[asterisk-users] OT - Is handover included in DECT GAP ?

[Robert Lister]

On Thu, Jan 10, 2008 at 02:40:21PM +0100, Olivier wrote:

> that is what I call handover
> roaming = without any ongoing call
> handover = with ongoing call
> 
> this would need the appropriate logic in the base
> > stations. I know such hardware exists ("Kirk"!?),
> 
> Kirk base stations support roaming and handover but it's very difficult to
> know which handsets, beside Kirk handsets, support such feature as vendor
> won't specify if "Kirk base stations don't support Siemens handsets, for
> instance, because working feature set is very poor or because we don't want
> to care or deal with non-Kirk handsets as we sell our own".

As far as I understand it, where you have a base station and one phone, you 
are creating a cell consisting of one antenna. It is possible with DECT to 
have one cell consisting of many antennas (base stations) Moving between 
base stations in the same DECT cell is called handover. The handset 
registers with any base in the same cell. If you only have one base station, 
then the base station and cell are effectively the same thing.

The base stations have to be connected somehow to a central system that 
manages the handover in the cell during a call, the system has to support 
multiple base stations in the DECT cell. No additional functionality should 
be needed in the handset, because it already has the capability to channel 
hop between DECT channels during a call, without the user noticing.

Many DECT handsets (but not all) support registration with multiple DECT 
cells (i.e. as well has having up to X handsets registered with the cell, a 
handset can register with up to X bases.) This would support 'roaming' in 
the sense that the handset would use the base it could register with. (i.e, 
if you had one DECT handset registered with a base at home and at work, the 
handset would work on both bases if the handset supports multiple bases.) 
This could be called "roaming" between DECT cells and is done by the 
handset, but handover between two completely different DECT cells during a 
call is not possible.

In a large PBX installation, you can have both working, so that if a user 
took a handset from one system in one city, to another office in another 
city, and these PBXs were connected together, the "Home" PBX receives 
registration request from the remote PBX, and diverts the calls for that 
user to the remote PBX. I believe this is done by proprietary vendor 
software magic though, and is not part of DECT itself.

Rob