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Evaluating AssistNow with u-center 2

Updated

u-center 2 is the u-blox evaluation tool to test and evaluate u-blox GNSS receiver performance. u-center 2 includes the capability to test u-blox location services, and it is designed to support the Plug&Play experience for AssistNow Live Orbits and Predictive Orbits.

When designing production firmware, additional implementation is required to access and use A-GNSS data. With Plug&Play mode, developers can skip setup steps and directly focus on evaluating the service, easily testing different environments and configurations without any pre-configuration. Simply connect your Evaluation Kit to u-center 2 and test different service options to compare performance improvements in positioning speed and accuracy. No coding, configuration, or registration is required; just connect and start evaluating using the Plug & Play feature in u-center 2.
 
If you are using a GNSS chip or module for your testing with u-center 2 (instead of an EVK), you need to retrieve the credentials to access the AssistNow service using the Zero Touch Provisioning procedure described in this article: AssistNow device registration. 

Getting started with an Evaluation Kit

To get started, a few simple steps are required:

  1. Get your Evaluation Kit (EVK) from the u-blox Product selector or your u-blox sales interface after confirming the EVK is compatible with AssistNow.
  2. Download u-center 2 and open the tool.
  3. Connect the EVK to your laptop using the provided USB cable, then add it in u-center 2. 
    1. Click the Data Sources icon (top-left) chip-160x160px.svg.
    2. Click on the + icon
    3. Choose the appropriate interface from the drop-down menu.
  4. Go to the 'Tools and Services' section and select AssistNow.
  5. Select EVK and hit the 'Get access' button.
  6. You can select the Predictive Orbits or the Live Orbits panel and choose the default settings or customize them using the user interface. To get the selected A-GNSS data from AssistNow, click the 'Download and Transfer' button to automatically download the A-GNSS data from the AssistNow service and transfer data to the GNSS receiver.

For more information about the available options, you can read the 'User guide' available in u-center 2 help center.

To evaluate the performance, we suggest repeating the test under different configurations, each time performing a cold start, and comparing both the Time-to-First-Fix (TTFF) and the accuracy of the initial position:

  • Performance with no AssistNow data, with AssistNow Predictive Orbits, and with AssistNow Live Orbits.
  • Performance during a cold, warm, and hot start.
  • Performance using only selected GNSS constellations.

Getting started without an Evaluation Kit

If you do not have an Evaluation Kit but your laptop is directly connected to a device with a u-blox GNSS module, steps 2 to 4 still apply. However, additional steps are required to connect to the AssistNow service.

Now you are ready to proceed with the evaluation and test using your own device and compare the performance with different setups.

Service query string

The User Interface includes a read-only field with the service query string (Request string) that changes according to the settings. This represents the HTTPS service request that you need to implement in the Firmware of the device, as described in the Service Integration and Host Software guides.

u-center 2 is also a very useful tool during firmware development, because it allows you to analyze firmware commands, receiver responses, and output messages to check that your firmware is behaving properly.

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