The UCCH primarily will have to achieve two objectives:

1. Initial synchronization and download support
2. Intersystem handoff support

As the UCCH component will be resident in the SDR terminal it is desirable that the UCCH implementation is light, i.e. it supports the bare minimum signaling required by a mobile terminal to sense and approach an access system and request for a download.In considering the utility of a signaling channel like the UCCH and development of UCCH with minimal capabilities, a few access scenarios are considered below.

• The Terminal starts from ground zero and wants to acquire a protocol personality – (non-time critical download)

• A terminal already has a protocol personality that is supported and the terminal wants to change to another personality also supported in the area for want of better data rates etc

• A terminal has a personality supported in the area, but wants to change (without service disruption) as it is moving towards another area. Also known as inter system handoff (Time Critical download). UCCH should support simultaneous negotiations between different access networks for services. The sensing of the target band-mode and signaling to the target mode access system can be achieved when the active mode is in an idle state or in a non-critical use state.

The development of a UCCH will also have to consider the following types of personality download to a user terminal, which are

1. Complete personality download : Full personality download
2. Incremental personality download : Involves just in time download of needed components
3. Partial personality download : Involves the user terminal to specify the exact components required (typically the case during inter system handoff).

For more details, see "A minimal signaling channel for SDR download support" .

see also :

"A minimal signaling channel for SDR download support