Nortel Networks DCT1900 - Manual (Page 29)

Technical Product Manual - DCT1900
System Description, System Overview
System-DCT1900/R8/mw 2-7
© 2000-2005
will still synchronize slaves connected to it, effectively forming a separate "sub cluster" within
which seamless handovers are still possible.
The delay in the cable used to synchronize the REs must be measured and entered into each of
the slave REs. The accuracy of this delay measurement is very important and must be taken with
care.
Registration
Registration entails the Portable Telephone establishing a link with the RE/MS, whereby the
Portable Telephone tells the RE/MS who it is, i.e. extension number, system number range, home
node number, and the RE/MS authorizes the Portable Telephone to use its resources to make and
receive calls.
In the case of a DCT1900 mobility configuration with multiple Mobility Servers:
z If the MS is not the Home MS, then there must be a physical connection (QSIG Tie Line)
between the Home MS and the MS the phone is trying to register to.
z The Portable Telephone’s PUN and authentication key must be known by its’ home MS.
z The system number of the RE must be within the system range initialized in the Portable
Telephone.
Start of Registration
Registration starts whenever:
z The Portable Telephone is switched on and sees a system (within the allowed system range).
z When the Portable Telephone sees a system with better receive signal strength quality than
the current one which is also in its system range (the Portable Telephone will roam to another
system).
z The system asks the Portable Telephone to do so (initiated by the RE/MS). This function
updates databases which may contain corrupted data (e.g. after restarts of system or RE/MS).
Note:
When a Portable Telephone goes out of range and comes back in range of the same RE, the
registration procedure will not be repeated.
Registration Successful
If all requirements are met, the registration will succeed. Note that this dynamic behavior means
that only at this point will a Portable Telephone be registered in a system. There will never be a
fixed relation between a system and a PUN!
Registration Failures
The registration process may result in a rejection from the RE/MS. If the PUN of the Portable
Telephone is not initialized in the RE/MS or when the authentication keys in the Portable
Telephone and RE/MS are different, the Portable Telephone will be rejected. The result will be that
the Portable Telephone will not try again. Only when the Portable Telephone is switched off and on
again, or searched by the RE/MS or by the system, will it try to register again.
The process can also fail because of other reasons. For example, when a connection set–up failed
or when congestion occurred in a particular Base Station RE/MS, the registration process will
automatically start again after some time.
When a Portable Telephone moves from a RE where it was registered to a new RE and the
registration fails on that new RE, it will still be registered in the RE where it came from.