A fixed wireless link connects stationary sites through radio. A dependable design starts with the required service at each end, then checks the radio path, usable capacity and recovery arrangements. Use this guide to prepare a site survey or evaluate a provider’s proposal.
Define the service before choosing radios
Write down the locations, required download and upload throughput, busiest operating hours and applications that must remain usable. A link between two buildings is a point-to-point connection. A base station serving several customer sites is point-to-multipoint; its shared airtime and upstream connection affect the service each site receives. For a household purchasing access, pair these questions with the rural wireless Internet guide.
Ask the supplier to distinguish advertised radio capacity, expected application throughput and any committed service rate. Record latency, packet-loss and availability targets alongside throughput. A fast file-transfer demonstration alone leaves voice quality and service continuity unresolved.
Survey the whole path
Collect coordinates, proposed antenna heights, photographs and a terrain profile. Record trees, roof edges and future building or vegetation changes. The Fresnel zone describes a volume around the direct path in which obstructions can affect propagation. Cambium’s planning documentation explains why optical visibility alone gives an incomplete clearance check.
Have the installer assess local interference, mounting access, alignment, power and the connection into each building. Use the regulator’s current rules for the country, band, power and installation: for example, Ofcom’s UK fixed-link guidance distinguishes available licensing arrangements. The equipment’s supported frequency range is only one input to that decision.
Read a link budget in useful units
A link budget estimates received power from transmitter power, antenna gains and losses. Cambium’s path-loss explanation distinguishes free-space loss, additional losses and the headroom needed for fading and seasonal change. Receiver thresholds depend on the equipment and operating mode; a link may maintain connectivity by falling back to a lower data rate.
Hypothetical budget, for interpretation only
Transmitter power of 20 dBm + two antenna gains of 18 dBi each − 2 dB of combined equipment losses − 110 dB of path loss = −56 dBm received power. Against a fictional −70 dBm threshold for the required mode, the margin is 14 dB.
This arithmetic explains the proposal’s columns. A deployment still needs the real radio specifications, legal limits, interference assessment and an availability calculation appropriate to the path and weather.
Turn the proposal into an acceptance test
| Record | Evidence to request | How to use it |
|---|---|---|
| Path and clearance | Profile, antenna heights, dated site photographs | Revisit obstructions and seasonal vegetation before committing. |
| Capacity | Throughput in both directions, test duration and competing load | Run the applications together during a representative busy period. |
| Quality | Latency, loss and radio signal statistics during the same test | Compare with agreed application and radio targets. |
| Continuity | Power arrangements, fault contact and recovery method | Confirm the service can be restored within the required window. |
Keep the test endpoints, time, configuration and results together. If throughput falls while radio statistics deteriorate, investigate the path, alignment or interference with the installer. If radio conditions stay stable, examine shared airtime, upstream congestion and the local network. Retest the same workload after a change so the comparison remains meaningful.
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