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Estimating coverage, keeping results and asking Telewave engineering

What these pages are for

Planning a site’s coverage, keeping your calculations, and sending them to Telewave engineering with a request for review.

Before you start

  • The Coverage Calculator needs an approved Telewave membership. A calculator opened from your own engineering request works without one, for that request.
  • Have the transmitter power, frequency, antenna gains and heights, and the receiver sensitivity.

Steps: estimating coverage

  1. Enter the TX power (W), Operating frequency (MHz) and both antenna gains, choosing dBd or dBi for each.
  2. Enter the RX sensitivity in dBm. Typical figures: −110 dBm for LMR two-way, −113 dBm at 12 dB SINAD, −116 dBm for P25.
  3. Enter a Fade margin (6–10 dB is typical for mobile) and the Feedline loss. If you do not know the feedline loss, work it out in the Feedline Calculator.
  4. Enter the antenna heights above ground and choose the Receiver environment: outdoor, vehicle, handheld, or indoor light or dense construction. Choose the heaviest case that applies.
  5. For a sector or Yagi antenna, give its beamwidth, the direction it points and the bearing to the service area.
  6. Leave the Propagation model on Auto unless you have a reason not to.

Reading the result

The result is a planning radius, with the model used and the notices that apply to it. Auto uses the Okumura-Hata land-mobile model where it is valid (150–1500 MHz) and gives no radius where no model applies. Free-space line of sight is a theoretical reference, not a prediction. Read every notice under the result: they say what the figure depends on.

Steps: keeping a result

  1. Signed in, name the result in Keep this result and choose Save privately. Nothing is sent to Telewave.
  2. Find it again under My results. Open in the calculator reloads its inputs and calculates them again with the current version. Delete removes a private result.

Steps: asking Telewave engineering

  1. Open the Engineering request form under Support.
  2. To include a calculation, choose Run the … calculator for the tool you need. The form is kept as a draft, and the calculator opens with your frequency, power and height filled in. When the result is right, choose Attach to your request; Back without attaching returns to the draft without it.
  3. Fill in your contact details, the system and site, and the notes, then choose Submit engineering request.
  4. You get a reference number, a receipt email, and a page for the request showing its state: received, in review, needs information or reviewed.

When Telewave asks you for a calculation

An engineer may email you a link asking for a specific calculation. The link opens a page with their question: choose Run the … calculator, check the values Telewave filled in, run it, and choose Send this result to Telewave. That sends the result straight away, with no draft and no separate submit.

Limits

  • Coverage figures are for planning. They are not a site survey or a guarantee of coverage.
  • A draft request lives in your browser. If your browser blocks cookies, the draft is lost when you open a calculator.
  • Anyone holding the link in your receipt can read the request, so forward it with care.

Next

A Telewave RF engineer reviews each request and usually responds within 1–2 business days. To add information, reply to your receipt email with the reference number.