A solution for poor LTE signal strength?

Mikrotik SXT LTE is an outdoor LTE modem and router, that may provide a far better signal and data rates for fixed installations than an indoor solution.

The best solution for a network uplink connection is fibre, but it is not always an option. Cellular data may deliver more bandwidth than ADSL connections which utilise old phone copper wires. WiFi-router-firewall-LTE combo boxes are gaining popularity for a reason. It is a unit that looks like a WiFi access point but contains a SIM card slot for uplink connection. In Finland these are common even in fixed locations like homes, small offices and rural locations because unlimited cellular data plans have been inexpensive. Too bad that many have been disappointed by the actual data rates they are getting. Concrete or brick buildings, especially with modern thermal glasses, are very good at keeping cellular signal from getting inside the building. In rural area the distance to the cell tower is often too long for good data rates. What can you do?

The most common solution is an external antenna. The problem with that solution is attenuation in the cable. As a rule of thumb the loss is 3dB per meter and an additional 3dB per connection. For a 5 meter (17 feet) antenna cable that totals for 5*3dB+2*3dB or 21dB loss. Since the internal antennas are typically 2dBi you would need to install a 23dBi external antenna just to get equal signal level. Of course you can install a 30dBi antenna for a 7dB net gain, but such high gain antennas have very narrow beams. Narrow beam requires precise alignment. If the antenna is just slightly off or moves with the wind,  you may end up with much worse signal than the internal antenna already provided.

MikroTik SXT LTE

MikroTik SXT LTE (~200€) is an outdoor antenna-LTE modem-router combo. The antenna is in the same box, so the antenna cable is just an inch long. The gain of the antenna is 9dBi (eightfold signal) but is not too difficult to align. The device is connected to the internal network by ethernet cable, that can be 100 meters long without any decrease in data rates. You could place the device on a nearby hilltop, if that’s what is obstructing your connection. The ethernet cable also supplies power, so you don’t need to worry about providing power. Just keep in mind that you need to use weatherproof ethernet cabling and protect it from surges. If the cable is longer than a stub, you need to put surge protectors at both ends.

MikroTik SXT LTE
MikroTik SXT LTE & Ubiquiti surge protector

SXT LTE can receive at 100Mbps and transmit at 50Mbps. The ethernet port is 100Mbps. There are LTE data plans with higher nominal rates, but SXT LTE cannot take advantage of them. The device comes with a 24V power supply and an ethernet adapter. For longer cable runs you should consider upgrading the voltage to 48V to minimize losses. The maximum rate is 57V.


Under a small protective door there is an ethernet port and a place for a legacy SIM card. The door is made of hard plastic, but seems to be fairly weatherproof when closed properly. There is no seal, so putting some sealing tape over the door seams and the ethernet opening should be considered. SXT LTE comes with hardware for mast attachment, but no surge protectors.

MikroTik routers use IP address by default. You can connect to it using a browser or MikroTik’s WinBox application. The default username is admin and password is empty. The only required setting is the PIN code for the SIM card, if it has one. The default is empty. In the browser user interface the path is: top right WebFig > top left Interfaces > select lte1 > enter PIN.

MikroTik WebFig
MikroTik WebFig

The outdoor device doesn’t contain an ethernet switch or a WiFi access point, so you need to provide those in the internal network. Usually they also provide a DHCP server that you need to switch off. A DHCP server provides IP addresses for clients, usually from subnets or If the clients get one of those addresses, they won’t be able to connect to the SXT LTE, because it is in a different subnet. The SXT LTE also runs a DHCP server by default providing addresses from subnet, but it has a two second delay. If there is some other DHCP server in the network, it will serve the clients first. That’s why you need to turn off all other DHCP servers. Typically this is the only configuration change required for the internal network.


LXT LTE only supports LTE bands 3 ja 7 (1800MHz and 2600MHz), there is no support for GPRS or EDGE. The fourth generation LTE network is not ubiquitous, so outside of it you need to find another solution.

The cell operators don’t volunteer their tower locations or info on the frequencies in use. This makes them free to change them without notice, since the customers aren’t promised anything. Unfortunately without tower location antenna alignment becomes a manual process. SXT LTE has five LEDs to show the signal strength, so you can align it at least approximately. Fortunately the 9dBi antenni is not too directional.

Different cell operators may have very different signal strength in any given location. You should have a handful of SIM cards to try when installing. The best signal for another operator may come from a different direction, so you should re-align the antenna for each SIM card.


