Dears, Lyle and ParaHo!
Additionally to ParaHo post I want to notice that both either ACCOLC or MTPAS are not GSM standards. They only use GSM standard feature, namely Access Class, for their own aims. Classes 0 to 9 are destined for ordinary subscribers (randomly allocated to SIM), 11 to 15 – for PLMN Staff, Emergency Services, Police etc. If network broadcasts Access restrictions for classes 0-9 on the all cells of some area, then ordinary subscribers don’t get access to network in this area. Only emergency calls is allowed. When network additionally broadcasts Access Class = 10, then emergency calls are not allowed for ordinary subscribers. There are no possibilities to override Access control for ordinary subscriber. However, ACCOLC or MTPAS are not only access control but also the “people giving orders” and “people carrying out” these orders. From this point of view any accidents are possible.