Further Information: Tektronix Communications maintains a comprehensive, constantly expanding collection of application notes, technical briefs and other resources to help engineers working on the cutting edge of technology. Please visit Contact Tektronix Communications: Please visit Phone: option Copyright Tektronix. All rights reserved. Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supersedes that in all previously published material. Specification and price change privileges reserved. TEKTRONIX and TEK are registered trademarks of Tektronix, Inc. All other trade names referenced are the service marks, trademarks or registered trademarks of their respective companies. 05/10 CAW

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