40 thoughts on “A solution for poor LTE signal strength?”

  1. Hi!
    I’ve been searching some info. guidance for this antenna with little luck.
    I’m from Spain, but I think that you could help anyways.
    I live in aparted home with no access to ADSL or fiber at all, so my only options to have internet access are WiMAX, Satellite and 4G/LTE networks.
    Nowadays I have WiMAX but it’s terrible, so since I have pretty good signal of 4G/LTE in my phone, and when that happens I can surf the web and play videogames pretty well, I came with the idea to buy an LTE antenna like this.
    If I buy this antenna and I have the APN settings of an operator, can I connect to it for free?
    I ask this questions, because as I can see the microSIM slots are for “backup”, but if you cannot connect for free, then I don’t know how the operator how can charge you your data usage of their network.
    If I don’t want to setup the APN settings, can I connect a SIM card and it will be Plug&Play or almost Plug&Play?
    Maybe I did stupid questions, but I don’t want to spend ~100€ for nothing.

    1. You will always need a SIM card with a data plan to connect to an operator’s network. In the new SXT LTE Kit there are two SIM card slots where the second one can be used for backup. You could use another operator’s SIM if the first one goes down.

      No, you won’t be able to connect for “free”. You need to pay to the operator to use their network. Perhaps you can get a secondary SIM card to the one in your phone? At least here in Finland that would save you some money. The secondary card will have the same phone number but of course the SXT LTE won’t ever answer your calls.

      Typically the SIM card contains all the necessary settings so you won’t have to configure anything except for the PIN code (if your SIM has it). It is virtually Plug’n’Play.

      The new SXT LTE Kit will replace the old SXT LTE. The new model has two SIM slots, two Ethernet ports and supports all possible cellular data connections. The old one only did LTE on bands 3 and 7, which are typically used in urban environment. Just make certain you get the new one and you’ll be fine.

      1. Wow! That was a fast response!
        Thank you!
        So it’s a must to have a SIM card, ok.
        I wasn’t sure that this let it you have free connection, but I asked anyways to clarify it.
        Ok, so if I buy this, and have a new number (it would be only for the SXT) I would remove the PIN using it first from my phone, so in the SXT it would be fully Plug&Play for the SIM part.
        But I have new questions.
        This device has some management utilities like QoS for example?
        Since it is made by Mikrotik and they have the RouterOS, I suspect that it will have typical routing and network management, but I want to be sure.
        If not my idea was to connect this antenna to a PC with two network interfaces and use that PC like a router, one interface connected to the SXT and the other to a switch, and then make QoS, NAT and this kind of things on that PC.
        And since the new SXT (is the only that I can find in Spain) has 2 SIMs, is the second only for backup? Or it can be used to do load balancing?
        It would be very interesting, so I could have two different data plans, one for web surfing and other typical services like FTP, IMAP and STMP, etc. and the other one for gaming.
        Thanks very very much again.

        1. Yes, SXT LTE has full RouterOS. However, you cannot access QoS on the LTE side, it is the operator’s network. You could create your own queues on the local network before the LTE to shape traffic.

          No, you don’t need any other router. SXT LTE has a firewall and can do NAT by itself.

          No, SXT LTE has only one LTE radio so it can connect to only one LTE network at a time. The other SIM is for failover only. You can’t use it while the other is in use.

  2. Hello,
    Is it possible to have the Mikrotik SXT LTE kit {RBSXTR&R11e-LTE} behave just like a modem ie
    WAN-Mikrotik SXT LTE kit-another router issuing LAN ip addresses by “turn off all other DHCP servers” as you say above, or something additional ?
    Thanks in advance,

    1. If you have the new model with dual Ethernet-ports and dual SIM slots you can set up SXT LTE Kit as a L2 bridge. It is known as passthrough mode in MikroTik parlance. You have to do it with command line, there is no GUI for it. See Passthrough Example

      If you only want to turn off the DHCP server you can do that in either model. In that case SXT LTE will still function as a NAT and route traffic.

  3. Hi Petri,
    Many thanks for writing such a detailed review of SXT-LTE, i dont think there is anyone other than you who has done it.
    I have also got the SXT-LTE (new model), yet to install it. However would like to understand is it fairly simple to connect a ethernet router to extend the internet over WIFI? Appreciate if you provide your guidance on it.
    Many thanks.

