Wireless communications always are a bit tricky because radio waves--even when carrying digital signals--are analog processes. Conditions in the physical environment--presence of nearby metal, human body parts, walls, trees and other obstructions directly affect signal propagation and signal strength.
A study by Professor Gert Frølund Pedersen of Aalborg University shows that downlink signals can easily vary by 10 decibels between various phone models and makes. Keep in mind that a 3 dB difference in signal strength means signal is cut by 50 percent. Each successive 3 dB drop means another 50 percent drop in signal strength.
Roughly, that means a signal intended to reach a receiver at any set level can be reduced to about 12.5 percent, at the same exact location, using some devices, and varies also when a device is used by different people, using the same device, at the same location.
That is because people hold the phones differently, and that affects signal reception, depending on placement of antennae in each device.
One clear conclusion of the study is that phones vary by an order of magnitude in terms of signal reception. The antennas inside the best phones are up to ten times better than those in the worst phones.
This study was performed in Denmark in autumn 2012. The four Danish network operators (TDC, Telenor, Telia and 3) were asked to provide a list of their top 10 selling phones from the past year.
On the basis of the four lists, nine phones were selected for testing on the GSM 900, GSM 1800, UMTS 900 and UMTS 2100 air interfaces.
The point is that mobile networks are not the only reasons why mobile customers encounter call drop, signal quality and other signal-strength-related issues.
Developments in wireless access platforms that will affect business models and signal strength will be part of the discussion at the Spectrum Futures conference. Here’s a fact sheet and Spectrum Futures schedule.
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