LoRaWAN Gateway Antennas: Siting and Selection

LoRaWAN networks depend on gateways, and gateway coverage depends on the antenna more than any other component. A well-sited gateway with the right antenna can cover several kilometres in a town and much more across open country. A poor one leaves sensors dropping packets at the edge of a site.

The UK band and power limits

In the UK and Europe, LoRaWAN uses the 863 to 870 MHz band. Transmit power is limited by effective radiated power, and antenna gain counts towards that limit. A high-gain antenna does not give you more transmit power to play with, but it does improve receive sensitivity, which is where most gateway coverage is won. Check your gateway's configuration so that total ERP stays within the limits for the sub-band in use.

Gain and height

• LTE900NB: 0 dBd. A broad vertical pattern suited to dense urban areas and rooftops close to the sensors they serve.
• LTE903NB: 3 dBd. A balanced choice for most town and campus gateways.
• LTE905NB: 5 dBd. Flatter pattern for long range across open, flat country.

All three cover 860 to 930 MHz. Higher gain narrows the vertical beam, so a 5 dBd antenna on a tall mast can overshoot sensors directly below it. Height usually matters more than gain, so get the antenna above surrounding rooftops and trees first.

Siting the gateway

• Mount the antenna clear of the roof edge and away from other antennas, ideally on its own pole.
• Keep it away from metal structures such as plant rooms and handrails, which distort the pattern.
• Consider where the sensors are. Basement water meters need a different plan from rooftop air quality monitors.

Cable loss at 868 MHz

At 868 MHz, thin coax loses signal quickly. Keep the run as short as possible, mounting the gateway close to the antenna where the enclosure allows. On longer runs, use low-loss cable and weatherproof every outdoor connector.

Sensor-side antennas

The device end matters too. For compact sensors, embedded and flexible antennas such as the 2JF0415P and swivel types such as the 2JW0515-868 cover the 868 MHz band. Mount them away from batteries and metal enclosure walls.

Frequently asked questions

What gain antenna should a LoRaWAN gateway use?

A 3 dBd antenna is a good default for towns and campuses. Use 0 dBd where sensors are close and below the gateway, and 5 dBd for long range over flat, open ground.

Does a higher-gain antenna break the ERP limit?

It can. Antenna gain adds to transmit power when calculating ERP. Reduce gateway transmit power if needed to stay within the limit for the sub-band in use.

How high should a LoRaWAN gateway antenna be?

Above surrounding rooftops and trees where possible. Height usually gives a bigger coverage gain than a higher-gain antenna.

For the wider context, read our guide to low-power IoT antennas. To plan gateway and sensor antennas for a deployment, contact sales@renair.co.uk.