Wi-Fi for warehouses and logistics

The reason has very little to do with the equipment. It is that the building is not the same building twice.

Racking, stock and attenuation that moves

Steel racking reflects. Stock absorbs. A rack bay filled with palletised drinks, tinned goods, cosmetics or anything else with water or metal content is close to opaque at 5 GHz; the same bay empty is largely transparent. Survey on a quiet Sunday with half the racking cleared and you will have measured a building that does not exist on a Tuesday in November. This is why so many warehouse networks are commissioned successfully and then start generating tickets weeks later — nothing broke, the stock arrived.

Stock profile matters as much as fill level. Cardboard, plastics and air are comparatively kind. Liquids, foils, canned goods, dense mixed pallets and anything on metal cages are not, and a design that assumed one and got the other will be short on signal exactly where the picking happens.

Narrow aisle behaves nothing like wide aisle

A narrow aisle acts as a waveguide. Signal is channelled along its length and confined by racking on both sides, which is useful — one correctly chosen and correctly aimed access point can serve a long run — but it also means coverage does not bleed sideways to help the next aisle. Every aisle has to be considered on its own terms, and an access point that looks like it covers three aisles on a plan very often covers one.

Wide aisles, cross-dock areas and pick faces behave more conventionally, and bring the opposite problem: with nothing to contain the signal, access points mounted high and left at default power reach far further than they should, and start contending with each other for airtime instead of serving clients.

Height, downtilt and where the energy goes

Clear heights of ten to fifteen metres are routine, and the standard mistake is to mount omnidirectional access points on the roof steel pointing at everything and nothing. Most of the radiated energy ends up above the racking, where nobody is working, and the useful signal at pick-face height — roughly where a person is holding a scanner — is a fraction of what the plan predicted. Antenna choice and mounting height are not details in a warehouse; they are the design.

5 GHz costs you range

Higher frequencies carry more capacity and survive obstruction less well. In an office that trade-off is comfortable. Through several bays of full racking at 5 GHz, and more so at 6 GHz, it is not, which is why warehouse designs frequently need more access points than the same floor area in an office rather than fewer — the opposite of what a per-square-metre rule of thumb predicts.

The devices are less tolerant than the surveyor's laptop

Handheld scanners, vehicle-mounted terminals and voice-picking headsets have smaller antennas, lower transmit power and far less tolerance of a marginal link than a laptop. They also make their own roaming decisions, on thresholds set by the manufacturer, and many of them are notoriously reluctant to let go of an access point they can still just about hear. A network validated on a laptop can be comfortably and consistently wrong for the devices that actually do the work.

Survey it as it operates

We survey with stock in, at representative fill, and we ask what the seasonal extremes look like. Where the operation swings hard between peak and trough, the design is worked to the harder case and the margin is stated rather than assumed. An on-site survey in a working warehouse also captures the interference sources a plan never shows — chargers, wireless bridges, neighbouring units, existing legacy kit nobody has switched off.

Antenna selection and mounting, aisle by aisle

Directional and patch antennas aimed down the aisle where the geometry calls for it; omnidirectional where the space is open. Mounting height chosen so the main lobe lands at pick-face and vehicle-cab height, not on the roof deck. Positions are checked for whether they can actually be fixed, cabled and reached again — which in a high-bay shed is a real constraint, not a formality.

Roaming designed for the worst device on site

We establish what the fleet actually is: scanner models, vehicle terminals, voice headsets, tablets, and anything embedded in the MHE. Signal thresholds, cell overlap along travel routes, minimum data rates and band steering are then set for the least capable of them. Voice picking is the strictest case — it needs continuous, low-latency coverage along every route a picker walks, with enough overlap that the handover completes before the old link degrades.

AGVs, AMRs and automation

Automated vehicles are less forgiving than people. They travel fixed routes at consistent speed, they hand over between access points at predictable points, and an interruption is not an inconvenience but a stopped vehicle in an aisle. Where AGVs or AMRs are in use or planned, we design the overlap along their routes specifically, confirm the handover behaviour their vendor requires, and validate it by walking those routes rather than sampling the floor. If automation is on your roadmap but not yet installed, say so at survey stage — retrofitting for it is considerably more expensive than allowing for it.

Cold stores, chill and freezer

Cold stores combine insulated panel construction that attenuates heavily, condensation and ice, and temperature limits that ordinary access points are not rated for. They usually need enclosures or externally mounted antennas with the radio kept outside the cold envelope, sealed penetrations, and cable specified for the environment. It is a small part of the floor area and a disproportionate part of the design work.

Mezzanines, offices and the transitions

Mezzanine floors change the vertical picture completely — an access point serving the floor below can be an interference source for the deck above. Offices inside the shed have office device density in a warehouse RF environment. And the transitions matter: through shutter doors, from warehouse into yard, from floor to mezzanine, in and out of chill. Sessions break at transitions far more often than in the middle of a well-covered area.

Loading bays, doors and yard

Loading bays are a moving RF environment — a shutter open to the yard and a shutter closed behind a trailer are different buildings. Yard coverage for trailer moves, gatehouse operations and vehicle-mounted terminals needs external-rated hardware, mounting on the building or on columns, and power and containment run to positions that were never intended to carry either. It is designed and priced separately from the indoor scheme because the constraints are genuinely different.