Anyone working in field service, on a construction site, or on a factory floor knows the workaround: the notebook or tablet connects to the cellular network through the hotspot on its own smartphone. That works – until the phone is in a pocket, the battery runs out, or reception drops out at exactly the moment data needs to be transferred. Rugged laptops and tablets solve this problem by building the cellular module directly into the device. This article explains why a built-in 4G LTE or 5G module beats a hotspot on a phone, what eSIM changes compared to a classic SIM card, why warehouses and basements in particular limit reception the most and what helps against it, and when a private cellular network on a factory site is actually worthwhile.
A smartphone hotspot is a compromise: the phone is built primarily for calls and apps, not for continuous duty as a cellular router next to a notebook. A cellular module built directly into a rugged device such as the Durabook R10 or the Durabook R8, on the other hand, is designed from the outset for continuous professional use. The difference shows up in four points.
A smartphone has a small antenna integrated into its housing, optimized for the space available inside a phone. Rugged laptops and tablets, by contrast, offer dedicated antennas for cellular, GPS, and WLAN – and on several models an additional connector to extend these antennas to the outside. On the Durabook R11, for example, the optional "RF Pass Through Connector" provides an "RF pass-through antenna connection for WWAN/GPS." On the laptops Durabook S14I and Durabook Z14I, the same option is called "RF Pass Through Connector (WWAN/GPS/WLAN)." Through this connector, an external antenna – mounted on a vehicle roof or on the outside of a metal cabinet, for instance – can be attached while the internal module stays built into the device. A smartphone offers no such option at all.
A smartphone that simultaneously works as a hotspot, drives its own display, and keeps apps running noticeably loses battery life – and that capacity is then no longer available for the phone's actual job. A built-in cellular module, by contrast, draws on the power supply of the rugged device itself. On several Durabook models, a high-capacity battery can additionally be configured, such as the "Extended Hi-Cap Battery" on the Durabook R10 and the Durabook R8. Cellular operation therefore does not depend on the charge level of a second, separate device.
A hotspot is tied to one individual's private or work smartphone. If that person is unavailable, the phone gets replaced, or its contract runs on a different cycle than the device's, the connection drops without the IT department being able to influence that in advance. A cellular module built into the device itself, on the other hand, is part of the device's equipment: it is configured at order time as its own "Communications" equipment group, as shown in the configuration options for the Durabook R10, the Durabook R8, and the Durabook S14I, and so stays tied to the device and its SIM card – regardless of which smartphone the employee happens to be using.
A built-in module does not fail simply because a second device happens to be offline, out of range, or in flight mode. Where extra redundancy is needed, some rugged tablets even support two active SIM cards at once: the Archos X67 5G provides two nano-SIM slots, and according to the product page "both SIM cards can access 4G simultaneously" and "both SIM cards can be 5G" – in other words, two independent cellular connections in a single device, for instance with two different carriers backing each other up.
The classic SIM card is a physical component that is inserted into a tray or slot in the housing. In the rugged devices from the RobustBook range, the compact nano-SIM form factor is most commonly used: the Durabook S14I and other models list a dedicated "SIM card slot" for this in the comparison table. According to its datasheet, the Getac ZX80 features "Or optionally: 1 hybrid SIM card reader (nano-SIM, 2FF) tray with microSD," while the Getac S510 has a "SIM card slot (nano-SIM, 4FF)."
An eSIM (embedded SIM), by contrast, is not a removable part but a chip built permanently into the device, whose carrier profile can be set up and changed through software, without opening a flap or swapping a card. Several devices in the range combine both approaches rather than choosing one: the Getac ZX80 lists "Optional: Dual SIM (nano-SIM 2FF and e-SIM)" in its communications equipment, and the Getac S510 correspondingly lists "Optional: Dual SIM (nano-SIM 4FF and e-SIM)." That means: alongside the physical card tray, an eSIM is also available, so a roaming profile can, for example, be set up via eSIM while the physical card for the home carrier stays inserted – or, conversely, a second provider can be activated briefly for testing purposes without opening the device.
For a purchasing decision, that means: anyone who works exclusively with a single, permanently assigned SIM card is well served by a classic card tray – as listed as a "SIM card slot" for most Durabook tablets in the Tablet Comparison Table. Anyone who needs to switch between carriers, cover several countries, or wants a second connection as a backup, on the other hand, benefits from a device with an additional eSIM, currently offered as an option on the Getac ZX80 and S510 models.
A cellular module with 4G LTE or 5G is only as good as the signal it receives. And that, in practice, is where the bigger problem actually lies – not in the device's own equipment. Reinforced concrete, metal cladding, thick walls, and floors below ground level attenuate radio signals considerably. In production halls, warehouses with steel racking, underground parking garages, or basements, reception can therefore be noticeably worse than right outside in the open – regardless of how capable the built-in module is.
