Ads
related to: modern mobile radio systems
Search results
Results From The WOW.Com Content Network
These systems run on push-to-talk-based infrastructure such as Nextel's iDEN, Specialized Mobile Radio (SMR), MPT-1327, Enhanced Specialized Mobile Radio (ESMR) or conventional two-way systems. Certain modern two-way radio systems may have full-duplex telephone capability.
A mobile radio telephone. Mobile radio telephone systems were mobile telephony systems that preceded modern cellular network technology. Since they were the predecessors of the first generation of cellular telephones, these systems are sometimes retroactively referred to as pre-cellular (or sometimes zero generation, that is, 0G) systems.
Professional mobile radio (also known as private mobile radio (PMR) in the UK) are person-to-person two-way radio voice communications systems which use portable, mobile, base station, and dispatch console radios. PMR systems are based on such standards as MPT-1327, TETRA, APCO 25, and DMR which are designed for dedicated use by specific ...
Modern mobile phone networks use cells because radio frequencies are a limited, shared resource. Cell-sites and handsets change frequency under computer control and use low power transmitters so that the usually limited number of radio frequencies can be simultaneously used by many callers with less interference.
World radio systems (Terrestrial) System Type Modulation Data rate Sidebands? Ch. Bandwidth Radio spectrum Sound Codec Digital subchannels SFN Metadata/RDS/RBDS; AM radio: Analog radio: Amplitude Modulation: N/A? 18–20 kHz: 148.5-283.5 kHz (Longwave) 510–1610 kHz (Europe) 510–1710 kHz (USA and Canada) N/A: N/A: No: None Motorola C-QUAM ...
This radio frequency link connects to the switching systems of a mobile phone operator, providing access to the public switched telephone network (PSTN). Modern mobile telephony relies on a cellular network architecture, which is why mobile phones are often referred to as 'cell phones' in North America.