Crossband repeating is a relatively inexpensive means for extending the range of handheld radios.
The typical crossband repeater (CBR) scenario involves a dual-band mobile rig capable of being configured as a simplex cross-band repeater and one or more HTs.
CBR can be a useful tool during emergency activation or public service events where net operations are being conducted on a 2 meter simplex frequency. The CBR effectively translates back and forth between a 2m simplex channel and a 70cm simplex channel. Thus, a low-power 70cm HT can work through a mobile CBR station to communicate with a 2m simplex net, taking full advantage of the mobile rig's hi-power capabilities. Any dual-band or dedicated 70cm HT can be used to operate through a CBR.
Some other situations where CBR operation may be useful:
A net operator needs to be on foot away from the mobile rig. With the mobile rig configured as a CBR, the operator can communicate with the 2m simplex net using a low-power 70cm HT.
A parked mobile station configured as a CBR and located on high ground can be used to provide a 70cm simplex link into low-lying areas with poor simplex coverage.
Using a low-power 70cm HT, an operator located deep within a building can operate through a mobile CBR in the parking lot to communicate with the 2m simplex net.