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LabVIEW Communications LTE Application Framework 1.0 and 1.1 Known Issues

Updated Mar 10, 2020

Overview

This document contains the LTE Application Framework known issues that were discovered before and since the release of LTE Application Framework. Not every issue known to NI appears on this list; it is intended to show the most severe and common issues that can be encountered.

Each issue appears as a row in the table and includes the following fields:

  • Issue ID - The number in at the top of each of the cells in the first column. When you report an issue to NI, you may be given this ID, you can also find IDs posted by NI on the discussion forums or in Knowledge Base articles.  "N/A" indicates that there is no ID assigned to the issue.
  • Issue Title (in italics) - Describes the issue in one sentence or less.
  • Problem Description - A few sentences which describe the problem in further detail. The brief description given does not necessarily describe the problem in full detail, and it is expected that you may want more information on an issue. If you would like more information on an issue, contact NI and reference the ID number given in the document.
  • Workaround - Possible ways to work around the problem. The workarounds that appear in the document are not always tested by NI and are not guaranteed to resolve the issue. If a workaround refers you to the NI KnowledgeBase, visit www.ni.com/kb/ and enter the KnowledgeBase number in the search field to locate the specific document.
  • Reported Version - The earliest version of the LTE Application Framework in which the issue was reported. If you discover the issue appears in an earlier version of the LTE Application Framework than is reported in this field, report the discrepancy to NI to have the field updated.
  • Resolved Version - Version in which the issue was resolved or was no longer applicable. "N/A" indicates that the issue has not been resolved.
  • Date Added - The date the issue was added to the document (not the reported date).
538847—802.11 and LTE Application Frameworks Examples with Video Streaming Does Not Work with Latest Version of VLC.
505728—RF performance degradation can be experienced on the high and low ends of the NI USRP RIO frequency range.
499345—Small RX signal power measurements may not be shown.

 

IDKnown Issue
538847

Return		802.11 and LTE Application Frameworks Examples with Video Streaming Does Not Work with Latest Version of VLC.
When running the commands specified in the help to launch the VLC receiver and transmitter, the 802.11 and LTE Application Frameworks example shows a blank screen in the receive window.

Workaround: Use an older version of VLC (2.1.5 or earlier).

Reported Version: 1.0  Resolved Version: 2.0  Added: 9/01/2015
505728

Return		RF performance degradation can be experienced on the high and low ends of the NI USRP RIO frequency range.
Close to the upper and lower limits of the NI USRP frequency range, there are degradations on the RF perfomance from the NI USRP device. For the LTE Application Framework, these degradations result in a noisy PDSCH constellation even at high signal power levels. In this situation, on the Advanced tab, the PDCCH constellation looks like small crosses. You can see the certain peaks in the channel estimation indicator where the normalized amplitude is usually flat when the framework is used in the RF Loopback use case described in the project documentation.

Workaround: Move the carrier frequency away from the limits. The distance to obtain a clean spectrum and constellation can be in the order of several hundred MHz.

Reported Version: 1.0  Resolved Version: N/A  Added: 11/25/2014
499345

Return		Small RX signal power measurements may not be shown.
The Signal Power [dBFS] indicator only shows values down to around -40 dBFS. Lower power values are shown as -Inf. This behavior is caused by the accumulation of data over time in the FPGA. The fixed-point scaling is not wide enough to handle such small values.

Workaround: None.

Reported Version: 1.0  Resolved Version: 1.1  Added: 11/25/2014

Contacting NI

Contact NI regarding this document or issues in the document. If you contact NI in regards to a specific issue, reference the ID number given in the document. The ID number contains the current issue ID number as well as the legacy ID number (use the current ID number when contacting NI). You can contact us through any of the normal support channels including phone, email, or the discussion forums. Visit the NI Website to contact us. Also contact us if you find a workaround for an issue that is not listed in the document.

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Glossary of Terms

 

  • Bug ID - When an issue is reported to NI, you may be given this ID or find it on ni.com.  You may also find IDs posted by NI on the discussion forums or in KnowledgeBase articles.
  • Legacy ID – An older issue ID that refers to the same issue.  You may instead find this issue ID in older known issues documents.
  • Description - A few sentences which describe the problem. The brief description given does not necessarily describe the problem in full detail.
  • Workaround - Possible ways to work around the problem.
  • Reported Version - The earliest version in which the issue was reported.
  • Resolved Version - Version in which the issue was resolved or was no longer applicable. "N/A" indicates that the issue has not been resolved.
  • Date Added - The date the issue was added to the document (not the reported date).