The radio that helps itself along to reach further.

Texecom is a British intruder detection manufacturer and its professional family is Premier Elite: panels that grow with expanders on a bus, with wired and wireless zones in the same system, an app for the user and a cloud service so the installer can maintain it remotely. The programming is done from the installer's software, which is where everything lives and where the copy should be kept.

You'll find it in retail, offices, schools, medium-sized warehouses and sports facilities. In the United Kingdom it is a reference brand; here it is less widespread than others on this list, and that is not a judgement on the product but a fact for deciding with. Where it turns up naturally is in the finished building with points that are hard to reach: an industrial unit with metal racking, thick walls, a basement, separate modules.

The wired side is the classic one: a panel with its zones, a bus with keypads and expanders hanging off it, zones with end-of-line resistors to tell alarm, tamper and cut apart, independent areas with their own arming and schedules, and a supervised power supply with batteries worked out by calculation.

The radio side is this house's own. On most systems each detector talks directly to the panel or to a repeater, and if it does not reach, it does not reach. Here the devices form a mesh: each one can pass on what another says, so a detector at the back of the basement reaches the panel by way of two or three neighbours. And the mesh remakes itself: if a path stops working because somebody has filled a corridor with metal pallets, the message looks for another.

What it solves is real —fewer repeaters and fewer impossible points—, and what it costs is real too: a mesh has to be designed. The hops need devices in intermediate places, so you cannot have a detector isolated a hundred metres away with nothing in between; each hop adds a little time; and repeating uses battery. Outwards, transmission over the network with backup over the mobile network and supervision, and remote maintenance that lets you diagnose half the alerts without getting in the car.

It brings what you need: confirmation between zones before treating an alert as a confirmed intrusion, automatic exclusion of a zone that trips repeatedly, per-zone supervision that separates alarm from tamper and from fault, entry times and routes per area, and a long log that can be read remotely.

On systems with radio there are also nuisance alerts that are not intrusion: low battery, loss of supervision, interference, cover open. They are necessary, but if they come in at any hour and in no order the user learns to ignore them just as they would ignore an alarm. The mesh helps with something specific: the system knows the route each device comes in by and with what quality, so a point with marginal signal is spotted at handover and not in the winter, when somebody fills the corridor with stock.

And what no brand fixes: detectors put where the signal reached instead of where the detection was needed. A microwave detector aimed at a plasterboard partition, which it goes straight through to see the forklift on the other side. An infrared detector facing a west-facing metal gate, which trips at sunset. A masking fault every morning at the same time, which is not a fault but a pallet in front of it. Three months of log per zone point to the two or three culprits, and then you change the place, the lens, the technology or the angle instead of turning the sensitivity down. And a zone under building works is isolated on paper and with a date for putting it back.

The European standards divide alarm systems into security grades according to the risk, and each grade demands things of the equipment, the cabling, the power supply, the tamper detection, the supervision of the transmission and, on radio, how often each device is checked and how interference is detected. It is set by the activity, very often by the insurance and sometimes by a specification. And two things always have to be kept apart: equipment certified to a grade is not an installation that meets that grade; the first is on a dated certificate, the second is signed off by whoever hands the project over. The receiving centre is another decision, with its own contract and its own regulations, and with the obligation to verify the alert before calling the police out — here, on top of that, with the check mentioned above.

It fits the finished building with difficult points, which is where its radio really wins: units with racking, thick walls, groups of modules, basements. It fits medium-sized installations with several areas and schedules, and when you want to mix cable on the important parts with radio on the difficult ones without the radio being the poor relation.

It doesn't fit if the installation is one of those that calls for a supervised ring bus, dozens of areas and managed multi-path transmission. Nor if the client wants a brand with technicians on every corner, and that argument is legitimate. And it doesn't fit if nobody is going to think the mesh through: a badly planned mesh is worse than a well-planned ordinary radio, because it gives a sense of coverage that depends on the intermediate devices still being where they were on the day of the build.

The client handles users and codes, who arms which area, part-arming, schedules, inhibiting one zone temporarily, the log and the state of the devices, and with the app also remote arming and checking whether it was left armed on the way out. Named users from day one: when everybody uses the same code, the log says «user 1» disarmed it and says nothing at all.

The thing peculiar to this system appears in no user manual: the wireless devices lean on each other, so taking one away, moving it or blocking off a corridor can affect the coverage of another one further off. It is not fragile; it has a dependency worth knowing about, and the practical rule is simple: if a device has to be moved or an area is going to be altered, you say so and the signal gets checked again afterwards.

What it asks of the installer is the layer underneath: pairing devices, adding or removing expanders and zones, changing times, routes or the confirmation logic, redoing areas, touching what is transmitted to the receiving centre and upgrading the version; and if it was handed over with a grade, every change means the documentation has to be reviewed. Training by role is handed over, and a folder with the plan showing every device, its battery type, which route it comes in by and with what margin on the day of handover, and who gets which alert and in what order.