Estimate the Range of Your Wireless Application

by Administrator llooper ‎08-17-2017 07:58 AM - edited ‎08-18-2017 09:31 AM

Silicon Labs provides RF range calculators for customers to help estimate the actual range of their wireless applications. Simple RF Range Calculator is available to download here.

 

Basics

RF range depends on the following parameters

  • Conducted TX output power, the power driven to the antenna input [dBm]
  • TX antenna gain [dBi]
  • Conducted receiver sensitivity [dBm]
  • RX antenna gain [dBi]
  • Frequency [MHz]

Propagation factor, depends on the environment

  • n = 2 for ideal free space propagation
  • n = 2.8-3 for typical line of sight propagation
  • n = 4 for outdoor wet soil
  • For multi-path propagation (indoor or outdoor with several buildings/objects) “n” can vary between 4 and 6 based on the actual environment

 

Simple RF Range Calculator

This simple RF range calculator is for those customers who don’t want to deal with difficult RF questions just simply would like to get fast and reasonable results for both outdoor and indoor environments.

 

Key Features:

  • Fast and simple while accurate
  • Built in propagation factors, based on field measurements
  • Antenna height fixed to 1 to 1.2 meters
  • Supports all the unlicensed bands and custom frequency channels as well

 

Usage:

Simple RF Range Calculator provides fast and accurate result as the customer selected the frequency band and set TX and RX parameters:

RC1 copy.png

Simple RF Range Calculator with frequency band selection

 

Frequency bands and custom frequency channels also can be selected:

RC2 copy.png

Simple RF Range Calculator with custom frequency channel set up

 

 

TX Output Power and RX Sensitivity need to set up based on the radio device’s actual link parameters based on the data sheet. If the exact antenna parameters are unknown notes at the right side can help to determine the closest values:

RC3 copy.png

 Simple RF Range Calculator with notes

 

Comments
by McDiver
on ‎09-13-2017 11:18 AM

I always thought 6dB was the equivalent of 2x the range when dealing with RF (volume is different). 

Spreadsheet seems to indicate 12dB doubles the range. Can you clarify why you see a difference?

 

Example: 

2440 freq at 0dBm TX + -93dBm RX + 0 TX/RX gain == 228.5m outside, 40m inside (93 dBm link budget)

2440 freq at 6dBm TX + -93dBm RX + 6 TX/RX gain == 322.8m outside, 59m inside (99 dBm link budget)

2440 freq at 6dBm TX + -93dBm RX + 12 TX/RX gain == 456m outside, 86m inside (105 dBm link budget)

 

Thanks!

 

by McDiver
on ‎09-13-2017 11:20 AM

CORRECTED (same issue, but made copy/paste error)

 

I always thought 6dB was the equivalent of 2x the range when dealing with RF (volume is different). 

Spreadsheet seems to indicate 12dB doubles the range. Can you clarify why you see a difference?

 

Example: 

2440 freq at 0dBm TX + -93dBm RX + 0 TX/RX gain == 228.5m outside, 40m inside (93 dBm link budget)

2440 freq at 6dBm TX + -93dBm RX + 0 TX/RX gain == 322.8m outside, 59m inside (99 dBm link budget)

2440 freq at 12dBm TX + -93dBm RX + 0 TX/RX gain == 456m outside, 86m inside (105 dBm link budget)

 

Thanks,

Michael

by <a href="http://community.silabs.com/t5/Welcome-and-Announcements/Community-Ranking-System-and-Recognition-Program/m-p/140490#U140490"><font color="#000000"><font size="2">Hero Employee</font></font> </a> dasimon
on ‎09-14-2017 10:12 AM

Hi Michael,

 

The following Knowledge Base Article might clarify your question:

http://community.silabs.com/t5/Proprietary-Knowledge-Base/Range-improvement-calculation-for-a-given-...

 

The 6dB link budget improvement is equivalent of 2x range when the propagation factor is 2, but actually this never happens on the field. In real environments, the propagation factor is 2.8-3.2 line of sight, and even higher when there is multipath propagation.

 

Daniel