Two-way Digital Radio Standards
The key breakthrough or key feature in digital radio transmission systems is that they allow lower transmission power, they can provide robustness to noise and cross-talk and other forms of interference, and thus allow the same radio frequency to be reused at shorter distance. Consequently the spectral efficiency (the number of phonecalls per MHz and base station, or the number of bit/s per Hz and transmitter, etc.) may be sufficiently increased. Digital radio transmission can also carry any kind of information whatsoever — just as long at it has been expressed digitally. Earlier radio communication systems had to be made expressly for a given form of communications: telephone, telegraph, or television, for example. All kinds of digital communications can be multiplexed or encrypted at will.
- Digital cellular telephony (2G systems and later generations):
- GSM
- UMTS (sometimes called W-CDMA)
- TETRA
- IS-95 (cdmaOne)
- IS-136 (D-AMPS, sometimes called TDMA)
- IS-2000 (CDMA2000)
- iDEN
- Digital Mobile Radio:
- Project 25 a.k.a. "P25" or "APCO-25"
- TETRA
- NXDN
- DMR
- Wireless networking:
- Wi-Fi
- HIPERLAN
- Bluetooth
- DASH7
- ZigBee
- 6LoWPAN
- Military radio systems for Network-centric warfare
- JTRS (Joint Tactical Radio System- a flexible software-defined radio)
- SINCGARS (Single channel ground to air radio system)
- Amateur packet radio:
- AX.25
- Digital modems for HF:
- PACTOR
- Satellite radio:
- Satmodems
- Wireless local loop:
- Basic Exchange Telephone Radio Service
- Broadband wireless access:
- IEEE 802.16
Read more about this topic: Digital Radio
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