TETRA walk-test solution
The CRIBS RF coverage measurement system is a complete turnkey solution for walk-test RF coverage measurement. It combines high speed sampling of the RF channels in addition to 'on the fly' analysis capability, with all functions controlled from the accompanying pre-configured tablet PC.
The sampling methodology is identical to that used in the world renowned CatchAll™ receiver, the de facto RF test measurement receiver for TETRA systems where sampling needs to be compliant with Lee Criterion. This sampling methodology presents advantages in the walk-test situation where the speed of sampling combats fading due to the rapid movement of nearby objects or vehicles. In addition the receiver provides a completely network independent method of measuring the data.
The Package
Contained within the CRIBS package are the CatchAll-SE RF measurement receiver, a rugged tablet PC with pre-installed software, a high capacity Lithium Ion battery and a padded backpack with a purpose-designed mounting frame.
The CatchAll-SE is a new, small, low power and light weight receiver with dual band capability. In addition the CatchAll-SE has an onboard accelerometer to enable more accurate position fixing at locations where the walk-test was slowed or halted. The receiver is mounted on a purpose-designed frame which is built into a backpack with padded shoulder straps for extended wearing. Easy access for insertion and removal of the unit is provided by a wide zip fastened opening in the backpack.
A high capacity Lithium Ion battery powers the CatchAll-SE for up to seven hours. Spare batteries are available.
The antenna protrudes from the backpack at approximately the same height as that of a device when worn by a public safety officer, therefore, the RF field measured by CRIBS is representative of that experienced by a typical device.
Control of the unit is by means of a tablet PC, provided as part of the package and pre-installed with all the necessary software to minimize set-up time and configuration issues. As well as providing the user interface, the tablet PC drives the capture algorithm and the on-the-fly analysis.
Floor Plans
A frustrating part of any walk-test can be the task of importing and scaling floor plans prior to the survey. In designing CRIBS specific attention has been paid to this aspect with the result that it is simplicity itself to import a floor plan or sets of building plans in gif, tiff or jpeg format. In seconds a floor plan in such a format can be imported, scaled appropriately and stored in a folder for later use.
Alternatively, when no floor plan is available, a simple scaled grid can be used as a substitute.
Waypoints
Waypoints can be input on to the floor plan as the walk-test is undertaken simply by tapping the screen, or alternatively waypoints defining a pre-determined route can be entered, in which case the walk-tester then clicks each one at the time of reaching that waypoint. This is a useful facility in metro systems, shopping malls or on extended walkways.
In each case, every waypoint is automatically numbered and displayed on the floor plan or grid as the walk-test progresses and for each waypoint encountered a time stamp is stored within the captured data.
On-the-Fly Analysis
Why wait to post-process the measurement data in order to determine the reasons for that poor coverage? Now CRIBS shows not only the signals received at any specific location but by clicking the tab 'Channel Information' the display then lists the channels with their associated signal strengths, the LAC (Location Area Code) of the base station and an estimate of carrier to interference ratio (CIR). The CIR parameter of the channels can be used to ascertain the Quality-of-Service (QoS) of the down link. The channel information display can be frozen for detailed analysis on site, while the unit continues to capture and store data, that can be further analysed at an office location using a tool such as TRAMPS™ (see the TRAMPS product information for more details).
Training
A very intuitive user interface of CRIBS translates into minimal training needed to operate this equipment. The extensive help menu provides guidance for setting up the reference building plans and for conducting a walk-test survey using the waypoint system.
If a formal training course is needed MAC Ltd will be pleased to provide a quotation upon request.
Example Outputs
Click on the images below to see larger plots and explanations of CRIBS display modes.
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| Example 1 Waypoint Capture | Example 2 On-the-Fly Data Processing | Example 3 Following a Pre- planned Route |
Product Datasheet
Further details about the CRIBS product may be obtained by downloading the product brochure.
Product Support
Software applications and documentation for CRIBS
™ CatchAll, CRIBS and TRAMPS are trademarks of Multiple Access Communications Limited