Technology · Targets

Every number
we have.

Target specifications for the Relay R1. Some numbers are pulled from the Qualcomm SDX35 reference, others are our own design targets — they'll firm up as we move through certification.

R1 · Space Black Relay in Space Black 70 × 35 × 7 mm · 22 g
§ 01 — Full spec sheet

The whole
spec sheet.

ModemQuectel RG255C-GL · Qualcomm SDX35
Standard5G NR RedCap · Release 17
Max downlink223 Mbps
Max uplink123 Mbps
macOSCatalina 10.15 + · zero-driver
Form factor70 × 35 × 7 mm
Weight~ 22 g
PowerUSB-C bus · ≤ 4.5 W peak
ShellPC/ABS V-0 FR · IPX4 · matte
SIMnano-SIM tray · eSIM (V2)
ColorsSilver · Space Black
Price$199 USD
§ 02 — Radio bands

Sub-6 GHz, everywhere it counts.

5G NR Sub-6

n1, n2, n3, n5, n7, n8, n20, n25, n28, n38, n40, n41, n66, n71, n77, n78, n79

Full US (T-Mobile n41/n71, Verizon n77, AT&T n5/n77) and full EU/Asia coverage.

LTE-A Cat 20 fallback

B1/2/3/4/5/7/8/12/13/14/17/18/19/20/25/26/28/29/30/32/34/38/39/40/41/42/43/46/48/66/71

When there's no 5G, Relay falls back to LTE-A with 5×CA. CBRS (B48) and public-safety (B14) included.

Not supported

mmWave (n257, n258, n260, n261)

We made a deliberate trade. mmWave needs four extra antennas and a different RF front-end. Roadmap target for R1 Pro, 2027.

§ 03 — Software

It looks like ethernet.
Because it is.

Relay enumerates as a CDC-ECM network adapter. No drivers, no carrier app on the critical path. Works the same way Apple's USB-C-to-Ethernet adapter works.

macOS · day one

Catalina 10.15 +

Universal binary menubar app is optional — gives you data caps, signal monitor, and eSIM (V2) management.

Linux · day one

Kernel 5.10 +

NetworkManager + ModemManager. Pi 5, Jetson Orin, x86 — anything with CDC-ECM works.

Windows · day one

Windows 11

Inbox NCM driver. Signed. WinUI 3 companion app available in the Microsoft Store.

iPadOS · day one

iPadOS 17 +

USB-C ethernet adapter API. iPad sees Relay as a real wired connection.

ChromeOS · day one

M118 +

crosvm USB passthrough. Works on every Chromebook with USB-C.

Android · Q4 2026

Android 14 +

Awaiting per-OEM USB host passthrough testing. Tablets first, phones next.

§ 04 — Antenna design

A dual PIFA array. In 7 mm.

The hardest engineering on Relay isn't the modem — it's making two planar inverted-F antennas coexist inside an aluminum-equivalent box without killing each other's isolation.

Isolation

> 18 dB

across all band pairs

Efficiency

52 – 71%

worst case n71 @ 52%

Polar gain · n78 · −3 dBi mean
−30 dBi0°+4 dBi
§ 05 — Certification

FCC · CE · IC
In progress.

USA · FCC

Modular approval under Quectel grant FK6-RG255C.

Relay FCC ID pending — expected April 2027. Pre-shipping units are governed by the modem's existing Part 15 modular approval.

EU · CE / RED

RED 2014/53/EU + EMC + LVD

Notified-body testing planned Q1 2027. EN 301 908, EN 301 489, EN 62311 (SAR) compliance.

Canada · IC

ISED RSS-130 / RSS-247

Filing in parallel with FCC. Same modular path.

Carrier · PTCRB

T-Mobile, Verizon, AT&T

PTCRB testing scheduled for Q1 2027. Each US carrier requires separate device approval for full 5G NR access.

§ 06 — Firmware

Signed updates. For the life of the device.

Every Relay shipped gets free signed firmware updates for as long as we make them — five years guaranteed. Bug fixes, modem revisions, new bands as carriers light them up. Delivered through the menubar app or a one-line CLI.

5-yr update guarantee Ed25519 signed 
$ relayctl status
relay  ▸ link acquired
band   ▸ n41 @ 100 MHz BW
rssi   ▸ -68 dBm
sinr   ▸ 22.4 dB
mcs    ▸ 27 / 27
plmn   ▸ T-Mobile US (310-260)
uptime ▸ 14h 22m 04s
fw     ▸ 1.0.0 · up to date
Have a technical question?

Just email us.

We answer our own mail. No support funnel, no ticket queue.

kavin@relay5g.com Reserve a unit