User's Manual

34
HomeRF Radio Communication
Like OpenAir, HomeRF devices also use frequency hopping
spread spectrum technology. This means that the radio signal is
constantly moving from one frequency to another while sending
packets of data.
Although a single radio can support either HomeRF or
OpenAir, these two standards are not the same. While OpenAir
lets a user designate a Master device and configure a cell’s
hopping pattern, the HomeRF standard does not support these
features.
A HomeRF network automatically determines what hopping
pattern to use and each device within the cell takes turns coordi-
nating the frequency hops. These are not parameters that can be
configured by the user. The only parameter that needs to be
configured to establish a HomeRF network is Security ID,
which is discussed below.
Also, since the standard does not support roaming, parameters
such as Domain and Roam Config are not valid for HomeRF
devices. Finally, an OpenAir CompactFlash Card operating in
HomeRF mode does not have an inactivity doze mode.
Security ID
To establish a HomeRF network, all devices must share the
same Security ID, which is also referred to as a Security Code
or Network ID. If two HomeRF devices do not share the same
Security ID, then they will not communicate.