Followings are the list of applications for Wireless communication that I can think of. This list would extend as I learn more. The entries below have almost nothing in common at the physical layer. They run from millimetres to tens of thousands of kilometres in range, and from a few hundred kilohertz up into visible light in frequency. A later section works through the five properties that separate them.
Which applications are on the list?
The list mixes things that are usually kept apart. Some entries are whole industries with their own standards bodies. Some are a single chip talking to the chip beside it. Where an entry links out, the linked page carries the protocol detail, and this page only places each one against the others.
- TV Broadcast
- Radio Broadcast (AM, FM)
- WLAN
- Bluetooth
- LoWPAN(LoRA, SigFox, ZigBee, XBee)
- Cellular Communication (2G, 3G, 4G, 5G, 6G)
- Satellite Communication
- Wireless Backhaul
- UAV Control
- Optical Communication (LiFi, VLC(Visible Light Communication) , Laser Communication, Lidar etc)
- Thz Imaging
- Chip to Chip Communication
- TPMS (Tire Pressure Monitoring System) Sensor
- RKE(Remote Keyless Entry) - e.g, Car Key, Garage Door Opener
- TV Remote Controller (IR, RF)
- Molecular Communication
Reading the list from top to bottom is not the most useful order. Grouping it helps. TV and radio broadcast are one-way links with no return path. WLAN, Bluetooth and the LPWAN family are short-range two-way links in unlicensed spectrum. Cellular, satellite and wireless backhaul are long-range licensed systems. The optical and THz entries sit at the far end of the spectrum, where the signal behaves more like light than like radio. TPMS, RKE and the TV remote are small control links that most people use daily without noticing them.
Range spans ten orders of magnitude : chip to chip communication is millimetres, and satellite communication is tens of thousands of kilometres.Most entries link out : the linked pages carry the protocol detail, so this page is a map rather than a description.One-way links are the simpler half : broadcast, TPMS and RKE need no return path, so they carry no retransmission machinery at all.
What separates one wireless application from another?
Every entry above solves the same problem, which is moving information without a wire. What makes them different designs is a small set of properties, and each one pushes the others. Choosing a band fixes the antenna size, and the antenna size fixes what the device can be built into.
Frequency comes first, because the rest follows from it. A lower carrier bends around obstacles and travels further for the same power. That is why AM radio broadcast at hundreds of kilohertz reaches past the horizon. A higher carrier offers more bandwidth and needs a smaller antenna, which is why the THz and optical entries are short range and need a clear line of sight.
Range and power together decide battery life. A TPMS sensor transmits a short burst at intervals and lives for years on a coin cell. A WLAN access point assumes mains power and transmits continuously.
Two more properties decide how hard the protocol has to work. A one-way link has no return path, so the transmitter never learns whether anything arrived. Broadcast systems answer that with heavy forward error correction rather than retransmission. A link in unlicensed spectrum has to tolerate interference from equipment it cannot coordinate with. That is why Bluetooth hops between channels and why WLAN listens and backs off before it transmits.
Property |
What it decides |
Example from the list |
Frequency band |
Antenna size, how far the signal bends around obstacles, and how much bandwidth is available |
AM radio broadcast reaches past the horizon. THz imaging does not leave the room. |
Range |
Transmit power, and whether the link needs a network of base stations behind it |
Chip to chip communication is millimetres. Satellite communication is tens of thousands of kilometres. |
One-way or two-way |
Whether retransmission is possible at all, and therefore how much coding the link has to carry |
TV broadcast is one-way. Cellular communication is two-way. |
Licensed or unlicensed |
Whether interference can be planned away, or only tolerated |
Cellular runs in licensed spectrum. WLAN and Bluetooth share unlicensed ISM bands. |
Duty cycle and power |
Battery life, and therefore what the device is allowed to be |
A TPMS sensor wakes briefly and lasts years. A WLAN access point assumes mains power. |
The five properties that separate the entries on this page. The first row drives most of the others, because the carrier frequency sets both the antenna and the bandwidth.
The band decides most of the rest : antenna size, obstacle penetration and available bandwidth all follow from the carrier frequency.Unlicensed spectrum buys access and costs certainty : Bluetooth hops and WLAN backs off because neither can plan the interference away.A one-way link cannot retransmit : broadcast spends its margin on forward error correction instead.Duty cycle is what makes a coin cell last : a TPMS sensor and an LPWAN endpoint are silent almost all of the time.