    1. Yes. However, you don’t need a router since the SXT-LTE will do routing, NAT and firewalling. You could just use bridged Wi-Fi access points. If you just connect a router’s uplink/Wan port to the SXT-LTE it will work. There will be double NATting, but for ordinary use it won’t do any harm.

  4. Thankyou Very much Petri. Your responses are very very insightful.

  5. Hi
    Would the MikroTik SXT LTE do the same job as an Archer Wireless Dual Band 4G LTE Router that I currently have.

    1. Quite close. SXT LTE doesn’t have an Wi-Fi access point built in. The benefit would be that SXT LTE has a directional antenna and is weatherproof. You should place SXT LTE outside, as high as possible and direct it to the nearest cell tower. You’d get a lot better signal than with an indoor omnidirectional device like Archer.

  6. Hi
    I was surprised how easy it was to get configured, just put in the APN, update it and it connected to EE in the UK. The signal strength LEDS do nothing, how do I get them running? Is there anything else that I should configure?
    Best regards


    1. I presume you have the new model with two SIM slots? The first firmware versions didn’t support the LEDs. Upgrading RouterOS should do the trick.

    2. Hi

      I can’t get the SXT LTE to work on an EE sim even after setting up the APN yet I have another SXT LTE from another company that came pre-configured which is password protected and it works straight away any help would be greatly appreciated I assume there is another setting I need to change to get it to work outside the LTE settings?

      Many Thanks

      1. Your best source for help would be MikroTik Forums either General of Wireless Networking. You should try to figure out whether the problem is connecting to the LTE network or some local issue. Do you get an IP address from the LTE network? Have you tried some other SIM card? These would be good clues to include in your post. By providing more information you increase your odds to get useful help.

  7. In theory great device, in practice – keeps disconnecting every couple of minutes in our case. The only way back is to reboot the device. We made it reboot automatically every time the connection is gone for over 45 seconds, so as the device goes down every few minutes, it makes it quite useless. Apparently there is a bug in the modem driver, which has not been fixed for the last two years.

    If you have any ideas about how to make the device more stable, I would really appreciate it.

    1. I wrote about the original SXT-LTE and I have deployed like a dozen of them and they all work fine AFAIK. I have deployed a couple of the later SXT-LTE Kit (with dual Ethernet ports) and I haven’t heard any complaints. I believe they run some old RouterOS, I don’t think their owners have upgraded them since I left.

      Could it be that you have a faulty unit? I haven’t followed the topic on MikroTik forum. Is this a known problem. They way you write makes me think so. In that case I can’t help. If this is the case then I’m just sorry, because the product is good. Too bad if the implementation sucks.

  8. Hello, i have two issues.
    I’ve tried to configure two different APNs, both associated with the LTE interface but the LTE interface does not become UP. Do you know if the R11e-LTE supports many different APN’s ?
    I want to simulate a failover between SIMA and B. I configured default APN and i put the SIM in slot B and from System Routerboard i have selected SIM A. I’ve applied the script presented here https://wiki.mikrotik.com/wiki/Dual_SIM_Application in order to force the modem to move traffic from SIM A to B. It doesn’t work.
    Does anyone know how it is working failover between SIM;s?

    1. Have you tried MikroTik Forums? There you’d get far larger audience and more combined experience. I have set these up as a failover for a cable connection, so I haven’t needed multiple SIMs. In some occasions you’d need to realign the device if the other cell operator is using some other tower.

  9. Hi there,

    Thanks for the info to date. My house, in a rural location in Ireland is approximately 3.5km from the nearest tower and we receive around 1MB download speed. Would the Mikrotik SXT LTE work in this situation?

    1. If you can receive 1Mbps indoors with cell phones or such, I would assume using a directional antenna higher up and placed outside would improve the reception. If the telco is the limiting factor (intentionally or unintentionally) then it won’t help. OTOH, SXT LTE is inexpensive enough to just try out. Just remember to place an Ethernet surge protector before you bring the cable indoors and ground the protector properly. (At least Ubiquiti sells an inexpensive protector but any brand will do.) Use outdoor cabling, too. Ordinary cables don’t like UV or outdoor temperatures.

