Pix, I like your response but have query…
“2) not ok : the cells that are neighbors in idle mode are described in the system information message. The MS cannot reselect a BCCH that’s not in the SI2 (or SI5 ? i always mistake). If the MS is in VPLMN, it’ll stay there, until rxlev(vPLMN) goes below RXLEV ACCESS MIN(vPLMN)”
Isn’t there a problem with that? If jean’s subs were in HPLMN why then would they stray to VPLMN. Surely, the subs will remain in HPLMN using your example?
3) Pix no worries about this one. What I meant was if MS timer for HPLMN not relevant and the MS simply selected MCC/MNC where there is no roaming agreement then VPLMN/HPLMN could bar access as it wouldn’t get paid, hence FPLMN would be updated.
Pix you said
“one more question : if a BCCH in the SI2 is the same as the BCCH of a vPLMN cell, can the cell mistakenly reselect the other vPLMN neighbor cell ? I would say “no”.. but i’m not sure. Any idea ?”
I would say in SI2 the answer is yes. This is exactly what happens on the South East Coast of England (UK) where MS can detect BCCH of HPLMN and then show same BCCH of VPLMN from operator in France. Its a commercial game operators play to entice revenue… its big business… to get dedicated mode traffic and control using SI5. This example fails with dropped calls due to quality, TA etc etc
BTW – I have screen prints of MS which is subscriber on the T-Mobile network where T-Mobile coverage get so bad at fringe coverage that MS goes into re-scan and MS show O2 or Vodafone as serving radio coverage. This is in rural area, but can be like border areas. However, as no roaming agreement the MS not make chargeable calls but could use competitive coverage for emergency calls.