User's Manual

Deployment requirements 19

Navigation

• “Radio synchronization” (page 19)

• “IP network configuration” (page 23)

•

“Location requirements” (page 26)

Radio synchronization

The radio network structure supports seamless handover of existing calls.

This means that, during a call, if a handset moves from the coverage area

of one DAP into the coverage area of another DAP, the new DAP can

take over the call. The call is not interrupted, and the user is not aware of

the handover. In the traditional DECT system, synchronization between

DAPs occurs over the wired network. SIP DECT requires an accurate

synchronization of the radio signals in the air to support handover.

ATTENTION

If a DAP cannot receive synchronization signals from at least one other DAP, it

operates in a single cell mode and cannot handover to other DAPs or receive

handover from them.

Represent each DAP cell as a circle indicating the radio signals around

the DAP. Figure 2 "DAP radio signal synchronization" (page 20) shows

two circles around the DAP.

•

an inner circle in which sufficient radio signal strength exists for

acceptable voice quality

•

an outer circle in which sufficient signal strength exists for

synchronization, but not enough for acceptable voice quality

Nortel Communication Server 1000

SIP DECT Fundamentals

NN43120-123 02.02 30 March 2010