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Ericsson Radio Systems AB was the name of a wholly owned subsidiary in the Ericsson sphere, founded on 1 January 1983 by buying out all former owners of Svenska Radioaktiebolaget (SRA). The company was well known in Scandinavia and elsewhere in the 1980s, as it was deploying NMT systems and developing a line of mobile telephones under the brand ...
The first digital voice mode developed for EDACS was GE's Voice Guard, utilizing sub-band coding for its datastream at a rate of 9600 bps. Voice quality was not great, however, with it quickly being replaced by AEGIS. AEGIS was the second generation EDACS digital voice mode, made once again by GE, with Adaptive Multiband Encoding as its coding ...
A trunked radio system is an advanced alternative in which the channel selection process is done automatically, so as to avoid channel conflicts and maintain frequency efficiency across multiple talkgroups. This process is handled by what is essentially a central radio traffic controller, a function automatically handled by a computer system.
Land mobile radio systems use channels in the VHF or UHF bands, since the antennas used at these short wavelengths are small enough to mount on vehicles or handheld transceivers. Transmitter power is usually limited to a few watts, to provide a reliable working range on the order of 3 to 20 miles (4.8 to 32 km) depending on terrain.
The term All American Five (abbreviated AA5) is a colloquial name for mass-produced, superheterodyne radio receivers that used five vacuum tubes in their design. These radio sets were designed to receive amplitude modulation (AM) broadcasts in the medium wave band, and were manufactured in the United States from the mid-1930s until the early 1960s.
The first two-way radio remote controls utilized a harness of wires extending speaker, microphone, and controls for options such as channel selection or CTCSS switches. This limited a base station to being within tens to hundreds of feet from the user's workstation. Early systems often had volume unit meters, clocks, and switchboard keys. [4]
A remote radio head (RRH), also called a remote radio unit (RRU) in wireless networks, is a remote radio transceiver that connects to an operator radio control panel via electrical or wireless interface. When used to describe aircraft radio cockpit radio systems, the control panel is often called the radio head.
HS 25 (modified from the Ericsson OL-100 system with double relays and 25-point selector (Ericsson license), mainly used for small villages and towns in the counties) HS 31 (new developed register system, introduced in 1931, based on a new flat type relay and a 100-point two-motion selector, suitable for small and large exchanges)