Multiple External Antennas for Multiple Locations

Hi! I’m new to Pepwave and new to the forums. I have been reading posts and articles here, as well as watching Peplink’s Youtube channel. I am with a Live Events AV company in the Eastern USA, and we have a MAX-HD4 LTEA-W-T. Right now we have a single SIM card in each modem, 2 from AT&T and 2 from Verizon. We also have a FusionHub instance and a SpeedFusion VPN set up between the HD4 and the FusionHub instance.

Our use for the HD4 will be to provide a solid internet connection for video streaming (primarily outbound) when the client needs a more robust connection. As such, all of the Cell, WAN, and WiFi connections are set to the same priority in SpeedFusion. Our location will vary from event to event, as well as our access to the outdoors (some convention center ballrooms are pretty far from outside access). I used the HD4 at an event this week and was pleased with the results. The location had internet with 10 Gbps upload, and with the HD4 we had 16-20 Gbps up during the event.

So, with that context, I have questions about antennas.

  1. Will an external antenna always give me a better signal? I am often surprised at how poor the RSRP number is as I move the HD4 around at a site. Will an Omnidirectional MIMO 2x2 antenna always improve my signal? I am still trying to understand how the RSRQ and SINR numbers are also affected by location and the antenna.
  2. Is there a situation where I would use some paddles on the unit and some external?
    3.If I do use external antennas, I am looking at 4 or 8 antennas. (Four MIMO 2x2 being the better idea). I understand now that they could cause interference with each other, but in the interest of convenience, equipment, and cost, what is the minimum distance I can mount them in relation to each other for 4G LTE bands? Would omnidirectional domes need to be mounted vertically from each other for maximum effectiveness? Or would arranging them horizontally be OK?

Thank you for reading this far. I appreciate any input, even if it is a link to where there is already a good answer.

Listening,
Aaron

Welcome!

It will always give you more signal. Is that always better? Well you hit the nail on the head when you then ask about signal to noise ratios an Reference signal receive quality.

Sure - when you have physical restrictions which limit where you can put external antennas, and those instances where time is very short.

The current trend is very much MIMO antenna arrays in a single antenna product. Personally on a HD4 if I was after omni antennas, I would be looking at four of the PUMA 221’s Peplink Puma Series Cellular Antenna | 5G Ready and IP67 Rated

I’d use two for wifi AP and WIFI WAN and pick one for the GPS when needed.

However. From experience, when you’re doing Live Events you tend to have a lot of people around you and those people tend to be using their phones a lot. So my preference is always to use directional antenna solutions when possible.

The idea is to deploy directional antennas that can talk to more distant towers when possible, or omni antennas when physical challenges arise. For example at a wedding in a barn in the countryside, directional antennas pointing to the nearest and furthest away cell towers will give the best results.

On the other hand, for an exhibition in a London hotel I would ask for a room on the other side of the hotel from the exhibition hall and install my HD4 there with Omnis (and sometimes just paddle antennas) and cable back through their structured cabling.

High gain directional antennas in the countryside make sense since there are fewer cell towers, often with good line of sight and so pointing an antenna and picking up one further away is feasible. Because of low RF density signal received tends to be clean too with a low RF noise floor.

In London however cell towers are everywhere, its built up and causes RF reflections, so a high gain directional antenna and even a mid gain omni will pick up RF noise from all over the place.

The more noise you have, the less usable quality bandwidth you can use.

I have done London installs where I have intentionally put MAX routers with paddle antennas behind RF blocking infrastructure to lower the noise floor (means only the strongest nearest cell tower signal can reach me). Although that is an extreme situation to be in.

A more recent approach to consider is to use integrated routers and antennas like the HD Dome series. Peter west has been championing this recently. With custom stands that hold 8 CAT 18 domes.

This lets you position the stands up to 100M away from your Peplink router (a WAN per dome is needed and Peter loves the SDX Pro for this) as they are powered over POE and so you can put the domes where the signal is and your router where the user devices are.

If you are working within a budget, get two omni antennas and two directional antennas. Peplink have a directional in the works but I don’t think you can buy it yet so look at the Poynting Xpol2 for now for that.

Those combined with some speaker stands (or mic stands at a push) so you can elevate them over the heads of the RF blocking humans in the vicinity on 5M / 15ft cables so you can run the cable through a window will be a good place to start.

Peplink is doing a webinar on the Puma Antennas on the 8th July you might find interesting too https://bit.ly/3xasDPp

This post is more than long enough, but before I sign off: its very easy to worry about lateral separation and antenna phase and VSWR and cable length and all the other stuff.

Don’t since so much is out of your control on live events anyway. Instead give yourself as much time as possible. Connect a directional and omni antenna to the modems for each provider and then run speed-tests on each cellular connection. If the modem with the directional is better use directional antennas. If its worse, rotate the antenna by 90 degrees and run the speedtest again, then repeat until you’ve done 360 degrees. Then use the antenna that works best in that situation and focus on the other stuff you need to do.

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Martin, thanks for answering my questions as well as your recommendations. It was helpful to read through how you might think through different situations. Your conclusion was spot on. As a part of a small AV company, I do have other things to do at each event. Your advice about what things matter most and keeping a simple workflow will be helpful.

With 2 omni antennas, can I place them side-by-side like Peter West’s integrated domes? or would they be better off vertically spaced to place them in the cancellation zone of each other?

Same question with the directional antennas? At what distance will they start interfering with each other?

The right technical answer is likely 3 x the wavelength in use as the space between mimo antennas in both directions - horizontally and vertically. There is a handy wavelength chart here so typically we’d see LTE frequencies range from 600Mhz (WL of 50cm) up to 2.6Ghz (WL of ~8.6cm).

Therefore, if you are in the countryside and using the lower frequencies because you are further from the tower, spreading your antennas 1.5m apart vertically and horizontally is arguably the right thing to do, and if you are in the city and using the 2.6Ghz mainly then at least ~26cm separation would be best.

In practice though you should spread the antennas as far apart as possible, and when not possible don’t worry about it.

I always try and keep at least 50cm between MIMO antennas when installing them on a vehicle roof or in a mobile deployment, and a meter or more when on stands if possible.

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