Giving a field team tablets is the easy part. Keeping them working at the far end of a site, in a plant room, or on a rural job where nobody has thought about signal is where it goes wrong. The mistake almost everyone makes is choosing the connection the way they would choose home broadband, by looking at download speed. For a tablet doing surveys, photos and job sheets, download is the number that matters least.
The 30-second version
- Give the tablet its own SIM. Tethering off a phone is the default and usually the wrong call, for reasons below.
- Upload is the number that matters, not download. Field work pushes data out: photos, survey data, signed forms, video.
- Coverage beats peak speed every time. 30Mb everywhere is worth more than 400Mb in town and nothing on site.
- Plan for no signal at all. Some sites have none. If the app cannot work offline and sync later, the job stops.
- The device leaves the building, so it needs managing differently from an office PC.
- Pool the data across the fleet rather than guessing a bundle per tablet.
On this page
Three ways to get a tablet online
There are only really three, and the choice has more consequences than it looks.
| Approach | Works well when | What it costs you |
|---|---|---|
| Tablet has its own SIM | The tablet is the working device and needs to be reliable on its own | A line per tablet, which pooling makes manageable. Needs a cellular model, so decide before you buy the hardware. |
| Tethered to a phone | Occasional light use, or a backup when something else fails | Phone battery, and a dependency on one person's handset being present, charged and willing. |
| Portable 4G or 5G router | Two or more people working together on one site, or kit that cannot take a SIM | Another device to charge and remember. Good for teams, awkward for lone workers. |
Decide before you buy the tablets
Cellular models cost more than Wi-Fi only ones and the difference looks avoidable at purchase. It is not. Retrofitting connectivity to a Wi-Fi only tablet means tethering or a portable router forever, and that decision is then locked in for the life of the fleet.
Why tethering looks cheapest
On paper, tethering costs nothing. The phone already has data, the tablet already has Wi-Fi, job done. In practice three things go wrong, and they go wrong on the days you least want them to.
- It flattens the phone. Acting as a hotspot is one of the hardest things you can ask a handset to do. The device your engineer needs for calls at four in the afternoon is the device that has been running a hotspot since nine.
- It couples two jobs together. If the phone rings, wanders out of range, or the owner walks to the van, the tablet drops mid form.
- It is nobody's fault when it fails. A tablet with its own SIM has one thing to check. A tethered one has a phone, a hotspot setting, a Wi-Fi link and a tablet, and the support call takes four times as long.
Tethering is a perfectly good fallback. It is a poor primary plan for anyone whose job depends on the tablet.
Upload is the number that matters
This is the part most people get backwards, because every broadband advert has trained us to look at download speed.
Think about what a field tablet actually does. It takes photographs of an installation and sends them. It uploads survey measurements, meter readings, before and after shots, a signed job sheet, sometimes a short video of a fault. Almost all of the meaningful traffic travels away from the device.
A connection that downloads at 300Mb and uploads at 8Mb will feel quick when you open an app and painfully slow when you try to send twenty photographs before leaving site. This is the single clearest practical argument for 5G over 4G in field work: the upload headroom is where the difference shows up, not the headline download figure.
A quick test worth doing
Before committing to a fleet, take one tablet to your three most awkward sites and upload a typical job's worth of photos. Time it. That one exercise tells you more than any coverage map, and it is the number your engineers will live with.
Coverage beats peak speed
A tablet that works at a steady 30Mb at every site your team visits is worth more than one that peaks spectacularly in the town centre and finds nothing behind a steel shutter.
This is why the network matters more than the tariff. We put users on Vodafone, O2 or EE based on where they actually work rather than where the office is, and for field teams who cover a wide area that choice is rarely obvious from a postcode.
Where coverage genuinely varies across a patch, a multi-network SIM is the honest answer. Rather than committing a tablet to one network and hoping, it uses whichever has usable signal at that location. For a team moving between industrial estates, rural sites and basements in the same week, it removes the most common cause of a tablet being useless for an hour.
Planning for no signal at all
No provider enjoys writing this section, so most skip it. Some sites have no usable mobile signal, from any network, and no SIM will change that. Plant rooms, basements, lift shafts, thick stone, the middle of a large steel-framed building, and plenty of genuinely rural jobs.
The answer is not a better SIM. It is choosing field apps that work properly offline, hold the job locally and sync when the device comes back into coverage. Ask the question before you buy the software, because retro-fitting offline working is usually impossible.
- Can the engineer complete a whole job with no connection? Forms, photos, signature, the lot.
- Does it sync automatically when signal returns, or does somebody have to remember?
- What happens if the tablet is lost before it syncs? That is a data question as much as an operational one.
How much data a field tablet uses
We get asked for a number and the honest answer is that it depends almost entirely on photographs and video. Text forms and readings are negligible. A job with thirty high resolution photos is not.
The things that actually drive the bill:
- Photos per job, and whether the app compresses them. The same job can be a few megabytes or a few hundred depending on this single setting.
- Video. One short clip can exceed a day of everything else.
- Maps and plans. Downloading drawings or satellite imagery on site, repeatedly, adds up. Caching them before leaving helps.
- Background sync and updates. Operating system updates over mobile data are a genuinely common surprise. Turn them off.
Rather than guessing a bundle per tablet and getting it wrong in both directions, pool the data across the fleet. A surveyor having a heavy week borrows from a colleague having a quiet one, and nobody gets a surprise charge for being busy.
The device leaves the building
An office PC sits behind your firewall. A field tablet sits in a van, on a roof, and occasionally in a cafe. It needs managing accordingly.
- Mobile device management. The ability to lock, locate and wipe a device remotely is the difference between a lost tablet and a data incident. Our guide to MDM for business devices covers what it does.
- Know what is on it. Customer addresses, photos of premises and signed documents are all personal data when they are on a device that can be left on a wall.
- If the tablet reaches internal systems, a fixed IP or private APN SIM lets you restrict access to known connections rather than opening a system to the public internet.
- Plan for the device being lost, not for it never happening. Our post on what to do when a device goes missing is worth reading before you need it.
Kitting out a field team?
Tell us where your people actually work and what the tablets need to do. We will tell you which networks cover your patch, whether multi-network is worth it, and how to size the data so nobody gets a surprise. We do this for engineers, surveyors and sales teams across the North West.