  10. Hello Petri,

    Your explanation is lucid and has cleared a lot of doubts.Which would be a better choice between the SXT LTE Kit and the SXT LTE 6 kit .I am located in a rural area in India and was using Wimax with the CPE mounted on a pole.The ethernet cable length is around 15 -20 metres between the antenna and my workspace.Will there be any loss of signal .Besides we are located at a height on a hill so it is prone to thunder.Would I need a surge protector at both the ends…Thank You For Your Support.

    1. A 20 meter Ethernet run is not a problem, it will run up to 100 meters (but can’t feed PoE power that far). If your local carrier supports the new features that come with SXT LTE 6 Kit then go for it. I haven’t had a change to install one yet.

      Yes, do install a surge protector at the point where you run the cable inside and ground it well. It is useless unless well grounded. I have used Ubiquiti’s surge protectors as they are reasonably priced around here, YMMV.

      1. Thank you for the prompt revert Petri.I”ll go with your advice.

        Just a single question .How well does the Mikrotik LDF LTE 6 Kit or the LHG LTE 6 Kit compare to this.Except Higher Gain due to a dish antenna are there any other specific advantages with respect to speed and operability

        1. LHG includes a bigger antenna with higher gain. It can connect to a further AP, but won’t necessarily improve your speed. The speed depends on your carrier. Higher gain antennas are trickier to aim.
          LDF on the other hand doesn’t include an antenna at all. You should install it in some other dish antenna, like an old satellite TV antenna. Then you will get even more gain.

  11. Hello Petri
    Great review, thanks. Please can you tell me if it will be straight forward to connect the SXT LTE6 to a Ubiquiti Edgerouter X, presumably the SXT LTE6 will need to be in bridge or passthrough mode? Do you know of any easy to follow guide for this type of setup? Thanks

    1. Yes, it will be easy to setup. SXT LTE will work as a layer 3 router doing network address translation (NAT). Cell operators don’t want to bridge any traffic towards their network (bridges work both ways). You can add another NAT layer in EX, for most purposes it won’t do any harm. Or you can use EX as a router only. The default IP address for SXT LTE is so most often you don’t have to worry about it.

      There is a way to force bridge mode on some MikroTik LTE cards, but it is not supported in the user interface. It is not recommended.

  12. Salut!
    Je suis vraiment content de l’éclaircissement dans l’exposé ainsi que dans les commentaires mais je voudrais connaître le niveau de sécurité de connexion entre le kit SXT LTE et le réseau UMTS?
    Merci une fois de plus pour l’exposé?

    1. The connection to the mobile network is the that as your phone uses. SXT LTE acts as a stationary cell phone, using the same LTE security mechanisms.

  13. Interesting review and it has helped me me halfway across the world and more than three years later. Thank you!

    For those outside Europe, please note that even today Mikrotik’s SXT LTE models have either Europe- or U.S.-centered modems. That means the frequency bands they can connect to might not be used in your area. In my specific case, in Brazil, the regular (non-U.S.) version covers bands 3 and 7, commonly used here for LTE service, but not band 28 (700 MHz-ish spectrum formerly used for analog TV) that’s being rolled out for rural coverage. And this is more of an edge-of-network-coverage device than a city/urban one. In a city you’re usually better off with an omnidirectional antenna than with a directional device like this.

    Another limitation of the SXT line is the fact that only includes 10/100 ethernet ports. This isn’t much of a problem with the category 3 and 4 modems, but may be the limiting factor on a cat6 device. To be sure, for the price difference, I’d still get the cat6 model because in my experience cat6 devices will net you 60mbps and above where a cat4 would only show 15-20, thanks to carrier aggregation. Again YMMV depending on where you are in the world (those bands again) and how your carrier’s network is set up.

    As for my particular setup, in the hope that it might be of interest or use to anyone out there, I opted for the SXT R model without an included LTE modem because I wanted to install my own. I chose a Quectel EP06E which has all the bands I need (3, 7 & 28) and is fully supported by the device, after a bit of a setup. Google for instructions, it isn’t hard. I tried it at home first (urban area, right next door to a Band 7 complementary cell site) and predictably it maxed out at 95-101 Mbps on speedtest.net. In comparison my home LTE router, a TP-Link MR600, also cat6, can get to 200 Mbps peaks on its little bunny ear antennas inside the house, and a solid 220 average on a Poynting external omni antenna. But where the Mikrotik shines is out in the middle of nowhere, which was its intended purpose in my case. Installed on top of a 5m pole on a hilltop 6km from the nearest tower, the little modem also maxed out its ethernet ports at times, and provided a solid 80Mbps average. Compare this with an average of 55Mbps that I was getting from a Huawei B535 inside a weatherproof junction box at the same spot (though not as high on the pole) – and the Huawei has 4 gigabit ports. Either modem/router fed a TP-Link AV1300 powerline adapter that took the internet to a house 230m away, at the bottom of a valley. In signal terms, I got a solid 2-3db improvement in RSRP and my RSRQ stayed at or below -8db the whole time, where the Huawei (granted, on a pair of bunny ears) would fluctuate between -11 and -8 when in a good mood. A definite improvement. Please note all the speed tests I mention were done at the pole site, not at the house.

