In-building, multi-frequency radio coverage mapping
In the past, radio coverage mapping requirements were driven by the need to verify a single transmitter channel to see where there was sufficient radio coverage and where coverage holes were located. However, today there are many applications where radio coverage must be verified for multiple channels across a very wide frequency range. With more than 80% of mobile traffic coming from indoor or in-building networks, it is now common to have multiple wireless networks on the same floor. While this helps with user experience, coverage testing of complex RF environments is a challenge. A good example is how various commercial cellular operators must verify reliable service and good throughput rates of indoor distributed antenna systems (DAS) found in many public spaces, such as shopping centres, airports, or sport stadiums. In many cases, multiple channels on multiple frequencies are used and they would ideally test all of these frequencies in parallel to maximize efficiency. Another example would be verifying the interaction of outdoor-to-indoor coverage for TETRA-based, in-building coverage systems and the resulting interferences.
The ideal test system should be able to track multiple frequencies by either walking or driving a given area. It needs to have the ability to perform coverage mapping without the need for a GPS signal and be able to handle difficult areas such as stairwells and hallways. It should also be lightweight, portable and battery operated, with a wide frequency range and fast scanning.
Channel scanner functionality is needed in order to scan through a defined set of frequency channels. For coverage mapping applications, it is important that the scanning speed is fast enough to capture all of the desired channels while seamlessly following the movements of the person making the measurements.
The Anritsu Remote Spectrum Monitor MS27101A offers outstanding sweep speeds even for smaller resolution (RBW) or video bandwidths (VBW), which is important for narrowband communications standards such as analogue FM, P25, TETRA, DMR, and dPMR. For instance, dPMR uses 6.25 kHz channels, P25 and DMR use 12.5 kHz channels, and TETRA channels are usually separated into 25 kHz blocks within a 5 MHz frequency segment.
The Anritsu TRX NEON Signal Mapper MA8100A is available for indoor/outdoor single- and multi-channel radio coverage mapping. This solution enables users to gather channel power and signal quality results by simply walking through an area of interest, as well as see coloured breadcrumb trails that indicate the power level and walking path. The TRX NEON Signal Mapper application allows for the definition of multiple frequency sets that are individually defined by centre frequency, SPAN, RBW, and desired reference level.
Five Easy Steps to Complete In-Building Coverage Mapping
- Import building floorplan
- Setup frequencies – up to 8 channels can be input at a time
- Calibrate the system with your current position and orientation, then begin the walk-through
- Upload results to cloud or store locally
- View results through command software in 2D or 3D. Thresholds can be set to indicate pass/fail for any particular grid or area. Multiple floors can be viewed simultaneously.
With the increasing requirements by various government agencies to comply with local requirements, network crews must validate compliance by ensuring that radio coverage meets these specifications. The Remote Spectrum Monitor MS27101A can facilitate the identification and removal of illegal or unlicensed interference signals. By monitoring spectrum on a continual basis, problem signals can be identified as they occur in real time. With the additional SpectraVision MX28010A software, the Remote Spectrum Monitor solution can also serve as a signal analysis platform for communications systems like TETRA, including panorama measurements showing the incoming direction of a signal or as a SatCom monitoring platform.
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