Measurement Journal Issue 6

Figure 1 shows an HSPA waveform in the time domain. It illustrates the power level changes that occur when HSDPA and HSUPA transmission are added to the W-CDMA signal. Note that in segment A, the HSUPA dominates because the Absolute Grant is set to a high level. Figure 2. Protocol log showing the effect of a missing parameter Figure 1. HSPA waveform showing (A) HSUPA, HSDPA and W-CDMA combined; (B) HSDPA control channel and W-CDMA; and (C) W-CDMA signal only Another challenge is protocol design. The fast scheduling ﬁrst introduced in HSDPA requires the mobile phone to respond with “correct” messages in terms of content, length, order of delivery, and delivery time. Moreover, the mobile phone needs to ignore messages from the network pertaining to any functionality it doesn’t support. Protocol errors can cause problems with handovers, resulting in lost data and dropped calls. Figure 2 shows a protocol log from a situation in which a message was missing certain content (e.g., the message length) and, as a result, all subsequent messages were misinterpreted. Memory management is yet another challenge for HSPA mobile phone designers. Because most applications deal with some type of data transfer, memory buffers must be kept optimally loaded. Any large changes in throughput or delay degrade the application’s performance. If a drop in bandwidth occurs, for example, the mobile phone is instructed to request a lower rate of data from the server. However, before the server receives the request and acts on it, the network will have continued to buffer data, awaiting delivery. Because a mobile phone operates on in-sequence delivery, the data being stored could create a bottleneck that, when cleared, ﬂoods the mobile phone with data. Agilent Measurement Journal 28

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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