Measurement Journal Issue 6

Figure 3. Data “drop outs” identiﬁed during physical layer integration The “before” measurement in Figure 3 suggested that the phone had detected a change in its power allocation for transmitting data. The designer explored this suggestion further by ﬁrst turning off the relative grant channel (E-RGCH) power. Because this did not affect the user equipment (UE) uplink data throughput, the next step was to signal that the relative grant channel power was “off.” This gave the correct results, as shown in the “after” measurement in Figure 3. Further investigation showed that the phone was interpreting a “HOLD” sent on the E-RGCH as a “DOWN,” resulting in the drop-outs. The problem could then be ﬁxed. In another example, a designer observed that data calls on the mobile phone were being disconnected whenever the serving grant varied widely over a period of time. This occurred when a video-streaming application was running. The environment was replicated using a packet-switched data call. Agilent’s Wireless Test Manager software was used to control the 8960 Test Set measurements and absolute grant pattern setups. The results were reviewed on the E-TFCI recording screen. Figure 4 shows the results after the test was run for several minutes. The behavior was determined to be caused by buffer overﬂow in the mobile phone. Figure 4. Calls being disconnected during a video streaming application Call drops Frequently during application integration, HSPA phones are found to have difﬁculty delivering maximum data rates to the application layer. The reasons are many. In the example illustrated in Figure 5, the designer was able to determine that his device could not handle the standard RLC polling rate. This determination was made by viewing the data throughput monitor and wireless protocol advisor protocol logs from an Agilent 8960 Test Set. The log on the left shows that the phone’s responses, occurring at 20-ms intervals, dominate the available resources. When the RLC polling rate was decreased, the phone was able to maintain higher data rates in a more stable manner. The protocol log on the right shows that the phone is less stressed by responding to polling at 120-ms intervals. Agilent Measurement Journal 30

Table of Contents Feed for the Digital Edition of Measurement Journal Issue 6

Measurement Journal Issue 6 Using a Few Words to Convey a Deeply-Held Spirit Charting a Unique Path to Technology Innovation Contents Announcing First Commercial GC/MS Metabolites Library Assessing Nonlinear Behavior Testing Combines Form and Function Testing Multiplay Networks Higher Sensitivity LC/MS Easing Military Radio Test Stepping Up Calibration Accuracy Increasing Spectrum Analyzer Bandwidth 3GPP Tool Supports TS 36 Standards The Olympic Story Spotlights Agilent's Continuing Contribution to Technology Innovation Ensuring a Level Playing Field in Competitive Sports GPS: Coming of Age Resolving Design Issues in HSPA Mobile Devices Achieving Accurate Results with Oscilloscope-Based Jitter-Analysis Software RF Handheld Testers Guarantee Traffic Stability Under Olympic-Sized Stress Conditions Utilizing LAN-Based Instrumentation to Measure Total Harmonic Distortion in Remote Facilities IMT-Advanced: 4G Wireless Takes Shape in an Olympic Year EPO Doping: A Speed Engine, Turbo-Charged by Chemistry

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