RF Physical Layer Conditioning is Linked to Capital Efficiency
The Situation
Wireless service providers are continuously growing their networks to deliver the capacity needed to satisfy data hungry smart phones and applications. Making sure the capital invested to deliver capacity meets expected financial returns requires the deployed equipment to operate as planned. ISCO has performed extensive analysis on numerous wireless networks around the world and consistently found PLI's caused by interference immediately degrade performance. The before and after analysis we routinely conduct has shown in some cases an impaired physical layer can dramatically increase dropped calls and ineffective attempts while reducing sector ERLANGS and attainable data modulation rates.
The Resolution
When problems arise or performance is not as expected in a communication network, diagnostics and analysis starts at layer-1 with visibility into the physical layer to allow real-time assessment of the quality of layer 1 and the presence of PLI's. Technicians can quickly determine whether or not the physical layer is a part of the problem or impacting performance.
Step 2 is to protect and condition the physical layer to minimize the likelihood of PLI's corrupting the physical RF link. Corrosion and aging equipment are maintenance related, border and adjacent RF energy can possibly be addressed with planning but interference is random and it will occur. The sources of interference are infinite and ever changing. They range from baby monitors to BDA's used on board ships, in automobiles, commercial and residential buildings and in DAS networks, to cable TV amplifiers, to 2-way radios and a variety of other wireless products. A microwave oven in a building can be amplified through a BDA and affect the performance of an entire cell site. Given its random nature, the technician can spend weeks to find the source. Having a conditioned link with visibility into the physical RF layer will protect the wireless network against rogue interferers and aid the trouble shooting and resolution process.
The Impact
The figure below depicts the impact of PLI's on the return on capital investment, linking together what is already known; the presence of unwanted interference reduces coverage area and the capacity of the radio link therefore reducing the expected ROI. In all cases, cell sites are built, remote radio heads are deployed, or more backhaul is installed with the expectation that the invested capital will operate at or very near its designed potential. When a PLI occurs it will immediately impact the performance - whether it is the reduction in voice and data traffic, underutilized costly licensed spectrum or the incremental cost of over-building, the expected ROI and payback period will be more difficult to realize.
Collecting data from the numerous networks where ISCO currently provides conditioning of the RF physical layer, the Company found that interference was present most of the time. In the cases where it caused a PLI the impact degraded capacity by as much as 50%. ISCO analysis tools allow a wireless operator to identify the cause of the PLI and assess the impact, improving the chances of meeting projected ROI.
ROI on Deployed 3G Capital