#wireless

Fresnel-zone and line-of-sight clearance maths for radio-link planning as an API, computed locally and deterministically. The radius endpoint computes the Fresnel-zone radius at any point along a path, rₙ = √(n·λ·d1·d2/(d1+d2)) with λ = c/f, together with the wavelength and the 60 % clearance that a near-free-space link needs. The midpoint endpoint gives the widest radius — the zone is fattest at the path midpoint — and its 60 % clearance, the figure you size antenna heights against. The earthbulge endpoint adds the earth-curvature bulge, h = d1·d2/(12.75·k) with k ≈ 4/3 for a standard atmosphere, and combines it with the Fresnel clearance into a total obstruction clearance for the path. Distances are in kilometres, frequency in gigahertz, radii in metres. Everything is computed locally and deterministically, so it is instant and private. Ideal for wireless, WISP, microwave-backhaul, LoRa and amateur-radio app developers, link-planning and coverage tools, and RF engineering education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is Fresnel-zone & line-of-sight clearance; for free-space path loss and link budget use a path-loss API and for antenna gain use an antenna API.

api.oanor.com/fresnel-api

RF path-loss and link-budget maths as an API, computed locally and deterministically. The fspl endpoint computes the free-space path loss, FSPL(dB) = 20·log₁₀(d_km) + 20·log₁₀(f_MHz) + 32.44, the ideal line-of-sight attenuation between two antennas, and the wavelength. The linkbudget endpoint computes the received power, Prx = Ptx + Gtx + Grx − path loss − cable losses, the EIRP, and — given a receiver sensitivity — the link margin and whether the link closes. The dbm endpoint converts RF power between dBm, watts and dBW (0 dBm = 1 mW, 30 dBm = 1 W). Everything is computed locally and deterministically, so it is instant and private. Ideal for wireless, IoT, LoRa, Wi-Fi and radio app developers, link-planning and coverage tools, and RF engineering education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is RF link budget; for VSWR and impedance match use a VSWR API and for antenna gain use an antenna API.

api.oanor.com/pathloss-api

Wi-Fi channel maths as an API, computed locally and deterministically from the standard channel-numbering formulas. The channel endpoint returns the centre frequency of a Wi-Fi channel on the 2.4, 5 or 6 GHz band — the band is auto-detected from the channel number or can be given explicitly (2.4 GHz: 2407 + 5·channel, with channel 14 at 2484; 5 GHz: 5000 + 5·channel; 6 GHz: 5950 + 5·channel). The frequency endpoint does the reverse, returning the nearest channel and band for a centre frequency in MHz or GHz. The overlap endpoint reports whether two channels overlap at a chosen channel width (two channels overlap when their centre-frequency separation is less than the width) and gives the recommended non-overlapping set — the classic 1, 6 and 11 on 2.4 GHz at 20 MHz. Everything is computed locally and deterministically, so it is instant and private. Channel availability is regulated and varies by country. Ideal for networking and Wi-Fi tools, site-survey and IoT apps, and router and access-point configuration software. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is Wi-Fi channel mapping; for general wavelength/frequency and photon energy use a wavelength API.

api.oanor.com/wifichannel-api