Connectivity
Advice supporting sensor wireless backhaul technologies and choices for different use cases
There are many options for wireless connectivity - this page of wFD will help you identify which types of wireless backhaul technologies you may want to include in your wireless networking subsystem. Greater detail in how to consider the costs/benefits and capabilities of each of these options are provided in related subsection links.
Wherever possible, we will describe options generically, and in such cases where a specific vendor or commercial product is mentioned, this is not an endorsement - names and brands are included for the sake of example only.
Modern field sensor system wireless network subsystems tend to be built around one (or more) of the following wireless technologies. While there are many others not listed here (Zigbee, Sigfox, Shortwave Data Radio) this reflects the most frequently used technologies as part of science support efforts in which we have been involved.
Short Range Wireless Links (meters to 100s of meters)
WiFi: WiFi (Wireless Fidelity) is currently available via unlicensed 2.5/5 Ghz spectrum. WiFi6 which is becoming increasingly available is provided using multiple unlicensed bands between 1 and 7 Ghz. WiFI5 supports up to 6.9Gb/sec, and WiFi6 can provide up to 9.6 Gb/sec.
- Provision: WiFi is available in almost all campus or facility situations, and in many urban outdoor field settings, via directional wifi antenna. It is also increasingly being used as part of existing fixed ISP, cable, and cellular "WiFi calling" or "W+" like networks as an inexpensive way to expand coverage in congested areas.
- Typical use case characteristics: Low Power, inexpensive, good data throughput, highly dependent on antenna and receiver placement, QoS not a major factor.
Bluetooth: Bluetooth and Bluetooth Low Energy (Bluetooth LE or BLE) use unlicensed shared spectrum in the 2.4 Ghz band to support short range (100m or less) IoT and device communications. Line of sight is required generally, and the maximum data rate is around 1-2 Mb/sec.
- Provision: Bluetooth is designed to support scatternets of up to 8 devices, however it is almost always used for device to device communications, very often supporting streaming such as music from a phone to a headset. Communications can be difficult to maintain and troubleshoot between devices for extended periods, but equipment is inexpensive, uses little power, and is readily available.
- Typical use case characteristics: Low Power, inexpensive, low data throughput, highly dependent on antenna and receiver placement, QoS not a major factor.
Medium Range Wireless Links (100s of meters to kilometers)
- LoRa: LoRa (Long Range) makes use of unlicensed spectrum in the 600 and 950 Mhz bands supporting relatively low data rates (~253 kbit/sec max) out to a couple of kilometers. Spectrum available varies by country and LoRA (a physical RF specification) may be used with a variety of communication protocols such as LoRaWAN, MloTy, DASH7, Wi-Fi HaLow, and others.
- Provision: LoRa capabilities can be obtained through private deployments as well as from commercial providers.
- Typical use case characteristics: Low Power, inexpensive, low data throughput, flexible architecture (can support mesh or star architectures), Line of sight available, quality of service not a major factor.
Cellular: Cellular services operate in multiple frequency bands, and have been allocated between 600 Mhz and 39 Ghz in the United States. Spectrum and band allocations vary by country and service may be provided by commercial cellular networks, or by Private Cellular systems using the 3.55-3.70 Ghz band allocated to Citizen Band Radio Systems (CBRS).
- Provision: Access to connectivity may be provided by cellular common carriers or via use of private cellular systems.
- Typical use case characteristics: Applications supporting sensor nodes where a per-node cost of $100+ makes sense, plus possible monthly/per KB data charges, or situations where reliable QoS and ability to allocate communication resources (5G), embedded security, range of several KM, speeds of 100 Mb/sec or more is needed.
mmWave point-to-point:
Free Optical Systems
Long Range (Beyond many kilometers)
Shortwave
Non-Terrestrial Networks (Low Earth Orbit)
-cellular from orbit goes here
-LoRa from orbit goes here
Non-Terrestrial Networks (Medium or Geosynchronous)
