Excel sheet to estimate range for Indoor and Outdoor

Hi Richard,

Thanks for sharing this.

Regards,
Raghavendra

Thank you for your upload.

Thanks a lot Richard. This is very helpful.

 

Regards,

Dham

Hi Richard,

Thanks for sharing.

Regards,
Geet

This is a great tool. Thanks for sharing.
Could you elaborate a little the difference between Chipset sensitivity and the Practical sensitivity levels? Is this due to the difference in PER, as in datasheets it tends to be specified as 8% or 10% (depending on data rate) but in the related document you mention 1%?

Hi,

The chipset sensitivity is normally specified as BER or PER. The 1% is a Bit Error Rate which is normally used for many chips to find the sensitivity level. i.e. the signal strength reduced to a level were the BER increases to 1 %.

As an example, let's presume the sensitivity level to -120 dBm. Most radio links require a robust link and with minimum amount of data loss. For all radio systems: due to multi-path propagation, the RSSI level can vary 15 dB within a square meter so this basically means than between -105 dBm and -120 dBm; data loss can occur. With a 20 dB guard band; the 15 dB variation will never be seen in the system. So when not using any antenna diversity, then the practical sensitivity limit is the actual sensitivity limit with a reduction of 20 dB to take into account the multi path propagation effects (15 dB). I used 20 dB but 15 dB could of been used as well.

When using antenna diversity, the 20 dB guard band can be reduced to 10 dB. The actual level of guard band is up to each engineer to decide themselves or application since lower or higher levels of guard band can be used. In the excel sheet, The guard band can be set to 20 dB (no ant diversity), 10 dB (ant diversity) or 0 dB.

So the practical sensitivity limit is the actual sensitivity level with an added guard band of 20 dB, 10 dB or 0 dB.

Regards, Richard

Got it. Many thanks

Hi Richard,

Can you please tell me which among the CC3xxxx in the drop down is specifically for CC3200?

 

Thanks in advance.

Pradnya 

Hi,

The CC3xxx sensitivity values are based upon the CC3200 datasheet (page 31).

Regards, Richard

Hi Richard,

When I use this tool to calculate the expected range I get different results depending on what I set for "Maximum scaling of graph". For example, with the scaling set to 300m the range expectation is 133m but with it set to 2000m I get a range of 108m with no other parameter changes. Why is this?

Can you provide a screen shot ?

Here are the screen shots:

Hi,

The ground model vertical polarisation plots are around the vicinity of the sensitivity limit - the guard band. On one scaling, the sensitivity point crossing the limit is taken at the second point and on the other the first point. The reason for the difference in the results.

The realistic range expectation should be lower than the friis calculation so I would keep to the 108 m result instead.

Regards, Richard

Richard - which antenna choice would be right for your CC3x00MOD products?

Hi,

If you are using the kit whip antennas, then use an antenna with a gain of 2.1 dBi. If you are using the small chip antennas onboard, then use 0 dBi.

Regards,

   Richard