Where to Put Your Modem: Placement Tips for Stronger Cellular Signal

The modem arrived. You set it on the desk in the back bedroom, next to the filing cabinet, under the metal shelf, and the internet is fine but not great.

Move it. Placement is the single biggest factor you control in how a cellular modem performs, and most people never move it after the first spot they tried. This guide covers how signal actually behaves inside a building, where the modem wants to live in a house, an RV, and a job trailer, and a ten minute test that finds the best spot without any tools.

Two signals, two jobs

A cellular modem handles two different links at once, and confusing them is where most troubleshooting goes wrong.

Link one: tower to modem. Cellular signal travels from the nearest tower to the modem. This is affected by distance, terrain, walls, windows, and what the modem is sitting next to. Placement is all about this link.

Link two: modem to your devices. The modem creates a wifi network, and your laptop, phone, and TV connect to it. This is affected by the same things any home wifi is affected by: distance and walls between the modem and your devices.

The ideal spot is good for both. When the two conflict, prioritize link one. A modem in a window with strong cellular signal will serve the house better than a modem in the center of the house with weak cellular signal, even if the wifi reach is slightly shorter.

What blocks cellular signal

Not all walls are equal. In rough order from worst to best for signal:

• Metal. Metal roofs, metal siding, steel framing, foil backed insulation, and metal shelving. Metal reflects signal. It is the reason RVs and job trailers are tricky.
• Concrete and stone. Thick, dense, and full of rebar in commercial buildings. Basements are surrounded by it.
• Brick. Better than concrete, worse than wood.
• Low emissivity window glass. Some energy efficient windows have a metallic coating that blocks signal. Older glass is better for this one thing.
• Wood and drywall. Mostly transparent to signal. Interior walls are usually fine.
• Plain glass. The best. Windows are where signal gets in.

If you remember one thing: get the modem near glass, away from metal.

Where the modem wants to live in a house

Start with these rules and adjust from there.

1. Near a window. Not across the room from one. Near one.
2. On the side of the house facing the tower. You may not know where the tower is. A good guess is the side facing the nearest town, highway, or hill with antennas on it. Test both sides if unsure.
3. Up high. Second floor beats first. First beats basement. A shelf beats the floor. Signal generally improves with height.
4. Away from big appliances. Refrigerators, microwaves, washing machines, furnaces, and anything with a large motor or a lot of metal.
5. Not in a closet, cabinet, or entertainment center. Enclosures made of wood are tolerable. Enclosures with metal brackets or doors are not.
6. Not behind the TV. The TV is a large metal backed panel. It is a wall.

For wifi reach, a central and elevated spot is best. If the best cellular spot is at one end of the house and the far bedroom struggles to get wifi, that is a wifi range question, not a placement failure, and the fix is different.

The ten minute test

You do not need an app or a meter. You need the modem, a phone, and a little patience.

1. Pick three candidate spots. A window on the side facing town, a window on the opposite side, and the highest window in the house.
2. Turn it on at spot one. Wait a minute or two for it to connect.
3. Load the same thing on your phone over the modem's wifi. A video, a large web page, whatever you normally do. Note how it feels.
4. Move to spot two. Repeat. Move to spot three. Repeat.
5. Pick the winner and leave it there.

If all three spots feel the same, you have good signal everywhere and can place for wifi convenience. If one spot is clearly better, that is your spot, even if it is not where you wanted the modem to be. Run an extension cord if you have to.

RV placement

An RV is a metal box, which makes it one of the harder places to put a modem. It is also one of the most common, so here is the specific advice.

• A window shelf, up high. Overhead cabinets near a window are often the best spot in the rig.
• The side facing open sky. If you are parked with one side against trees or a rock face, use the other side.
• Away from the inverter, the fridge, and the microwave. These live close together in many rigs, so find the corner that is farthest from all of them.
• Not in a bay or storage compartment. Those are below the floor, surrounded by frame, and often lined with metal.
• Consider the roof vent. A modem placed on a shelf under a roof vent or skylight gets a bit of open sky above it.

When you change campsites, the best spot may change. Most RVers settle on one location and only move it when a site is unusually bad. Our RV internet guide has more on running the modem on the road.

Job trailer and shop placement

Job trailers and metal shops share the RV problem with extra steel.

