Short answers, pulled from the story.
ReFLEX is a wireless protocol developed by Motorola for two-way paging, messaging, and low-bandwidth data transmission. It operates on synchronous 1.875-second frames using 4-level FSK modulation, supporting multiple forward and return channels along with roaming between networks.
ReFLEX50 was developed first to support a messaging service launched by MTEL in the mid-1990s, using 50 kHz channel spacing. ReFLEX25 came several years later as an upgrade path for traditional one-way paging carriers, using 25 kHz channel spacing. Both variants supported flexible channel configurations despite their names.
ReFLEX 2.7 unified the ReFLEX25 and ReFLEX50 variants into a single protocol. Devices compliant with ReFLEX 2.7 are backwards compatible with both earlier networks, and the update introduced new features to improve roaming, performance, and interoperability between different networks.
The Motorola PageWriter, released in 1996, was one of the first devices to use the ReFLEX network protocol.
ReFLEX systems support forward channel speeds of 1600, 3200, and 6400 bits per second. Return channel speeds run at 800, 1600, 6400, and 9600 bits per second.
ReFLEX is still in use despite limited commercial viability. Current applications include Automatic Meter Reading, public safety networks, and low-cost machine-to-machine data applications.