    The little SXT R has since been replaced by another Mikrotik, the LHGG modem/router. The LHGG is only available with an included cat6 modem which I replaced with a Quectel EM12G cat 12 module (that this requires an M.2 key E to mini PCIE adapter). This setup nets me 150+ Mbps at the same spot, but I reckon that has more to do with the Gigabit port on the LHGG than the higher gain antenna or newer modem as I’m probably reaching the limits of my network this far from the tower and without band 7 (at this distance we’ve only ever “seen” band 3 and band 28 signals). And in any case I’m severely limited by the powerline run. It links the two TP-Link adapters point to point with no interruptions, but that still is a 235m run of 4mm sq. cable at 127V. Well, 121V at the other end! So again, all my measurements are done at the pole, not at the house. At the house I went from 50 to 70 to 100-ish Mbps from the Huawei to SXT to the larger Mikrotik. I’m happy with the setup now and it’ll be a while before they bring 5G to that sparsely populated part of the country. When they do, I think I’ll run a fibre link from the pole to the house and replace the modem module.

    One final note, if you made this far: please heed Petri’s advice and install surge protectors. What’s missing from my long post til now is why I replaced the SXT – it wasn’t for the performance but rather because it got fried! Thunderstorms are common in tropical climates like the one we luckily have in this part of Brazil, and lightning strikes are even more common there (Minas Gerais, large iron deposits and rainy summers). Poor SXT didn’t stand a chance, even with everything grounded – you DO need the third, ground conductor for higher powerline network speed. Install surge protection, prefer a cat6 modem that supports you local LTE frequencies, keep in mind the limited 10/100 ethernet and you’ll be happy with the Mikrotik SXT LTE. Oh, it looks cute too. Much better than the LHGG.

    Hope this helps anyone!

    1. Thank you for your detailed comment! I hope someone will find it useful.

      MikroTik is currently selling SXT LTE Kit, which supports LTE bands 1, 2, 3, 7, 8, 20, 38 and 40 (at least the int’l version), but not 28. The Ethernet ports are still 10/100 Mbps, though. There are also new CAT6 products, but most of them still have slow Ethernet ports. LHGG LTE6 Kit has gigabit Ethernet.

      The surge protectors won’t probably save your SXT. The protectors are meant to prevent the current flowing inside your house. The SXT should be considered expendable. If you have frequent thunderstorms then you should consider keeping a spare at hand. Thunderstorms are just too powerful.

      1. Bonsoir je viens d’acheter un KIT Mikrotik SXT LTE6, j’ai essayé de configurer mais sans résultats et j’ai rencontré un autre problème je n’arrive plus à accéder à son interface ni avec ni avec Winbox. Sachant que j’habite au Maroc Vous pouvez m’aider SVP

        1. In Winbox you should see the device by its MAC address and make a L2 connection. If that doesn’t work out, you should reset the device: Unplug the device, press and hold the reset button, apply power, keep the button pressed until the LED start flashing. After reset the device should again show up as

  14. Sir it was enlightening ! i got installed SXT XTR R11e-LTE. it worked fine for 2 months. now it doesn’t show LTE signal strength and doesn’t connect. Can it be due to change in band frequencies of telecom service provider ? as i dont see any damage in unit. and if its so the do i need to change band configuration ?

    1. Check the SIM card. In Finland (w/ harsh winters) SIM cards last outdoors for a year or so. You can try to clean the contact areas with a pencil eraser (or if you can find a coarser pen eraser, even better). Some SIM cards are quite thin. Apply some tape on the backside to make the SIM thicker and thus press harder on the contacts.

      OTOH, some electronic devices have some manufacturing fault and will break within the first three months (typically). That’s what the warranty is for. But check the SIM card first!

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