User Manual

Table Of Contents
RF-Orchestra!™ Transmitter Installation and Operation System Description
July 2000 6880493G02-C 2-5
FLEX, ReFLEX, and InFLEXion Messaging Protocol Overview
The delivery of advanced messaging is augmented by a family of Motorola over-the-air (OTA)
message protocols. The FLEX messaging protocol provides one-way text messaging, the
ReFLEX protocol provides two-way text messaging, and the InFLEXion messaging protocol
provides two-way voice and data messaging. Two-way messaging, using the ReFLEX and
InFLEXion protocols, provides guaranteed message delivery because a received message is
acknowledged by the pager. If a message is not acknowledged after a transmission, the system
retransmits the message intermittently until it is received.
The primary difference between the ReFLEX and InFLEXion protocols is in the outbound
(transmitter to pager) signal path. ReFLEX is strictly a data messaging protocol, whereas the
InFLEXion protocol also supports voice messaging. The protocols are identical with respect to
the inbound (pager to receiver) signal path.
FLEX Messaging Protocol
FLEX is a synchronous, multispeed time-slot paging protocol. This protocol is a continuously
active paging channel where the data is transmitted at 1600, 3200, or 6400 bps. To decode this
continuous stream of data, a FLEX pager synchronizes itself with the channel so that it can
find the beginning and end of data blocks.
The continuous data which is transmitted on the FLEX RF channel is segmented into FLEX
frames. There are a total of 128 frames (numbered 0 through 127) in a FLEX system. It takes
exactly four minutes to transmit all 128 frames on the RF channel regardless of the FLEX
speed. The transmission of all 128 frames is called a FLEX cycle.
Because FLEX messaging is a one-way protocol, FLEX systems cannot offer guaranteed
delivery of messages.
ReFLEX Messaging Protocol
Key features of the ReFLEX messaging protocol are the ability of the system to guarantee
delivery of a data message and the ability of the subscriber to reply to the message. These
functions create the closed-loop performance that makes advanced messaging a quantum leap
in wireless data communications.