For exactly this scenario, several rugged devices in the range offer a pass-through antenna or RF pass-through connector. This lets the device's internal antenna be connected to an externally mounted antenna placed above the interference zone – for example, above a warehouse roof or on the outside of a vehicle. The Getac ZX80 lists "Optional: RF pass-through antenna for GPS, WWAN, and WLAN" for this, and the Getac S510 lists the identical "Optional: RF pass-through antenna for GPS, WWAN, and WLAN." On the Durabook tablets, the same function is available through vehicle docks with what is called Tri RF Pass-Through, for example as the "R10 Vehicle Lite Dock with Tri RF Pass-through" or the "R8 vehicle dock with Tri RF Pass-through." This does not amplify the signal inside the device itself, but instead makes it receivable in the first place through a better-placed external antenna.
While cellular networks with sufficient transmit power can at least bring a weak signal into a building, GPS needs a direct line of sight to satellites and drops out almost entirely inside enclosed warehouses, basements, and underground parking garages. Here too, the RF pass-through antenna is the solution documented in the range, since datasheets explicitly design it for "GPS, WWAN, and WLAN" together – so an externally mounted antenna restores both cellular and GPS reception to the device.
Important for the purchasing decision: on most models, the RF pass-through option has to be configured at the time of ordering, and it cannot always be added afterward. Anyone who knows in advance that devices will regularly be used in warehouses, basements, or shielded buildings should factor this option into the equipment list from the start, rather than trying to retrofit it once reception problems appear during operation.
External antennas and RF pass-through connectors improve reception of the public cellular network at a single device or vehicle. But they do not solve every problem: in very large steel-frame halls, sprawling production facilities with many shielded areas, or on sites where dozens or hundreds of devices need to stay reliably online at the same time, simply improving individual device antennas reaches its limits. In such cases, operators are increasingly examining whether it is worth setting up their own local cellular infrastructure on the factory site, rather than relying entirely on the public network at the edge of the property.
In practice, whether this step pays off depends on three factors. First, the size and construction of the site – the more steel, concrete, and underground areas there are, the less reliable the public network remains even with optimized external antennas. Second, the number of devices that need to stay permanently online – for a handful of devices, a good single-device antenna solution is usually enough, while for a larger fleet of rugged laptops and tablets, of the kind described on the industry pages Industry and Transport, shared infrastructure tends to pay off more readily. Third, security and data protection requirements – anyone who does not want to route machine data or operational data over a public network gains extra control over data paths with a private infrastructure.
Technically, the prerequisite stays identical to that of a public network: the devices need a cellular module with SIM or eSIM support, as offered by the Durabook and Getac models in the range, and ideally the already-described option for an externally connected antenna. That means the same devices that use the public network out in the field can also be connected to an in-house factory infrastructure without any hardware change.
That depends on the model. On several Durabook devices, the cellular equipment is part of the configuration at order time, for example as a choice between "Multi-Carrier 4G LTE Mobile Broadband + GPS combo" and "Multi-Carrier 5G Mobile Broadband + GPS combo" on the Durabook R10. Whether a later retrofit is possible should be clarified case by case before ordering.
On several models, such as the Durabook R10 and the Durabook R8, the configuration states literally: "dedicated GPS (mutually exclusive with 4G LTE + GPS combo)." This means buyers have to choose between two options: either a combined module that provides 4G LTE and GPS together, or a separate module dedicated solely to GPS. Both variants cannot be built into one device at the same time. On the Ex-protected variant of the R8 (R8-EX), the dedicated GPS is additionally "not combinable with the RF pass-through connector option" – so here two equipment features are mutually exclusive with each other.
Not always, but it often helps significantly. In areas with thin walls or close to a building's edge, the internal module is often already enough. In windowless halls with a lot of steel, in basements, or in underground parking garages, on the other hand, only an external antenna connected through an RF pass-through connector reliably restores reception, as offered as a configuration option on several Getac and Durabook models.
The SIM card is a physical component inserted into a card tray – for instance as a nano-SIM on the Getac S510. The eSIM is built permanently into the device and gets a carrier profile assigned through software. Devices with a "Dual SIM" option, such as the Getac ZX80 and the Getac S510, combine both approaches and thereby allow two active profiles at once, or a quick switch, without opening the housing.
A built-in cellular module beats a hotspot on a phone in nearly every professional use case: it uses dedicated, sometimes externally connectable antennas, shares the power supply of the rugged device, can be managed centrally as part of the device fleet, and does not depend on the charge level or availability of a second device. eSIM complements the classic SIM card wherever switching carriers, covering several countries, or running a second profile is needed, without having to open the housing. The bigger practical problem, however, remains reception itself: in warehouses and basements, an externally connected antenna via an RF pass-through connector helps most, as offered as a configuration option on several Durabook and Getac models. Only once site size, device count, and security requirements go beyond that does a private cellular network on the factory site become a sensible addition. A complete overview of the cellular and GPS options for each model is provided by the Tablet Comparison Table and the Laptop Comparison Table.
If you have questions about the right cellular and antenna equipment for your application, the RobustBook team is happy to help you choose the suitable configuration.