User's Manual

EAC-2100 Manual: (Draft, 02/01) Page 6-1

6. Optimizing Performance

6.1 Introduction

After the EAC-2100 has been installed, the system must be checked out to determine if

adjustments to the hand-in and handback thresholds are needed to ensure optimum

performance.

6.2 Handoff from EAC back to donor – “Handback”

When the subscriber is operating on the EAC 2100 DTC, the donor cell is not aware

that the EAC is handling the call. Should the subscriber move towards the donor, the

EAC itself must initiate the handoff. To facilitate this, the subscriber unit is directed to

make and report MAHO measurements on the donor and all the neighbors of the donor.

The EAC looks at two of the RSSI measurements. The MAHO RSSI report for the

donor DCCH would be the RSSI at the mobile from the donor, if the donor were to

handle the call. The RSSI report for “current” channel is the RSSI at the mobile from

the EAC. The EAC will send a handoff message to the portable, directing it back to the

donor DTC (same slot) if one of the two following criteria are met:

a) Donor RSSI reported by the mobile’s MAHO list is better than the EAC

parameter:

“HAND-BACK THRESHOLD – DTC –LOAD SHED LEVEL”

b) Donor RSSI is better than the EAC RSSI reported by the mobile’s MAHO list

by at least the level set for the EAC parameter:

“HANDBACK THRESHOLD – DTC – MINIMUM IMPROVEMENT”.

So, with DTC, the presence of the MAHO information allows the EAC to hand a call

back to the donor if the donor can handle it, even if the call would be stronger on the

EAC (option a above, load shed level). This allows the EAC to reserve its DTC

resources for calls that only it can serve.

Note that either parameter may be set to disabled to disable handback due to that

criteria, and if both are set to “disabled” handback by the EAC to the donor will be

disabled altogether.