User's Manual
Table Of Contents
- Volume III
- e. Technical Description Of Operation
- Fixed channel Mode
- Auto-select Channel Mode
- g. OEM radio card
- All three cards have a transmitting frequency range of 2.4 GHz to 2.4835 GHz with a transmitting power measured at the antenna of 100 milliwatts. The radio functions as a "frequency hopper" and by definition will "hop" between a preset range of frequenci
- h. Understanding Signal Interference
- Physical Obstructions and Communication Range
- RF Interference
- i. Coverage Area
- j. Possible Monitor & WNI Configurations
- k. Communication Limitations of the Wireless Network
- m. Installation Hardware
Range
Range is the RF coverage distance between a master and a slave on the same channel. The absolute
maximum range between a master and a slave is nominally 500 feet. This range is achieved only under
ideal conditions. A more realistic maximum for very open areas in hospitals is 250 feet. Objects
obstructing the line of sight between the master and slave reduce transmission distance.
Range vs. Cell
Even though a slave is within RF range of a master, it may not be seen within that cell. This is because
the radios may see adequate RF signal strength, yet they may not be able to decode the network packets
adequately to ensure communication.
Roaming
Roaming is the ability of a slave to change from one master to another and continue communications
using the new master. Roaming occurs when the synchronized master stops transmitting or
acknowledging transmissions. This includes both master failures and out of range conditions.
Roaming occurs as a slave moves in and out of various cells. In some installations, there may be more
than one cell in an environment using the same channel (in the event you need to cover another area
blocked by a solid RF impenetrable object you might use another master set for the same channel). A
slave using the fixed channel mode may only communicate with masters on the same channel, so as the
slave moves out of the cell of the first master, it loses synch, then acquires the signal of the second
master.
Other installations may have overlapping cells of different masters. Wireless bedsides in the auto-channel
select mode have the ability to move in and out of active cells of different masters. This would allow the
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