• In the trailer, near a window, on a high shelf. Same rule as everywhere.
• Never inside a steel gang box or a metal cabinet. If the modem needs to be locked up, use a plastic enclosure and keep the modem near the top of it.
• In a metal shop, put it in the office if the office has a window. Or near a door that stays open during work hours.
• Away from welders, compressors, and generators. Both for signal noise and because those things vibrate.

Apartment and basement placement

Interior units with no exterior windows and basement apartments are the hardest residential cases.

• Find any window. Even a small one. Even one that faces a courtyard.
• If there is no window, get as close to the exterior wall as possible, ideally on the side facing the street.
• Height still helps. A high shelf near an exterior wall beats a low one.
• Test near the door if the hallway side of the building has better exposure.

If none of that works, the honest answer is that the building may block signal from everyone, and the 30 day return exists for that. Our Coverage page is upfront about it.

Placement for a second floor bedroom that cannot get wifi

A common follow up: the modem is in the best cellular spot downstairs, but the upstairs corner bedroom cannot hold a wifi connection. This is a link two problem, not a placement mistake.

Options, in order of effort:

1. Move the modem up one floor, near a window. Height often improves cellular signal anyway, so you may gain on both links.
2. Move it toward the center of the house on the same floor, as long as it stays near a window.
3. Reduce what is between the modem and the bedroom. Open interior doors. Get the modem out from behind furniture.
4. Accept that a large house may need more than one radio. That is a wifi coverage question, and it is true of any internet provider, not something specific to a cellular modem.

Most homes never get past step one.

Seasonal changes

Signal is not fixed. Leaves come in during spring and add a little attenuation to a tower behind a tree line. Snow on a metal roof changes reflections. A new building down the street changes the path. If a spot that worked all winter feels worse in June, run the ten minute test again. The winner may have moved one window over.

Cords and where the outlet is

The best window is rarely next to an outlet. People solve this by putting the modem next to the outlet instead, which is backwards. Solve it with a cord, or let the battery cover the gap.

A basic extension cord or a small power strip lets the modem sit on the window shelf while the charger plugs in across the room. Route the cord along the baseboard so nobody trips on it, and avoid running it under a rug where it can overheat. If the ideal spot is a windowsill with no shelf, a small bracket or a stack of books works. The modem is light. It does not need furniture.

Things that do not help

A few common ideas that people try and that do not do anything useful.

• Wrapping the modem in foil. No. This blocks signal, it does not focus it.
• Putting it on the roof in a plastic bag. Water damage voids the working condition standard, and the deposit. Keep it inside.
• Stacking it on top of the wifi router from your old provider. Two radios stacked together interfere with each other. Give it its own spot.
• Buying an app that claims to boost signal. Software cannot change where the tower is.

When placement is not the problem

If you have tried the ten minute test in three spots and every spot is bad, placement is probably not the issue. Two other possibilities.

Signal is weak everywhere at your location. Check your phone around the house. If it is also struggling, the location is the limit. This is where satellite or a local fixed wireless provider may be the better tool, and we say so in our rural internet comparison.

The modem needs a restart. Turn it off, wait thirty seconds, turn it back on. It is the oldest advice in technology because it keeps working. If restarting and relocating both fail, contact us through the Support page. If the modem is defective, we replace it at no charge.

A note on the charger

Use the charger that came in the box. It is matched to the modem, and it is part of what you return when you cancel. A random charger from a drawer can under power the modem and cause intermittent behavior that looks exactly like a signal problem.

If the charger is damaged, contact us for a replacement rather than substituting one. At home, keep the modem on the charger. It is designed to stay there. The battery is for the days it leaves the house.

Placement checklist

Print this, or do not, but at least read it once.

• Near a window.
• On the side facing town or the highway.
• Up high.
• Away from metal, appliances, and motors.
• Not in a cabinet with metal parts.
• Tested in three spots before committing.
• Left alone once it works.

The bottom line

Cellular signal wants glass, height, and distance from metal. Give the modem those three things and most placement problems disappear. Run the ten minute test on day one, pick the winner, and stop thinking about it.

If you have not ordered yet and want to know what the setup looks like end to end, read How it Works. If you have ordered and the box is on the way, check Track Order and pick your three windows in the meantime.