Just see this….
A BTS-1 with LA1 has neighbors (BA list) which a MS1 Continuously monitors and if needed a C2 (cell reselection) is performed.
Another BTS-2 with LA2 is in the BA list of BTS-1 of LA1.
Both BTS-1 and BTS-2 are situated on a Highway.
MS1= Sony Ericsson
The MS1 is in IDLE mode. MS1 is initially camped on BTS-1. The MS1 is moving towards BTS-2. A stage comes when the MS1 performs a cell reselection to BTS-2. Here just note that BTS-1 one is in the LA served by Ericsson MSC and the BTS-2 is in the LA served by Nokia MSC.
A new BTS-3 comes into the network just between BTS-1 and BTS-2 on the highway. The BTS-3 is of LA3. Unfortunately the RF planner did some mistake in defining the BTS-3 as the neighbors of BTS-1 and BTS-2.
With the above inputs, I request you all to give your comments on the scenario which I am describing here….
The MS1 is in the IDLE mode and it is camped on BTS-1 and is moving towards BTS-3. But since the BTS-3 is not in the BA list of BTS-1 no cell reselection was performed. The same happens in case if the MS is camped initially on BTS-2 and is moving towards BTS-3.
Why the MS2 is able to camp on BTS-3?
Assume that MS2 has higher Rx-sensitivity. While moving from BTS-1 to BTS-3 a stage comes when MS1 enters into No service Mode (SOS). While the MS2 is able to reselect a far BTS-4 having LA3. This BTS-4 has BA list which contains BTS-3 as its neighbor.
Isn’t it possible?