Reliable planning of small cells is essential for important and critical deployments. Consider hospitals, manufacturing facilities or VIP (CxO) office floors and meeting rooms (the list of examples is endless). Successful and cost-effective planning, and with it small cell deployments, require planning tools that ensure highest reliability and accuracy. This, however, is not always the case as floor plans might be outdated and change records of live deployments not properly updated. Scanners and test transmitters are a sure way to verify small cell planning for critical sites.
Well before the site survey, an indoor deployment has been designed in a back-office, using planning tools to capture and centralize customer requirements. For example, with the help of the industry’s leading indoor planning software supplier iBwave, whose file format our measurement solutions support.
The process of reliable small cell planning
The next step of the planning phase entails the verification of the initial plan during the site survey. The technician records the actual situation without the planned small cell. To get this data, he simply does a scanner measurement without a test transmitter.
In LTE networks, the result typically includes signals with low RSRP (Reference Signal Receive Power) and SINR (Signal to Interference and Noise Ratio) performance indicators. While RSRP indicates the coverage at the measurement position, the SINR value indicates signal quality in relation to the interference. With bad coverage and low signal quality, only a low data throughput can be expected.
With the scanner measurement at hand, the technician continues to verify the planning by emulating an LTE installation with a test transmitter, for example with our SGT100A. When employing a test transmitter, it is important to use the correct band intended for the small cell deployment. Technicians need to be aware that they are transmitting in licensed bands that might belong to another operator.
Our recommendation: use the frequency that is owned by the operator who intends to install the small cell. With the test transmitter up and running, further scan measurements of the selected band(s) will show much improved RSRP and SINR values, despite the test transmitter’s low power.
Continuous wave versus modulated signal when testing
Test transmitters that only generate a continuous wave (CW) signal are usually less expensive than those generating modulated signals. There is, however, a drawback to CW signals as the receiver measuring signal levels totals up all energy on the frequency (in a frequency band).
Yet, to perform a proper performance prediction, specific and technology-related information is required in the form of coverage (e.g. RSRP in LTE) and capacity figures (e.g. SINR in LTE). Only these figures help predict the performance (data rates/capacities) of a planned small cell. Consequently, a test transmitter is required to transmit modulated signals (here LTE).
Reliable indoor small cell planning with a test transmitter takes place during the site survey. Typically, staff conducting these types of surveys is more experienced in handling tasks concerning RF, base stations, or antennas than those installing the small cell during the second visit. Site survey engineers use planning software offering floor plans, proposals for the location of small cells, simulated coverage, and capacity predictions, etc., and are optimally equipped to verify planning in critical areas with the help of a real test transmitter.
Test solutions for small cell planning
We offer a scanner-transmitter test solution to verify indoor small cell planning in critical areas during the site survey. On the one hand, our test solution improves the indoor small cell performance for critical areas (we call it measurement-based planning); and, on the other hand, it improves indoor simulation and the planning software itself by feeding results back from real measurements. Overall, the outcome is a more reliable site survey to ensure that the small cell deployment will deliver the expected performance.
Combining one of our scanners – for example, the TSME together with ROMES4 – with the SGT100A test transmitter enables engineers to truly measure performance (coverage and capacity) and accurately verify the new small cell’s optimal location.
Next week’s post will cover the installation phase of DAS and small cell indoor deployments.