Correct Antenna for Long Distance

[ToddRihn]

We are currently supporting a tennis complex which has outlining courts.  The coverage to the outlining courts is very weak and the customer would like to see better coverage.  One set of courts are about 100' from the externally mounted MR74.  The other set of courts are close to 350' from external AP.  We are hoping to get the range using antennas instead of deploying a repeater.  Can I get some idea on what type of antenna would be best for the two scenarios.

Thank you,

Todd

[kYutobi]

Dual-Band patch antenna:

https://meraki.cisco.com/products/wireless/antennas

[ToddRihn]

Appreciate the information

[GIdenJoe · Accepted solution]

Hmm if using outdoor antennas please use the sector antennas instead.  MA-ANT-27.

They provide greater gain (up to 12 dBi) and a nice 60 degree beamwidth.
The patch does improve the range a bit but it's nowhere near the sector antenna.

Using an online FSPL calculator I found the following

350 feet = 106 meters
Channel 100 = 5500 MHz

If using a Tx power of 14 dBm and counting max gain 12dB you have a path loss of 87.7.  So if you use a 0 dBi gain on the receiver you will have -61.7 dBm at 106 meters.  Since the beamwidth is calculated from -3 to -3 points you'll have -61.7 -3 = -64.7 dBm at the outer edge of the beam at 106 meters which is still well within the -67 typical receive needs.  That should give you a nice 30 dB SNR and a nice MCS of 7 to 9 depending on your channel bandwidth.

[MerakiDave]

@ToddRihn both of the previous answers are correct, you would likely be fine with either a pair of ANT-25 dual band patch antennas or ANT-27 dual-band sector antennas.  At 100+ meters / 300+ feet and if you're expecting mostly smartphones (typically 1x1) probably the sector to better focus the signal and have better data rates.  It depends on the overall coverage area that will determine if you go patch vs sector and how to best aim the antennas, or if a 2nd AP is going to be required.

[RobustMeraki]

@GIdenJoe , @MerakiDave 

I am in a similar situation where the customer wants to monitor his employee parkplace in open space with 4 Meraki 72 Outdoor cameras but does not have wifi in that area. For that Purpose I offered the customer an Access Point MR76 in the parkplace and a gateway for wifi. The cameras will also be uploading video data via cloud archive.

The problem is that the customer due to some reason does not want wifi via LTE in their company, so they want a solution that they can extend their office internet to the parkplace location. In this situation I am thinking to offer them one more MR76 that will be installed on the building with sector antenna pointing to the pole in parkplace area where another MR76 is installed.

My question is how long is the range of the sector antenna in meters that it can support extending a strong signal to another access point which is wirelessly supporting 4 Meraki cameras that are also uploading video to the cloud archive.

[GIdenJoe]

In what regulatory area are you? FCC, ETSI?
If you want to do a sort of point to point connection you'll need to know how much you can transmit.

Because AP to AP can be higher powered than AP client.  But it depends how much you can transmit in your area.

[RobustMeraki]

Hi @GIdenJoe 

we are in the ETSI area. Could you suggest a solution for such an area?

[GIdenJoe]

Well I did a fun calculation and access point to access point traffic can reach very high distances with the MA-ANT-27 if you aim them well, have not much interference and can use both spatial streams (which is not easy outdoors).  Since AP to AP signals can be much higher than AP to client the distances really can be large.

Free space path loss calculation
MR76 bridge

Goal throughput: +/- 200 Mbps
Possible matching MCS values at 2x2:2 with channel width:

40 MHz MCS 6 = 270 PHY @ 3/4 = 202.5 Mbps throughput -> necessary RSSI -74 dBm @ 5 GHz
80 MHz MCS 4 = 390 PHY @ 3/4 = 292.5 Mbps throughput -> necessary RSSI -77 dBm @ 5 GHz

MR76 + MA-ANT-27 gain 12 dBi @ 5 GHz
ETSI EIRP 5 GHz (ch 100 = 30 dBm)

Situation 1: 5 GHz channel 100@40 (HE40) (= free channels needed 100,104)

Tx Power: 18 dBm
Antenna gain: 12 dBi
EIRP = 30 dBm

Minimum needed power at antenna receiver: -86 dBm
Free space path loss allowance (including antena gains): 116 dB
Free space path loss allowance (excluding antena gains): 92 dB
Distance = 2.7 km

Situation 2: 5 GHz channel 100@80 (HE80) (= free channels needed 100,104,108,112)

Tx Power: 18 dBm
Antenna gain: 12 dBi
EIRP = 30 dBm

Minimum needed power at antenna receiver: -89 dBm
Free space path loss allowance (including antena gains): 119 dBm
Free space path loss allowance (excluding antena gains): 95 dB
Distance = 3.8 km

I based the minimum needed RSSI values on the MR76 datasheet receive sensitivity values.

If you need a calculation with 1x1 which is more common outdoor if you cannot have any reflections I can do that one too but I'm out of time now 😉

[RobustMeraki]

Thank you for taking out the time to do this for me. Appreciate your support. These Infos schould definitely help the customer in taking a decision.