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ROUND 10: MIGRATING FROM FLEX™ to ReFLEX™
When migrating a FLEX™ network into a ReFLEX™ network several things have to be taken into account. First, in order to minimize inter-symbol interference, all transmitter antennas has to be lowered to a height of less than 200 feet. This is especially important when the network manages longer messages, being more sensitive to interference. Second, ReFLEX™ devices have half the sensitivity of one-way FLEX™ devices, resulting in less coverage. (The sensitivity of a FLEX and ReFLEX pager should be about the same)
Third, if a ReFLEX™ zone is reduced to consist of only one transmitter and a few receivers in order to increase two-way capacity, multicast benefits are lost at the fringe between zones resulting in less received signal strength by the end-user devices. This also affects existing FLEX™ customers. In addition, since ReFLEX™ requires a higher C/I margin when managing longer messages as mentioned before, increased amount of zones inevitably require additional frequencies in order to avoid interference from adjacent zones. Consequently, message length has a direct effect on link budget.
Also, the ReFLEX™ zone registration process, increasing in importance with reduced size of zones, is not seamless, creating delays when a device registers in a new zone.