External LTE antenna for 4G router

[joencurran91]

Hi guys

Just wondering if anyone has any experience with attaching an outdoor antenna to a 4G router to increase speed?

I'm currently pulling 30-40mbps and a ping of 20-30ms but out of curiosity I ran a speed test in a town near me and got a download of 115mbps which really surprised me (I'll leave a link to the pic). I'm not expecting speeds anything like that as my house is quite rural but wondering if it would be beneficial in investing in an external antenna.

Sorry for sounding like a complete noob

 

[joencurran91]

Speed Test https://imgur.com/a/8brpi

 

[bill001g]

The first problem is the router would need connections for external cell antenna...or you would have to hope you could disconnect the internal antenna and use that connector on the main board.

You also likely need 2 antenna mounted 90 degrees off each other. LTE uses Mimo to get those high speeds.

Next you need antenna for the proper frequencies. You will have to do some research to find what is being used. It is not consistent even within a single provider, they use different frequencies on different cell towers. This is because of how they originally obtained the frequencies and all the merging of cell companies over the years.

Most times you use yaggi antenna for the frequencies you need but they do make some triangle shaped antenna that cover a large range of cell frequencies.

You also need to keep the antenna leads as short as you can. Every foot of cable drops your signals quite a bit at the frequencies used. You need to use the best cable you can afford. LMR600 or better but it get expensive. This is why you don't see those big cable going up cell towers anymore, they mount the radios inside the antenna now that the electronics is small.

After all this it is in the grey area of being legal to do this. Cell companies operate on licensed frequencies so technically your cell phone needs a license to use it. You will see on many antenna marketed for mobile broadband use the disclaimer...."use must be approved by provider". This is because technically the cell provider must ensure that no device in outputting more power than their license allows. The providers also dynamically adjust the output power of any device connected to their network so they use minimum output power that works. This is why your cell phone battery dies quicker in a weak signal area than a strong one even when it is not being used.